Pressurized Microwave-Assisted Hydrothermal Treatment with Various Salts for Efficient Production of Monosaccharides from Rice Straw

This study proposed a two-stage pressurized microwave hydrothermal treatment with a catalyst, followed by enzymatic saccharification, as a pretreatment method for efficiently converting cellulose and hemicellulose from rice straw into glucose and xylose. The use of various inorganic salts and dilute sulfuric acid as catalysts enhances sugar production. Using 1 wt% sulfuric acid as a catalyst at 150 °C for 5 min for the first-stage and then 180 °C for 5 min for the second-stage yielded the highest sugar production from rice straw compared with other inorganic salts tested. The filtrate and enzymatic saccharification solution contained a total sugar of 0.434 g/g-untreated rice straw (i.e. 0.302 g-glucose/g-untreated rice straw and 0.132 g-xylose/g-untreated rice straw). When inorganic salts such as NaCl, MgCl, CaCl, and FeCl were used as catalysts, the highest sugar yield of 0.414 g/g-untreated rice straw (i.e. 0.310 g-glucose/g-untreated rice straw and 0.104 g-xylose/g-untreated rice straw) was obtained when using 1 wt% FeCl at 170 °C for 5 min in the first-stage and 190 °C for 5 min in the second-stage, with a value close to that of 1 wt% sulfuric acid. These findings suggest that two-stage treatment with a catalyst is a suitable pretreatment method for the production of glucose and xylose from rice straw owing to the different hydrolysis temperatures of cellulose and hemicellulose.


Investigation and Evidence of Bioaerosol Transportation by Typhoons-Change in the Bacterial Composition of Rain in Typhoon No. 5 (Noru) at Tokushima, 2017-

台風によるバイオエアロゾル輸送の実証と実相調査-2017年台風第5号(Noru)通過時の徳島市における降雨中細菌種組成変化-


Formulation of Topical Gel Cinnamomum Burmannii Extract with Carboxy Methyl Cellulose and Its Physical Stability Testing for Oral Wound Healing Purposes


Antioxidant and antimicrobial activities of lignin-derived products from all steam-exploded palm oil mill lignocellulosic biomass waste

Chemical and Biological Technologies in Agriculture


Efficiency of β-Glucan Production by Sparassis crispa Depends on Mycelium Shape


Cured Epoxy Resin Synthesized Using Acetone-Soluble Lignin and Ligno-p-Cresol Obtained from Steam-Exploded Wheat Straw


Extraction, Separation, and Utilization of Components Contained in Waste Bamboo by Pressurized Microwave-Assisted Ethanol Solvent Treatment


Efficient Conversion of Moso Bamboo Components into Glucose, Lignocellulose Nanofiber, and Low-Molecular-Weight Lignin through Deep Eutectic Solvent Treatment


Production and Antioxidant Activity of Phenolic Compounds from Indigo Plant Waste Using Pressurized Microwave-Assisted Hydrothermal Treatment Followed by Water Extraction


Antioxidant Activity of Water Extract from Bamboo by High-Temperature and High-Pressure Steam Treatment


Production of polylactic acid biocomposite reinforced with environmentally friendly cellulose nanofiber derived from steam-treated bamboo


Effects of Tween Series and Agar Additives on Mycelia Biomass and β-Glucan Production by Hericium erinaceus in Submerged Culture


Effect of hydrothermal treatment on organic matter degradation, phytotoxicity, and microbial communities in model food waste composting

Journal of Bioscience and Bioengineering


Utilization of Steam-Treated and Milling-Treated Lignin from Moso Bamboo as Curing Agent of Epoxy Resin


Preparation of Biopolymer Composite Using Cedar-Derived Cellulose Nanofibers


TGF-β1 facilitates MT1-MMP-mediated proMMP-9 activation and invasion in oral squamous cell carcinoma cells


Effect of Activated Cow Dung as Inoculum on Methane Production of Steam-Exploded Rice Husks


