Tokushima University / Educator and Researcher Directory --- Shirai, Akihiro

Personal Web Page

https://researchmap.jp/shiraiakihiro (researchmap)

Field of Study

○	Organic Chemistry, Microbiology

Subject of Study

○	環境調和型微生物制御剤の開発に関する研究

Book / Paper

Book:

1.	Retsuo Kawakami and Akihiro Shirai : 第7章第3節第2項「LEDと光触媒」, NTS Inc., Tokyo, Dec. 2019.
2.	Akihiro Shirai and Takeshi Omasa : 第10章「バイオ医薬品における生産性向上手法とその課題」, サイエンス&テクノロジー株式会社, Tokyo, Aug. 2011.

Academic Paper (Judged Full Paper):

1.	Akihiro Shirai and Ami Tanaka : Effects of ferulic acid combined with light irradiation on deoxynivalenol and its production in Fusarium graminearum, Fungal Biology, Vol.128, No.2, 1684-1690, 2024. (Summary) This study aimed to investigate the effects of ferulic acid (FA), a natural phenolic phytochemical, in combination with light irradiation at three wavelengths (365, 385 and 405 nm) on the concentration and toxicity of deoxynivalenol (DON), a mycotoxin produced by Fusarium graminearum. Moreover, this study examined the influence of the combination treatment on DON production in the cultured fungus. FA activated by light at a peak wavelength of 365 nm exhibited the most effective decrease in DON concentration of the tested wavelengths; a residual DON ratio of 0.23 at 24 h exposure was observed, compared with the initial concentration. The reduction in DON using 365-nm light was dependent on the concentration of FA, with a good correlation (r2 = 0.979) between the rate constants of DON decrease and FA concentration, which was confirmed by a pseudo-first-order kinetics analysis of the photoreaction with different FA concentrations (50 400 mg/L) for 3 h. The viability of HepG2 cells increased by 56.7% following in vitro treatment with a mixture containing the photoproducts obtained after treatment with 20 mg/L DON and 200 mg/L FA under 365-nm irradiation for 6 h. These results suggested that the photoreaction of FA under 365-nm irradiation induces the detoxification of DON through degradation or modification of DON. The antifungal effects of the combination (FA and 365-nm light) on F. graminearum were investigated. Conidia treated with the combination did not show additive or synergistic inhibition of fungal biomass and DON production in 7-day cultivated fungal samples compared with samples after single treatment. However, successive treatment, composed of 90 min irradiation at 365 nm and then treatment with 200 mg/L FA for 90 min in the dark, suppressed fungal growth and DON yield to 70% and 25% of the untreated sample level, respectively. This photo-technology involving the two treatment methods of 365-nm irradiation and FA addition as a food-grade phenolic acid in combination or successively, can aid in developing alternative approaches to eliminate fungal contaminants in the fields of environmental water and agriculture. However, further research is required to explore the underlying mechanisms of DON decontamination and its biosynthesis in F. graminearum. (Keyword) Deoxynivalenol / Ferulic acid / Light irradiation / Cytotoxicity / Antifungal assay (Tokushima University Institutional Repository) ● Metadata: 119040 (Link to Publication Site) ● Publication site (DOI): 10.1016/j.funbio.2024.02.003 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1016/j.funbio.2024.02.003 (Tokushima University Institutional Repository: 119040, DOI: 10.1016/j.funbio.2024.02.003)
2.	Retsuo Kawakami, Yuta Makino, Shin-ichiro Yanagiya, Akihiro Shirai, Masahito Niibe and Yoshitaka Nakano : Plasma-Assisted Annealing of Pt-Doped Rutile TiO2 Nanoparticles for Enhanced Decomposition and Bacterial Inactivation under General Lighting, Journal of Vacuum Science and Technology. B, Nanotechnology & Microelectronics : Materials, Processing, Measurement, & Phenomena : JVST B, Vol.42, 012203:1-012203:12, 2024. (Tokushima University Institutional Repository) ● Metadata: 118889 (Link to Publication Site) ● Publication site (DOI): 10.1116/6.0003101 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1116/6.0003101 (Tokushima University Institutional Repository: 118889, DOI: 10.1116/6.0003101)
3.	Qingyi Lin, Mutsumi Aihara, Akihiro Shirai, Ami Tanaka, Koki Takebayashi, Naoaki Yoshimura, Nanaka Torigoe, Megumi Nagahara, Takeo Minamikawa and Takeshige Otoi : Porcine embryo development and inactivation of microorganisms after ultraviolet-C irradiation at 228 nm, Theriogenology, Vol.197, 252-258, 2023. (Summary) It is important to prevent contamination inside the incubator as a method of preventing microbial infections during the embryo culture. In the present study, we examined the effects of ultraviolet-C (UV-C) irradiation, used for microorganism inactivation, on embryo development and the growth of bacteria, including Escherichia coli and Staphylococcus aureus, and the fungus Cladosporium cladosporioides. In the embryo irradiation experiment, we examined the effects of the plastic lid of the culture dish, irradiation distances (10, 20, and 25 cm), and different irradiation wavelengths (228 and 260 nm) during embryo culture for 7 days on the development and quality of porcine in vitro-fertilized embryos. None of the embryos cultured in dishes without plastic lids developed into blastocysts after irradiation with 228 nm UV-C. When porcine embryos were cultured in a culture dish with lids, the 228 nm UV-C irradiation decreased blastocyst formation rates of the embryos but not their quality, irrespective of the UV-C irradiation distance. Moreover, irradiation with 260 nm UV-C, even with plastic lids, had more detrimental effects on embryo development than irradiation with 228 nm UV-C. Investigation of the inactivating effects of UV-C irradiation at 228 nm and 260 nm on the growth of the bacteria and fungus showed that 260 nm UV-C reduced the viability to a greater extent than 228 nm UV-C. Moreover, the disinfection efficacy for the bacteria increased when the irradiation duration increased and the distance decreased. In conclusion, porcine embryos can develop into blastocysts without loss of quality even after continuous long-duration irradiation (7 days) with 228 nm UV-C, which can inactivate the growth of bacteria and the tested fungus; however, the development rate of the embryo is reduced. (Keyword) Animals / Swine / Embryonic Development / Blastocyst / Embryo, Mammalian / Fertilization in Vitro / Escherichia coli / Bacteria / Ultraviolet Rays (Link to Publication Site) ● Publication site (DOI): 10.1016/j.theriogenology.2022.12.015 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 36525864 ● Search Scopus @ Elsevier (PMID): 36525864 ● Search Scopus @ Elsevier (DOI): 10.1016/j.theriogenology.2022.12.015 (DOI: 10.1016/j.theriogenology.2022.12.015, PubMed: 36525864)
4.	Retsuo Kawakami, Yuki Takao, Akihiro Shirai and Takashi Mukai : Remote Bactericidal Effect of Anatase TiO₂ Photocatalytic Nanoparticles Annealed with Low-Temperature O₂ Plasma, Biocontrol Science, Vol.27, No.4, 217-222, 2022. (Summary) The remote bactericidal effect of TiO photocatalyst, i.e., the bactericidal effect away from the photocatalyst, was successfully achieved using a humidified airflow. The TiO photocatalyst used was anatase-type TiO nanoparticles (NPs) annealed with a low-temperature O plasma. For comparison, anatase-type TiO NPs annealed in the air were used. The bacteria, Bacillus subtilis, were placed away from the TiO NPs. The plasma-assisted-annealed TiO NPs significantly inactivated 99% of the bacterial cells in 5 h, whereas the pristine and air-annealed TiO NPs inactivated 88-90% of the bacterial cells. The remote bactericidal effect of plasmaassisted-annealed TiO NPs would be attributed to a larger amount of HO molecules traveled by the airflow from the TiO NPs. The molecules were generated by chemically reacting more photoexcited carriers on the TiO surface with HO and O in the airflow. These photoexcited carriers originated from more oxygen-based species adsorbed and more oxygen vacancies introduced on the TiO surface by the plasma-assisted-annealing. (Keyword) Hydrogen Peroxide / Temperature / Nanoparticles / Oxygen / Anti-Bacterial Agents (Tokushima University Institutional Repository) ● Metadata: 117872 (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.27.217 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 36567118 ● Search Scopus @ Elsevier (PMID): 36567118 ● Search Scopus @ Elsevier (DOI): 10.4265/bio.27.217 (Tokushima University Institutional Repository: 117872, DOI: 10.4265/bio.27.217, PubMed: 36567118)
5.	Retsuo Kawakami, Mutsumi Aihara, Takuto Izumi, Akihiro Shirai and Mukai Takashi : Bactericidal Effects of Low-Temperature Atmospheric-Pressure Air Plasma Jets with No Damage to Plant Nutrient Solutions, Biochemical Engineering Journal, Vol.187, 108661:1-108661:9, 2022. (Tokushima University Institutional Repository) ● Metadata: 117580 (Link to Publication Site) ● Publication site (DOI): 10.1016/j.bej.2022.108661 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-85139727087 (Tokushima University Institutional Repository: 117580, DOI: 10.1016/j.bej.2022.108661, Elsevier: Scopus)
6.	Akihiro Shirai, Kaito Kawasaka and Koichiro Tsuchiya : Antimicrobial action of phenolic acids combined with violet 405-nm light for disinfecting pathogenic and spoilage fungi, Journal of Photochemistry and Photobiology B: Biology, Vol.229, 112411, 2022. (Summary) The aim of this study is to investigate the fungicidal spectrum of six phenolic-cinnamic and -benzoic acid derivatives using four fungi, Aspergillus niger, Cladosporium cladosporioides, Trichophyton mentagrophytes and Candida albicans, in a photocombination system with violet 405-nm light. This is the first study to examine the fungicidal mechanism involving oxidative damage using the conidium of A. niger, as well as an assessment of cellular function and chemical characteristics. The results of the screening assay indicated that ferulic acid (FA) and vanillic acid (VA), which possess 4-hydroxyl and 3-methoxy groups in their phenolic acid structures, produced synergistic activity with 405-nm light irradiation. FA and VA (5.0 mM) significantly decreased the viability of A. niger by 2.4 to 2.6-logs under 90-min irradiation. The synergistic effects were attenuated by the addition of the radical scavenger dimethyl sulfoxide. Generation of reactive oxygen species (ROS), such as hydrogen peroxide and hydroxyl radicals, were confirmed in the phenolic acid solutions tested after irradiation with colorimetric and electron spin resonance analyses. Adsorption of FA and VA to conidia was greater than other tested phenolic acids, and produced 1.55- and 1.85-fold elevation of intracellular ROS levels, as determined using an oxidant-sensitive probe with flow cytometry analysis. However, cell wall or membrane damage was not the main mechanism by which the combination-induced fungal death was mediated. Intracellular ATP was drastically diminished (5% of control levels) following combined treatment with FA and light exposure, even under a condition that produced negligible decreases in viability, thereby resulting in pronounced growth delay. These results suggest that the first stage in the photofungicidal mechanism is oxidative damage to mitochondria or the cellular catabolism system associated with ATP synthesis, which is a result of the photoreaction of phenolic acids adsorbed and internalized by conidia. This photo-technology in combination with food-grade phenolic acids can aid in developing alternative approaches for disinfection of pathogenic and spoilage fungi in the fields of agriculture, food processing and medical care. (Keyword) Synergistic antifungal activity / Fungicidal action / Phenolic acid / Violet 405-nm light / Oxidative stress / Growth delay (Tokushima University Institutional Repository) ● Metadata: 116754 (Link to Publication Site) ● Publication site (DOI): 10.1016/j.jphotobiol.2022.112411 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 35219030 ● Summary page in Scopus @ Elsevier: 2-s2.0-85125124978 (Tokushima University Institutional Repository: 116754, DOI: 10.1016/j.jphotobiol.2022.112411, PubMed: 35219030, Elsevier: Scopus)
7.	Akihiro Shirai, Haruka Kunimi and Koichiro Tsuchiya : Antifungal action of the combination of ferulic acid and ultraviolet-A irradiation against Saccharomyces cerevisiae, Journal of Applied Microbiology, Vol.132, No.4, 2957-2967, 2022. (Summary) Aims To examine the antifungal action of photocombination treatment with ferulic acid (FA) and ultraviolet-A (UV-A) light (wavelength, 365 nm) by investigating associated changes in cellular functions of Saccharomyces cerevisiae. Methods and Results When pre-incubation of yeast cells with FA was extended from 0.5 to 10 min, its photofungicidal activity increased. Flow cytometry analysis of stained live and dead cells revealed that 10-min UV-A exposure combined with FA (1 mg ml-1) induced a ~ 99.9% decrease in cell viability although maintaining cell membrane integrity when compared with pre-exposure samples. When morphological and biochemical analysis were performed, treated cells exhibited an intact cell surface and oxidative DNA damage similar to control cells. Photocombination treatment induced cellular proteins oxidation, as shown by 2.3-fold increasing in immunostaining levels of ~49-kDa carbonylated proteins compared with pre-irradiation samples. Pyruvate kinase 1 (PK1) was identified by proteomics analysis as a candidate protein whose levels was affected by photocombination treatment. Moreover, intracellular ATP levels decreased following FA treatment both in darkness and with UV-A irradiation, thus suggesting a possible FA-induced delay in cell growth. Conclusions FA functions within the cytoplasmic membrane; addition of UV-A exposure induces increased oxidative modifications of cytosolic proteins such as PK1, which functions in ATP generation, without causing detectable genotoxicity, thus triggering inactivation of yeast cells. Significance and Impact of Study Microbial contamination is a serious problem that diminishes the quality of fruits and vegetables. Combining light exposure with food-grade phenolic acids such as FA is a promising disinfection technology for applications in agriculture and food processing. However, the mode of photofungicidal action of FA with UV-A light remains unclear. This study is the first to elucidate the mechanism using S. cerevisiae. Moreover, proteomics analyses identified a specific cytosolic protein, PK1, which is oxidatively modified by photocombination treatment. (Keyword) Antifungal action / Ferulic acid / Ultraviolet-A / Synergism / Oxidative stress / Pyruvate kinase 1 (Tokushima University Institutional Repository) ● Metadata: 116597 (Link to Publication Site) ● Publication site (DOI): 10.1111/jam.15407 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 34894031 ● Search Scopus @ Elsevier (PMID): 34894031 ● Search Scopus @ Elsevier (DOI): 10.1111/jam.15407 (Tokushima University Institutional Repository: 116597, DOI: 10.1111/jam.15407, PubMed: 34894031)
8.	Akihiro Suzuki, Akira Emoto, Akihiro Shirai and Kentaro Nagamatsu : Ultraviolet Light-Emitting Diode (UV-LED) Sterilization of Citrus Bacterial Canker Disease Targeted for Effective Decontamination of Citrus Sudachi Fruit, Biocontrol Science, Vol.27, No.1, 1-7, 2022. (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.27.1 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.4265/bio.27.1 (DOI: 10.4265/bio.27.1)
9.	Akihiro Shirai, Yu-ko Yasutomo and Yuka Kanno : Effects of violet-blue light-emitting diode on controlling bacterial contamination in boiled young sardine, Biocontrol Science, Vol.27, No.1, 9-19, 2022. (Summary) The aim of this study was to evaluate bacterial decontamination of boiled young sardine by treatment with violet-blue light followed by cooling storage of the irradiated boiled sardine. Viable cell count in the samples was evaluated after irradiation with four types of violet-blue light-emitting diodes (LEDs; peak wavelength at 405, 412, 421 or 455 nm) and subsequent cooling storage for two days. LED (405 nm) exhibited bactericidal and growth suppression effects. The irradiation gave a 47% bactericidal rate in comparison with no irradiation samples (control) and the two-day storage suppressed the increase in cell counts to 24%, while the rate of increase was 545% for the control. Integrated viability (IV) based on growth delay analysis was estimated after irradiation of four isolates from boiled sardine with 405 nm light. The irradiation caused growth delay against all isolates, resulting in smaller IV values for three isolates compared to those viabilities estimated from colony forming units. Exposure (405 nm) at 432 J/cm2 fluence resulted in a decrease in water content, resulting in an increase in salinity of the samples. This study demonstrated the advantages of light emitting a narrow violet region as a non-thermal disinfection technology in the processing and storage of boiled sardines. (Keyword) Violet-blue light-emitting diode / Microbial decontamination / Boiled young sardine / Growth suppression / Food quality (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.27.9 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 35314562 ● Search Scopus @ Elsevier (PMID): 35314562 ● Search Scopus @ Elsevier (DOI): 10.4265/bio.27.9 (DOI: 10.4265/bio.27.9, PubMed: 35314562)
10.	Retsuo Kawakami, Yuki Mimoto, Shin-ichiro Yanagiya, Akihiro Shirai, Masahito Niibe, Yoshitaka Nakano and Takashi Mukai : Photocatalytic Activity Enhancement of Anatase/Rutile-Mixed Phase TiO2 Nanoparticles Annealed with Low-Temperature O2 Plasma, Physica Status Solidi (A) Applications and Materials Science, Vol.218, 2100536-1-2100536-13, 2021. (Tokushima University Institutional Repository) ● Metadata: 117581 (Link to Publication Site) ● Publication site (DOI): 10.1002/pssa.202100536 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1002/pssa.202100536 (Tokushima University Institutional Repository: 117581, DOI: 10.1002/pssa.202100536)
11.	Tohru Tasaka, Katsuhiko Maehashi, Hisatsugu Yamada, Akihiro Shirai, Hideki Unuma, Ken Tokunaga, Akio Hayakawa, Akiteru Go, Kikyo Go and Yoshihiro Uto : Therapeutic Effect and Mechanism of Action of Low-molecular-weight Whey Protein Capable of Activating Macrophages in Bovine Mastitis, Anticancer Research, Vol.40, No.8, 4701-4706, 2020. (Summary) Bovine mastitis is caused by the invasion and propagation of pathogenic microorganisms into the udder and mammary gland tissues of cattle. In this study, the therapeutic effect of a low-molecular-weight whey protein (LMW-WP) on bovine mastitis was evaluated. LMW-WP was orally, intraperitoneally, and vaginally administered to bovine with mastitis. The number of somatic cells in milk was measured 24 h before the administration of LMW-WP. The effect of LMW-WP on cytokine production was measured with a microarray that evaluates the expression of cytokines. In the group that received 1,000 mg intraperitoneally, the somatic cell count was reduced to less than 400,000 at the shipment standard value in three of the four udders, indicating 75% efficacy. The group that received 1,000 mg by vaginal administration showed 67% efficacy. It was confirmed that LMW-WP increased the production of cytokines such as IL-5, IL-6, IL-9, IL-12, MCP-1, and VEGF in mouse macrophage cells, but it did not show any antibacterial activity. LMW-WP may be an effective therapeutic agent for bovine mastitis. (Keyword) Low-molecular-weight whey protein / bovine mastitis / cytokines / macrophages (Link to Publication Site) ● Publication site (DOI): 10.21873/anticanres.14470 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 32727795 ● Search Scopus @ Elsevier (PMID): 32727795 ● Search Scopus @ Elsevier (DOI): 10.21873/anticanres.14470 (DOI: 10.21873/anticanres.14470, PubMed: 32727795)
12.	Retsuo Kawakami, Yuki Yoshitani, Akihiro Shirai, Shin-ichiro Yanagiya, Hirofumi Koide, Yuki Mimoto, Kosuke Kajikawa, Masahito Niibe, Yoshitaka Nakano, Chisato Azuma and Takashi Mukai : Effects of Nonequilibrium Atmospheric-Pressure O2 Plasma-Assisted Annealing on Anatase TiO2 Nanoparticles, Applied Surface Science, Vol.526, 146684:1-146684:12, 2020. (Tokushima University Institutional Repository) ● Metadata: 117582 (Link to Publication Site) ● Publication site (DOI): 10.1016/j.apsusc.2020.146684 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1016/j.apsusc.2020.146684 (Tokushima University Institutional Repository: 117582, DOI: 10.1016/j.apsusc.2020.146684)
13.	安友優子, 葉田敬子, 田端京子, 菅野由佳 and Akihiro Shirai : Phylogenetic Analysis of Bacterial Isolates from Boiled Sardine and the Effect of Ultraviolet Light-Emitting Diode Light on Them, Journal of Antibacterial and Antifungal Agents, Vol.47, No.5, 191-198, 2019. (Keyword) Ultraviolet light emitting diode / UV LED / 280 nm / Boiled sardine / Additive-free / Non-thermal / Bactericidal effect / Growth suppression (Tokushima University Institutional Repository) ● Metadata: 113335 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1050020697876354176 (Tokushima University Institutional Repository: 113335, CiNii: 1050020697876354176)
14.	Akihiro Shirai and Yu-ko Yasutomo : Bactericidal action of ferulic acid with ultraviolet-A light irradiation, Journal of Photochemistry and Photobiology B: Biology, Vol.191, 52-58, 2019. (Summary) The bactericidal activity of ferulic acid (FA) against various microorganisms was remarkably enhanced by ultraviolet-A (UV-A) irradiation (wavelength, 365 nm). However, the bactericidal mechanism in the photo-combination system has not been evaluated. In the present study, this combined treatment was characterized by investigating associated changes in cellular functions of Escherichia coli, including assessments of respiratory activity, lipid peroxidation, membrane permeability, and damage to DNA and the cell surface. FA adsorbed onto and was incorporated into bacterial membranes, and the affinity resulted in decreased respiratory activity and enhanced lipid peroxidation in the cytoplasmic membrane with low-fluence (1.0 J/cm2) UV-A irradiation. Flow cytometry analysis revealed that additional exposure (8 J/cm2) combined with FA (1 mg/mL) induced increased cell permeability, yielding a 4.8-log decrease in the viable cell count. Morphologically, the treated cells exhibited a bacterial membrane dysfunction, producing many vesicles on the cell surface. However, despite this effect on the cell surface, plasmid DNA transformed into FA-treated E. coli maintained supercoiled integrity with negligible DNA oxidation. Our data strongly suggested that FA functions inside and outside the bacterial membrane; UV-A exposure in the presence of FA then causes increased oxidative modification and subsequent disruption of the bacterial membrane, without causing detectable genotoxicity. (Keyword) Bactericidal action / Ferulic acid / Ultraviolet-A / oxidative stress / lipid peroxidation / Membrane damage (Tokushima University Institutional Repository) ● Metadata: 112825 (Link to Publication Site) ● Publication site (DOI): 10.1016/j.jphotobiol.2018.12.003 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 30580185 ● Summary page in Scopus @ Elsevier: 2-s2.0-85058717143 (Tokushima University Institutional Repository: 112825, DOI: 10.1016/j.jphotobiol.2018.12.003, PubMed: 30580185, Elsevier: Scopus)
