• Microbiology and Biotechnology Letters
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• v.7 no.4
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• pp.191-195
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• 1979

This study was conducted to investigate the effect of saccharified extract of ginseng meal on alcohol fermentation and reproduction of yeast. Different concentrations of saccharified extract of ginseng meal in liquid medium were tested, and the experimental results obtained were summarized as follows : 1. In the process of alcohol fermentation of yeast, $CO_2$ output was much accelerated by the higher concentration of saccharied extracts from 1％ to 6％, but $CO_2$ output was disurbed at the concentrations of 10％ and 15％. .2. In the process of alcohol fermentation of yeast, the production of alcohol was increased by the higher concentration of saccharified extracts from 1％ to 6％, but decreased at the concentrations of 10％ and 15％. 3. Number of reproduced yeast cell after aerobic culture of Sacc. cervisiae was increased by the higher concentration of saccharified extracts from 1％ to 10％, but decreased at the concentration of 15％. The number of yeast cell at the concentratin of 10％ extract was 1.6 times more than that of control.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.610-616
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• 2002

In order to improve a complicated Cheongju manufacturing process, saccharification process with gelatinized rice flour was employed during a Cheongju fermentation. High sugar content without unsaccharified residue appeared to impede the yeast growth and fermentation. To solve this problem, addition of zeolite to the saccharifying solution containing 20% (w/v) sugar and fed-batch system were employed. These adjustments resulted in a increase of yeast viability and 40% time-saving alterations of fermentation. The Cheongju, having 18% (v/v) of ethanol content and fresh and rich flavor, could be made in 12 days. Yeast cells recovered from the fermentation precipitates could be reused up to four times without any adverse effect on cell viability, alcohol production, and flavor of the product. The complicated conventional brewing process of Cheongju can thus be simplified effectively.

• Food Engineering Progress
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• v.15 no.4
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• pp.413-419
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• 2011

For producing a high added-value natural seasoning ingredient, a yeast extract (Yx) was supplemented with a rice protein residue fermented with Bacillus licheniformis (Rfl) or with Bacillus subtilis (Rfs). A rice protein residue was obtained after enzymatic hydrolysis of rice protein which was used for preparing a yeast culture medium. Overall acceptabilities of the supplemented yeast extracts (YxRfl or YxRfs) were higher compared to pure yeast extract. Savory taste like umami was found to increase noticeably by adding a fermented rice protein residue to yeast extract, which was confirmed in taste sensor analysis and in sensory test. Beyond the presence of savory tasting amino acids such as Glu and Asp in a fermented rice protein residue, it is assumed that other soluble peptide fractions remained play an important role in enhancing taste of the supplemented yeast extracts. Thus, the yeast extract added with a fermented rice protein residue could be applied to manufacture a natural seasoning ingredient.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.224-227
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• 2022

In this study, the protective effects of turanose on Saccharomyces cerevisiae (Baker's yeast) were examined during the freeze-drying process to evaluate the feasibility of utilizing turanose as a novel cryoprotectant. The survival rate of the Baker's yeast cells improved substantially with a cryoprotective medium containing turanose in a substitution-dependent manner. In accordance with these survival rates, the yeast cell surfaces became smoother as the turanose content increased. Turanose with skim milk maintained the viability of the Baker's yeast, which improved substantially upon storage at -20℃. Thus, it is thought that turanose will exhibit excellent preservation effects during the distribution of Baker's yeast. Finally, these results suggest that turanose has the potential to be used as a novel cryoprotectant against various microorganisms.

• Microbiology and Biotechnology Letters
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• v.36 no.3
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• pp.215-220
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• 2008

Rahnella aquatilis AY2000 has an unique characteristic which produces an anti-yeast substance (AYS). The AYS of the strain AY2000 was always secreted on agar plate, however, its activity in liquid culture was labile upon storage of the medium. In this paper, cultural conditions of the strain AY2000 for the AYS production were investigated in liquid culture, and minimal inhibitory concentration (MIC) against Saccharomyces cerevisiae was determined for the AYS activity. MIC of the AYS cultured in PYG broth at $^25{\circ}C$ for 24 hr was $23.5{\mu}g/mL$, however, that in MYCS (pH 5.5) broth at the same condition was $15.5{\mu}g/mL$. The activity of the AYS had increased rather in MYCS broth excluded $NH_4$-citrate than in the same broth contained $NH_4$-citrate, and MIC of the AYS produced in MYCS broth without $NH_4$-citrate was $15.5{\mu}g/mL$. When the strain AY2000 was maintained in MYCS broth without $NH_4$-citrate but added $100{\mu}M$ $FeCl_3$, the activity of the AYS had increased and its MIC was $7.8{\mu}g/mL$. MIC of the AYS was $7.8{\mu}g/mL$ after the strain AY2000 was cultured in MYCS broth containing $100{\mu}M$ $FeCl_3$ without $NH_4$-citrate, however, its MIC was $31.3{\mu}g/mL$ after 48-60 hr culture in the same broth.