Structure Activity Relationships of UTX-121 Derivatives for the Development of Novel Matrix Metalloproteinase-2/9 Inhibitors


Production of Spiculisporic Acid by Talaromyces trachyspermus in Fed-Batch Bioreactor Culture


Microwave-assisted hydrolysis of cellulose in towel and wheat straw using freeze-thawing with NaOH


Production of Eco-Refinery Pulp from Moso Bamboo Using Steam Treatment Followed by Milling Treatment


Microwave-assisted hydrolysis of cotton waste to glucose in combination with the concentrated sulfuric acid impregnation method


Ethanol Production from Sugarcane Bagasse Using Pressurized Microwave Treatment with Inorganic Salts and Salt-Tolerant Yeast


Effects of Hydrothermal Methods such as Steam Explosion and Microwave Irradiation on Extraction of Water Soluble Antioxidant Materials from Garlic Husk


Glucose and Valuable Chemicals Production from Cotton Waste Using Hydrothermal Method


Isolation and identification of an angiotensin I-converting enzyme inhibitory peptide from pearl oyster (Pinctada fucata) shell protein hydrolysate


High concentration ethanol production from mixed softwood sawdust waste


Microwave-assisted glucose production from bode (Styrax tonkinensis) woody biomass for bioethanol production

Journal of Material Cycles and Waste Management


Total biorefinery process of lignocellulosic waste using steam explosion followed by water and acetone extractions


Cellulose-binding activity of a 21-kDa endo-ß-1,4-glucanase lacking cellulose-binding domain and its synergy with other cellulases in the digestive fluid of Aplysia kurodai

Endo-ß-1,4-glucanase AkEG21 belonging to glycosyl hydrolase family 45 (GHF45) is the most abundant cellulase in the digestive fluid of sea hare (Aplysia kurodai). The specific activity of this 21-kDa enzyme is considerably lower than those of other endo ß-1,4-glucanases in the digestive fluid of A. kurodai, therefore its role in whole cellulose hydrolysis by sea hare is still uncertain. Although AkEG21 has a catalytic domain without a cellulose binding domain, it demonstrated stable binding to cellulose fibers, similar to that of fungal cellobiohydrolase (CBH) 1 and CBH 2, which is strongly inhibited by cellohexaose, suggesting the involvement of the catalytic site in cellulose binding. Cellulose-bound AkEG21 hydrolyzed cellulose to cellobiose, cellotriose and cellotetraose, but could not digest an external substrate, azo-carboxymethyl cellulose. Cellulose hydrolysis was considerably stimulated by the synergistic action of cellulose-bound AkEG21 and AkEG45, another ß-1,4-endoglucanase present in the digestive fluid of sea hare; however no synergy in carboxymethylcellulose hydrolysis was observed. When AkEG21 was removed from the digestive fluid by immunoprecipitation, the cellulose hydrolyzing activity of the fluid was significantly reduced, indicating a critical role of AkEG21 in cellulose hydrolysis by A. kurodai. These findings suggest that AkEG21 is a processive endoglucanase functionally equivalent to the CBH, which provides a CBH-independent mechanism for the mollusk to digest seaweed cellulose to glucose.


Production of cellulose nanofibers from Aspen and Bode chopsticks using a high temperature and high pressure steam treatment combined with milling

Holocellulose was generated from Aspen and Bode chopsticks by high temperature, high pressure steam treatment combined with milling. The steam treatment conditions were increased, the holocellulose component ratio in the treated sample as well as its molecular weight decreased. The treated holocellulose was subjected to grinder treatment to obtain cellulose nanofibers (CNF). Field-emission scanning electron micrographs indicated that CNF were successfully produced. The maximum tensile strength values of 86.9 and 109.9 MPa/(g/cm) for Aspen and Bode, respectively, were obtained at a steam pressure of 15 atm and steaming time of 5 min. Furthermore, it was demonstrated that the optimal molecular weight of holocellulose to produce CNF with high tensile strength was around 1.2 × 10, while the optimal holocellulose recovery rate (HR; the degree of fibrillation was defined as HR in this study) was around 1.00.