15.	Akihiro Shirai, Takashi Watana and Hitoshi Matsuki : Inactivation of foodborne pathogenic and spoilage microorganisms using ultraviolet-A light in combination with ferulic acid, Letters in Applied Microbiology, Vol.64, No.2, 96-102, 2017. (Summary) The low energy of UV-A (315 400 nm) is insufficient for disinfection. To improve UV-A disinfection technology, the effect of ferulic acid (FA) addition on inactivation by UV-A light-emitting diode (LED) light (350 385 nm) was evaluated in the eliminating of suspensions of various food spoilers and pathogens (seven bacteria and four fungi). Photoantimicrobial assays were performed at FA concentrations below the MIC. The MIC of the isomerized FA, consisting of 93% cis-form and 7% trans-form, was very similar to that of the commercially available FA (trans-form). Irradiation with UV-A (1.0 J cm-2) in the presence of 100 mg l-1 FA resulted in enhanced reducing of all of the tested bacterial strains. A combination of UV-A (10 J cm-2) and 1000 mg l-1 FA resulted in enhanced reducing of Saccharomyces cerevisiae and one of the tested filamentous fungi. These results demonstrated that the combination of a short-term application of UV-A and FA at a low concentration yielded synergistic enhancement of antimicrobial activity, especially against bacteria. (Tokushima University Institutional Repository) ● Metadata: 111085 (Link to Publication Site) ● Publication site (DOI): 10.1111/lam.12701 (Link to Search Site for Scientific Articles) ● Search Scopus @ Elsevier (DOI): 10.1111/lam.12701 (Tokushima University Institutional Repository: 111085, DOI: 10.1111/lam.12701)
16.	Akihiko Tsuji, Shuji Kuwamura, Akihiro Shirai and Keizo Yuasa : Identification and Characterization of a 25 kDa Protein That Is Indispensable for the Efficient Saccharification of Eisenia bicyclis in the Digestive Fluid of Aplysia kurodai, PLoS ONE, Vol.12, No.1, e0170669, 2017. (Summary) The digestive fluid of the sea hare Aplysia kurodai can liberate approximately 2.5 mg of glucose from 10 mg of dried Eisenia bicyclis powder. Although laminaran, a major storage polysaccharide in E. bicyclis, is easily digested to glucose by the synergistic action of the 110 and 210 kDa A. kurodai -glucosidases (BGLs), glucose is not liberated from E. bicyclis by direct incubation with these BGLs. To clarify this discrepancy, we searched for an Eisenia hydrolysis enhancing protein (EHEP) in the digestive fluid of A. kurodai. A novel 25 kDa protein that enhances E. bicyclis saccharification by -glucosidases was purified to a homogeneous state from the digestive fluid of A. kurodai, and its cDNA was cloned from total cDNAs reverse-transcribed from hepatopancreas total RNA. The E. bicyclis extract strongly inhibited BGLs, suggesting some compound within this brown alga functioned as a feeding deterrent. However, when E. bicyclis was incubated with BGLs in the presence of EHEP, glucose production was markedly increased. As E. bicyclis is rich in phlorotannin, which are only found in brown algae, our study suggested that these compounds are the main BGL inhibitors in E. bicyclis extract. EHEP protects BGLs from phlorotannin inhibition by binding to phlorotannins and forming an insoluble complex with phloroglucinol and phlorotannins. These findings indicated that EHEP plays a key role in the saccharification of brown seaweeds containing phlorotannins in the digestive fluid of A. kurodai. This is the first report of EHEP as a phlorotannin-binding protein that protects BGLs from inhibition. (Tokushima University Institutional Repository) ● Metadata: 111878 (Link to Publication Site) ● Publication site (DOI): 10.1371/journal.pone.0170669 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 28129373 ● Summary page in Scopus @ Elsevier: 2-s2.0-85010878231 (Tokushima University Institutional Repository: 111878, DOI: 10.1371/journal.pone.0170669, PubMed: 28129373, Elsevier: Scopus)
17.	Akihiro Shirai, Masato Kajiura, Kyohei Matsumura and Takeshi Omasa : Improved photobactericidal activity of ultraviolet-A light in combination with isomerizable p-coumaric acid derivatives, Biocontrol Science, Vol.20, No.4, 231-238, 2015. (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.20.231 (Link to Search Site for Scientific Articles) ● Summary page in Scopus @ Elsevier: 2-s2.0-84952787499 (DOI: 10.4265/bio.20.231, Elsevier: Scopus)
18.	Akihiro Shirai, Masato Kajiura and Takeshi Omasa : Synergistic photobactericidal activity based on ultraviolet-A irradiation and ferulic acid derivatives, Photochemistry and Photobiology, Vol.91, No.6, 1422-1428, 2015. (Summary) Ultraviolet-A (UV-A)-mediated bactericidal activity was enhanced by combined treatment with trans-ferulic acid (trans-FA, compound 1) or its derivatives. Derivative compounds 4 and 10 contain a phenyl group or an L-tyrosine HCl tert-butyl ester, respectively, linked to the carboxyl group of trans-FA. Of the three compounds, 10 exhibited the highest synergistic activity in a photobactericidal assay based on treating Escherichia coli with a derivative compound and UV-A irradiation (wavelength 350-385 nm). Inactivation of viable cells at a 4.9 J/cm(2) UV-A fluence increased from 1.90 to 5.19 logs in the presence of 10 (100 μM); a 4.95-log inactivation was achieved with 10 (5 μM) and a 7.4 J/cm(2) UV-A fluence. Addition of antioxidants significantly suppressed photosynergistic bactericidal activity, suggesting that reactive oxygen species (ROS) are involved in the combined bactericidal mechanism. Flow cytometry revealed that combined treatment with UV-A and compound 10, which showed the highest photobactericidal activity, generates an excess of oxidative radicals in bacterial cells. The bactericidal activity of compound 10 may be due to electrostatic interaction between the molecule's cationic moiety and the cell surface, followed by amplification of ROS generation in the cells. This article is protected by copyright. All rights reserved. (Link to Publication Site) ● Publication site (DOI): 10.1111/php.12507 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 26268548 ● Search Scopus @ Elsevier (PMID): 26268548 ● Search Scopus @ Elsevier (DOI): 10.1111/php.12507 (DOI: 10.1111/php.12507, PubMed: 26268548)
19.	Akihiro Shirai, Masayoshi Onitsuka, Hideaki Maseda and Takeshi Omasa : Effect of polyphenols on reactive oxygen species production and cell growth of human dermal fibroblasts after irradiation with ultraviolet-A light, Biocontrol Science, Vol.20, No.1, 27-33, 2015. (Summary) Ultraviolet-A (UV-A) can damage microbes by generating reactive oxygen species (ROS), singlet oxygen, superoxides, hydrogen peroxide and hydroxyl radicals. These species readily react with lipids, proteins, DNA and other constituents of cells, leading to oxidative deterioration and the eventual death of the microbe. However, the oxidative ability of these reactive species also harms the viability of mammalian cells such as fibroblasts and keratinocytes, as they cause both acute and chronic damage, photo-aging, and photo-carcinogenesis. This study describes a UV-A treatment that does not affect the viability or growth of human neonate dermal fibroblasts, as determined by examining the post-irradiation cell density after the addition of polyphenols as antioxidants. The results demonstrate the possible wide applicability of UV-A sterilization. The potency of polyphenols for attenuating UV-A-induced ROS generation in cells was tested using (+)-catechin hydrate, (-)- epigallocatechin gallate hydrate, morin hydrate, quercetin hydrate and resveratrol. The lowest concentration of polyphenols required to reduce ROS by 50% in cells upon exposure to a dose of 15 J cm-2 was determined and defined as its IC50. Pre-treatment with morin hydrate at its IC50 allowed cells irradiated with 5.0 J cm-2 UV-A to recover to the level of the specific growth rate of cells incubated without UV-A irradiation. However, the growth rate of cells exposed to 15 J cm-2 UV-A irradiation was scarcely influenced by co-incubation with morin hydrate; this dose of UV-A also suppressed cell growthcompletely in the absence of morin hydrate, although co-incubation resulted in no decrease in cell viability. This study demonstrates the potential of polyphenols for protecting both the viability of cells and their ability to proliferate from damage caused by UV-A-irradiation. (Keyword) Polyphenol / Ultraviolet-A / Reactive oxygen species / Cell proliferation (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.20.27 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 25817810 ● CiNii @ National Institute of Informatics (CRID): 1390282679440670976 ● Summary page in Scopus @ Elsevier: 2-s2.0-84926366827 (DOI: 10.4265/bio.20.27, PubMed: 25817810, CiNii: 1390282679440670976, Elsevier: Scopus)
20.	Masayoshi Onitsuka, Miki Tatsuzawa, Ryutaro Asano, Izumi Kumagai, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : Trehalose suppresses antibody aggregation during the culture of Chinese hamster ovary cells, Journal of Bioscience and Bioengineering, Vol.117, No.5, 632-638, 2014. (Summary) The aggregation of therapeutic antibodies during the manufacturing process is problematic because of the potential risks posed by the aggregates, such as an unexpected immune response. One of the hallmark effects of trehalose, a disaccharide consisting of two alpha-glucose units, is as a chemical chaperone with anti-aggregation activity. In this study, Chinese hamster ovary (CHO) cell line producing a diabody-type bispecific antibody were cultured in medium containing trehalose and the aggregation of the secreted proteins during the culture process was analyzed. An analysis of the various forms of the antibody (monomeric, dimeric, and large aggregates) showed that trehalose decreased the relative content of large aggregates by two thirds. The aggregation kinetics indicated that trehalose directly inhibited the polymerization and aggregation steps in a nucleation-dependent aggregation mechanism. Moreover, both specific and volumetric antibody production were increased in CHO cells cultured in trehalose-containing medium. Thus, the addition of trehalose to recombinant CHO cell cultures would offer a practical strategy for quality improvement in the production of therapeutic antibodies. (Keyword) Animals / Antibodies, Bispecific / Bioreactors / CHO Cells / Cricetinae / Cricetulus / Culture Media / Kinetics / Protein Binding / Trehalose (Link to Publication Site) ● Publication site (DOI): 10.1016/j.jbiosc.2013.10.022 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 24315529 ● CiNii @ National Institute of Informatics (CRID): 1522262180374430720 ● Summary page in Scopus @ Elsevier: 2-s2.0-84897055074 (DOI: 10.1016/j.jbiosc.2013.10.022, PubMed: 24315529, CiNii: 1522262180374430720, Elsevier: Scopus)
21.	Akihiro Shirai, Mutsumi Aihara, Akira Takahashi, Hideaki Maseda and Takeshi Omasa : Synergistic antimicrobial activity based on the combined use of a gemini-quaternary ammonium compound and ultraviolet A light, Journal of Photochemistry and Photobiology B: Biology, Vol.130, 226-233, 2014. (Summary) This study examined the utility of synergistic disinfection employing a gemini-quaternary ammonium salt (a gemini-QUAT, namely 3,3'-(2,7-dioxaoctane)bis(1-decylpyridinium bromide)), as an organic biocide in combination with irradiation by an ultraviolet-A (UV-A) light-emitting diode (LED) with a peak wavelength of 365nm. The combined system represents a novel disinfection method utilizing facilitated in situ oxidation depending on overproduction of reactive oxygen species (ROS) triggered by the initial action of the gemini-QUAT on the bacterial membrane. We demonstrate that this combination decreased the viability of pathogenic bacteria in a significant and rapid manner, and depended on doses of the gemini-QUAT and the fluence: the viability of Escherichia coli was reduced by greater than 5.0-logs by the combination procedure, but the decrease in viability was only 2.3-logs for exposure to UV at the same fluence dose in the absence of the gemini-QUAT. Adding catalase as a radical scavenger decreased bacterial inactivation by the combined disinfection procedure. Flow cytometric analysis indicated superoxide and hydrogen peroxide overproduction within cells treated with the combined disinfection procedure. The excessive superoxide, detected only in the combined system, appeared to be generated by the action of the gemini-QUAT at the bacterial membrane, leading to excessive and rapid generation of ROS in the system. Our data strongly suggested that this ROS promoted bacterial membrane peroxidation during initial treatment by the combination method, resulting in increased oxidative modification of DNA. These oxidative reactions may play an important role in the efficacy of this disinfection procedure. (Keyword) Anti-Bacterial Agents / Bacteria / Bacterial Load / DNA / Lipid Peroxidation / Pyridinium Compounds / Quaternary Ammonium Compounds / Reactive Oxygen Species / Ultraviolet Rays (Link to Publication Site) ● Publication site (DOI): 10.1016/j.jphotobiol.2013.11.027 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 24362318 ● Summary page in Scopus @ Elsevier: 2-s2.0-84890840874 (DOI: 10.1016/j.jphotobiol.2013.11.027, PubMed: 24362318, Elsevier: Scopus)
22.	Akihiro Shirai, Toshiyuki Endo, Hideaki Maseda and Takeshi Omasa : Synthesis of thiazole derivatives and evaluation of their antiamoebic activity and cytotoxicity, Biocontrol Science, Vol.18, No.4, 183-191, 2013. (Summary) Five ethyl (5-alkyl-2-amino-1,3-thiazol-4-yl) acetates (designated compounds 4a-e) incorporating octyl, decyl, dodecyl, tetradecyl, and hexadecyl alkyl chains, respectively, were prepared by reacting 4-alkyl-4-bromo-3-oxobutyric acid ethyl esters (3a-e) with thiourea in dried acetonitrile. Compounds 3a-e were synthesized by reacting alkylated ethyl acetoacetates with bromine. The newly synthesized compounds were characterized by mass spectrometry, NMR, and elemental analysis. Compounds 4a-c demonstrated good in vitro antiamoebic activity against Acanthamoeba polyphaga exposed to 10 mg L(-1) for 6 h at 28 °C. Compound 4b showed the highest antiamoebic activity among the tested compounds, comparable to that of chlorhexidine dihydrochloride (CHX), decreasing the number of viable cells to below the detection limit of 1 cell mL(-1). The activity of compounds 4a and 4c was similar to that of the commercial antifungal agent fluconazole (Flu). The cytotoxic and hemolytic activity of the compounds was assayed against human neonate dermal fibroblasts and sheep erythrocytes, respectively. Compounds 4a-c were less cytotoxic than Flu and CHX. Our results suggest that compound 4b, which is composed of a 2-amino-thiazole attached to a decyl group and an ethyl ester moiety, is a particularly safe and effective alternative amoebicidal agent. (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.18.183 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 24366623 ● Summary page in Scopus @ Elsevier: 2-s2.0-84892843299 (DOI: 10.4265/bio.18.183, PubMed: 24366623, Elsevier: Scopus)
23.	Akihiro Shirai, Yasuko Fumoto, Tomoaki Shouno, Hideaki Maseda and Takeshi Omasa : Synthesis and biological activity of thiazolyl-acetic acid derivatives as possible antimicrobial agents, Biocontrol Science, Vol.18, No.2, 59-73, 2013. (Summary) 5a-h, a series of (5-substituted-2-methyl-1,3-thiazole-4-yl) acetic acids as heterocyclic acetic acid derivatives, was designed and synthesized from ethyl acetoacetate. The synthesized compounds were screened for their antimicrobial activities against bacterial and fungal strains, and their characteristics were investigated by assays under various temperature and pH conditions. Cytotoxicity was evaluated with the use of sheep erythrocytes and human neonate dermal fibroblasts. Similarly, agents such as lauric acid 6 and parabens 7a-b, which are used as preservative agents for commercial cosmetics and detergents, were assayed for comparison. Although the structure of 5a is simple, comprising a thiazole attached with an octyl group and acetic acid moiety, the compound showed stronger and broader antibacterial and antifungal activities among the 5 series against the tested microbes other than gram-negative bacteria. Interestingly, 5a overcame the weak antifungal activity of parabens 7a-b. Also, the cytotoxicity of 5a was less than that of parabens 7a-b, especially to human dermal fibroblasts. These results suggest that thiazolyl-acetic acid 5a is a potentially effective biocide, and that it could be used as a preservative agent in commercially sold cosmetics and detergents, facilitated by the hydrophilic and charge properties of its carboxylic acid moiety. (Keyword) Thiazolyl-acetic acid derivatives / Antibacterial / Antifungal / Cytotoxicity / Surfactant (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.18.59 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390282679442225536 ● Search Scopus @ Elsevier (DOI): 10.4265/bio.18.59 (DOI: 10.4265/bio.18.59, CiNii: 1390282679442225536)
24.	Maki Uwate, Yu-ki Ichise, Akihiro Shirai, Takeshi Omasa, Nakae Taiji and Hideaki Maseda : Two routes of MexS-MexT-mediated regulation of MexEF-OprN and MexAB-OprM efflux pump expression in Pseudomonas aeruginosa, Microbiology and Immunology, Vol.57, No.4, 263-272, 2013. (Summary) The NfxC-type mutant of Pseudomonas aeruginosa produces the MexEF-OprN efflux pump and down-regulates expression of the quorum-sensing-dependent efflux pump MexAB-OprM and production of virulence factors in the presence of an active transcriptional regulator, MexT. Consequently, these cells are resistant to chloramphenicol and hypersusceptible to β-lactam antibiotics. An upper negative regulator, MexS, has been assumed to inactivate MexT in wild-type strains, hence shutting down production of the MexEF-OprN pump. This observation was, however, reported in only one clinical strain and not confirmed in well-characterized laboratory strains. Moreover, it is not known whether MexS is involved in the quorum-sensing-dependent regulation of virulence factor production. To assess these issues, a plasmid carrying wild-type mexS was introduced into three NfxC-type mutants from laboratory strains, which carry an impaired mexS and unimpaired mexT. Unexpectedly, all the transformants produced an increased amount of MexEF-OprN proteins. Three clinical NfxC strains were similarly transformed and although MexEF-OprN was undetectable in two of these strains, one produced an increased amount of these proteins, similar to the laboratory strains. These results were interpreted to mean that P. aeruginosa takes two separate routes in MexT-mediated regulation of mexEF-oprN expression: the MexS-bypassed pathway and MexS-mediated pathway. On the other hand, the transformants of both the laboratory and clinically derived NfxC-type cells produced increased amounts of MexAB-OprM and virulence factors, suggesting that production of these proteins occurs via the MexS-mediated pathway. (Keyword) Anti-Bacterial Agents / Bacterial Proteins / Gene Expression Regulation, Bacterial / Microbial Sensitivity Tests / Plasmids / Pseudomonas aeruginosa / quorum sensing / Sequence Analysis, DNA / Transformation, Bacterial / Virulence Factors (Link to Publication Site) ● Publication site (DOI): 10.1111/1348-0421.12032 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 23586630 ● Summary page in Scopus @ Elsevier: 2-s2.0-84876433725 (DOI: 10.1111/1348-0421.12032, PubMed: 23586630, Elsevier: Scopus)
25.	Akihiro Shirai, Shoko Ueta, Hideaki Maseda, Hiroki Kourai and Takeshi Omasa : Action of reactive oxygen species in the antifungal mechanism of gemini-pyridinium salts against yeast, Biocontrol Science, Vol.17, No.2, 77-82, 2012. (Summary) We previously found that the gemini quaternary salt (gemini-QUAT) containing two pyridinium residues per molecule, 3,3'- (2,7-dioxaoctane) bis (1-decylpyridinium bromide) (3DOBP-4,10) , exerted fungicidal activity against <I>Saccharomyces cerevisiae</I> and caused respiration inhibition and the cytoplasmic leakage of ATP, magnesium, and potassium ions. Here, we investigated how the gemini-QUAT, 3DOBP-4,10, exerts more powerful antimicrobial activity than the mono-QUAT <I>N</I>-cetylpyridinium chloride (CPC) and examined the association between reactive oxygen species (ROS) and the antimicrobial mechanism. Antifungal assays showed that the activity of 3DOBP-4,10 against two yeasts, <I>S. cerevisiae</I> and <I>Candida albicans</I>, was significantly elevated under aerobic conditions, and largely reduced under anaerobic conditions (nitrogen atmosphere) . Adding radical scavengers such as superoxide dismutase, catalase and potassium iodide (KI) also decreased the fungicidal activity of 3DOBP-4,10 but negligibly affected that of CPC. We measured survival under static conditions and found that the rapid fungicidal profile of 3DOBP-4,10 was lost, whereas that of CPC was slightly affected in the presence of KI. Our results suggest that 3DOBP-4,10 exerts powerful antimicrobial activity by penetrating the cell wall and membrane, which then allows oxygen to enter the cells, where it participates in the generation of intracellular ROS. The activity could thus be attributable to a synergic antimicrobial combination of the disruption of organelle membranes by the QUAT and oxidative stress imposed by ROS. (Keyword) Aerobiosis / Anaerobiosis / Antifungal Agents / Candida albicans / Cell Membrane / Cell Respiration / Cell Wall / Drug Synergism / Free Radical Scavengers / Microbial Sensitivity Tests / Oxidative Stress / Pyridinium Compounds / Quaternary Ammonium Compounds / Reactive Oxygen Species / Saccharomyces cerevisiae / Time Factors (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.17.77 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 22790843 ● CiNii @ National Institute of Informatics (CRID): 1390001204464716032 ● Search Scopus @ Elsevier (PMID): 22790843 ● Search Scopus @ Elsevier (DOI): 10.4265/bio.17.77 (DOI: 10.4265/bio.17.77, PubMed: 22790843, CiNii: 1390001204464716032)
26.	Uwate Maki, Ichise Yu-ki, Kayama Shizuo, Akihiro Shirai, Miyake Yoichiro, Takeshi Omasa, Nakae Taiji and Hideaki Maseda : Functionalization of MexT Enhances MexEF-OprN Expression to Overcome Its Repression by MvaT in Pseudomonas aeruginosa, Journal of Bioindustrial Science, Vol.1, 10-14, 2012.
27.	Hideaki Maseda, Hashida Yumiko, Akihiro Shirai, Takeshi Omasa and Nakae Taiji : Mutation in the sdeS gene promotes expression of the sdeAB efflux pump gene and multidrug resistance in Serratia marcescens, Antimicrobial Agents and Chemotherapy, Vol.55, No.6, 2922-2926, 2011. (Summary) Serratia marcescens gained resistance to both biocides and antibiotics on expressing the SdeAB efflux pump, following exposure to increasingly higher concentrations of a biocide (H. Maseda et al., Antimicrob. Agents Chemother. 53:5230-5235, 2009). To reveal the regulatory mechanism of sdeAB expression, wild-type cells were subjected to transposon-mediated random mutagenesis, and a mutant with antibiotic resistance, which mimicked the phenotype of the previous biocide-resistant cells, was obtained. The transposon element was found in the chromosomal DNA downstream of the sdeAB operon. Sequencing revealed the presence of an open reading frame (ORF) encoding a protein with 159 amino acid residues that is highly similar to the BadM-type transcriptional repressor, designated sdeS. The level of sdeB::xylE reporter gene expression, undetectable in the wild-type cells, appeared to be fully comparable to that in the biocide-resistant cells. Nucleotide sequencing of the mutant revealed sdeS to have a single G-to-A base substitution at position 269 that converted Trp90 to a stop codon. Introduction of a plasmid-borne intact sdeS into the mutant cells and the biocide-resistant cells resulted in a reduction in sdeB::xylE reporter activity to an undetectable level. These results suggested that SdeS functions as a repressor of the sdeAB operon. It was concluded that the original biocide-resistant cells had an impaired sdeS and, therefore, a derepressed level of the SdeAB efflux pump. (Keyword) Disinfectants / Drug Resistance, Multiple, Bacterial / Gene Expression Regulation, Bacterial / Genes, Bacterial / Microbial Sensitivity Tests / Norfloxacin / Operon / Serratia marcescens (Link to Publication Site) ● Publication site (DOI): 10.1128/AAC.01755-10 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 21422216 ● Summary page in Scopus @ Elsevier: 2-s2.0-79956305749 (DOI: 10.1128/AAC.01755-10, PubMed: 21422216, Elsevier: Scopus)
