• Journal of Microbiology and Biotechnology
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• 제1권3호
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• pp.207-211
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• 1991

Yeast fermentation at $40^{\circ}C$ was conducted for microbial protein production and COD reduction in three different sugar beet stiIlages by a thermo- and acid-tolerant yeast Candida rugosa isolated from East Africa. The assimilation proceedings of some main components such as protein, carbohydrate, total titrable acids and glycerol in stillages were observed with growth kinetics of the yeast. Most of glycerol and organic acids were rapidly assimilated at the beginning of the fermentation. Protein assimilation was slowly accelerated with the proceeding of fermentation time and its assimilation rate reached only 14.2%-28.4%. Though Candida rugosa was a flocculent yeast, the flocculation characteristics of the yeasts grown in three stillages were different from each other.

• Journal of Ginseng Research
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• 제3권2호
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• pp.95-104
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• 1979

The effects of ginseng extracts on carbon dioxide generation, alcohol fermentation, and yeast cell production by Saccharomyces cerevisiae were investigated. The results are as follows. 1) In the process of fermentation, CO2 generation by yeast is faster in ginseng extracts media of 0.3%, 0. l% than in control. As the concentration of the extracts increases by 0.7% and 1.5%, CO2 generation is decreased. Among all these concentrations, CO2 generation is fastest in 0.3% of the extracts. 2) In the process of fermentation, the production of alcohol is larger in the order of 0.3%, 0.7% and 0.1% than in the control and least in 1.5%. 3) The number of yeast cell rapidly increased from 12 hours to 18 hours after cultivation and conspicuously increased in the order of 0.3%, 0.7%, 0.1%, control and 1.5%. 4) Dried yeast cell weight increased more in all the above concentration than control and among these it increased visibly in 0.3% of the extracts.

• KSBB Journal
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• 제6권2호
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• pp.189-194
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• 1991

The effect of wtlitc light on unaeraten growth of Baker's yeast and the accompanying ethanol production has been studied in a batch process at 27$^{\circ}C$. Over the 80-hour period of the Champagne yeast process without pH control, the cull growth was inhibited by the fluorescent light. Another observed difference between the runs is that the drop and subsequent rise in redox potential occurred much sooner in the fermentation with light than in the fermentation without light. This preliminary study indicated that ethanol production could be enhanced by light as the cell concentration is repressed. The possible pathway, shift of the sugar substrate toward ethanol and away from cells was manifested by another difference as well. As observed under the microscope, many of the yeast cells grown under light budded without dividing by the normal fission process as they did in the dark. Furthermore, the undivided and branched (light grown) cell did not agglutinate at the end of the fermentation process as did the distinct spherical (dark grown) cells.

• Food Science and Biotechnology
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• 제15권3호
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• pp.469-473
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• 2006

Film-forming yeasts generate an undesirable yeasty flavor in fermented vegetables such as kimchi in the presence of oxygen. Antimicrobial materials including garlic oil (GO), heated garlic (HG), and allyl alcohol (AA) were investigated for use as alternative natural food preservatives to inhibit the growth of film-forming yeasts in fermented vegetables. Using the fermentation of cucumber pickles as a model system, GO, HG, and AA were effective in preventing film formation at concentrations of 0.006, 3.0, and 0.02%, respectively. The effectiveness of HG in preventing the growth of a film yeast, Hansenula anomala, was not influenced by pH, while that of potassium sorbate, a typical anti-yeast food preservative, was highly dependent on pH. All tested materials were effective when added at the beginning of fermentation due to their negligible inhibitory activity toward lactic acid bacteria.

• 한국식품영양과학회지
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• 제27권6호
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• pp.1065-1070
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• 1998