Characterization of cellulose nanofiber from steam exploded Japanese cedar


Cholininum ionic liquid/cosolvent pretreatment for enhancing enzymatic saccharification of sugarcane bagasse


Total utilization of Japanese pear tree prunings: extraction of arbutin and production of bioethanol


Comparison of choline acetate ionic liquid pretreatment with variouspretreatments for enhancing the enzymatic saccharification ofsugarcane bagasse


Chemical characteristics and enzymatic saccharification of lignocellulosic biomass treated using high-temperature saturated steam: Comparison of softwood and hardwood

This study investigated the effect of high-temperature saturated steam treatments on the chemical characteristics and enzymatic saccharification of softwood and hardwood. The weight loss and chemical modification of cedar and beech wood pieces treated at 25, 35, and 45 atm for 5 min were determined. Fourier transform infrared and X-ray diffraction analyses indicated that solubilization and removal of hemicellulose and lignin occurred by the steam treatment. The milling treatment of steam-treated wood enhanced its enzymatic saccharification. Maximum enzymatic saccharification (i.e., 94% saccharification rate of cellulose) was obtained using steam-treated beech at 35 atm for 5 min followed by milling treatment for 1 min. However, the necessity of the milling treatment for efficient enzymatic saccharification is dependent on the wood species.


Functionalization of the active ingredients of Japanese green tea (Camellia sinensis) for the synthesis of bio-based epoxy resin


Epoxy resin synthesis using low molecular weight lignin separated from various lignocellulosic materials

A low molecular weight lignin from various lignocellulosic materials was used for the synthesis of bio-based epoxy resins. The lignin extracted with methanol from steam-exploded samples (steaming time of 5 min at steam pressure of 3.5 MPa) from different biomasses (i.e., cedar, eucalyptus, and bamboo) were functionalized by the reaction with epichlorohydrin, catalyzed by a water-soluble phase transfer catalyst tetramethylammonium chloride, which was further reacted with 30 wt% aqueous NaOH for ring closure using methyl ethyl ketone as a solvent. The glycidylated products of the lignin with good yields were cured to epoxy polymer networks with bio-based curing agents i.e., lignin itself and a commercial curing agent TD2131. Relatively good thermal properties of the bio-based epoxy network was obtained and thermal decomposition temperature at 5% weight loss (Td5) of cedar-derived epoxy resin was higher than that derived from eucalyptus and bamboo. The bio-based resin satisfies the stability requirement of epoxy resin applicable for electric circuit boards. The methanol-insoluble residues were enzymatically hydrolyzed to produce glucose. This study indicated that the biomass-derived methanol-soluble lignin may be a promising candidate to be used as a substitute for petroleum-based epoxy resin derived from bisphenol A, while insoluble residues may be processed to give a bioethanol precursor i.e., glucose.

International Journal of Biological Macromolecules


Conversion of steam-exploded cedar into ethanol using simultaneous saccharification, fermentation and detoxification process

In this study, we investigated the simultaneous saccharification, fermentation and detoxification SSDF process of steam-exploded cedar using a detoxification microorganism, Ureibacillus thermosphaericus A1, to facilitate efficient ethanol production. Steam explosion was applied as a pretreatment before enzymatic saccharification followed by alcohol fermentation. The highest glucose conversion rate was observed in the sample pretreated with a steam pressure of 45atm for 5min. Alcohol production by a heat-tolerant yeast, Saccharomyces cerevisiae BA11, was inhibited strongly by inhibitory materials present in the steam-exploded cedar, such as formic acid, furfural, and 5-hydroxymethylfurfural. The maximum amount of ethanol, i.e., 0.155g ethanol/g dry steam-exploded cedar, which corresponded to 74% of the theoretical ethanol yield, was obtained using the SSDF when U. thermosphaericus A1 degraded the inhibitory materials. A fed batch SSDF culture, in which U. thermosphaericus A1 was used to maintain low concentrations of inhibitory materials, was effective for increasing the ethanol concentration.