28.	Akihiro Shirai, 久保山泰典, 室巻良彦, Hideaki Maseda and Hiroki Kourai : The Quantitative Assay of Trophozoites and Cysts of Acanthamoeba by Applying ATP Measurement and the Establishment of an Amoebicidal Test Method, Journal of Antibacterial and Antifungal Agents, Japan, Vol.38, No.10, 651-660, 2010. (Summary) 栄養体およびシストアメーバを対象にした細胞内ATP抽出によるATP測定法を用いたアメーバ定量法を確立した．可溶性有機物を含まないPage's Amoeba Saline (PAS)培地で調製されるAcanthamoebaは，プロテオースペプトン-酵母エキス-グリシン-システイン(PYGC)液体培地で培養し，次に有機物量を1/2量とするPYGC液体培地で培養することにより調製された．アメーバ懸濁液を48穴マイクロプレートに分注し，浮遊(上清)および付着アメーバ由来のATP量を測定した．調整アメーバ数とATP量の間には明らかな直線関係を示し，算出される栄養体アメーバとシストアメーバ1細胞当たりのATP量は，それぞれ5.00×10-2 pmol， 8.50×10-3 pmolであった．本手法を用いたATP測定によれば，1生細胞まで検出可能であることも特徴であった．次に，このATP測定法によるアメーバ定量法を抗微生物剤の抗アメーバ活性試験に応用することを検討した．各薬剤接触後，形態観察とATP量測定により，形態変化とATP量変化に密な関係があることが認められた．これらの結果は，アメーバのATP評価にとっての操作法の基礎と抗アメーバ性標準試験法としての応用性を示した． (Keyword) Quantitative assay of amoebae / Amoebicidal test method / ATP measurement / Acanthamoeba / ATP measurement / ATP測定 / Acanthamoeba / アカントアメーバ (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520572360017073408 (CiNii: 1520572360017073408)
29.	Akihiro Shirai, 森下裕生, Hideaki Maseda and Hiroki Kourai : The Development of Gemini-Quaternary Ammonium Compound-Supported Inorganic-Organic Hybrids as Antimicrobial Materials, Journal of Antibacterial and Antifungal Agents, Japan, Vol.38, No.3, 133-142, 2010. (Summary) Gemini型第四アンモニウム塩(gemini-QAC)である1,4-ビス[3,3-(1-デシルピリジニウム)メチルオキシ]ブタンジブロマイド(Hygenia)を含む3種類のQACを層状アルミノシリケートであるモンモリロナイト(MMT)の層間に担持した無機-有機ハイブリッドを合成した．合成したハイブリッドは，元素分析，粉体X線結晶回折，TG-DTAにより物性評価され，そしてQAC遊離パターンと抗菌活性を調べ，徐放的殺菌性能を明らかにした．さらに，Hygenia-MMTを含む塗料の薄膜は，Aspergillus niger胞子に対し，菌糸の成長を阻害した． (Keyword) Inorganic-organic hybrid / Gemini-quaternary ammonium compound / Extended-release / Antimicrobial activity / Antimicrobial constitution / 徐放性 / Antimicrobial activity / 抗菌活性 / Antimicrobial constitution / 抗菌組成物 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520290885041045504 (CiNii: 1520290885041045504)
30.	Hideaki Maseda, Yumiko Hashida, Rumi Konaka, Akihiro Shirai and Hiroki Kourai : Mutational upregulation of a resistance-nodulation-cell division-type multidrug efflux pump, SdeAB, upon exposure to a biocide, cetylpyridinium chloride, and antibiotic resistance in Serratia marcescens, Antimicrobial Agents and Chemotherapy, Vol.53, No.12, 5230-5235, 2009. (Summary) Serratia marcescens is an important opportunistic pathogen in hospitals, where quaternary ammonium compounds are often used for disinfection. The aim of this study is to elucidate the effect of a biocide on the emergence of biocide- and antibiotic-resistant mutants and to characterize the molecular mechanism of biocide resistance in Serratia marcescens. A quaternary ammonium compound-resistant strain, CRes01, was selected by exposing a wild-type strain of S. marcescens to cetylpyridinium chloride. The CRes01 cells exhibited 2- to 16-fold more resistance than the wild-type cells to biocides and antibiotics, including cetylpyridinium chloride, benzalkonium chloride, chlorhexidine gluconate, fluoroquinolones, tetracycline, and chloramphenicol, and showed increased susceptibilities to beta-lactam antibiotics and N-dodecylpyridinium iodide. Mutant cells accumulated lower levels of norfloxacin than the parent cells in an energized state but not in a de-energized state, suggesting that the strain produced a multidrug efflux pump(s). To verify this assumption, we knocked out a putative efflux pump gene, sdeAB, in CRes01 and found that the knockout restored susceptibility to most quaternary ammonium compounds and antibiotics, to which the CRes01 strain showed resistance. On the basis of these and other results, we concluded that S. marcescens gains resistance to both biocides and antibiotics by expressing the SdeAB efflux pump upon exposure to cetylpyridinium chloride. (Keyword) Anti-Bacterial Agents / Bacterial Proteins / Cetylpyridinium / Disinfectants / Drug Resistance, Multiple, Bacterial / Membrane Proteins / Mutation / Norfloxacin / Quaternary Ammonium Compounds / Serratia marcescens (Link to Publication Site) ● Publication site (DOI): 10.1128/AAC.00631-09 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 19752278 ● Summary page in Scopus @ Elsevier: 2-s2.0-71249085152 (DOI: 10.1128/AAC.00631-09, PubMed: 19752278, Elsevier: Scopus)
31.	Akihiro Shirai, Tomoko Sumitomo, Mayuko Kurimoto, Hideaki Maseda and Hiroki Kourai : The mode of the antifungal activity of gemini-pyridinium salt against yeast, Biocontrol Science, Vol.14, No.1, 13-20, 2009. (Summary) The gemini quaternary salt (gemini-QUAT) containing two pyridinium residues per molecule, 3,3'-(2,7-dioxaoctane) bis (1-decylpyridinium bromide) (3DOBP-4,10), exerted fungicidal activity against Saccharomyces cerevisiae accompanied by respiration inhibition and the cytoplasmic material leakage of ATP, magnesium, and potassium ions. We previously found that gemini-QUAT exerted bacterioclastic action against Escherichia coli by causing the rapid and abundant leakage of turbid materials from the cells. In addition, the first stage of the bacterioclastic action was the leakage of magnesium ions, outer membrane protein E, ATP, and lipopolysaccharides. Here, we investigated how the gemini-QUAT 3DOBP-4,10 exerts fungicidal action against S. cerevislae. The results showed that that > or = 0.4 microM 3DOBP-4,10 stopped respiration and that > or = 3.0, 1.0 and 1.0 microM caused the leakage of cytoplasmic components ATP, magnesium and potassium ions, respectively. Scanning and transmission electron micrographs showed a preserved cell wall structure, whereas intracellular organelles were destroyed in cells incubated with 3DOBP-4,10. We postulated that 3DOBP-4,10 exerts its fungicidal action against S. cerevisiae not through cell wall destruction and protein leakage, but rather by penetrating the cell wall and disrupting the membranes of organelles. (Keyword) Antifungal Agents / Microbial Sensitivity Tests / Microscopy, Electron, Scanning / Microscopy, Electron, Transmission / Oxygen / Pyridinium Compounds / Quaternary Ammonium Compounds / Saccharomyces cerevisiae (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.14.13 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 19344094 ● Search Scopus @ Elsevier (PMID): 19344094 ● Search Scopus @ Elsevier (DOI): 10.4265/bio.14.13 (DOI: 10.4265/bio.14.13, PubMed: 19344094)
32.	Akihiro Shirai, Tomoko Sumitomo, 岡村菜穂, 大久保彰洋, 湯浅明彦, Hideaki Maseda and Hiroki Kourai : 銀担持アクリル繊維を含む抗菌紙の魚病原因細菌に対する殺菌特性, Journal of Antibacterial and Antifungal Agents, Japan, Vol.36, No.9, 579-585, 2008. (Summary) 銀担持アクリル繊維，ポリエステル，ポロプロピレンの3種混抄紙(izi)の魚病原因細菌に対する殺菌特性を明らかにした．iziは，アユ養殖場から分離された魚病原因細菌に対して強い殺菌力を有していた．また，iziの殺菌力は，一般細菌と魚病原因細菌を含むアユ養殖場のプール水の殺菌に有効であることを示した． (Keyword) Silver-supported acrylic fiber / 銀担持アクリル繊維 / Bactericidal activity / 殺菌活性 / Fish diseases / 魚病 / Hydroxyl radical disinfection / ヒドロキシラジカル殺菌 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520009410063770496 (CiNii: 1520009410063770496)
33.	Akihiro Shirai, Takuya Maeda, Motoaki Ohkita, Hideaki Nagamune and Hiroki Kourai : Antibacterial activity and characteristics of modified ferrite powder coated with a gemini pyridinium salt molecule, Biocontrol Science, Vol.12, No.3, 83-91, 2007. (Summary) This report describes the synthesis of an antibacterial material consisting of a gemini quaternary ammonium salt (gemini-QUAT) immobilized on ferrite powder, and its antibacterial activity. A gemini-QUAT containing two pyridinium residues per molecule, 4,4'-[1,3-(2,2-dihydroxylmethyl-1,3-dithiapropane)]bis (1-octylpyridinium bromide), was immobilized on ferrite powder by a reaction between the hydroxyl group of the QUAT and trimethoxysilane. Immobilization of the gemini-QUAT on ferrite (F-gemini-QUAT) was confirmed when the dye, bromophenol blue, was released from F-gemini-QUAT-dye after contact between ferrite and the dye. Elemental analysis of the QUAT-ferrite determined the molar amount of QUAT on the ferrite. The antibacterial effect of the ferrite was investigated using a batch treatment system, and this effect was compared with that of another QUAT-ferrite (F-mono-QUAT) binding a mono-QUAT, which possesses one pyridinium residue, prepared by the same immobilization method as F-gemini-QUAT. Results indicated the F-gemini QUAT possessed a higher bactericidal potency and broader antibacterial spectrum compared to F-mono-QUAT. In addition, this study suggested that gemini-QUATs possessed high bactericidal potency without being influenced by immobilization to materials, and the antibacterial activity and characteristics of F-gemini-QUAT could be attributed to the unique structure of the immobilized gemini-QUAT. (Keyword) Anti-Bacterial Agents / Ferric Compounds / Magnetic Resonance Spectroscopy / Microbial Sensitivity Tests / Microscopy, Electron, Scanning / Pyridines / Quaternary Ammonium Compounds (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.12.83 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 17927048 ● CiNii @ National Institute of Informatics (CRID): 1390282679441345152 ● Search Scopus @ Elsevier (PMID): 17927048 ● Search Scopus @ Elsevier (DOI): 10.4265/bio.12.83 (DOI: 10.4265/bio.12.83, PubMed: 17927048, CiNii: 1390282679441345152)
34.	Tomoko Sumitomo, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : Construction of a leftover bath water model for microbial testing, Biocontrol Science, Vol.11, No.3, 107-114, 2006. (Summary) In this study, in order to construct a model of leftover bath water, we analyzed one hundred samples of used bath water samples which were provided by twenty-eight volunteer families. It appeared that the number of detected bacteria from such bath water was correlated closely with the number of bathers. Moreover, the pH, acidity, chemical oxygen demand (COD), ion, protein content of the leftover bath water were measured. The number of bathers had no connection with the pH, acidity, COD, and ion content of the leftover bath water. However, the protein content of the bath water correlated with the number of detected bacteria. Based on these results, the model of leftover bath water was constructed. Achromobacter xylosoxidans, Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa were incubated with the model bath water as indices of bath water contamination. The number of incubated viable cells in the model bath water increased with increasing concentrations of casamino acid. Consequently, it was suggested that varying the concentration of casamino acid based on family size or contamination would be necessary in the efficient use of the constructed model of leftover bath water for microbial testing. (Keyword) Baths / Colony Count, Microbial / Conservation of Natural Resources / Escherichia coli / Humans / Hydrogen-Ion Concentration / Klebsiella pneumoniae / Laundering / Microbiological Techniques / Models, Biological / Pseudomonas aeruginosa / Staphylococcus aureus / Staphylococcus epidermidis / Water / Water Microbiology (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.11.107 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 17017128 ● Search Scopus @ Elsevier (PMID): 17017128 ● Search Scopus @ Elsevier (DOI): 10.4265/bio.11.107 (DOI: 10.4265/bio.11.107, PubMed: 17017128)
35.	Akihiro Shirai, Tomoko Sumitomo, Munehiro Yoshida, Tomoyo Kaimura, Hideaki Nagamune, Takuya Maeda and Hiroki Kourai : Synthesis and biological properties of gemini quaternary ammonium compounds,5,5'-[2,2'-(α,ω-polymethylnedicarbonyldioxy)diethyl]bis(3-alkyl-4-methylthiazolium iodide) and 5,5'- [2,2'-(ρ-phenylenedicarbonyldioxy)diethyl] bis(3-alkyl-4-methylthiazolium bromide), Chemical & Pharmaceutical Bulletin, Vol.54, No.5, 639-645, 2006. (Summary) We synthesized gemini quaternary ammonium compounds (gemini QACs) having two thiazolium moieties in a molecule, 5,5'-[2,2'-(alpha,omega-polymethylnedicarbonyldioxy)diethyl]bis(3-alkyl-4-methylthiazolium iodide) (5DEBT-m,n), on which the carbon number of the methylene chain linking the two thiazoles (m) is 2, 6 or 8 and that of the alkyl group (n) is 8, 10, 12, 14 or 16. 5,5'-[2,2'-(p-Phenylenedicarbonyldioxy)diethyl]bis(3-alkyl-4-methylthiazolium bromide) (5DEBT-P,n) was then synthesized, which is composed of a p-phenylene as the methylene spacer. For five gemini QAC series, in addition to the previously described 5DEBT-4,n to the four new compound series, their antimicrobial activities were determined. 5DEBT-m,10 and -P,10 exhibited a wide and strong bacteriostatic activity against gram-negative and -positive bacteria, fungi and then yeast in comparison with N-tetradecyl-5-(2-hydroxyethyl)-4-methylthiazolium iodide as a mono-QAC. The bactericidal activity of the 5DEBT series against Escherichia coli IFO 12713 and Staphylococcus aureus IFO 12732 was investigated on the basis of the effects of their alkyl chain length and their molecular hydrophobicity. It was found that the effect of theses factors on their activity significantly changes by the difference between the gram-negative and -positive bacteria. Although against the gram-negative bacterium, the change in the activity due to extension of the alkyl group for each compound affected the kind of methylene spacer, against the gram-positive bacterium, it was almost equal in spite of the methylene spacer. This result could be responsible for the bactericidal mechanism of the gemini QACs being influenced by the diversity of the steric structure participating in the methylene chain length and by the bacterium cell surface hydrophobicity. (Keyword) Alkylation / Anti-Bacterial Agents / Anti-Infective Agents / Antifungal Agents / Chemistry, Physical / Chromatography, Thin Layer / Escherichia coli / Fungi / Magnetic Resonance Spectroscopy / Microbial Sensitivity Tests / Physicochemical Phenomena / Quaternary Ammonium Compounds / Staphylococcus aureus / Structure-Activity Relationship / Thiazoles / Yeasts (Link to Publication Site) ● Publication site (DOI): 10.1248/cpb.54.639 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 16651758 ● Search Scopus @ Elsevier (PMID): 16651758 ● Search Scopus @ Elsevier (DOI): 10.1248/cpb.54.639 (DOI: 10.1248/cpb.54.639, PubMed: 16651758)
36.	Hiroki Kourai, Tadao Yabuhara, Akihiro Shirai, Takuya Maeda and Hideaki Nagamune : Syntheses and antimicrobial activities of series of new bis-quaternary ammonium compounds, European Journal of Medicinal Chemistry, Vol.41, No.4, 437-444, 2006. (Summary) A series of new bis-quaternary ammonium compounds (bis-QACs), 4,4'-(2,9-dioxadecane) bis(1-alkylpyridinium bromide)s, 3,3'-(2,9-dioxadecane)bis(1-alkylpyridinium bromide)s and 3,3'-(2,7-dioxaoctane)bis(1-decylpyridinium bromide) was synthesized. The compounds were evaluated by their activities against bacteria, molds and yeasts; the activities were expressed as the minimum inhibitory concentrations (MIC) and/or the minimum bactericidal concentrations (MBC). Compound 4,4'-(2,9-dioxadecane) bis(1-decylpyridinium bromide) had MIC values which exceeded those of benzalkoniumchloride and thiabendazole. It was in vitro active against a broad spectrum of Gram-negative and Gram-positive bacteria, against yeasts and some molds, it had high solubility and thermal decomposition temperature. The relationships between structure and biological activity of the tested bis-QACs are discussed. (Keyword) Anti-Bacterial Agents / Antifungal Agents / Bacteria / Chemistry, Physical / Fungi / Hemolysis / Humans / Hydrogen-Ion Concentration / Indicators and Reagents / Magnetic Resonance Spectroscopy / Microbial Sensitivity Tests / Physicochemical Phenomena / Quaternary Ammonium Compounds / Structure-Activity Relationship / Temperature (Link to Publication Site) ● Publication site (DOI): 10.1016/j.ejmech.2005.10.021 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 16517025 ● Search Scopus @ Elsevier (PMID): 16517025 ● Search Scopus @ Elsevier (DOI): 10.1016/j.ejmech.2005.10.021 (DOI: 10.1016/j.ejmech.2005.10.021, PubMed: 16517025)
37.	Kiyo Okazaki, Munehiro Yoshida, Mari Mayama, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : Antifungal characteristics of N,N'-hexamethylenebis (4-carbamoyl-1-decylpyridinium bromide), Biocontrol Science, Vol.11, No.1, 37-42, 2006. (Summary) A bis-quaternary ammonium compound (bis-QAC), N,N'-hexamethylenebis(4-carbamoyl-1decylpyridinium bromide) (D-38), exhibited a wide antifungal spectrum and a strong activity against sixteen strains of fungi including nine strains isolated from various kinds of food. The antifungal activity was higher than that of N-dodecylpyridinium Iodide, a typical mono-QAC, and that of the commonly used fungicide, 2-(4-thiazolyl) benzimidazole. The activity of D-38, however, was comparatively low when it was measured by the agar dilution method. It is considered that the hydrophobic D-38 molecules, having two long alkyl chains, interacted with the agar medium, and therefore showed lower activity results. On the other hand, the activity of D-38 against Aspergillus niger IFO 6342 was not significantly influenced by temperature, pH and the initial spore concentration. These results indicate that bis-QACs can exhibit a high antifungal activity whether or not the environmental conditions change. (Keyword) Quaternary ammonium compound / Antifungal activity / N,N'-Hexamethylenebis (4-carbamoyl-1-decylpyridinium bromide) (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.11.37 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 16637437 ● CiNii @ National Institute of Informatics (CRID): 1390001204465013632 ● Search Scopus @ Elsevier (PMID): 16637437 ● Search Scopus @ Elsevier (DOI): 10.4265/bio.11.37 (DOI: 10.4265/bio.11.37, PubMed: 16637437, CiNii: 1390001204465013632)
38.	Akihiro Shirai, Takuya Maeda, Hideaki Nagamune, Hitoshi Matsuki, Shoji Kaneshina and Hiroki Kourai : Biological and physicochemical properties of gemini quaternary ammonium compounds in which the positions of a cross-linking sulfur in the spacer differ, European Journal of Medicinal Chemistry, Vol.40, No.1, 113-123, 2005. (Summary) Gemini型第四アンモニウム化合物(gemini QAC)の架橋構造のスルフィド結合の位置に着目した．メチレンスルフィド，エチレンジスルフィド，スルフィドがピリジン環に連結したgemini QACの3種のを合成し，抗菌活性，ヒト赤血球溶血毒性，界面活性能に関するスルフィド結合位置の影響について検討した．ピリジン環に連結したスルフィド結合を有する化合物は，抗菌力，溶血毒性，界面活性能いずれにおいても，他の2種薬剤よりも高いことが分かった．その強い抗菌力と溶血毒性は，スルフィド結合の共鳴効果によるアンモニウムカチオン電子密度の上昇，スルフィドがテトラメチレンスペーサ鎖両末端に存在することによるスペーサ鎖の高い伸縮性に起因した小さい分子占有面積，そして高い薬剤分子疎水性に寄与すると考え，スペーサ鎖の立体構造に影響し，スルフィドの位置がアンモニウムカチオン電子密度に影響を及ぼすと結論した． (Keyword) Anti-Bacterial Agents / Bacteria / Hemolysis / Humans / Hydrophobic and Hydrophilic Interactions / Microbial Sensitivity Tests / Quaternary Ammonium Compounds / Structure-Activity Relationship / Sulfides / Surface Tension (Link to Publication Site) ● Publication site (DOI): 10.1016/j.ejmech.2004.09.015 (Link to Search Site for Scientific Articles) ● PubMed @ National Institutes of Health, US National Library of Medicine (PMID): 15642416 ● Search Scopus @ Elsevier (PMID): 15642416 ● Search Scopus @ Elsevier (DOI): 10.1016/j.ejmech.2004.09.015 (DOI: 10.1016/j.ejmech.2004.09.015, PubMed: 15642416)
39.	Akihiro Shirai, Takuya Maeda, Ichiro Hara, Azumi Yoshinari, Hideaki Nagamune and Hiroki Kourai : Antimicrobial characteristics of bis-quaternary ammonium compounds possessing a p-phenylene group in their spacer chains, Biocontrol Science, Vol.8, No.4, 151--157, 2003. (Summary) p-フェニレンスペーサにより連結された2つのピリジニウム塩から成るフェニレン-ビス型四アンモニウム化合物 (Ph-bis-QACs)の抗菌特性および構造活性相関についてメチレンスペーサ鎖により連結されたメチレン-ビス型四アンモニウム化合物(M-bis-QACs)と比較検討した．Ph-bis-QACsは，高い殺菌活性と広い抗菌スペクトルを示した．Ph-bis-QACsの抗菌活性は，M-bis-QACsのメチレンスペーサ鎖をp-フェニレンスペーサ鎖に変換することによってM-bis-QACsの活性より高くなった．M-bis-QACsの活性は，アンモニウム窒素の電子密度に影響を受けるが，Ph-bis-QACsはそれに依存しないことが分かった．従って，bis-QACの抗菌活性は，アンモニウム窒素の電子密度よりもスペーサ鎖の回転軸を減少させること，分子構造の剛直性を上昇させることによって，より強化されると考えられ，bis-QACの立体構造が，bis-QACの抗菌活性の重要な因子であると示唆した． (Keyword) Bis-quaternary ammonium compound / Antimicrobial activity / Structure-activity relationship (Link to Publication Site) ● Publication site (DOI): 10.4265/bio.8.151 (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1390001204464609920 ● Summary page in Scopus @ Elsevier: 2-s2.0-0346787725 (DOI: 10.4265/bio.8.151, CiNii: 1390001204464609920, Elsevier: Scopus)
40.	Akihiro Shirai, 佐久間貴子, 青木美保, Hirokazu Miyoshi, Takuya Maeda and Hiroki Kourai : 銀担持アクリル繊維を含む抗菌紙の殺菌作用機構, Journal of Antibacterial and Antifungal Agents, Japan, Vol.31, No.4, 173-181, 2003. (Summary) 銀担持アクリル繊維とポリエステル繊維から作製したiziの抗菌特性と殺菌作用機構を検討した．iziは，病原性細菌，Legionella pneumophila Sg1 IID 5232などを含む13菌株に対して広く高い抗菌スペクトルを示した．iziの殺菌力は，食塩，ペプトン共存下で低下することを認めた．iziの殺菌化学種は，電子スピン共鳴スペクトルと，スーパーオキシドジスムターゼもしくはヨウ化カリウムのようなラジカルスカベンジャーにより活性阻害が起こることから，ヒドロキシラジカルであることを証明し，細菌細胞中で変換されたリビングラジカルが，継続的な殺菌効果を示すことを示唆した．また，細菌細胞が，iziから銀イオンを引き抜くことを示唆した． (Keyword) Silver-supported acrylic fiber / Bactericidal activity / Bactericidal chemical species / Hydroxyl radical / Quantification of silver (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520853834993299712 (CiNii: 1520853834993299712)
41.	Akihiro Shirai, Takuya Maeda, Ichiro Hara, Hideaki Nagamune and Hiroki Kourai : Synthesis and antimicrobial characteristics of 4,4',4''-(1,2,3-propylene trithio)tris(1-alkylpyridinium iodide)s, Biocontrol Science, Vol.7, No.2, 55-61, 2002. (Summary) トリス型四級アンモニウム化合物 (tris-QAC) 4,4',4''-(1,2,3-propylene-trithio)tris (1-alkylpyridinium iodide)s (4TP-n: アルキル基の炭素数 n = 4,6,8,10,12,14)を合成し，抗菌特性を検討した．4TP-nは，3つのN-alkyl-4-thiopyridinium iodideをプロパンの1,2,3位で結合したトリス型構造を有する．4TP-nの抗菌特性を，ビス型四級アンモニウム化合物 (bis-QAC) 4,4'-(1,6-hexamethylenedithio)bis(1-alkylpyridinium iodide)s (4DTBP-6,n)，モノ型四級アンモニウム化合物 (mono-QAC) N-alkylpyridinium iodide (P-n)，そして商業的な抗菌剤，防黴剤と比較した．4TP-nの静菌，殺菌活性は，4DTBP-6,nと同様に高く，またアルキル鎖長の影響をほとんど受けなかった．4TP-nは，広くかつ強い抗菌スペクトルを有していた．4TP-nの殺菌活性は，pH，温度の影響を受け，その影響を全く受けない4DTBP-6,8とは異なっていた．
42.	Akihiro Shirai, Takuya Maeda, Masayo Ito, Genji Kawano and Hiroki Kourai : Control of Legionella species and host amoeba by bis-quaternary ammonium compounds, Biocontrol Science, Vol.5, No.2, 97-102, 2000. (Summary) レジオネラ属菌(Legionella species)はレジオネラ症の原因菌であり，アメーバ類に寄生し増殖することが知られている．レジオネラ属菌の制御を行うためには，宿主アメーバに対しても高い活性を有する殺菌剤が必要である．そこで，一般的な薬剤と比較して広くかつ強い抗菌スペクトルを示し低毒性のビス型第四アンモニウム化合物(bis-QAC)，4,4'-(1,6-hexamethylenedithio)bis(1-octylpyridimium iodide) (4DTBP-6,8) および N,N'-hexamethylenebis(4-carbamoyl-1-decylpyridinium bromide) (D-38)の適用を検討した．これらのbis-QACは，レジオネラ属菌(L. pneumophila 2種とL. bozemanii 1種)に対して従来の薬剤よりも高い殺菌効果を示しただけでなく，Acanthamoebaの栄養型とそのシストに対しても非常に強い効果を示す殺菌剤であった．