Lactic acid bacteria KL 1, KD 6, KL 4 strains isolated from kimchi, or obtained Lactobacillus acidophilus, Lactobacillus plantarum, Leuconostoc mesenteroides with and without yeast(Saccharomyces cerevisiae) were inoculated in fruit vegetable juice for mixed culture fermentation 3 days at 3$0^{\circ}C$, and then their chemical changes were studied during fermentation. The amount of organic acid produced by the mixed culture fermentation of KL 1 and yeast was 0.82%(3 days) or 0.58%(1 day) and with the final pH of 3.3(3 days) or 4.2(1 day). These mixed culture systems of isolated strains or other bacterial strains had almost similar results of growth rate and acid production. The contents of vitamin C and carotene were retained and stabilized as 70~80% level of their initial values after 24 hrs fermentation. And also ethanol was produced as of the range in 9.6mg%(W/V) by the mixed culture fermentation of KL 1 and yeast, however, the content of ethanol in single culture fermentation by KL 1 strain was much lower than that of mixed culture. The major components of organic acids in fermented juice by mixed culture were considered as malic(26.0%), lactic(49.9%), succinic and citric acid, whereas these of unfermented juice were malic(53.2%), citric and other acids. On other hand, reducing sugar was decreased from 18.3mg/ml in fresh juice to about 12mg/ml in juice by mixed culture fermentation. Concentrations of fructose, glucose and sucrose were also greatly reduced in fermented juice.

• 한국미생물·생명공학회지
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• 제17권6호
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• pp.619-623
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• 1989

효모의 성장 및 에탄을 생산에 미치는 온도의 영향에 대해서 회분식 배양을 실시한 결과 최대의 비효모 성장속도를 나타내는 온도는 36$^{\circ}C$였고 최대의 비에탄을 생산속도를 나타내는 온도는 33$^{\circ}C$임을 알 수 있었다. 온도의 영향에 대한 실험을 토대로 수학적 모델식을 선정했으며 매개변수를 추정하여 모사를 해 본 결과 배양 초기에는 36$^{\circ}C$ 정도의 온도에서 배양하다가 점차로 온도를 낮추어 3$0^{\circ}C$ 정도로 배양하는 것이 최적의 발효공정임을 알 수 있었다.

• 한국식품영양학회지
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• 제1권2호
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• pp.102-107
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• 1988

Production of calcium lactate very useful for medical supplies of Ca-therapy was obtained by lactic acid fermentation of lactobacillus sporogenes, a spore forming lactic acid bacterium. Corn steep liquor 1%, soybean enzyme hydrolysate 3%, yeast extract powder 2% can substitute for yeast extract and peptone as nutrient sort traces in fermentation medium using 10% glucose concentration. In the calcium lactate production medium containing yeast extract powder 2%, glucose 18%, CaCO3 12%, the lactic acid fermentation was carried out at 45$^{\circ}C$ for 4days with continuous agitation of 100 rpm. As results, fermentation yield was 97.5%. The five steps such as protein coagulation, decolorizing evaporating, crystallizing, and drying were carried out to harvest calcium lactate from 10l of supernatant of fermented medium to be removed cell and CaCO3. As results, 2065.0g of white crystal calcium lactate dihyrate was recovered and a yield of 84.9% was obtained.

• 생명과학회지
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• 제18권4호
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• pp.550-555
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• 2008

홍삼액의 첨가에 따른 발효가능성을 알아보기 위하여 홍삼액의 첨가량을 달리하여 발효특성을 조사하였다. 본 실험에서는 Saccharomyces cerevisiae JF-Y3을 이용하여 발효를 실시하였으며, 홍삼액($20\;^{\circ}brix$) 함량 $10{\sim}50%$, yeast extract $0.5{\sim}2.5%$의 범위로 중심합성계획법에 의하여 10개의 구간으로 홍삼액의 알코올 발효특성을 살펴보았다. 효모수는 홍삼액 및 yeast extract 농도 모두에 영향을 받고 있었으며, 홍삼액 농도에 더 많은 영향을 받는 것으로 나타났다. 홍삼액 농도가 감소하고, yeast extract 농도가 증가할수록 효모수가 증가하는 것으로 나타났다. 알코올 함량이 가장 높게 나타난 발효조건은 홍삼액 함량 30%, yeast extract 함량 0.50%이었으며, 이때의 최대값은 12.45%로 예측되었다. 당도 및 총당 함량의 경우 각각 1%이내의 유의수준에서 유의성이 인정되었고, 당도의 경우 홍삼액 및 yeast extract 함량 두 조건에 모두 영향을 받는 것으로 나타났으며, 총당 함량의 경우 주로 홍삼액 농도에 영향을 받는 것으로 나타났다. 홍삼액 $20\;^{\circ}brix$의 함량을 $10{\sim}50%$까지 증가하여도 발효액의 알코올 함량이 모두 10% 이상이었으며, 전반적으로 홍삼액 첨가에 따른 발효의 저해는 크게 일어나지 않는 것으로 나타나 홍삼의 유효한 성분을 이용한 기능성 주류 개발 시 홍삼농축액을 효율적으로 활용할 수 있을 것이다. 또한, 앞으로 홍삼액 발효 시의 알코올 성분에 대한 분석, 발효액에 대한 관능적 특성, 유효성분 등에 대한 특성 변화 등을 통한 고품질 홍삼주 제조와 관련하여 추가적인 연구가 필요할 것으로 생각된다.