Acetone-butanol-ethanol production by separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) methods using acorns and wood chips of Quercus acutissima as a carbon source


Extraction of arbutin and its comparative content in branches, leaves, stems, and fruits of Japanese pear Pyrus pyrifolia cv. Kousui

Arbutin is a tyrosinase inhibitor and is extensively used as a human skin-whitening agent. This study investigated the optimum conditions for extracting arbutin by ultrasonic homogenization from discarded branches pruned from Japanese pear (Pyrus pyrifolia cv. Kousui) trees. The arbutin content was measured in the branches and also in the leaves, stems, fruit peel, and fruit flesh.

Bioscience, Biotechnology, and Biochemistry


Steam explosion treatment for ethanol production from pear tree prunings by simultaneous saccharification and fermentation

This study investigated the production of ethanol from unutilized branches pruned from pear trees by steam explosion pretreatment. Steam pressures of 25, 35, and 45 atm were applied for 5 min, followed by enzymatic saccharification of the extracted residues with cellulase (Cellic CTec2). High glucose recoveries, of 93.3, 99.7, and 87.1%, of the total sugar derived from the cellulose were obtained from water- and methanol-extracted residues after steam explosion at 25, 35, and 45 tm, respectively. These values corresponded to 34.9, 34.3, and 27.1 g of glucose per 100 g of dry steam-exploded branches. Simultaneous saccharification and fermentation experiments were done on water-extracted residues and water- and methanol-extracted residues by Kluyveromyces marxianus NBRC 1777. An overall highest theoretical ethanol yield of 76% of the total sugar derived from cellulose was achieved when 100 g/L of water- and methanol-washed residues from 35 atm-exploded pear branches was used as substrate.


Extraction method for increasing antioxidant activity of raw garlic using steam explosion


Evaluation of epoxy resins synthesized from steam-exploded bamboo lignin


Efficient extraction of starch from microalgae using ultrasonic homogenizer and its conversion into ethanol by simultaneous saccharification and fermentation


Acceleration of Hericium erinaceum mycelia growth in submerged culture using yogurt whey as an alternative nitrogen source

Advances in Bioscience and Biotechnology


Evaluation of buckwheat and barley tea wastes as ethanol fermentation substrates

Journal of Material Cycles and Waste Management


Effects of washing with water on enzymatic saccharification and D-lactic acid production from steam-exploded sugarcane bagasse


Examination of incubation conditions for production of Hericium erinaceum

International Journal of Modern Physics: Conference Series


Evaluation of waste mushroom medium as a fermentable substrate and bioethanol production


Direct hydrolysis of cellulose to glucose using ultra-high temperature and pressure steam explosion


Effect of steam explosion pretreatment with ultra-high temperature and pressure on effective utilization of softwood biomass


Characterization of the steam-exploded spent Shiitake mushroom medium and its efficient conversion to ethanol

Spent Shiitake mushroom medium was subjected to steam explosion followed by simultaneous saccharification and fermentation (SSF) using Meicelase and Saccahromyces cerevisiae AM12. Water extraction of the medium exposed to steam at 20 atm for 5 min enhanced the saccharification rate by about 20% compared to steam-exploded medium before water extraction and resulted in the production of 23.8 g/l ethanol from a substrate concentration of 100g/l. This corresponded to 87.6% of the theoretical ethanol yield, i.e., 15.9 g ethanol was obtained from 100g of spent Shiitake mushroom medium. Spent Shiitake mushroom medium subjected to steam explosion and then water extraction appears to be a candidate for efficient bioconversion to ethanol.