Academic Paper (Unrefereed Paper):

1.	田中彩水 and Akihiro Shirai : Effects of light irradiation on deoxynivalenol production and TRI genes expression in Fusarium sp., 次世代光フォーラム2024 in 徳島論文集, Vol.P-7, 99-100, 2024.
2.	Akihiro Shirai and Koichiro Tsuchiya : フェルラ酸とUV-Aの併用殺菌力における酸素の影響, LED総合フォーラム 2022 in 徳島論文集, Vol.P-8, 143-144, 2022.
3.	Kawasaka Kaito, Hideaki Nagamune and Akihiro Shirai : フェノール酸とブルーライトを併用した真菌の光不活性化, LED総合フォーラム 2021 in 徳島論文集, Vol.P-6, 149-150, 2021. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1010853567258226176 (CiNii: 1010853567258226176)
4.	Akihiro Shirai, Ichimura Yu-ichiro, Nakamura Rei, Okahisa Naoki, Emoto Yasushi and Okada Hiroshi : 深紫外線および青色LEDによる釜揚げしらすの光殺菌, LED総合フォーラム 2021 in 徳島論文集, Vol.P-5, 147-148, 2021.
5.	Suzuki Akihiro, Kunihiro Otsuka, Hiroki Takanari, Kentaro Nagamatsu and Akihiro Shirai : 次世代光による細胞光応答の解明, LED総合フォーラム 2020 in 徳島論文集, Vol.P-17, 105-106, 2020.
6.	Akihiro Shirai, Ichimura Yu-ichiro, Yasutomo Yu-ko, Kanno Yuka, Ikeda Hiroyuki, Emoto Yasushi and Okada Hiroshi : 紫外線および青色LEDによる釜揚げしらすの細菌の不活化, LED総合フォーラム 2020 in 徳島論文集, Vol.P-5, 81-82, 2020.
7.	Kunimi Haruka, Hideaki Nagamune and Akihiro Shirai : フェルラ酸と紫外線-Aの酵母に対する併用殺菌機構の解析, LED総合フォーラム 2019 in 徳島論文集, Vol.P-6, 67-68, 2019.
8.	Akihiro Shirai, Kanno Yuka and Yasutomo Yu-ko : 紫外線および青色LEDによる釜揚げしらすの微生物制御, LED総合フォーラム 2019 in 徳島論文集, Vol.P-5, 65-66, 2019.
9.	Kunimi Haruka, Hideaki Nagamune and Akihiro Shirai : フェルラ酸と紫外線-Aの酵母に対する併用殺菌機構とそのポストハーベスト保存法としての検討, LED総合フォーラム 2018 in 徳島論文集, Vol.P-16, 119-124, 2018.
10.	Akihiro Shirai, Kunimi Haruka and Yokota Yu-ko : フェルラ酸と紫外線-Aの併用殺菌機構, LED総合フォーラム 2018 in 徳島論文集, Vol.P-15, 113-117, 2018.
11.	Akihiro Shirai and Yuko Yokota : Bactericidal action of UV-A light-irradiated ferulic acid, 4th World Congress and Expo on Applied Microbiology J. Microb. Biochem. Technol., Vol.9, No.6, 114, 2017. (Tokushima University Institutional Repository) ● Metadata: 116572 (Tokushima University Institutional Repository: 116572)
12.	Akihiro Shirai, Takashi Watanabe and Hitoshi Matsuki : フェルラ酸と紫外線(UV-A)の併用による食品媒介病原性微生物および食品腐敗微生物の不活化, LED総合フォーラム 2016 in 徳島論文集, Vol.P-9, 145-150, 2016.
13.	Akihiro Shirai, Masato Kajiura and Takeshi Omasa : フェルラ酸とその誘導体を用いた近紫外光殺菌とその殺菌機構, LED総合フォーラム 2015 in 徳島論文集, Vol.P-7, 109-112, 2015.
14.	Akihiro Shirai, Kyohei Matsumura, Masato Kajiura, Hideaki Maseda and Takeshi Omasa : フォトクロミック分子を応用した光応答型殺菌剤の開発, LED総合フォーラム2014-2015 in 徳島論文集, Vol.P-8, 121-122, 2015.
15.	Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : ジェミニ型抗菌剤ハイジェニアとLED近紫外光の併用による相乗殺菌効果とその殺菌機構の解明, LED総合フォーラム2013 in 徳島論文集, Vol.P-8, 73-74, 2013.
16.	Akihiro Shirai, 大津勇貴 and Hiroki Kourai : ジェミニ型抗菌剤とUVA-LED照射による殺菌相乗効果とその殺菌機構, LED総合フォーラム2012 in 徳島論文集, Vol.P-8, 81-82, 2012.
17.	Uwate Maki, Nakae Taiji, Akihiro Shirai, Takeshi Omasa and Hideaki Maseda : MexT-mediated Regulation of MexEF-OprN Multidrug Efflux Pump via Nod Box in Pseudomonas aeruginosa, Resouces Envionment Life, 191-198, 2011.
18.	Akihiro Shirai, 大津勇貴 and Hiroki Kourai : ジェミニ型抗菌剤とUVA-LED照射による殺菌相乗効果とその殺菌機構, LED総合フォーラム2011 in 徳島論文集, Vol.P-11, 93-94, 2011.
19.	Akihiro Shirai, 大津勇貴 and Hiroki Kourai : ジェミニ型抗菌剤とUVA-LED照射による殺菌相乗効果, LED総合フォーラム論文集, No.P-6, 75-76, 2010.
20.	Takuya Maeda, Kazuki Yoshiura, Akihiro Shirai and Hiroki Kourai : Novel antimicrobial agents, immobilized 1-alkyl-1'-(ω-hydroxypolymethylene)-4,4'-dipyridinium dibromides on inorganic materials, Proceedings of the 2nd International Conference on Advanced Materials Development and Performance Evaluation and Application, Vol.2, 649-654, 1999. (Summary) 論文題目:新規無機担体に固定化した1-Alkyl-1'-(ω-ヒドロキシポリメチレン)-4,4'-ジピリジニウムジブロマイド抗菌剤，新規第四アンモニウム塩1-アルキル-1'-(ω-ヒドロキシポリメチレン)-4,4'-ジピリジニウムジブロマイドの合成方法を確立し，抗菌特性を調べた．その結果，抗菌活性に及ぼすアルキル鎖長の影響は小さく，1-アルキル-4,4'-ピリジルピリジニウムブロマイド，1-アルキルピリジニウムアイオダイド，塩化ベンザルコニウム，チアベンダゾールと比較して広い抗菌スペクトルと高い抗菌·抗黴活性を有し，抗菌活性はpHや温度の影響を受けにくいことが判明した．さらにガラスビーズに固定化し抗菌活性を確認した．

Review, Commentary:

1.	Akihiro Shirai : 光殺菌力を強化するフェノール酸とリグニン分解物の活用, アグリバイオ, Vol.7, No.6, 49-51, Jun. 2023.
2.	Akihiro Shirai : 防菌防黴における研究・技術の過去・現在・未来の展望「光殺菌」, Journal of Antibacterial and Antifungal Agents, Vol.51, No.6, 347-354, Jun. 2023. (Tokushima University Institutional Repository) ● Metadata: 118950 (Tokushima University Institutional Repository: 118950)
3.	Akihiro Shirai : 釜揚げしらすの細菌汚染の制御におけるバイオレット-ブルーLEDの効果, Journal of Antibacterial and Antifungal Agents, Japan, Vol.50, No.8, 345-346, Aug. 2022.
4.	Akihiro Shirai and Mutsumi Aihara : LEDの放射特性を利用した微生物制御と食品衛生分野への応用, Journal of Antibacterial and Antifungal Agents, Vol.50, No.3, 121-128, Mar. 2022. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1521699231205516544 (CiNii: 1521699231205516544)
5.	Akihiro Shirai : 図書紹介食品事業者のための次亜塩素酸の基礎と利用技術, Journal of Antibacterial and Antifungal Agents, Japan, Vol.49, No.11, 562, Nov. 2021.
6.	Retsuo Kawakami and Akihiro Shirai : 医療・食品・環境分野で注目される抗菌技術:光触媒による殺菌と食品鮮度保持, Journal of Antibacterial and Antifungal Agents, Vol.46, No.7, 321-327, Jul. 2018. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1520572359244390016 (CiNii: 1520572359244390016)
7.	Akihiro Shirai : 近紫外線反応を利用した殺菌:第四アンモニウム塩とフェノール酸による相乗殺菌効果, クリーンテクノロジー, Vol.28, No.6, 10-14, Jun. 2018.
8.	Akihiro Shirai : 医療・食品・環境分野で注目される抗菌技術:開講にあたって, Journal of Antibacterial and Antifungal Agents, Japan, Vol.46, No.4, 175-176, Apr. 2018.
9.	Akihiro Shirai : 抗菌剤と芳香分子を徐放するケイ酸アルミニウム系ハイブリッドの開発, Aroma Research, Vol.53, No.14, 51-52, Feb. 2013.
10.	Masayoshi Onitsuka, Akihiro Shirai and Takeshi Omasa : 糖タンパク質生産における翻訳後プロセスの解明と制御(バイオ医薬製造技術シリーズ), PHARM TECH JAPAN, Vol.28, No.5, 73-78, Apr. 2012.

