• Korean Chemical Engineering Research
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• v.54 no.6
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• pp.806-811
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• 2016

Organosolv pretreatment is the process to frationation of lignocellulosic feedstocks to enhancement of enzymatic hydrolysis. This process has advantages that organic solvents are always easy to recover by distillation and recycled for pretreatment. The chemical recovery in organosolv pretreatment can isolate lignin as a solid material and carbohydrates as fermentable sugars. For the economic considerations, using of low-molecular-weight alcohols such as ethanol and methanol have been favored. When acid catalysts are added in organic solvent, the rate of delignification could be increased. Mineral acids (hydrochloric acid, sulfuric acid, and phosphoric acid) are good catalysts to accelerate delignification and xylan degradation. In this study, the biomass was pretreated using 40~50 wt% ethanol at $170{\sim}180^{\circ}C$ during 20~60 min. As a results, the enzymatic digestibility of 2-stage pretreatment of rigida using 50 wt% ethanol at $180^{\circ}C$ was 40.6% but that of 1-stage pretreatment was 55.4% on same conditions, therefore it is shown that the pretreatment using mixture of the organosolv and catalyst was effective than using them separately.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.9-15
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• 2015

The seaweed, Gracilaria verrucosa, was fermented to produce bioethanol. Optimal pretreatment conditions were determined to be 12% (w/v) seaweed slurry and 270 mM sulfuric acid at 121℃ for 60 min. After thermal acid hydrolysis, enzymatic saccharification was carried out with 16 U/ml of mixed enzymes using Viscozyme L and Celluclast 1.5 L to G. verrucosa hydrolysates. A total monosaccharide concentration of 50.4 g/l, representing 84.2% conversion of 60 g/l total carbohydrate from 120 g dw/l G. verrucosa slurry was obtained by thermal acid hydrolysis and enzymatic saccharification. G. verrucosa hydrolysate was used as the substrate for ethanol production by separate hydrolysis and fermentation (SHF). Ethanol production by Candida lusitaniae ATCC 42720 acclimated to high-galactose concentrations was 22.0 g/l with ethanol yield (Y_EtOH) of 0.43. Acclimated yeast to high concentrations of specific sugar could utilize mixed sugars, resulting in higher ethanol yields in the seaweed hydrolysates medium.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1975.12a
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• pp.182.1-182
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• 1975

L-Glutamic acid 발효생산에 있어서 당밀대체의 목적으로 Tapioca전분의 효소당화액의 이편 가성을 검토하여 다음과 같은 결과를 얻었다.(중략)

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.199.1-199
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• 2003

제주민속주인 좁쌀약주의 제조를 위하여 전국에서 수집된 35종의 누룩으로부터 우수 곰팡이와 효모를 분리하였다. 수집된 누룩의 균수는 곰팡이가 6.4$\times$105~107개, 효모는 1.4$\times$104~107개로 나타났고, 이 중에서 곰팡이 169균주, 효모 103균주를 분리하였으며 전분당화력이 좋은 곰팡이 16균주와 효모 1균주를 선발하였다. 이 중에서 전분당화 균주의 효소활성을 분석한 결과 Aspergillus속으로 동정된 A8-3이 glucoamylase 활성, 액화력, xylanase 활성이 가장 높았고, Rhizopus속으로 동정된 B23-3은 당화력이 가장 우수하였다. 우수효모를 선발하기 위하여 pH, 무게 감량, 내당성, 내알코올성 등을 측정한 결과, Saccharomyces속인 A10-4가 가장 우수하였다. 같은 원료비율로 만든 누룩에 우수균주를 접종하였을 때, 단일 균주를 처리할 때보다 A8-3과 B23-3인 두 균주를 혼합하여 처리한 경우가 당화력이 높게 나타났다. 누룩을 원반형의 누룩과 팰릿(개량형) 형태로 만들어 혼합종균 배양액을 접종한 후 당화력을 측정한 결과, 비슷한 당화력을 나타내었다. 개량형 누룩을 사용하여 양조하는 경우, 좁쌀주 양조에 발효효율을 높일 수 있을 것으로 판단되었다. 수집된 누룩은 수분이 10~13%, 총당은 55~70%, 조단백질은 10~18% 조지방은 0.2~l.0%, 회분은 1.8~2.1%이었다. 본 연구에서 제조한 누룩은 수분이 12~15%, 총당은 61~7l%, 조단백질은 15~20%, 조지방은 0.4~1.5%, 회분은 1.1~1.5%이었다.