Ethanol production from disposable aspen chopsticks using delignification pretreatments


Bioconversion of Soy Sauce Residue Treated with Steam Explosion into Ethanol by Meicelase and Mucor indicus


Phytoremediation of Soil Contaminated with Heavy Metals and Recovery of Valuable Metals

重金属汚染土壌のファイトレメディエーションと有価金属の回収

Phytoremediation, which is a plant-based technology for the removal of toxic contaminants from soil, has been receiving renewed attention as an environmentally friendly purification method. In this work, phytoremediation of soil contaminated with heavy metals and a novel recovery method of valuable metals were investigated. Athyrium yokoscense was used as a hyperaccumulating plant. The plants were separated into water-soluble material, holocellulose, methanol-soluble lignin (low-molecular-weight lignin), and Klason lignin (high-molecular-weight lignin) using steam-explosion and Wayman's extraction method, and the concentrations of metals, i.e., copper and iron, were measured. Levels of 15 mg of copper and 2.6 mg of iron were found in 1 g of the water-soluble material component of aboveground parts, i.e., leaf blades and petioles; and 41 mg of copper and 4.2 mg of iron in 1 g of the Klason lignin (high-molecular-weight lignin) component of underground parts, i.e., rhizomes and roots. This suggests that these components can be used for recovery of metals. The amounts of heavy metals in contaminated soil and plants were estimated. It was found that 1 g of copper and 0.1 g of iron were recovered from 500 g of contaminated soil, and the removal ratios of copper and iron in the contaminated soil were 82 and 95%, respectively.

ファイトレメディエーションは土壌から有毒な汚染物を回収するための植物を利用した技術であり，新規な環境保全型浄化方法として期待されている．本研究では，重金属汚染土壌のファイトレメディエーションと有価金属の新規回収法について検討した．ヘビノネゴザ(Athyrium yokoscense)を重金属蓄積植物として用いた．植物体は水蒸気爆砕とWaymanの抽出法によって水可溶性物質，メタノール可溶性リグニン(低分子リグニン)，ホロセルロース，Klasonリグニン(高分子リグニン)に分離され，銅と鉄の重金属濃度が測定された．15 mgの銅と2.6 mgの鉄が葉身や葉柄などの地上部分における水可溶性物質成分1 g, 41 mg銅と4.2 mg鉄が根茎や根などの地下部分におけるKlasonリグニン(高分子リグニン)成分1 gに存在した．これらの成分は重金属の回収に用いることができることがわかった．汚染土壌と植物中の重金属(銅と鉄)の存在量を推算した．銅1 gと鉄0.1 gが汚染土壌500 gから回収され，土壌中の銅と鉄の除去率はそれぞれ82と95%であった．


Chemical Characteristics and Ethanol Fermentation of the Cellulose Component in Autohydrolyzed Bagasse

Biotechnology and Bioprocess Engineering


Waste Reduction System for Production of Useful Materials from Un-utilized Bamboo Using Steam Explotion Followed by various Conversion Methods


Development of a Novel Pulping Method without Generating Wastewater Using a Sodium Hydroxide Pretreatment and Steam Explosion

A novel pulping method without generating pollutants consists of a sodium hydroxide (NaOH) treatment followed by steam explosion was proposed and evaluated in this investigation. The cellulose component (degree of glucose polymerization: about 500) from Eucalyptus globlus chips treated with 10 g·dm-3 NaOH and then exploded with steam at 2.5 MPa for a steaming time of 5 min, was converted into pulp with physical properties almost the same as those of conventional hardwood pulp.

Journal of Chemical Engineering of Japan


Methane Production from Steam- Exploded Bamboo

To convert unutilized plant biomass into a useful energy source, methane production from bamboo was investigated using a steam explosion pretreatment. Methane could not be produced from raw bamboo but methane production was enhanced by steam explosion. The maximum amount of methane produced, i.e., about 215 ml, was obtained from 1 g of exploded bamboo at a steam pressure of 3.53 MPa and a steaming time of 5 min. A negative correlation between the amount of methane produced and the amount of Klason lignin was observed in the methane fermentation of steam-exploded bamboo.

Journal of Bioscience and Bioengineering


Production of antibacterial violet pigment by psychrotropic bacterium RT102 strain