• Journal of Life Science
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• v.18 no.10
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• pp.1426-1434
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• 2008

This study was conducted to investigate the effects of supplementation of synbiotics manufactured with anaerobic bacteria, yeast and mold on preservation of total mixed ration (TMR) by exposing days. Eight treatments were composed of untreated synbiotics(US), bacterial synbiotics (BS), yeasty synbiotics (YS), moldy synbiotics (MS), bacterial and mouldy synbiotics (BMS), yeasty and moldy synbiotics (YMS), bacterial and yeasty synbiotics (BYS), and bacterial, yeasty and moldy synbiotics (BYMS). After 7 days of anaerobic fermentation, fermented-TMRs were exposed to the air during 1, 3, 5, 7, 14 and 21 days. One hundred forty four (8 treatments${\times}$6 days${\times}$3 replications) fermented-TMRs were manufactured by vinyl bag ($43\;cm{\times}58\;cm$). Although no significant differences in the activities of carboxymethylcellulase, xylanase and amylase were observed among treatments, theirs acivities were seemed to increase by treatment of BYS or YMS containing yeast. Total bacterial and mold counts also decreased in the treatments containing yeast. Potential pathogenic bacteria were less detected in BYS and BMYS for E. coli, BMYS and YS for Salmonella, and BMS and BMYS for Shigella than those of the other treatments, MS was, however, contaminated easier than US by pathogenic bacteria. From above results, synbiotics containing facultative anaerobic yeast have effects for preservation of TMR fermented anaerobically. Particularly, BMYS treatment having good results in nutrient contents, dry matter loss and pathogenic bacteria amounts was a resonable synbiotics for preservation of the fermented-TMR.

• The Korean Journal of Mycology
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• v.43 no.1
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• pp.64-67
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• 2015

Several kinds of wild yeasts were isolated and identified from some cereals. A total of twenty six yeast strains were isolated from eleven kinds of cereals. Among twenty six yeast strains, Saccharomyces cerevisiae were five strains and Pseudozyma antarctica were four strains. Five species of Cryptococcus including Cryptococcus magnus were also isolated. Pseudizyma aphidis were isolated from black bean, and Saccharomyces cerevisiae, Cryptococcus flavescens, Cryptococcus magnus and Hannaella zeae were also isolated from glutinous millet.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.426-429
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• 2009

본 연구에서는 바이오에탄올 가격 경쟁력 확보를 위하여 옥수수 및 사탕수수와 같은 식량자원이 아닌 맥주 제조 후 발생되는 폐기물로부터 바이오에탄올을 제조함으로써 기존의 바이오에탄올의 원료로 사용되는 작물의 수급의 불안정 및 곡물가격의 상승에 의한 원료의 가격상승 등에 따른 높은 생산단가에 대한 문제점을 해결할 수 있을 것으로 기대하며, 맥주발효 폐효모액을 이용한 바이오에탄올 제조 특성을 살펴보기 위하여 1일 30톤의 바이오에탄올 제조 공정 해석을 수행하였다.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.630-636
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• 1992

Hansenula nonfermentans KYP-l was selected and identified from 19 methanol utilizing yeasts isolated from soil samples by the enrichment culture technique. This strain showed a high cell concentration and a high aldehyde production. Aldehyde production was carried out in a resting cell system using methanol utilizing yeast as a biocatalyst. The molar yield of acetaldehyde was the highest among the aldehyde investigated, and the maximum amount of aldehyde was produced by cells obtained from a 40 hours' culture.

• Korean Journal of Microbiology
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• v.24 no.4
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• pp.385-388
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• 1986

In a study of the aerobic growth of Baker's yeast (Saccharomyces cerevisiae) on Maxon-Johnson medium (with glucose as substrate) solidified with kudzu root starch, it was observed that between 8 and 24 hour incubation. 10 and 12% solids stimulated greater cell production than did 6 and 8% solids. The concentration of solids also affected thd secretion of protein from the yeast cells with the highest content of extracellular protein at 10-24 hour incubation stimulated by 10% starch solids.