• 생명과학회지
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• 제11권3호
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• pp.211-217
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• 2001

Optimum processing conditions of vinegar using esa tangle extracts were investigated. Sea tangle vineagr was prepared by adding 3% and 5% of glucose, 6% and 10% of ethanol to sea tangle extracts and inoculating acetic acid bacteria. After fermentation for 30 days at 3$0^{\circ}C$, pH was similar to 3.22, 3.21, 3.25 and 3.28 days it was 4.75%, 4.77%, 5.61% and 5.87% respectively. Contents or reducing sugar was 0.70%, 0.70%, 0.88% and 0.89% in initial time of fermentation but it was rapidly decreased by 10 days of fermentation to 0.20%, 0.19%, 0.22%, and 0.21%, respectively. Ethanol contents was 5.88%, 9.77%, 5.75% and 9.68% in initial time of fermentation but it was rapidly decreased by 15 days of fermentation to 1.05%, 1.62%, 0.45% and 1.23%, respectively and it was addition of 5% glucose and 6% ethanol and fermentation for 20 days at 3$0^{\circ}C$. Quality for sea tangle vinegar manufactured using optimum condition were as follows respectively; pH 3.25, acidity 5.38%, total sugar 1.72%, iodine 1,537.2 ppm.

• 한국식품과학회지
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• 제29권6호
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• pp.1144-1150
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• 1997

찹쌀로 담금한 콩고오지 사용의 개량식 고추장 숙성과정 중 휘발성 향기성분을 purge and trap 장치로 포집하여 GC-MSD로 분석 , 동정한 결과 alcohol 16종, ester 15종, acid 7종, aldehyde 4종, alkane 5종, ketone 3종, benzene 1종, alkene 1종, phenol 2졸, 기타 2종 등 56종의 휘발성 향기성분이 동정되었다. 동정된 향기성분 수는 담금직후에 alcohol 9종, ester 8종, aldehyde 3종 등 총 32종이 검출되었으나, 30일에는 alcohol 5종, ester 6종을 비롯한 15종이 추가 검출되어 46종으로 증가되었다. 90일에는 55종으로 향기성분 수가 최대에 달하였다. 숙성 전 과정을 통하여 검출된 향기성분은 2-methyl-1-propanol, ethanol, 3-methyl-1-butanol 등 alcohol류 9종, methyl acetate, ethyl acetate, 2-methylpropyl acetate 등 ester류 8종, butanal, acetaldehyde, furfural 등 aldehyde 3종, 기타 11종 등 총 31종이었다. 향기성분의 면적비율(peak area%)은 숙성기간에 따라 다소 차이가 있으나 ethanol. ethyl acetate, ethyl butanoate, 2-methylpropyl acetate, 2-methyl-1-propanol, 3-methyl-1 -butanol 등이 높아 이들 성분이 콩고오지사용 고추장의 향미 주 성분으로 나타났다 이들성분 중 숙성시기별로 가장 높은 면적비율을 보인 향기성분은 담금직후와 90일에 ethanol, $30{\sim}60$일에는 ethyl acetate 가, $120{\sim}150$일에는 3-methyl-butanol 이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권5호
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• pp.636-642
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• 2011

The effect of different rates of ethanol additive on fermentation quality of napiergrass (Pennisetum purpureum) and residual water soluble carbohydrate were studied in the experiment. The addition rate of ethanol was 0%, 1.5%, 2.5%, 3.5%, 4.5% on fresh weight of napiergrass. The laboratory silos were kept in the room, then were opened on 1, 3, 5, 7, 14, 30 days after ensiling and the changes of silage quality were analyzed, respectively. There was a fast and large reduction in pH from the 5th day of ensiling to below 4.2 except for the 4.5% treatment. After five days the pH of silage decreased slowly and the pH of the ethanol additions was lower than the control. Lactic acid content of ethanol treatments increased significantly (p<0.05) from the 5th day of ensiling, reaching the highest value on either the 7th day or 14th day. The ethanol additive inhibited the break down of silage protein and the ammonia nitrogen content of ethanol addition silage was significantly (p<0.05) lower than the control after 30 days of ensiling. Within the initial first day of ensiling the water soluble carbohydrate content declined quickly. The efficiency of water soluble carbohydrate usage was higher in silage with ethanol than in the control. The acetic acid of ethanol treatment was significantly (p<0.05) lower than control on first and 14th day, but there was no significant (p>0.05) difference among the ethanol addition silages. The volatile fatty acids content of silage increased gradually from the first day of ensiling and reached the peak on 14th day or 30th day and the content of ethanol addition treatment was significantly (p<0.05) lower than the control. The experimental results indicated that adding ethanol inhibited the use of protein and water soluble carbohydrate of aerobic bacteria and reduced the silage losses during the early stage of ensiling and thus supplied more fermentation substrate for lactic acid bacteria and improved the fermentation quality of napiergrass.