Proceeding of International Conference:

1.	Akihiro Shirai, Ami Tanaka and Atsushi Tabata : Influences of light-irradiation wavelength and irradiance on growth and deoxynivalenol production in Fusarium graminearum, ASM Microbe 2024, Vol.4247, No.MBP-FRIDAY-610, Atlanta, Jun. 2024.
2.	Akihiro Shirai and Ami Tanaka : Deoxynivalenol degradation and the antifungal effects of light exposure combined with ferulic acid against Fusarium graminearum, Global Meet on Food Science and Nutrition Technology 2023, Zoom Meeting, Nov. 2023.
3.	Makino Yuta, Akihiro Shirai, Shin-ichiro Yanagiya, Niibe Masahito, Nakano Yoshitaka and Retsuo Kawakami : Bacterial Inactivation of Pt-doped Rutile TiO2 Nanoparticles Annealed with Low-Temperature O2 Plasma, Proceedings of International Symposium of Dry Process 2023, 173-174, Nagoya, Nov. 2023.
4.	Nomoto Kazuki, Izumi Takuto, Mutsumi Aihara, Takagi Kousuke, Suzuki Misato, Matsumura Takumi, Akihiro Shirai, Takashi Mukai and Retsuo Kawakami : Damage-Less Microbial Inactivation of Plant Nutrient Solutions Irradiated with Atmospheric-Pressure Low-Temperature Air Plasma Jets, Proceedings of International Symposium of Dry Process 2022, 127-128, Osaka, Nov. 2022.
5.	Kaito Kawasaka, Hideaki Nagamune, Koichiro Tsuchiya and Akihiro Shirai : Investigation of photoinactivation mechanism of fungal conidia using blue light in combination with phenolic acids, 2021 International Chemical Congress of Pacific Basin Societies (PACIFICHEM 2021), Vol.3417683, Honolulu, Dec. 2021.
6.	Akihiro Shirai, Koichiro Sato, Hiroki Kourai and Hirobumi Nobeshima : Design of cationic biocide-containing germinants suitable for Bacillus subtilis spore germination and disinfection, 2021 International Chemical Congress of Pacific Basin Societies (PACIFICHEM 2021), Vol.3399739, Honolulu, Dec. 2021.
7.	Retsuo Kawakami, Mimoto Yuki, Akihiro Shirai, Shin-ichiro Yanagiya, Niibe Masahito, Nakano Yoshitaka and Takashi Mukai : Photobactericidal Activity of Anatase Titanium Dioxide Nanoparticles Annealed with the Assistance of Nonequilibrium Atmospheric-Pressure Oxygen Plasma, Proceedings of International Symposium of Dry Process 2021, 127-128, Tokyo, Nov. 2021.
8.	Izumi Takuto, Aihara Mutsumi, Retsuo Kawakami, Akihiro Shirai, Urakami Tomona, Katsuyuki Miyawaki and Takashi Mukai : Bactericidal Effects of Nonequilibrium Atmospheric-Pressure Plasma Jet on Hydroponic Nutrient Solutions, Proceedings of International Symposium of Dry Process 2021, 129-130, Tokyo, Nov. 2021.
9.	Oyama Eiji, Akihiro Shirai, Tadahiko Nakagawa, Masahiro Sogabe, Toshiya Okahisa and Kenji Teranishi : Effects of Physiological Saline Solution Treated by Ar Dielectric Barrier Discharge on Proliferation of Jurkat Cell, 74th Annual Gaseous Electronics Conference, Online, Oct. 2021.
10.	Akihiro Shirai, Watanabe Takashi and Hitoshi Matsuki : Effect of ferulic acid addition on the photobactericidal activity of ultraviolet-A light against food-borne pathogenic and spoilage microbes, IV International Conference on Antimicrobial Research, Vol.T7, 149, Torremolinos-Malaga, Jun. 2016.
11.	Akihiro Shirai, Matsumura Kyohei, Masayoshi Onitsuka, Hideaki Maseda and Takeshi Omasa : Application of photochromism to the molecular design of antimicrobial agents: synthesis of phenolic derivatives and their bactericidal activity based on a photo-reaction with ultraviolet-A light, III International Conference on Antimicrobial Research, No.T64, 289, Madrid, Oct. 2014.
12.	Yu-ki Ichise, Maki Uwate, Akihiro Shirai, Taiji Nakae and Hideaki Maseda : Role of MexEF-OprN efflux pump in wild type strain of Pseudomonas aeruginosa, 114th General Meeting, American Society for Microbiology, 145, Boston, May 2014.
13.	Maki Uwate, Yu-ki Ichise, Taiji Nakae, Akihiro Shirai and Hideaki Maseda : The mechanism of mexT gene activation in the expression of the mexEF-oprN operon in Pseudomonas aeruginosa, 114th General Meeting, American Society for Microbiology, 168, Boston, May 2014.
14.	Noda Masahiro, Tatsuzawa Miki, Masayoshi Onitsuka, Akihiro Shirai and Takeshi Omasa : Chemical shaperon suppresses the antibody aggregation in CHO cell culture, ESACT Meeting 2013 in Lille, No.A121, 97, Lille,France, Jun. 2013.
15.	Masayoshi Onitsuka, Tatsuzawa Miki, Noda Masahiro, Koguma Ichiro, Akihiro Shirai and Takeshi Omasa : Dynamical analysis of antibody aggregation in the CHO cell culture with thermo responsive protein A (TRPA) column, ESACT Meeting 2013 in Lille, No.A122, 97, Jun. 2013.
16.	Mai Takahashi, Syuichi Kimura, Haghparast Mohammad Ali Seyed, Yihua Cao, Takayuki Itoi, Akihiro Shirai, Masayoshi Onitsuka and Takeshi Omasa : Relationship between chromosomal instability an cell characterization in Chinese hamster ovary cell line, 25th Annual and international meeting of Japanese Association for Animal Cell Technology (JAACT 2012), 108, Nagoya, Nov. 2012.
17.	Tomomi Tsutsui, Akitoshi Nishizawa, Akihiro Shirai, Masayoshi Onitsuka, Hideaki Maseda and Takeshi Omasa : Expression profiling in UPR-regulated Chinese hamster ovary cell line, 25th Annual and international meeting of Japanese Association for Animal Cell Technology (JAACT 2012), 107, Nagoya, Nov. 2012.
18.	Miki Tatsuzawa, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : Trehalose suppress the antibody aggregation in CHO cell culture, 25th Annual and international meeting of Japanese Association for Animal Cell Technology (JAACT 2012), 106, Nagoya, Nov. 2012.
19.	Masayoshi Onitsuka, Akihiro Shirai and Takeshi Omasa : Rapid evalution of glycosylation CHO antibody production, 25th Annual and international meeting of Japanese Association for Animal Cell Technology (JAACT 2012), 110, Nagoya, Nov. 2012.
20.	Masayoshi Onitsuka, Miki Tatsuzawa, Kazuo Okuyama, Ichiro Koguma, Akihiro Shirai and Takeshi Omasa : Purification and aggregation analysis of humanized IgG-like bispecific diabody-Fc with thermo responsive Protein A (TRPA) column, 25th Annual and international meeting of Japanese Association for Animal Cell Technology (JAACT 2012), 111, Nagoya, Nov. 2012.
21.	Akihiro Shirai, Ohtsu Yuki and Hiroki Kourai : Synergistic antimicrobial activity of a gemini-quaternary ammonium compound and ultraviolet A light generated by a light-emitting diode, II International Conference on Antimicrobial Research, 98, Lisbon, Nov. 2012.
22.	Michiko Hoashi, Mai Takahashi, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : Construction of new mammalian expression vector on the basis of gene-amplified structure in CHO genome, The 18th Young Asian Biochemical Engineers' Community (YABEC), 118, Tokushima, Oct. 2012.
23.	Mai Takahashi, Syuichi Kimura, Haphparast Mohammad Ali Seyed, Yihua Cao, Takayuki Itoi, Akihiro Shirai, Masayoshi Onitsuka and Takeshi Omasa : Clonal variability and chromosomal heterogeneity in Chinese hamster ovary cell lines during long-term cultivation, The 18th Young Asian Biochemical Engineers' Community (YABEC), 117, Tokushima, Oct. 2012.
24.	Tomomi Tsutsui, Akitoshi Nishizawa, Akihiro Shirai, Masayoshi Onitsuka, Hideaki Maseda and Takeshi Omasa : Expression profiling in UPR-engineered Chinese hamster ovary cell line, The 18th Young Asian Biochemical Engineers' Community (YABEC), 116, Tokushima, Oct. 2012.
25.	Miki Tatsuzawa, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : Aggregation-controlled Chinese hamster ovary cell cultivation in antibody production, The 18th Young Asian Biochemical Engineers' Community (YABEC), 115, Tokushima, Oct. 2012.
26.	Akihiro Shirai, Koichiro Sato, Masayoshi Onitsuka, Hideaki Maseda and Takeshi Omasa : The effect of WFS1 over-expression on recombinant protein production in Chinese Hamster Ovary Cells, The 18th Young Asian Biochemical Engineers' Community (YABEC), 113, Tokushima, Oct. 2012.
27.	Ichise Yu-ki, Uwate Maki, Akihiro Shirai, Takeshi Omasa, Nakae Taiji and Hideaki Maseda : Regulation of mexT-Mediated mexEF-oprN Expression and mexAB-oprM Depression by An Upper Regulator mexS in Pseudomonas aeruginosa, The 5th Japan-China-Korea Graduate Student Forum, 110, Tsukuba, Sep. 2012.
28.	Uwate Maki, Ichise Yuki, Akihiro Shirai, Takeshi Omasa, Nakae Taiji and Hideaki Maseda : Regulation of mexT-Mediated mexEF-oprN Expression and mexAB-oprM Depression by an Upper Regulator mexS in Pseudomonas aeruginosa, American Society for Microbiology 112th General Meeting, 143, San Francisco, Jun. 2012.
29.	Masayoshi Onitsuka, Miki Tatsuzawa, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : Suppression of antibody aggregation in CHO cell culture by trehalose addition, Cell Culture Engineering XIII, 210, Scottsdale, Arizona, USA, Apr. 2012.
30.	Tomomi Tsutsui, Akitoshi Nishizawa, Akihiro Shirai, Masayoshi Onitsuka, Hideaki Maseda and Takeshi Omasa : Gene expression profiles in ATF4-overexpressing CHO cell line, Cell Culture Engineering XIII, 275, Scottsdale, Arizona, USA, Apr. 2012.
31.	Masayoshi Onitsuka, Tatsuzawa Miki, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : Effects of trehalose on antibody production: Supression of protein aggregation and enhancement of productivity, The 17th Young Asian Biochemical Engineers' Community (YABEC), No.F-9, 121, Incheon, Oct. 2011.
32.	Akihiro Shirai, kuboyama Yasunori, Masayoshi Onitsuka, Katsu Satoshi, Takami Takayuki, Hideaki Maseda and Takeshi Omasa : The effects of CHOP over-expression/down-regulation on recombinant Antithrombin III production in Chinese Hamster Ovary Cells, The 17th Young Asian Biochemical Engineers' Community (YABEC), No.F-8, 120, Incheon, Oct. 2011.
33.	Uwae Maki, Ichise Yuki, Akihiro Shirai, Takeshi Omasa, Nakae Taiji and Hideaki Maseda : MexS cancels the MexT-dependent repression of MexAB-OprM efflux pump in Pseudomonas aeruginosa, International Union of Microbiology Societies 2011 Congress, 221, Sapporo, Sep. 2011.
34.	Akihiro Shirai, Yasuko Fumoto, Hideaki Maseda and Hiroki Kourai : Synthesis and biological properties of novel anionic surfactant, potassium acetate salt of (5-alkyl-2-methyl-1,3-thiazole)s, The 2010 International Chemical Congress of Pacific Basin Societies (PACIFICHEM 2010), No.04-ORGN-1613, 139, Honolulu, Dec. 2010.
35.	Toshiyuki Endoh, Kanae Sakaguchi, Hideaki Maseda, Hiroki Kourai, Akihiro Shirai and Takeshi Omasa : Development of new antimicrobial agents: synthesis and biological properties of hybrid-type quaternary ammonium salts as a safe antimicrobial agent, The 16th Young Asian Biochemical Engineers' Community (YABEC), No.F-13, 72, Taoyuan, Nov. 2010.
36.	Akihiro Shirai, Yuki Ohtsu, Yasunori Kuboyama, Hideaki Maseda, Hiroki Kourai and Takeshi Omasa : Water disinfection system based on the combined use of gemini-quaternary ammonium salt and ultraviolet (A)-light emitting diode, The 16th Young Asian Biochemical Engineers' Community (YABEC), No.F-17, 74, Taoyuan, Nov. 2010.
37.	Akihiro Shirai, Yasuko Fumoto, Shou Nashino, Hideaki Maseda and Hiroki Kourai : Synthesis and antimicrobial properties of novel anionic heterocyclic surfactant derivatives of 5-alkyl-2-methyl-1,3-thiazole, 42nd IUPAC Congress: Chemistry Solutions, Vol.P206_018, Glasgow, Aug. 2009. (Summary) Biocides such as `Parabens' and glycerol esters of fatty acids added to cosmetics, detergents and other products for domestic and personal use aim to prevent biodeterioration caused by bacteria, yeasts and fungi. However, few additive biocidals have combined antimicrobial potency, detergent properties and low toxicity. The present study focuses on the development of new biocides for detergents composed of long alkyl chain and anionic functional groups that confer antimicrobial and detergent properties, and of thiazole derivatives with a skeleton corresponding to that of `Sulfrol' for use as safe food additives. Novel anionic thiazole (5-alkyl-2-methyl-1,3-thiazole-4-yl)acetic acids bind acetic acid at the 4 position and hydrophobic alkyl chains at the 5 position by hydrolyzing ethyl acetate structures such as (5-alkyl-2-methyl-1,3-thiazole-4-yl)acetates. Novel thiazole derivatives were synthesized as described in scheme 1. The α-position of ethyl acetoacetate (1) was alkylated by adding sodium hydride and n-butyl lithium, followed by 1-bromoalkane.1 The α-position of the alkyl compounds was subsequently bromo-substituted.2 According to the synthetic method,3 five 1,3-thiazole products (4a-4e) were derived by refluxing the α-bromo-substituted compounds and thioacetamide in anhydrous ethyl alcohol with a yield of 4.8 to 16%. The intended acetic acid derivatives (5a-5e) were finally obtained at a yield of 69-90% by 4a-4e being hydrolyzed with LiOH. The synthesized compounds, 4a-4e and 5a-5e were determined by NMR and mass spectrometry. Tube standard dilution resolved the antimicrobial activities based upon the minimum inhibitory concentration (MIC) of two thiazole series against 10 bacteria, two yeasts and four fungi. Their MICs were compared with those of anionic propyl-p-hydroxybenzoate as a `Paraben' series, sodium 4-dodecylbenzenesulfonate and lauric acid, and the non-ionic glycerol mono-ester of lauric acid. Thiazole-acetic acid derivatives, 5a and 5b were more effective antimicrobial agents against gram-positive bacteria, yeasts and fungi among all synthesized thiazole derivatives. We concluded that thiazole-acetic acid derivatives are novel anionic surfactants with potent antimicrobial properties.