• Journal of Animal Science and Technology
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• 제47권4호
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• pp.607-614
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• 2005

본 시험은 맥주박의 알코올 발효가 발효특성 및 사료의 영양적 가치에 미치는 영향을 검토하기 위하여 실시하였다. 본 시험에 이용한 시험사료는 맥주박과 파쇄 옥수수를 50:50(풍건상태)의 비율로 혼합하여 혐기 발효에 의하여 발효사료를 제조하였다. 발효 조건은 당밀 첨가 수준(0, 2 및 5%), yeast 첨가 수준(0, 0.1, 0.5, 1.0 및 2.0%) 및 발효 온도(4, 10, 30, 40 및 50$^{\circ}C$)에 따른 변화를 검토하였으며, 각 조건에 의한 알코올 함량, live yeast cell number (LYCN) 및 pH 변화를 조사하였다. 당밀 첨가에 따른 알코올 함량은 첨가수준이 증가할수록 높게 생성되었다. 발효 24시간 동안에 yeast 0.1, 0.5, 1.0 및 2.0% 첨가에 따른 알코올 함량은 각각 1.9, 2.4, 3.1 및 3.1%로 나타나, yeast 첨가수준 1% 까지는 yeast의 첨가수준이 증가할수록 시험사료중의 알코올 생성량도 비례적으로 증가하였으나(P<0.05), yeast 첨가수준 1.0 이상에서는 일정한 양의 알코올 이 생성되었다. 발효 초기의 LYCN은 yeast 첨가수준이 높을수록 높게 나타났으나(P<0.05), 발효 48시간 후의 LNCN은 0.1% 이하에서는 유의적으로 낮게 나타났다(P<0.05). 발효 온도에 따른 알코올 생성량은 발효 온도 30 및 40$^{\circ}C$에서 유의적으로 높은 결과를 보였으며(P<0.05), 30$^{\circ}C$와 40$^{\circ}C$ 간의 알코올 생성량은 30$^{\circ}C$에서 높은 경향이었다. 발효 온도에 따른 pH는 발효 온도가 낮을수록 발효 24시간까지 급격히 감소하는 것으로 나타났다(P<0.05). 이상의 결과로 미루어 맥주박의 사료적 가치를 높이기 위해 yeast의 첨가량, 당밀(발효기질), 발효온도 및 발효시간 등의 요인을 고려하였을 경우, 본 시험의 조건하에서 원활한 알코올 발효와 발효사료의 품질을 향상시키기 위한 적정 발효조건은 당밀 5%와 yeast 1%를 첨가하여 30$^{\circ}C$에서 24시간 동안 발효시키는 것이 가장 바람직한 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.776-783
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• 2000

Various alcohol yeast strains have been isolated from main mashes of Korean traditional liquors, and their genetic diversities were previously reported [23]. In this study, the strain SHY111, showing the highest alcohol production, was tested for its fermentation and sporulation characteristics. Additionally, its haploid cells were isolated and tested for their growth and fermentation patterns. The strain was identified as Saccharomyces cerevisiae based on its morphological and physiological characteristics. The sequences of the ITS(internal transcribed spacer) and 5.8S rDNA regions of S. cerevisiae SHY111 were found to be identical to those of S. cerevisiae that was obtained from through the yeast genome project. The maximum fermentation ratio obtained by the strain SHY111 (96.7%) was almost the same as that by S. cerevisiae Balyun No. 1 (96.5%) that was a little higher than that by S. cerevisiae KCCM11215(95.8%). The strain was induced for sporulation in a sporulation liquid medium using log phase cells grown in different types of pre-sporulation media, and its haploid cells were obtained by spore dissection using a micromanipulator. The majority of the spores formed a small colony on a YPD agar plate, and the haploid yeast cells derived from the strain SHY111 showed a variety of growth and alcohol fermentation patterns. It was proposed that the fermentation patterns were related to their growth phenotypes in the most haploid strains, but possible not in some strains.