• 한국식품조리과학회지
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• 제31권6호
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• pp.725-732
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• 2015

김치 양념의 유통 중 품질 유지기한 연장 효과를 확인하기 위해 농도별 에탄올이 첨가된 양념을 $4^{\circ}C$에 35일간 저장하면서 pH, 산도, 환원당, 미생물 수, 및 관능적 특성을 확인하였다. 김치 양념에 에탄올을 0~3.0% 첨가하여 pH 변화를 조사한 결과 에탄올 함량이 높을수록 김치 양념의 발효가 지연되어 pH 감소가 적었다. 산도의 경우 에탄올 무첨가 김치 양념은 0.87%에서 1.57%까지 증가한 반면 3.0% 에탄올 첨가 김치 양념은 0.73%에서 0.88%로 에탄올 첨가는 김치 양념의 산도 증가를 억제하였다. 3.0% 에탄올 첨가는 김치 양념의 일반세균수, 유산균수, 효모와 곰팡이 생성을 효과적으로 억제하였으나 pH 저하 지연으로 대장균군 수 감소가 지연되었다. 관능평가에서는 0.5~1.5% 에탄올 첨가는 에탄올 무첨가 김치 양념과 비교하여 유의적인 차이를 보이지 않았다. 하지만 2.0%이상 에탄올 첨가시 에탄올 무첨가 김치 양념에 비하여 관능적 선호도가 낮아짐을 확인하였다. 따라서 이화학적 특성, 미생물학적 특성 및 관능검사 결과를 고려할 때 1.5% 에탄올 첨가가 김치 양념의 관능적 선호도를 유지하면서, 김치 양념의 발효를 지연시키는 최적 첨가량으로 사료되었다.

• Journal of Microbiology and Biotechnology
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• 제20권4호
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• pp.828-834
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• 2010

An ethanol-producing yeast strain, CHFY0201, was isolated from soil in South Korea using an enrichment technique in a yeast peptone dextrose medium supplemented with 5% (w/v) ethanol at $30^{\circ}C$. The phenotypic and physiological characteristics, as well as molecular phylogenetic analysis based on the D1/D2 domains of the large subunit (26S) rDNA gene and the internally transcribed spacer (ITS) 1+2 regions, suggested that the CHFY0201 was a novel strain of Schizosaccharomyces pombe. During shaking flask cultivation, the highest ethanol productivity and theoretical yield of S. pombe CHFY0201 in YPD media containing 9.5% total sugars were $0.59{\pm}0.01$ g/l/h and $88.4{\pm}0.91%$, respectively. Simultaneous saccharification and fermentation for ethanol production was carried out using liquefied cassava (Manihot esculenta) powder in a 5-l lab-scale jar fermenter at $32^{\circ}C$ for 66 h with an agitation speed of 120 rpm. Under these conditions, S. pombe CHFY0201 yielded a final ethanol concentration of $72.1{\pm}0.27$ g/l and a theoretical yield of $82.7{\pm}1.52%$ at a maximum ethanol productivity of $1.16{\pm}0.07$ g/l/h. These results suggest that S. pombe CHFY0201 is a potential producer for industrial bioethanol production.

• 한국미생물·생명공학회지
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• 제44권2호
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• pp.145-149
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• 2016

해조류 중 홍조류인 K. alvarezii로부터 동시 당화 발효(SSF)를 위한 효소 당화 및 균 배양 온도를 검토하고, 기존의 동시 당화 발효(SSF) 를 개선하기 위해 2단계 동시 당화 발효(SSF)를 수행하였다. 효소 당화와 균 성장 온도를 고려하였을 때 동시 당화 발효(SSF)에 적용하는 배양 온도는 40°C를 선택하여 실험을 진행하였다. 비순치 효모(wild type)와 고농도 갈락토오스에 순치한 효모(adapted yeast to galactose)를 이용한 동시 당화 발효(SSF)를 실시한 결과 발효 156시간에 9.1 g/l의 에탄올 수율(Y_EtOH) 0.24와 10.2 g/l의 에탄올 수율(Y_EtOH) 0.27을 나타내었다. 이러한 기존의 동시 당화 발효(SSF)를 개선한 2단계 동시 당화 발효(SSF)는 에탄올 생산 수율이 0.27에서 0.35로 27.5% 증가하였으며, 에탄올 발효 시간도 156시간에서 96시간으로 61.5% 감소하였다. 이러한 연구결과는 해양 바이오매스인 해조류로부터 바이오연료 생산과정에 있어 기초적인 정보를 제공할 것이다.