Proceeding of Domestic Conference:

1.	MIYAUCHI Yutaro, Kenji Teranishi and Akihiro Shirai : プラズマ照射ミスト中に生成される化学活性種の調査, 令和6年度放電学会年次大会講演論文集, 8, Nov. 2024.
2.	市村篤識, Akihiro Shirai, Shin-ichiro Yanagiya, Retsuo Kawakami, 中野由祟 and 新部正人 : 405 nm LED 照射によるg-C3N4ナノシートの殺菌力, 令和6年度電気・電子・情報関係学会四国支部連合大会, 77, Sep. 2024.
3.	細野小次郎, 田中彩水, Atsushi Tabata and Akihiro Shirai : Gibberella zeaeのデオキシニバレノール生合成およびその関連遺伝子に及ぼす光照射の影響, 日本防菌防黴学会第51回年次大会要旨集, No.2P-Ca18, 139, Sep. 2024.
4.	佐々木蒼斗, Chikako Asada, Yoshitoshi Nakamura and Akihiro Shirai : 水蒸気爆砕リグニンと光を併用したジベレラ属菌の生育抑制効果の検討, 日本防菌防黴学会第51回年次大会要旨集, No.2P-Cp12, 189, Sep. 2024.
5.	矢崎夕奈, Koichiro Tsuchiya and Akihiro Shirai : 酸素由来の活性種に因らない近紫外線下でのフェルラ酸の殺菌機構の検討, 日本防菌防黴学会第51回年次大会要旨集, No.2P-Cp09, 186, Sep. 2024.
6.	Akihiro Shirai, 鈴木昭浩, Chikako Asada and Yoshitoshi Nakamura : 稲わら由来のリグニン分解物と近紫外光(365 nm)の併用による殺菌特性ならびにその殺菌機構の検討, 日本防菌防黴学会第51回年次大会要旨集, No.2P-Cp05, 182, Sep. 2024.
7.	井上朋也, 宮路裕貴, Akihiro Shirai, Shin-ichiro Yanagiya, 中野由祟, 新部正人 and Retsuo Kawakami : TiO2/Au/TiO2/Au/TiO2ナノ構造体の光触媒活性化効果, 2024年度応用物理・物理系学会中国四国支部合同学術講演会, Jul. 2024.
8.	Kenji Teranishi, MIYAUCHI Yutaro, Ryo Hamaoka, Akihiro Shirai and Kenji Teranishi : プラズマ照射ミスト生成時のプラズマからの発光スペクトル観測, 令和6年電気学会全国大会講演論文集, 101, Mar. 2024.
9.	CHIKAKIYO Yuito, Tadahiko Nakagawa, Akihiro Shirai, Masahiro Sogabe, Toshiya Okahisa and Kenji Teranishi : 誘電体バリア放電を生理食塩水に照射した際に生成される活性酸素・窒素種の生成特性, 令和6年電気学会全国大会講演論文集, 100, Mar. 2024.
10.	Retsuo Kawakami, Yuta Makino, Akihiro Shirai, Shin-ichiro Yanagiya, 中野由祟 and 新部正人 : 大気圧プラズマ支援アニーリングした白金ドープ酸化チタンナノ粒子の酸化分解力と殺菌力, 令和6年電気学会全国大会, 95, Mar. 2024.
11.	Akihiro Shirai : 物理的微生物制御技術の基礎, 令和5年度微生物汚染と対策に関する基礎講座, 23-30, Dec. 2023.
12.	中杉昌太, 鈴木昭浩, Chikako Asada, Yoshitoshi Nakamura and Akihiro Shirai : 水蒸気爆砕による稲わら由来のリグニン分解物を利用した光殺菌の検討, 日本防菌防黴学会第50回年次大会要旨集, No.2P-Bp04, 170, Aug. 2023.
13.	田中彩水, Atsushi Tabata and Akihiro Shirai : Fusarium graminearumの生育とデオキシニバレノール生合成に及ぼす光波長と照度の影響, 日本防菌防黴学会第50回年次大会要旨集, No.2P-Dp05, 200, Aug. 2023.
14.	田中彩水 and Akihiro Shirai : 光とフェルラ酸の併用によるFusarium graminearumの増殖とデオキシニバレノール生合成に対する抑制効果, 日本農芸化学会2023年度大会講演要旨集, No.3C01-05, 999, Mar. 2023.
15.	Mutsumi Aihara, Takuto Izumi, Akihiro Shirai, Takashi Mukai and Retsuo Kawakami : Hygiene technology for plant nutrient solution using nonequilibrium atmospheric pressure plasma jets., 第96回日本細菌学会総会, Mar. 2023. (Keyword) プラズマジェット / 植物栽培養液 / 衛生管理技術 / ダメージレス
16.	Akihiro Shirai : 食品分野で使用される物理的殺菌技術とUV-LED殺菌の基礎知見, 令和4年度微生物汚染と対策に関する基礎講座, 40-49, Dec. 2022.
17.	田中彩水 and Akihiro Shirai : 近紫外線照射によるデオキシニバレノールの分解とその産生カビの生育抑制におけるフェルラ酸の併用効果, 日本食品微生物学会学術総会要旨集, No.P-35, 103, Sep. 2022.
18.	Akihiro Shirai, 吉本春奈, 佐藤浩一郎, 高麗寛紀 and 延嶋浩文 : 芽胞の殺菌に有効な発芽促進剤の開発, 日本食品微生物学会学術総会要旨集, No.P-33, 101, Sep. 2022.
19.	Kenji Teranishi, Ryo Hamaoka and Akihiro Shirai : プラズマ照射ミストによる大腸菌の殺菌, 2022年度第49回日本防菌防黴学会年次大会講演要旨, 142, Sep. 2022.
20.	Akihiro Shirai, 吉本春奈, 佐藤浩一郎, 高麗寛紀 and 延嶋浩文 : Bacillus subtilis芽胞の殺菌に適した発芽促進剤の開発, 日本防菌防黴学会第49回年次大会要旨集, No.2P-Ca02, 115, Sep. 2022.
21.	田中彩水 and Akihiro Shirai : 近紫外線とフェルラ酸の光反応を利用したデオキシニバレノールの分解の速度論的解析とその産生菌Fusarium graminearumの生育抑制, 日本防菌防黴学会第49回年次大会要旨集, No.2P-Ca23, 136, Sep. 2022.
22.	野本和希, 泉匠人, Mutsumi Aihara, Kohsuke Takagi, SUZUKI Misato, 松村拓海, Akihiro Shirai, Takashi Mukai and Retsuo Kawakami : 植物養液への大気圧低温空気プラズマジェットによるダメージレス微生物不活化効果, 2022年第83回応用物理学会秋季学術講演会, 07-041, Sep. 2022.
23.	Kenji Teranishi, Ryo Hamaoka and Akihiro Shirai : プラズマ照射ミスト中に生成される化学活性種の検出と殺菌効果の検証, 令和4年電気学会基礎・材料・共通部門大会, Sep. 2022.
24.	Yuki Mimoto, Retsuo Kawakami, Akihiro Shirai, Shin-ichiro Yanagiya and Takashi Mukai : 大気圧低温プラズマ支援熱焼結したアナターゼ/ルチル混晶型TiO2ナノ粒子の殺菌効果, 日本防菌防黴学会第48回年次大会, 137, Sep. 2021.
25.	Yuki Takao, Retsuo Kawakami, Akihiro Shirai, Yuki Mimoto, Mutsumi Aihara and Takashi Mukai : アナターゼ型光触媒TiO2ナノ粒子による非接触殺菌効果, 日本防菌防黴学会第48回年次大会, 136, Sep. 2021.
26.	Eiji Ohyama, Yoshinori Tateishi, Tadahiko Nakagawa, Akihiro Shirai, Masahiro Sogabe, Toshiya Okahisa and Kenji Teranishi : アルゴン誘電体バリア放電を照射した生理食塩水に曝露した Jurkat 細胞の生存率, 令和3年電気学会基礎・材料・共通部門大会, Sep. 2021.
27.	泉匠人, Retsuo Kawakami, Mutsumi Aihara, Takumi Matsumura, Akihiro Shirai, Katsuyuki Miyawaki and Takashi Mukai : 植物養液への大気圧低温空気プラズマジェット殺菌効果, 2021年度応用物理・物理系学会中国四国支部合同学術講演会, 40, Jul. 2021.
28.	Kawasaka Kaito, Koichiro Tsuchiya, Hideaki Nagamune and Akihiro Shirai : フェノール酸とブルーライトを併用した真菌の光不活性化, 日本農芸化学会2021年度仙台大会, Vol.3G01-06, 829, Mar. 2021.
29.	Takuto Izumi, Retsuo Kawakami, Mutsumi Aihara, Akihiro Shirai, Katsuyuki Miyawaki and Takashi Mukai : 大気圧低温プラズマジェット照射による植物養液殺菌効果, 第68回春季応用物理学会学術講演会, 07-070, Mar. 2021.
30.	Yoshinori Tateishi, Eiji Ohyama, Sho Sakamaki, Akihiro Shirai, Tadahiko Nakagawa, Masahiro Sogabe, Toshiya Okahisa and Kenji Teranishi : 放電プラズマを照射した生理食塩水がJurkat細胞に及ぼす影響, 第58回日本人工臓器学会大会, Nov. 2020.
31.	Eiji Ohyama, Yoshinori Tateishi, Sho Sakamaki, Akihiro Shirai, Tadahiko Nakagawa, Masahiro Sogabe, Toshiya Okahisa and Kenji Teranishi : 放電プラズマを照射した生理食塩水が血液の溶血と凝固に及ぼす影響, 第58回日本人工臓器学会大会, Nov. 2020.
32.	泉匠人, Retsuo Kawakami, Mutsumi Aihara, Akihiro Shirai, Katsuyuki Miyawaki and Takashi Mukai : 植物養液への非平衡大気圧空気プラズマジェット照射効果, 2020年度応用物理・物理系学会中国四国支部合同学術講演会, 10, Aug. 2020.
33.	Akihiro Shirai : 物理的殺菌手法を用いた殺菌技術-プラズマ，UV-LED-, 令和元年度微生物汚染と対策に関する基礎講座, 35-39, Dec. 2019.
34.	芳谷勇樹, Akihiro Shirai, 梶川耕介, 安友優子, 小出洋史, 東知里, 向井孝志 and Retsuo Kawakami : 酸素プラズマ支援アニーリング処理した酸化チタンナノ粒子の殺菌効果, 日本防菌防黴学会第46回年次大会, 196, Sep. 2019.
35.	Kenji Teranishi, Naoki Oda, Koji Mizuta, Akihiro Shirai and Naoyuki Shimomura : ヘリウム誘電体バリア放電型プラズマジェットのプラズマ内部に酸素あるいは窒素を供給した際の枯草菌芽胞の不活化特性, 日本防菌防黴学会第46回年次大会要旨集, 215, Sep. 2019.
36.	Akihiro Shirai : LEDによる殺菌と食品に対するLED照射の実際, 日本防菌防黴学会第46回年次大会要旨集, No.1S1-Bp02, 141, Sep. 2019.
37.	市村優一朗, 安友優子, 菅野由佳 and Akihiro Shirai : 405nmをピークとするLEDによる徳島県産釜揚げしらすの殺菌処理としらす由来分離株に対する殺菌効果, 日本防菌防黴学会第46回年次大会要旨集, No.1P-AC42, 85, Sep. 2019.
38.	Akihiro Shirai, 國見明加 and Hideaki Nagamune : 紫外線-Aとフェルラ酸の併用殺菌機構の解析とポストハーベスト殺菌への応用, 日本防菌防黴学会第46回年次大会要旨集, No.2P-AA36, 201, Sep. 2019.
39.	Koji Mizuta, Sohsuke Akada, Kenji Teranishi, Akihiro Shirai and Naoyuki Shimomura : 周囲ガス供給型プラズマジェットの放電電力と照射距離が枯草菌芽胞の不活化に及ぼす影響, 平成30年度第45回日本防菌防黴学会年次大会講演要旨集, 215, Nov. 2018.
40.	安友優子, 菅野由佳 and Akihiro Shirai : 可視光領域のLED照射による徳島県産釜揚げしらすの殺菌処理の検討, 日本防菌防黴学会第45回年次大会要旨集, No.2P-Ca50, 231, Nov. 2018.
41.	Akihiro Shirai, 菅野由佳 and 安友優子 : 農水産物に対する405nm LEDの殺菌・増殖抑制効果, 日本防菌防黴学会第45回年次大会要旨集, No.2P-Ca51, 232, Nov. 2018.
42.	Haruka Kunimi, Hideaki Nagamune and Akihiro Shirai : 酵母に対する紫外線-Aとフェルラ酸の併用殺菌機構の解析, 日本防菌防黴学会第45回年次大会要旨集, No.2P-Cp70, 329, Nov. 2018.
43.	Akihiro Shirai, 菅野由佳 and 安友優子 : 405 nm照射による水産物の微生物汚染低減効果の検討, 第39回日本食品微生物学会学術総会講演要旨集, No.P20, 110, Sep. 2018.
44.	安友優子, 菅野由佳 and Akihiro Shirai : 紫外および可視光領域のLED照射による徳島県産釜揚げしらすの殺菌処理の検討, 第39回日本食品微生物学会学術総会講演要旨集, No.P19, 109, Sep. 2018.
45.	Haruka Kunimi, Hideaki Nagamune and Akihiro Shirai : 紫外線-Aとフェルラ酸を利用したポストハーベスト殺菌手法の検討, 第39回日本食品微生物学会学術総会講演要旨集, No.P18, 108, Sep. 2018.
46.	Akihiro Shirai, 横田優子, 田端京子 and 葉田敬子 : 釜揚げしらす由来分離菌の菌種同定と280 nmの光による分離菌の不活化, 第91回日本細菌学会総会, Vol.73, No.P-101, 75, Mar. 2018.
47.	Haruka Kunimi, Hideaki Nagamune and Akihiro Shirai : ポストハーベスト殺菌に資する紫外線-Aとフェルラ酸の併用手法の検討, 第38回日本食品微生物学会学術総会講演要旨集, No.P38, 130, Oct. 2017.
48.	横田優子, 田端京子, 葉田敬子 and Akihiro Shirai : 280 nm LEDによるしらすの細菌汚染低減効果の検討, 第38回日本食品微生物学会学術総会講演要旨集, No.P37, 129, Oct. 2017.
49.	Kenji Teranishi, Sohsuke Akada, Koji Mizuta, Eiki Kimura, Akihiro Shirai and Naoyuki Shimomura : 周囲ガス供給型ジェット状プラズマ源による枯草菌芽胞の不活化, 平成29年度第44回日本防菌防黴学会年次大会講演要旨集, 151, Sep. 2017.
50.	Akihiro Shirai : 光反応分子を利用した殺菌, 日本防菌防黴学会第44回年次大会要旨集, No.1S2-Bp02, 118, Sep. 2017.
51.	横田優子, 田端京子, 葉田敬子 and Akihiro Shirai : 徳島県産釜揚げしらす由来分離菌の菌種同定および280 nm LEDの殺菌力の検討, 日本防菌防黴学会第44回年次大会要旨集, No.2P-Aa08, 145, Sep. 2017.
52.	Haruka Kunimi, Hideaki Nagamune and Akihiro Shirai : 紫外線-Aとフェルラ酸の併用殺菌法を用いた酵母の増殖抑制の検討, 日本防菌防黴学会第44回年次大会要旨集, No.2P-Aa52, 189, Sep. 2017.
53.	Yosuke Bando, Hideaki Nagamune and Akihiro Shirai : 紫外線-A反応分子であるフェルラ酸を用いたフェノール酸誘導体の合成とその殺菌特性, 日本防菌防黴学会第44回年次大会要旨集, No.2P-Aa58, 195, Sep. 2017.
54.	Akihiro Shirai and Haruka Kunimi : 紫外線-A照射におけるフェルラ酸の殺菌機構の解明, 日本防菌防黴学会第44回年次大会要旨集, No.2P-Aa63, 200, Sep. 2017.
55.	Koji Mizuta, Sohsuke Akada, Kenji Teranishi, Akihiro Shirai and Naoyuki Shimomura : 周囲ガス供給型プラズマジェットによる枯草菌芽胞の殺菌特性(II) - 枯草菌芽胞の試料厚さが殺菌特性に及ぼす影響 -, 平成29年度電気関係学会四国支部連合大会講演論文集, 35, Sep. 2017.
56.	Haruka Kunimi, Hideaki Nagamune and Akihiro Shirai : 酵母に対する紫外線-Aとフェルラ酸の併用殺菌力とその殺菌機構, 日本農芸化学会中四国支部第48回講演会, No.A-2, 21, Jun. 2017.
57.	Sohsuke Akada, Eiki Kimura, Koji Mizuta, Kenji Teranishi, Akihiro Shirai and Naoyuki Shimomura : 周囲ガス供給型プラズマジェットによる枯草菌芽胞の殺菌特性, 平成29年電気学会全国大会講演論文集, Vol.1, 136, Mar. 2017.
58.	Akihiro Shirai, Takashi Watanabe and Hitoshi Matsuki : 紫外線(UV-A)殺菌におけるフェルラ酸の併用効果, 日本防菌防黴学会第43回年次大会要旨集, No.27Pa-D01, 245, Sep. 2016.
59.	上手麻希, 市瀨裕樹, 北島圭, Akihiro Shirai, 中江太治 and Hideaki Maseda : Novel gene regulation system mediated by rearrangement, 日本細菌学会雑誌, Vol.71, No.1, 144, Mar. 2016.
60.	市瀨裕樹, 上手麻希, 北島圭, Akihiro Shirai, 中江太治 and Hideaki Maseda : Analysis of the transient resistant cells in Pseudomonas aeruginosa, 日本細菌学会雑誌, Vol.71, No.1, 143, Mar. 2016.
61.	香川悠馬, 野村嘉紀, Masayoshi Onitsuka, Noriko Yamano, Akihiro Shirai and Takeshi Omasa : ヒト及びサメ由来抗体配列の融合による新規定常領域創製の試み, 化学工学会第81年会, Mar. 2016.
62.	阿賀万里菜, Noriko Yamano, 隈元信貴, Jana Frank, Masayoshi Onitsuka, Akihiro Shirai and Takeshi Omasa : de novo型DNAメチル化酵素欠損CHO細胞株の構築とその応用, 化学工学会第81年会, Mar. 2016.
63.	Yuanshan Lai, Noriko Yamano, Masayoshi Onitsuka, Jana Frank, Akihiro Shirai and Takeshi Omasa : Artificially induced chromosomal instability leads to increased antibody productivity in Chinese hamster ovary cells, 第67回日本生物工学会大会, Oct. 2015.
64.	阿賀万里菜, Noriko Yamano, 隈元信貴, Jana Frank, Masayoshi Onitsuka, Akihiro Shirai and Takeshi Omasa : Construction of Dnmt3 knock out CHO cell lines by CRISPR/Cas9 system, 第67回日本生物工学会大会, Oct. 2015.
65.	川村菜美子, 松山莉麻, 筒井智美, Kyoungho Lee, Noriko Yamano, Masayoshi Onitsuka, Akihiro Shirai and Takeshi Omasa : Establishment of efficient gene amplification system by the cell cycle checkpoint regulation, and its application to recombinant protein production, 第67回日本生物工学会大会, Oct. 2015.
66.	Noriko Yamano, 高橋舞, Jana Frank, Masayoshi Onitsuka, Akihiro Shirai and Takeshi Omasa : Stability difference and sequence analysis of each chromosome in CHO cells by using the genomic library, 第67回日本生物工学会大会, Oct. 2015.
67.	Yuma Kagawa, Masayoshi Onitsuka, Noriko Yamano, Akihiro Shirai and Takeshi Omasa : 2P-266 Expression and purification of IgNAR heavy chain antibody in CHO cells, 日本生物工学会大会講演要旨集, Vol.67, 241, Oct. 2015. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1541135670268993920 (CiNii: 1541135670268993920)
68.	Yuki Fujino, Toshitaka Kumamoto, Masayoshi Onitsuka, Noriko Yamano, Akihiro Shirai and Takeshi Omasa : 2P-261 Construction of IgG1-producing CHO cells by a combination of transcriptional and post-translational technology, 日本生物工学会大会講演要旨集, Vol.67, 240, Oct. 2015. (Link to Search Site for Scientific Articles) ● CiNii @ National Institute of Informatics (CRID): 1541980095199124992 (CiNii: 1541980095199124992)
69.	Akihiro Shirai : 薬剤による殺菌・除菌技術の現状と新展開:界面活性剤, 日本防菌防黴学会第42回年次大会要旨集, No.1S2p-02, 107, Sep. 2015.
70.	Akihiro Shirai, Hitoshi Ohno, Takamune Kishimoto, Takeshi Omasa and 延嶋浩文 : アニオン種の異なるピリジニウム塩系抗菌剤の熱化学的特性と抗菌特性, 日本防菌防黴学会第42回年次大会要旨集, No.2Pp-49, 255, Sep. 2015.
71.	浜垣秀平, Masayoshi Onitsuka, 角屋行紀, Noriko Yamano, Akihiro Shirai and Takeshi Omasa : 抗体医薬品の凝集抑制を目指したケミカルシャペロン添加培養法の開発, 第15回日本蛋白質科学会年会, Jun. 2015.
72.	Masayoshi Onitsuka, 野田真広, 浅野竜太郎, 熊谷泉, Noriko Yamano, Akihiro Shirai and Takeshi Omasa : CHO細胞培養における非天然型抗体の凝集性解析, 第15回日本蛋白質科学会年会, Jun. 2015.
73.	北島圭, 上手麻希, 市瀬裕樹, Akihiro Shirai, 中江太治 and Hideaki Maseda : 多剤耐性緑膿菌NfxC変異株におけるOprDポーリンの発現機構の解析, Nihon Saikingaku Zasshi, Vol.70, No.1, 194, Feb. 2015. (Keyword) 北島圭 / 上手麻希 / 市瀬裕樹 / 中江太治 / 間世田英明
74.	市瀬裕樹, 上手麻希, 北島圭, Akihiro Shirai, 中江太治 and Hideaki Maseda : 緑膿菌MexEF-OprN薬剤排出ポンプの新規発現機構の解析, Nihon Saikingaku Zasshi, Vol.70, No.1, 192, Feb. 2015.
75.	Akihiro Shirai, Kyohei Matsumura, Masayoshi Onitsuka, Hideaki Maseda and Takeshi Omasa : 新規抗菌剤の分子設計におけるフォトクロミック特性の応用, 日本防菌防黴学会第41回年次大会要旨集, No.24Ap-12, 55, Sep. 2014.
76.	Uwate Maki, Yuko Yokota, Kuroyama Ami, Ichise Yu-ki, Akihiro Shirai, Nakae Taiji and Hideaki Maseda : 多剤耐性緑膿菌NfxC変異株におけるイミペネム耐性機構の解析, 日本細菌学会雑誌, Vol.69, No.1, 201, Mar. 2014.
77.	Ichise Yu-ki, Uwate Maki, Kuroyama Ami, Yuko Yokota, Akihiro Shirai, Nakae Taiji and Hideaki Maseda : MexEF-OprN薬剤排出ポンプの発現と緑膿菌野生株での役割, 日本細菌学会雑誌, Vol.69, No.1, 200, Mar. 2014.
78.	Kuroyama Ami, Ichise Yu-ki, Uwate Maki, Yuko Yokota, Akihiro Shirai, Nakae Taiji and Hideaki Maseda : 多剤耐性緑膿菌NfxC変異株におけるイミペネム耐性機構の解析, 日本細菌学会雑誌, Vol.69, No.1, 200, Mar. 2014.
79.	Yuko Yokota, Uwate Maki, Ichise Yu-ki, Kuroyama Ami, Akihiro Shirai, Nakae Taiji and Hideaki Maseda : 特定の塩基配列の欠失による耐性関連遺伝子出現機構の解析, 日本細菌学会雑誌, Vol.69, No.1, 200, Mar. 2014.
80.	野田真広, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : 二重特異性抗体のドメイン配置が凝集性に及ぼす影響, 第65回日本生物工学会大会, 245, Sep. 2013.