• Microbiology and Biotechnology Letters
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• v.44 no.4
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• pp.529-534
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• 2016

Bioethanol was produced using the separate hydrolysis and fermentation (SHF) method with macroalgal polysaccharides from the seaweed, Undaria pinnatifida as biomass. This study focused on the pretreatment, enzymatic saccharification, and fermentation of yeasts in co-culture. Ethanol fermentation with 14.5% (w/v) seaweed hydrolysate was performed using the yeasts, Saccharomyces cerevisiae KCTC 1126 alone, Pichia angophorae KCTC 17574 alone, and their co-cultures with the yeasts either adapted to mannitol or not. Among the combinations, the co-culture of non-adapted S. cerevisiae and P. angophorae adapted to mannitol showed high bioethanol production of 12.2 g/l and an ethanol yield ($Y_{EtOH}$) of 0.41. Co-culture in the SSF process was employed in this study, to increase the ethanol yields of 35.2% and reduction of 33.3% in fermentation time. These results provide suitable information on ethanol fermentation with marine seaweeds for bioenergy production.

• KSBB Journal
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• v.4 no.3
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• pp.276-280
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• 1989

The effect of the pretreatment by solvent extraction on the saccharification of poplar (Populus euramencana) was studied. The solvent system was Phenol/H2O(Uncatalyzed)and Phenol/H2O/HCl catalyst system. When the poplar was pretreated by uncatalyzed system, the best result of the saccharification was total of 43.9 g/1 reducing sugar produced and 83.5% of carbohydrated conversion was obtained at 19$0^{\circ}C$, 60 minutes. Total wood yield and the lignin removal were 46.3% and 98.2% respectively. The use of acid catalyst was unsuitable to increase he efficiency of saccharification.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.18 no.1
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• pp.64-80
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• 1992

Considerable interest has been generated in age-related non-enzymatic glycosylation and crosslinking of collagen in view of its extracellular nature, and its long biological half-life. The effects of UVA, which penetrates deep in dermis, and reactive oxygen species (ROS) on age- related changes of dermal collagen were studied. The amount of nonenzymatic glycosylation, fragmentation, and crosslinking of collagen were monitored from the mixtures of Type I collagen from calf skin and glucose, irradiated by UVA, with or without scavengers of ROS. At both high and low glucose dosages, non-enzymatic glycosylation was not affected by UVA irradiation. At high glucose dosage, however, glycosylation was reduced by the scavengers of superoxide radical and singlet oxygen, bolt not by hydroxyl radical scavengers. Fragmentation was increased by UVA and decreased by all ROS scavengers. Crosslinking was also enhanced by UVA, and effectively blocked crosslinking. Superoxide radical and singlet oxygen, which were produced by autoxidation of glucose independently to UVA, may encounter the initial phase of glycation. ROS generated from Amadory compounds by UVA enhanced fragmentation and crosslinking Hydroxyl radical was thought to be a major ROS affecting crosslinking. These results suggest that UVA and ROS are able to enhance age-related structural changes of collagen, as affecting many other tissue and cellular components.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.331-336
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• 1991

In order to utilize natural cellulosic materials as a fermentative substrate, saccharification of a various kind of native cellulosic materials was performed by using cellulase from the isolated strain, Pseudomonas sp. LBC-505 which potently produced cellulase complex and xylanase. Cellulase complex production was repressed by the low concentration of glucose, induced by cellulosic compounds such as CMC, wheat bran and rice straw et al. and showed to be highest on the PY-CMC medium containing 5% (w/v) wheat bran instead of CMC. Optimal temperature for enzyme reactions of CMCase and xylanase was $50^{\circ}C$, and $55^{\circ}C$ for $\beta$-glucosidase. Optimal pH for these enzyme reaction was 6.6. Rate of saccharification for natural cellulose was low by the treatment of crude enzyme. Among their substrates, rice straw was the most effective substrate of enzymatic reaction in this work. After treating rice straw with 5% (v/v) HC1 and hydrolysing with crude enzyme, rate of saccharification was 18.4% (w/w) on dry substrate. Sugars of cellulosic hydrolyzate mainly contained glucose, xylose and cellobiose.

• Journal of the Korean Wood Science and Technology
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• v.37 no.4
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• pp.381-387
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• 2009

Enhancing enzymatic saccharification of corn stover by aqueous ammonia soaking pretreatment was investigated on chemical compositional changes and enzymatic hydrolysis characteristics. At three different levels of aqueous ammonia soaking temperature and time ($140^{\circ}C$-1 h, $90^{\circ}C$-16 h and $50^{\circ}C$-6 days), higher temperature and shorter treatment time led to more xylan and lignin removal based on overall composition analysis and carbohydrate compositional analysis. More xylan and lignin removal in higher temperature treatment led to higher enzymatic saccharification of cellulose and xylan to monosaccharide by commercial cellulase mixtures (Celluclast 1.5L and Novozym 342 from Novozyme, Denmark).

• Korean Chemical Engineering Research
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• v.59 no.1
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• pp.54-59
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• 2021

The pretreatment of cellulosic biomass is essentially needed because it has more lignin compared with a starch biomass. Ethanol as an organosolv for pretreatment can easily separate some components which can inhibit enzymatic hydrolysis and be re-usuable by distillation. The flow-through process have some strength, separating components continuously, development for scale up. In this research, two-kinds (wheat straw, miscanthus) of biomass was pretreated for development of enzymatic hydrolysis by adoption of pretreatment process of corn stover.