• Journal of Microbiology and Biotechnology
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• 제29권4호
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• pp.625-632
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• 2019

The unified saccharification and fermentation (USF) system was developed for direct production of ethanol from agarose. This system contains an enzymatic saccharification process that uses three types of agarases and a fermentation process by recombinant yeast. The $pGMF{\alpha}-HGN$ plasmid harboring AGAH71 and AGAG1 genes encoding ${\beta}-agarase$ and the NABH558 gene encoding neoagarobiose hydrolase was constructed and transformed into the Saccharomyces cerevisiae 2805 strain. Three secretory agarases were produced by introducing an S. cerevisiae signal sequence, and they efficiently degraded agarose to galactose, 3,6-anhydro-L-galactose (AHG), neoagarobiose, and neoagarohexose. To directly produce ethanol from agarose, the S. cerevisiae $2805/pGMF{\alpha}-HGN$ strain was cultivated into YP-containing agarose medium at $40^{\circ}C$ for 48 h (for saccharification) and then $30^{\circ}C$ for 72 h (for fermentation). During the united cultivation process for 120 h, a maximum of 1.97 g/l ethanol from 10 g/l agarose was produced. This is the first report on a single process containing enzymatic saccharification and fermentation for direct production of ethanol without chemical liquefaction (pretreatment) of agarose.

• 한국미생물·생명공학회지
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• 제24권5호
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• pp.604-612
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• 1996

To improve the fermentation characteristics of the haploid starch-fermenting recombinant yeast strain K114/YIpMS$\Delta$R(LEU2/URA3) secreting both $\alpha$-amylase and glucoamylase was rare-mated with polyploid industrial yeast Saccharomyces sp. K35. The K35 strain had good fermentation-characteristics such as ethanol-tolerance, high temperature and sugar-tolerance, and high fermentation rate. Among the resulting 66 hybrids, the best strain RH51 was selected. The RH51 exhibited amylolytic activity of K114/YIpMS$\Delta$R(LEU2/URA3) as well as ethanol and sugar tolerance of K35. The optimum temperature of hybrid RH51 for starch fermentation was 34$\circ$C which was same as that of K35 but different from that (30$\circ$C) of K114/YIpMS$\Delta$R(LEU2/URA3). The optimum pH was 5.0. The optimum size of inoculum was 2% as the pellet (w/v) of yeast cells. The hybrid strain RH51 produced 7.0% ethanol (w/v) from 20% (w/v) soluble starch while K35 formed almost no ethanol, 0.3% (w/v). RH51 strain produced 7.5% (w/v) ethanol after 8 days in a 2.5 l fermenter containing 800 ml of 20% (w/v) soluble starch. The residual starch content in the fermentation medium was 1.68% (w/v), and therefore almost all the starch was fermented completely.

• Journal of Microbiology and Biotechnology
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• 제4권1호
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• pp.7-12
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• 1994

A yeast strain secreting glucoamylase was transformed with an expression vector (pMS12) containing the promoter of yeast alcohol dehydrogenase I gene ADC1, mouse salivary $\alpha$-amylase cDNA, and a segment of yeast $21\mu m$ plasmid. The transformed strain could produce ethanol from starch (4%, w/v) through a direct one-step process with the conversion efficiency of 93.2%, during 5 days of fermentation, while the original, untransformed strain exhibited a conversion efficiency of 38.1% under the same condition. When the regulatory site of the ADC1 promoter region was removed, the production of ethanol increased to 29~37% in the presence of exogenous 3%(v/v) ethanol in the fermentation medium.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.203-206
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• 1997

Takju is a traditional alcoholic beverage that has been prepared by fermenting the cooked rice and Nuruk (Korean-style bran koji). During fermentation. bacterial contamination is a problem which inhibits the growth of yeast and thus lowers the ethanol production from starch of rice, and causes souring. Major contaminants were known to be gram-positive acid producers at the early stage of fermentation. This problem would be solved if the contaminated bacteria could be controlled. Nisin, a GRAS-grade preservative, was added at the level of 500 iu/g as it retards the growth of the gram-positive bacteria. It was possible to control acid and ethanol production during fermentation. This process increased the ethanol production by 2 % comparing with control.