81.	森下明彦, 高橋舞, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : 異数性を有するChinese hamster ovary細胞における染色体不安定性解析, 第65回日本生物工学大会, 245, Sep. 2013.
82.	高橋舞, 森下明彦, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : Chinese hamster ovary 細胞株における染色体不安定性解析と抗体生産への応用, 第65回日本生物工学大会, 73, Sep. 2013.
83.	筒井智美, Kyoung Ho Lee, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : 細胞周期制御による抗体医薬品高生産CHO細胞株構築系の確立, 第65回日本生物工学大会, 73, Sep. 2013.
84.	Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : ジェミニ型抗菌剤ハイジェニアとUVA波長光を併用することによる相乗殺菌効果とその殺菌機構の解明, 日本防菌防黴学会第40回年次大会要旨集, No.10Pp-44, 81, Sep. 2013.
85.	Yukie Kinoshita, Tomomi Tsutsui, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : 抗体生産CHO細胞株におけるNFKBIZ発現の影響, 日本動物細胞工学会2013年度大会(JAACT2013), 68, Jul. 2013.
86.	Tomomi Tsutsui, KyoungHo Lee, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : 細胞周期エンジニアリングによるChinese hamster ovary (CHO) 細胞における効率的な遺伝子増幅システムの構築, 日本動物細胞工学会2013年度大会(JAACT2013), 50, Jul. 2013.
87.	Shizuka Matsumura, Shota Ikawa, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda, Keiji Uchiyama and Takeshi Omasa : CHO細胞における小胞出芽関連因子Arfのクローニングと発現抑制によるタンパク質生産への影響, 日本動物細胞工学会2013年度大会(JAACT2013), 69, Jul. 2013.
88.	Akihiko Morishita, Mai Takahashi, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : 組換えバイオ医薬品生産CHO細胞株構築過程における染色体不安定性解析, 化学工学会第77年会, Mar. 2013.
89.	Masahiro Noda, Miki Tatsuzawa, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : トレハロース添加によるCHO細胞培養過程の抗体凝集抑制, 化学工学会第77年会, Mar. 2013.
90.	Yukie Kinoshita, Tomomi Tsutsui, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : NFKBIZ発現による高生産CHO細胞株の構築と解析, 化学工学会第77年会, Mar. 2013.
91.	Yuki Ichise, Uwate Maki, Akihiro Shirai, Nakae Taiji and Hideaki Maseda : 緑膿菌mexS遺伝子による多剤耐性化抑制機構の解析, 日本細菌学会, Vol.68, No.1, 195, Mar. 2013.
92.	Hideaki Maseda, Uwate Maki, Nakae Taiji, 市瀬裕樹, Akihiro Shirai and Takeshi Omasa : 緑膿菌多剤耐性株におけるmexS-mexT遺伝子による耐性制御, 第41回薬剤耐性菌研究会, 31, Oct. 2012.
93.	Akihiro Shirai, 佐藤浩一郎, Masayoshi Onitsuka, Hideaki Maseda and Takeshi Omasa : 組換えタンパク質高生産CHO細胞株におけるWFS1発現の影響, 第64回日本生物工学会大会, 33, Oct. 2012.
94.	龍澤実季, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : トレハロースを用いたCHO細胞培養における抗体の凝集抑制, 第64回日本生物工学会大会, 33, Oct. 2012.
95.	筒井智美, Akihiro Shirai, Masayoshi Onitsuka, 西沢明敏, Hideaki Maseda, 本田孝祐, 大竹久夫 and Takeshi Omasa : ATF-4高発現CHO細胞における遺伝子発現解析, 第64回日本生物工学会大会, 33, Oct. 2012.
96.	Ami Kuroyama, Uwate Maki, Akihiro Shirai, Nakae Taiji and Hideaki Maseda : 高度多剤耐性緑膿菌nfxC変異株の出現はmexT遺伝子の転写に依存する?, 日本細菌学会, Oct. 2012.
97.	Yuko Yokota, Uwate Maki, Akihiro Shirai, Nakae Taiji and Hideaki Maseda : ダイレクトリピートの欠失による緑膿菌mexT遺伝子出現機構の解析, 日本細菌学会, Oct. 2012.
98.	Akihiro Shirai, 遠藤聡志, Hideaki Maseda and Takeshi Omasa : チアゾール系新規抗アメーバ剤の抗微生物活性および細胞毒性, 日本防菌防黴学会第39回年次大会要旨集, No.12Pa-01, 157, Sep. 2012.
99.	Miki Tatsuzawa, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : CHO細胞培養における凝集体抑制培養:トレハロース添加の影響, 日本生物工学会西日本支部第2回講演会, 33, Jul. 2012.
100.	Hideaki Maseda, 上手麻希, Akihiro Shirai and Takeshi Omasa : 緑膿菌多剤耐性株の耐性機構の解析とその性状, 日本生物工学会西日本支部第2回講演会, 24, Jul. 2012.
101.	松本知浩, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : The effect of medium additive on glycosylation of antibody produced by CHO cell, 第63回日本生物工学会大会講演要旨集, No.1Gp14, 51, Sep. 2011.
102.	帆足理子, Masayoshi Onitsuka, 木村修一, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : Construction of mammalian expression vector using gene-amplified structure, 第63回日本生物工学会大会講演要旨集, No.1Gp13, 51, Sep. 2011.
103.	Yasunori Kuboyama, Akihiro Shirai, Masayoshi Onitsuka, Satoshi Katsu, 高見貴之, Hideaki Maseda and Takeshi Omasa : The effects of CHOP over/down-regulation on recombinant AT-III production, 第63回日本生物工学会大会講演要旨集, No.1Gp12, 51, Sep. 2011.
104.	龍澤実季, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : トレハロースを用いた細胞培養過程における抗体凝集抑制の検討, 化学工学会第43回秋季大会, 628, Sep. 2011.
105.	遠藤聡志, Akihiro Shirai, 久保山泰典, Hideaki Maseda and Takeshi Omasa : チアゾールを主骨格とする新規抗アメーバ剤の合成とその生物学的特性, 日本防菌防黴学会第38回年次大会要旨集, No.P39-31P, 117, Aug. 2011.
106.	Akihiro Shirai : 微生物胞子の化学的殺菌を考える, 日本防菌防黴学会第38回年次大会要旨集, No.S2-5, 47, Aug. 2011.
107.	龍澤実季, Masayoshi Onitsuka, Akihiro Shirai, Hideaki Maseda and Takeshi Omasa : トレハロース添加による一本鎖二重特異性抗体の凝集抑制効果の検討, 日本農芸化学会中四国支部第30回講演会, 30, May 2011.
108.	Akihiro Shirai, Kanae Sakaguchi, Hideaki Maseda, Hiroki Kourai and Takeshi Omasa : ハイブリッド型第四アンモニウム塩の抗菌特性と安全性, 日本化学会第91春季年会, No.1B5-56, 41, Mar. 2011.
109.	西沢明敏, Ahmad Haredy, Akihiro Shirai, 高見貴之, 大屋智資, 本田孝祐, 大竹久夫 and Takeshi Omasa : 細胞内品質管理機構を用いた蛋白質生産向上法の開発, 化学工学会第76年会, No.A104, 4, Mar. 2011.
110.	石橋学, 清水和也, 小林弘明, Akihiro Shirai, Takeshi Omasa, 杉浦則夫 and Hideaki Maseda : ミクロシスチンの分解に関わるMlrDタンパク質の関与, 日本水処理生物学会誌, No.30, 28, Nov. 2010.
111.	久保山泰典, Akihiro Shirai, 室巻良彦, Hideaki Maseda and Hiroki Kourai : 栄養体およびシストアメーバに対する抗アメーバ性試験法とその評価法の確立, 第37回日本防菌防黴学会年次大会, No.2PP-17, 215, Sep. 2010.
112.	Akihiro Shirai, 大津勇貴 and Hiroki Kourai : ジェミニ型抗菌剤ハイジェニアとUVA-LED照射による殺菌相乗効果, 第37回日本防菌防黴学会年次大会, No.1PP-19, 110, Sep. 2010.
113.	Akihiro Shirai, 庄野知明, 布本泰子, 室巻良彦, Hideaki Maseda and Hiroki Kourai : 新規チアゾール系抗菌剤の合成とその抗菌特性, 第37回日本防菌防黴学会年次大会, No.1PA-07, 58, Sep. 2010.
114.	Akihiro Shirai, 伊藤優花, Hideaki Maseda and Hiroki Kourai : ジェミニ型第四アンモニウム化合物を吸着させた無機-有機ハイブリッド抗菌剤の開発, 日本化学会第90春季年会(2010), No.1G7-03, 95, Mar. 2010.
115.	布本泰子, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 新規アニオン性界面活性剤の開発, 日本防菌防黴学会2009年度若手の会, Dec. 2009.
116.	坂口香苗, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 新規ハイブリッド型第四アンモニウム塩の合成と抗菌特性, 日本防菌防黴学会2009年度若手の会, Dec. 2009.
117.	Akihiro Shirai, 谷村賢一, 遠藤聡志, Hideaki Maseda and Hiroki Kourai : 徐放性を付与したポリマー型固定化殺菌剤の構築, 日本防菌防黴学会2009年度若手の会, Dec. 2009.
118.	室巻良彦, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : Gemini型第四アンモニウム塩の最適構造の検討, 日本防菌防黴学会2009年度若手の会, Dec. 2009.
119.	Akihiro Shirai, 大徳桃子, 大平匡彦, Hideaki Maseda and Hiroki Kourai : 対称・非対称型ジェミニ新規抗菌剤の合成と抗菌機能, 日本防菌防黴学会2009年度若手の会, Dec. 2009.
120.	Akihiro Shirai, 冨脇真理, 室巻良彦, Hideaki Maseda and Hiroki Kourai : 抗菌タイマー機能を付与したジェミニ型第四アンモニウム塩の構築, 日本防菌防黴学会2009年度若手の会, Dec. 2009.
121.	大平匡彦, Akihiro Shirai, Yoichiro Miyake, Hideaki Maseda and Hiroki Kourai : Synthesis and biological properties of strain-specific peptide derivative modified with a gemini quaternary ammonium salt, 第61回日本生物工学会大会, Sep. 2009.
122.	Akihiro Shirai, 黒木祐輔, Hideaki Maseda and Hiroki Kourai : 新規gemini型ベタインの合成とその殺菌特性, 第36回日本防菌防黴学会年次大会, Sep. 2009.
123.	坂口香苗, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 新規ハイブリッド型第四アンモニウム塩の合成とその生物学的特性, 第36回日本防菌防黴学会年次大会, Sep. 2009.
124.	筒井舞子, Akihiro Shirai, 室巻良彦, Hideaki Maseda and Hiroki Kourai : Gemini型第四アンモニウム塩による環境病原性アメーバの制御, 第36回日本防菌防黴学会年次大会, Sep. 2009.
125.	室巻良彦, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : Gemini型第四アンモニウム塩の抗菌活性および細胞毒性評価, 第36回日本防菌防黴学会年次大会, Sep. 2009.
126.	大津勇貴, Akihiro Shirai and Hiroki Kourai : 第四アンモニウム塩で修飾された菌種特異的ペプチド誘導体の合成と生物学的特性, 日本化学会第3回関東支部大会, Sep. 2009.
127.	Akihiro Shirai and Hiroki Kourai : ジェミニ型ピリジニウム分子をインターカレーションしたモンモリロナイトを担体とする無機-有機ハイブリッドの抗菌特性とその特性, 日本化学会第3回関東支部大会, Sep. 2009.
128.	橋田裕美子, Hideaki Maseda, Akihiro Shirai and Hiroki Kourai : 多剤耐性Serratia marcescens の抗菌剤耐性に関与する遺伝子の同定, 第82回日本細菌学会総会, Mar. 2009.
129.	上手麻希, Hideaki Maseda, Akihiro Shirai and Hiroki Kourai : 緑膿菌多剤排出ポンプMexEF-OprNの発現制御の解析, 第82回日本細菌学会総会, Mar. 2009.
130.	Shoko Ueta, 橘あゆみ, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 真菌類に対するジェミニ型第四アンモニウム塩の作用機構, 日本防菌防黴学会2008年度若手の会, Nov. 2008.
131.	森下裕生, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 無機/有機ハイブリッド抗菌剤の収着・徐放性に関する研究, 日本防菌防黴学会2008年度若手の会, Nov. 2008.
132.	室巻良彦, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : ジェミニ型第四アンモニウム塩の安全性評価, 第121回徳島生物学会, Nov. 2008.
133.	上手麻希, Hideaki Maseda, Akihiro Shirai and Hiroki Kourai : 緑膿菌多剤排出ポンプMexEF-OprNの発現に及ぼすmvaT遺伝子の効果, 第61回日本細菌学会中国・四国支部総会, Oct. 2008.
134.	橋田裕美子, Hideaki Maseda, Akihiro Shirai and Hiroki Kourai : 多剤耐性Serratia marcescensの抗菌剤耐性に関与する遺伝子の同定, 第61回日本細菌学会中国・四国支部総会, Oct. 2008.
135.	藤岡耕太郎, Akihiro Shirai, Hiroki Kourai, 斉藤美佳子 and 松岡英明 : 超深焦点可変域顕微システムを使用した抗菌加工固相表面の抗菌作用機作の迅速評価方法の検討, 第35回日本防菌防黴学会年次大会, Sep. 2008.
136.	大徳桃子, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 新規ハイブリット型第四アンモニウム塩の合成, 第35回日本防菌防黴学会年次大会, Sep. 2008.
137.	冨脇真理, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : エステル結合型疎水性基を有する新規抗菌剤の合成と抗菌活性, 第35回日本防菌防黴学会年次大会, Sep. 2008.
138.	谷村賢一, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 徐放型固定化殺菌剤の合成とその特性, 第35回日本防菌防黴学会年次大会, Sep. 2008.
139.	森下裕生, 室巻良彦, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : ジェミニ型第四アンモニウム塩の毒性・抗菌活性の定量的構造活性相関解析, 第35回日本防菌防黴学会年次大会, Sep. 2008.
140.	室巻良彦, Akihiro Shirai, 森下裕生, Hideaki Maseda and Hiroki Kourai : ジェミニ型第四アンモニウム塩の環境毒性および抗菌性の評価, 第35回日本防菌防黴学会年次大会, Sep. 2008.
141.	Akihiro Shirai, 小野勉, Hideaki Maseda and Hiroki Kourai : 新規gemini型グリシンベタインの合成とその抗菌特性, 第35回日本防菌防黴学会年次大会, Sep. 2008.
142.	Hideaki Maseda, 上手麻希, Akihiro Shirai and Hiroki Kourai : 緑膿菌多剤耐性化遺伝子mexTの機能解析, 第81回日本細菌学会総会, Mar. 2008.
143.	Hideaki Maseda, 橋田裕美子, Akihiro Shirai and Hiroki Kourai : Serratia marcescensの抗菌剤耐性に関与する遺伝子の同定と解析, 第81回日本細菌学会総会, Mar. 2008.
144.	Shoko Ueta, 栗本麻友子, Tomoko Sumitomo, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 酵母に対するジェミニ型第四アンモニウム塩系薬剤の殺菌機構, 第119回徳島生物学会, Dec. 2007.
145.	辻陽平, 伊藤雅代, 延嶋浩文, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : ジェミニ型第四アンモニウム塩化合物のレジオネラ殺菌に及ぼすCa²⁺，Mg²⁺の影響, 日本防菌防黴学会第34回年次大会, Aug. 2007.
146.	冨脇真理, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 種々のN-側鎖を有するビス型第四アンモニウム塩の合成とその抗菌活性, 日本防菌防黴学会第34回年次大会, Aug. 2007.
147.	谷村賢一, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 第四アンモニウム塩系ポリマー型固定化殺菌剤の合成とその殺菌特性, 日本防菌防黴学会第34回年次大会, Aug. 2007.
148.	大徳桃子, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : モノ型とジェミニ型第四アンモニウム塩の抗菌特性の差異, 日本防菌防黴学会第34回年次大会, Aug. 2007.
149.	森下裕生, 室巻良彦, Tomoko Sumitomo, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : ジェミニ型第四アンモニウム塩系薬剤の毒性と化学構造の定量的構造活性相関解析, 日本防菌防黴学会第34回年次大会, Aug. 2007.
150.	福居麻弓, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : エーテル結合を有するGemini型第四アンモニウム塩の合成及び殺菌特性の検討, 日本防菌防黴学会第34回年次大会, Aug. 2007.
151.	岡村菜穂, Tomoko Sumitomo, 大久保彰洋, 湯浅明彦, Akihiro Shirai, Hideaki Maseda and Hiroki Kourai : 魚病細菌に対する光触媒抗菌紙の殺菌特性, 日本防菌防黴学会第34回年次大会, Aug. 2007.
152.	Akihiro Shirai, 栗本麻友子, Tomoko Sumitomo, Hideaki Maseda and Hiroki Kourai : 酵母に対するジェミニ型ピリジニウム塩系薬剤の殺菌機構, 日本防菌防黴学会第34回年次大会, Aug. 2007.
153.	Tomoko Sumitomo, Akihiro Shirai, Hideaki Nagamune, Takuya Maeda and Hiroki Kourai : ビス型第四アンモニウム塩系薬剤の殺菌メカニズムの解明, 日本防菌防黴学会第32回年次大会, May 2005.
154.	Tomoko Sumitomo, Akihiro Shirai, 藪原忠男, 吉成安純, 唐木真理, 渡辺裕子, 浅田舞子, 栗本麻友子, 野々宮正晃, 浜川智江, 林正道, 三上勝弘 and Hiroki Kourai : 微生物試験用モデル残り湯の構築, 日本防菌防黴学会第32回年次大会, May 2005.
155.	Tomoko Sumitomo, Akihiro Shirai, 藪原忠男, 吉成安純, 唐木真理, 渡辺裕子, 浅田舞子, 栗本麻友子, 野々宮正晃, 浜川智江, 林正道, 三上勝弘 and Hiroki Kourai : 風呂残り湯の微生物学的及び化学的解析, 日本防菌防黴学会第32回年次大会, May 2005.
156.	野々宮正晃, Akihiro Shirai, Takuya Maeda and Hiroki Kourai : Carbamate結合を有するgemini型第四アンモニウム塩系殺菌剤の合成とその抗菌活性, 日本防菌防黴学会第32回年次大会, Vol.IC-33, May 2005.
157.	吉成安純, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : 新規gemini型第四アンモニウム塩殺菌剤の合成とその抗菌活性, 日本防菌防黴学会第32回年次大会, May 2005.
158.	栗本麻友子, 藪原忠男, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : Saccharomycesに対するビス型第四アンモニウム塩系薬剤の殺菌特性, 日本防菌防黴学会第32回年次大会, May 2005.
159.	浅田舞子, 藪原忠男, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : ビス型第四アンモニウム塩系薬剤の殺カビ特性, 日本防菌防黴学会第32回年次大会, May 2005.
160.	三上勝弘, Akihiro Shirai and Hiroki Kourai : Gemini型第四アンモニウム塩の物理化学的特性と定量的構造活性相関研究, 日本防菌防黴学会第32回年次大会, May 2005.
161.	藪原忠男, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : 新規ビス型第四アンモニウム塩の抗菌活性とその溶血活性, 日本防菌防黴学会第32回年次大会, May 2005.
162.	藪原忠男, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : 新規ビス型第四アンモニウム塩の合成とその抗菌活性, 日本防菌防黴学会第32回年次大会, May 2005.
163.	唐木真理, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune, Hiroki Kourai, 山中一也, 西田守 and 福士英明 : ポリリジンの抗菌特性, 日本防菌防黴学会 2004年度若手の会, Oct. 2004.
164.	渡辺裕子, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : セラチアの殺菌消毒剤耐性化機構の解明, 日本防菌防黴学会 2004年度若手の会, Oct. 2004.
165.	Tomoko Sumitomo, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : ビス型第四アンモニウム塩系殺菌剤の殺菌メカニズムの解明, 日本防菌防黴学会 2004年度若手の会, Oct. 2004.
166.	吉成安純, 藪原忠男, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : 新規gemini型第四アンモニウム塩系殺菌剤の合成とその抗菌活性, 日本防菌防黴学会 2004年度若手の会, Oct. 2004.
167.	野々宮正晃, 藪原忠男, Akihiro Shirai, Takuya Maeda, Hideaki Nagamune and Hiroki Kourai : Carbamate結合を有するgemini型第四アンモニウム塩系殺菌剤の合成とその抗菌活性, 日本防菌防黴学会 2004年度若手の会, Oct. 2004.
168.	Akihiro Shirai, 片岡大也, Takuya Maeda and Hiroki Kourai : 新規ハイブリッド型第四アンモニウム塩の合成とその抗菌活性, 日本防菌防黴学会第31回年次大会, Vol.IIDp-3, May 2004.
169.	Akihiro Shirai, 川端サヤカ, Takuya Maeda and Hiroki Kourai : 新規gemini型第四アンモニウム塩系殺菌剤の合成とその抗菌活性, 日本防菌防黴学会第31回年次大会, Vol.IIDp-2, May 2004.
170.	Akihiro Shirai, Takuya Maeda, Hiroki Kourai, 青木美保 and 竹田茂 : 銀担持アクリル繊維の光触媒殺菌機構による浴槽レジオネラ属菌の殺菌, 日本防菌防黴学会第30回年次大会, May 2003.
171.	Akihiro Shirai, Takuya Maeda and Hiroki Kourai : ビス型四級アンモニウム塩の抗菌活性においてのスぺーサ鎖の影響, 日本防菌防黴学会第30回年次大会, May 2003.
172.	Akihiro Shirai, Takuya Maeda and Hiroki Kourai : アメーバと共生するレジオネラの制御, 徳島生物学会会報第100回総会, Vol.50, No.2, 5, Dec. 1997.

Et cetera, Workshop:

1.	Retsuo Kawakami, ICHIMURA Atsunori, Akihiro Shirai, Katsuyuki Miyawaki, 立木弥生, 吉田雅彦 and 福光秀之 : 405-nm LED照射とg-C3N4ナノシートによる果実鮮度保持効果, 次世代光フォーラム2024 in 徳島, 103-104, Jan. 2024.
2.	Akihiro Shirai : 光と併せて活用する光殺菌分野の革新, 第2回オンラインびざん会, May 2023.
3.	Retsuo Kawakami, Kohsuke Takagi, Akihiro Shirai, Katsuyuki Miyawaki, 立木弥生, 吉田雅彦 and 福光秀之 : 可視光LED照射したグラファイト状窒化炭素の鮮度保持効果, 次世代光フォーラム2023 in 徳島, 111-112, Feb. 2023.
4.	Akihiro Shirai : 紫外線LEDおよび青色LEDを用いた農水産物殺菌技術の基礎知見, 食品の非加熱殺菌技術の利用可能性, Aug. 2022.
5.	高尾祐希, Akihiro Shirai, Yuki Mimoto, Mutsumi Aihara and Retsuo Kawakami : LED照射下でのアナターゼTiO2ナノ粒子の非接触殺菌効果, LED総合フォーラム2022 in 徳島, 137-138, Jan. 2022.
6.	味元勇樹, Akihiro Shirai, Shin-ichiro Yanagiya and Retsuo Kawakami : プラズマ支援アニーリングしたアナターゼ/ルチル混晶型酸化チタンナノ粒子の光分解と光殺菌効果, LED総合フォーラム2022 in 徳島, 135-136, Jan. 2022.
7.	Retsuo Kawakami, Jin Ueda, 味元勇樹, Akihiro Shirai, Katsuyuki Miyawaki and 吉田雅彦 : プラズマ支援熱焼結処理したアナターゼTiO2ナノ粒子の光殺菌と鮮度保持効果, LED総合フォーラム2022 in 徳島, 133-134, Jan. 2022.
8.	Akihiro Shirai : 光殺菌の基礎と応用, 第52回生活環境とカビ管理対策セミナー, Dec. 2021.
9.	Retsuo Kawakami, 味元勇樹, Katsuyuki Miyawaki, Akihiro Shirai and 吉田雅彦 : 熱支援プラズマ処理したアナターゼ/ルチル混晶型光触媒TiO2ナノ粒子の光分解と鮮度保持効果, LED総合フォーラム2021 in 徳島, 145-146, Feb. 2021.
10.	Akihiro Shirai : 紫外線LEDおよび青色LEDを用いた殺菌技術, 令和2年度地域産業技術セミナー, Nov. 2020.
11.	Akihiro Shirai : UV-LEDを活用した殺菌∼釜揚げしらすおよび農作物の殺菌への応用∼, 2020年6月例会・講演会(Web会議), Jun. 2020.
12.	Akihiro Shirai : 釜揚げしらすLED殺菌, 徳島新聞, 8, May 2020.
13.	芳谷勇樹, Retsuo Kawakami, 梶川耕介, Akihiro Shirai and 東知里 : 紫外線LED照射によるTiO2ナノ粒子の光触媒効果, LED総合フォーラム2020 in 徳島, 85-86, Feb. 2020.
14.	Retsuo Kawakami, 髙見直樹, 芳谷勇樹, 味元勇樹, 東知里, Katsuyuki Miyawaki, Akihiro Shirai, 吉田雅彦 and 山路諭 : 可視光LED照射下でのプラズマ支援アニーリングした光触媒TiO2ナノ粒子の鮮度保持効果, LED総合フォーラム2020 in 徳島, 83-84, Feb. 2020.
15.	Akihiro Shirai : 「徳島大学ポストLEDフォトニクス研究所研究紹介」近紫外線LEDを活用した殺菌技術, All about Photonics 2020, No.2W-P15-02, Jan. 2020.
16.	Akihiro Shirai : "未来へのバイオ技術" 勉強会「もっと光を!!次世代の光が魅せる新しい未来」紫外線と光反応分子フェルラ酸の及ぼす驚異の殺菌力 ∼食品，医療分野の革新, Jan. 2020.
17.	Akihiro Shirai : UV-LEDを活用した医療・食品用殺菌技術, 第9回おおた研究・開発フェア, No.67, Oct. 2019.
18.	Akihiro Shirai, 池田博行, 榎本康 and 岡田宏 : 深紫外線および可視光LEDを利用した食品用殺菌装置の開発-LEDによる徳島県産釜揚げしらすの殺菌処理-, 第9回おおた研究・開発フェア, No.69, Oct. 2019.
19.	Akihiro Shirai, 池田博行, 榎本康 and 岡田宏 : 深紫外線および可視光LEDを利用した食品用殺菌装置の開発-LEDによる徳島県産釜揚げしらすの殺菌処理-, 徳島ビジネスチャレンジメッセ, Oct. 2019.
20.	Retsuo Kawakami, Katsuyuki Miyawaki, Akihiro Shirai, 吉田雅彦, 芳谷勇樹, 髙見直樹, 東知里 and 山路諭 : 可視光LEDによる光触媒ナノ複合材シートの鮮度保持効果, LED総合フォーラム2019 in 徳島, 77-78, Feb. 2019.
21.	Akihiro Shirai : 徳島大学ライフオプティクス研究プロジェクト・光反応を利用した微生物制御, 赤外・紫外応用技術展, Vol.E-35, Apr. 2018.
22.	Akihiro Shirai : 紫外線LEDによる釜揚げしらす殺菌について, 徳島新聞, 8, Mar. 2018.
23.	Akihiro Shirai : 紫外線反応を利用した微生物制御, LED関連技術講座, Mar. 2018.
24.	Akihiro Shirai : 紫外線LEDによる食品表面殺菌, 徳島県LEDバレイ構想推進協議会, Feb. 2018.
25.	Akihiro Shirai : 徳島大学ライフオプティクス研究プロジェクト・光反応を利用した微生物制御, メディカルジャパン2018, Vol.8-70, Feb. 2018.
26.	Retsuo Kawakami, Katsuyuki Miyawaki, Akihiro Shirai, 東知里, 芳谷勇樹, 吉岡誠人, 南雄也, 山路諭, 吉田雅彦, 大西和男 and 大野民之助 : LED照射下での光触媒ナノ複合材の鮮度保持機能, LED総合フォーラム2018 in 徳島, 125-126, Feb. 2018.
27.	Akihiro Shirai : 光反応を利用した微生物制御, BioOpto Japan 2017, Vol.22-H6, Oct. 2017.
28.	Akihiro Shirai, 横田優子 and 菅野由佳 : 徳島県産釜揚げしらすの鮮度保持を目的とする紫外線LED殺菌技術の開発, 第17回社会産業理工学研究交流会2017 SCI-Tech Festival, No.40, 26, Sep. 2017.
29.	Akihiro Shirai and 國見明加 : 紫外線(UV-A)とフェルラ酸を併用した殺菌, 平成28年度LED総合プラットフォーム事業&LEDライフプロジェクト合同シンポジウム, Mar. 2017.
30.	Retsuo Kawakami, Katsuyuki Miyawaki, Akihiro Shirai, 東知里, 冨士本賢吾, 大塩誠二, 山路諭, 吉田雅彦, 大西和男, 大野民之助 and 松下俊雄 : LED光触媒ナノ粒子を使った鮮度保持技術の開発, LED総合フォーラム2016 in 徳島, 157-160, Dec. 2016.
31.	Akihiro Shirai : 紫外光(UV-A)反応分子を利用した生体制御技術の構築, 第6回次世代ものづくり基盤技術産業展TECH Biz EXPO 2016, Nov. 2016.
32.	Akihiro Shirai : 光反応分子を利用した微生物制御, 第16回エンジニアリングフェスティバル2016, No.16, 15, Sep. 2016.
33.	Akihiro Shirai : 紫外光(UV-A)反応分子を利用した生体制御技術の構築, BioOpto Japan 2016, Sep. 2016.
34.	Akihiro Shirai : 有機化合物を併用した近紫外線殺菌, LEDバレイ徳島・新用途開発フォーラム, Mar. 2016.
35.	Akihiro Shirai : 光反応分子を利用した微生物制御, 県と徳島大学との農林水産関係研究推進ワークショップ, Mar. 2016.
36.	Akihiro Shirai : LED近紫外線殺菌の向上に資するフェノール酸誘導体の創製, 平成27年度革新的特色研究シンポジウム LEDライフフォトニクス研究プロジェクト, Dec. 2015.
37.	Kimura Eiki, Ando Kota, Ueno Yuka, Kenji Teranishi, Akihiro Shirai and Naoyuki Shimomura : Discharge Characteristics of Surrounding Gas-Fed Plasma Jet and Experiment on Sterilization of Bacillus Subtilis Spore, The Papers of Technical Meeting, IEE JAPAN, Vol.ED-15-152, 11-16, Dec. 2015. (Keyword) plasma jet / dielectric barrier discharge / emission spectrum / Bacillus Subtilis spores / sterilization
38.	Akihiro Shirai : 光反応を利用した抗生物活性分子による生体制御技術の構築, BioOpto Japan 2015, Oct. 2015.
39.	Akihiro Shirai, Kyohei Matsumura, Masato Kajiura, Hideaki Maseda and Takeshi Omasa : LED光殺菌に及ぼす有機系抗菌剤の相乗効果, 平成26年度革新的特色研究シンポジウム LEDライフフォトニクス研究プロジェクト・LEDライフイノベーション研究プロジェクト, Feb. 2015.
40.	Akihiro Shirai : 光反応を利用した抗生物活性分子による生体制御技術の構築, 第4回次世代ものづくり基盤技術産業展TECH Biz EXPO 2014, Oct. 2014.
41.	Akihiro Shirai : 光反応と有機系化合物による微生物制御, 第4回次世代ものづくり基盤技術産業展TECH Biz EXPO 2014, 12, Oct. 2014.
42.	Akihiro Shirai : LED光殺菌への有機系抗菌剤の併用効果, 平成25年度革新的特色研究シンポジウム LEDライフフォトニクス研究プロジェクト, Feb. 2014.
43.	Akihiro Shirai : LED光反応とジェミニ型抗菌剤ハイジェニアの併用による有害微生物の制御とその殺菌機構の解明, 第3回次世代ものづくり基盤技術産業展TECH Biz EXPO 2013, Oct. 2013.
44.	Akihiro Shirai : 有害微生物の制御とその殺菌機構の解明, 第3回次世代ものづくり基盤技術産業展TECH Biz EXPO 2013, Oct. 2013.
45.	Akihiro Shirai : ジェミニ型抗菌剤とUVA-LED照射を併用した殺菌法の構築, 赤外・紫外・可視光応用技術展 2013, Apr. 2013.
46.	Akihiro Shirai : カチオン交換能およびエーテル加水分解能を有するケイ酸アルミニウムを利用した新規抗菌-芳香性ハイブリッドの開発, 日経産業新聞, 11, Nov. 2012.
47.	Akihiro Shirai and Hiroki Kourai : ジェミニ型抗菌剤とUV-A-LED照射を併用した殺菌法の構築, BioOpto Japan 2012, Sep. 2012.
48.	Akihiro Shirai, 大津勇貴 and Hiroki Kourai : ジェミニ型抗菌剤とUVA-LED照射による殺菌相乗効果とその殺菌機構, 赤外・紫外・可視光応用技術展 2012, Apr. 2012.
49.	Hiroki Kourai, Akihiro Shirai and 大津勇貴 : ジェミニ型抗菌剤と紫外部(UV-A)LEDライト照射による殺菌相乗作用メカニズム, 赤外・紫外・可視光応用技術展 2011, Apr. 2011.
50.	Akihiro Shirai, Shoko Ueta, Hideaki Nagamune and Hiroki Kourai : The Mode of the Antifungal Activity of Gemini-pyridinium Salt against, 神戸学院大学ライフサイエンス産業連携研究センター研究成果発表会, Sep. 2009.

Patent:

1.	Nobeshima Hirobumi and Akihiro Shirai : Disinfection composition and method for removing bacterial spores, PCT/JP2020/038418 (Oct. 2020), WO2021/075391 (Apr. 2021), .
2.	延嶋浩文 and Akihiro Shirai : 除菌組成物及びそれを用いる細菌芽胞の除菌方法, 2021-528335 (Oct. 2020), WO2021/075391 (Apr. 2021), 7101375 (Jul. 2022).
3.	Akihiro Shirai, 安友優子, 菅野由佳, 岡田宏 and 板東知裕 : 可視光LEDを用いた微生物の増殖抑制方法及び装置, 2019-157391 (Aug. 2019), 2020-036589 (Mar. 2020), 7425456 (Jan. 2024).
4.	Akihiro Shirai, 安友優子, 菅野由佳, 岡田宏 and 板東知裕 : 可視光LEDを用いた微生物の増殖抑制方法及び装置, 2018-163762 (Aug. 2018), 2020-036589 (Mar. 2020), .
5.	Akihiro Shirai and 延嶋浩文 : 抗菌・抗黴性ピリジン化合物，抗菌・抗黴性樹脂組成物，及び樹脂成形品, 2015-087255 (Apr. 2015), 2016-204301 (Dec. 2016), 6403161 (Sep. 2018).
6.	Akihiro Shirai and Hiroki Kourai : 除菌方法, 2011-87753 (Apr. 2011), 2012-77065 (Apr. 2012), 5833332 (Nov. 2015).
7.	Hiroki Kourai and Akihiro Shirai : 抗菌性・抗黴性ケイ酸アルミニウムおよびその製造方法, 2010-013162 (Jan. 2010), 2011-148754 (Aug. 2011), 5542460 (May 2014).
8.	Hiroki Kourai and Akihiro Shirai : 抗菌性モンモリロナイトおよびその製造法, 2009-189706 (Aug. 2009), 2011-42582 (Mar. 2011), .
9.	Hiroki Kourai, Hideaki Maseda and Akihiro Shirai : ペプチド, 2009-65464 (Mar. 2009), 2009-254355 (Nov. 2009), .
10.	Yoshito Andou, Jae-Mun Jeong, Masao Kaneko, Haruo Nishida, Takeshi Endo and Akihiro Shirai : Gas Phase Radical Polymerization for Fabric Treatment, WO2006EP12559 (Dec. 2006), WO2007087892 (Aug. 2007), .
11.	Hiroki Kourai, Akihiro Shirai and 野々宮正晃 : ビス四級アンモニウム塩化合物およびその製造方法, 2005-104970 (Mar. 2005), 2006-151942 (Jun. 2006), .
12.	Hiroki Kourai, Akihiro Shirai and 吉成安純 : ビス四級アンモニウム塩化合物およびその製造方法, 2005-104958 (Mar. 2005), 2006-151941 (Jun. 2006), .
13.	Hiroki Kourai, 伊藤雅代, 風間真知子 and Akihiro Shirai : 水系の処理方法, 2000-132086 (May 2000), 2001-310191 (Nov. 2001), .
14.	Hiroki Kourai, 河野源 and Akihiro Shirai : 固定化殺菌材，その製造方法及びビス第四アンモニウム化合物, H11-330171 (Nov. 1999), 2001-151608 (Jun. 2001), .
15.	Hiroki Kourai, 遠藤卓郎, 河野源, 石間智生 and Akihiro Shirai : 水系中のレジオネラ属細菌の除菌方法, H10-2246 (Jan. 1998), H11-197673 (Jul. 1999), 2969133 (Aug. 1999).

Grants-in-Aid for Scientific Research (KAKEN Grants Database @ NII.ac.jp)

Generation Technology of Plasma-Treated Mists Aiming for Use of Short-Lived Chemical Active Species and Application to Sterilization (Project/Area Number: 24K07432 )
バイオマス由来の低分子化リグニンを活用したカビの次世代型光殺菌技術の開発 (Project/Area Number: 23K27041 )
Research on Active Species Produced in Plasma Treated Solutions and Their Effect on Human T Cells (Project/Area Number: 21K04003 )
Studies on the electrostatic surface potential analysis of fungus spores for the improvement of photofungicidal technology by the combination with polyphenols (Project/Area Number: 20H02934 )
Development of sterilization technique based on the use of photo-sensitive bactericidal molecules for cell and tissue processed products (Project/Area Number: 15K05632 )
Construction of sterilization technique based on the use of bactericidal isomerizable derivatives for practical application of regenerative medicine (Project/Area Number: 25870476 )
Construction of sterilization technique based on biocidalradicals-producing photoreaction for the progression of regenerative medicine (Project/Area Number: 23750217 )
Next generation protein production on cellular quality-control process (Project/Area Number: 23360371 )
Genome-wide analysis and its application in Chinese hamster ovary cells (Project/Area Number: 20360373 )
Search by Researcher Number (40380117)

Associate Professor : Shirai, Akihiro

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Grants-in-Aid for Scientific Research (KAKEN Grants Database @ NII.ac.jp)