• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.568-572
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• 2005

Saccharomyces yeast spores are more resistant to drying and storage than vegetative cells. For the mass production of yeast spores, compressed yeast was directly inoculated into a sporulation medium (SM). The effects of inoculum size and the addition of rice wine cake (RWC) into SM on the sporulation were examined using flasks. With $1\%$ inoculum of compressed yeast, $1.45{\times}10^8/ml$ of asci was obtained. The addition of $0.5\%$ RWC into SM improved the cell growth and spore yield, and the number of asci formed was $2.31{\times}10^8/ml$. The effects of culture temperature, temperature-shift, and concentrations of inoculum, potassium acetate, and RWC on the sporulation were also evaluated using a jar fermentor. The optimum temperature for spore formation was $22^{\circ}C$ where the number of asci formed was $2.46{\times}10^8/ml$. The shift of culture temperature from initial $30^{\circ}C$ for 1 day to $22^{\circ}C$ for 3 days increased the number of asci formed to $2.96{\times}10^8/ml$. The use of $2\%$ (w/v) inoculum of compressed yeast, $2\%$ potassium acetate, and $1\%$ (w/v) RWC in SM with the shift of culture temperature of initial $30^{\circ}C\;to\;22^{\circ}C$ resulted in $90\%$ sporulation ratio and formation of $6.18{\times}10^8\;asci/ml$.

• Journal of Pharmaceutical Investigation
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• v.8 no.2
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• pp.1-10
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• 1978

During the course of studies on the production of glutathione from yeast, process development and optimization was carried out. The optimal pH for the extraction of glutathione was found to be 2.5 to 4.0 and the maximum yield for glutathione was obtained when the extraction temperature was 25 to $45^{\circ}C$. The cuprous salt of glutathione was recovered maximally at the range of 2 to 4g of cuprous oxide per 10 Kg of compressed yeast. Further purification was needed for the removal of impurities from glutathione. Cation exchange resin, anion exchange resin and Sephadex G-25 were employed for this purpose. 13 to 15 g of glutathione was obtained from 10 Kg of compressed yeast and the purity was above 99.3%.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.510-516
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• 1991

To improve the stability of frozen yeast raised dough for doughnuts, amounts of sugar, sodium steroyl lactylate(SSL) and $KBrO_{3}$ to be added to the premix were optimized, using the fractional factorial design with 3 variables and 3 levels, by a RSM computer program. The optimum sugar, SSL and$KBrO_{3}$ levels to be added to the premix were 2%, 0.3% and 25 ppm for a desired doughnut volume, and 2%, 0.4% and 10 ppm for a desired doughnut texture, and 2%, 0.4% and 20 ppm, respectively, for an overall optimum quality of doughnuts. The frozen stored yeast raised dough prepared without floor time resulted in better doughnut volume and texture than that with floor time. The yeast raised dough prepared with the formula for overall optimum quality, was formed to ‘plain ring’ type doughnuts and stored at $-18^{\circ}C$ for 5 weeks. Volume and texture of fried doughnuts were comparable to those of control for 2 weeks of storage, and then deteriorated noticeablly from 3 weeks of storage.

• Korean Journal of Microbiology
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• v.16 no.3
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• pp.93-102
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• 1978

Saccharomyces cerevisiae strain M was cultured in a molasses-containing media with repeated transplantations of the yeasts from one culture to another to adapt to molasses. After that only different amounts of phosphorous and nitrogen sources were added to the media. And then some variations during the culture time and the effects of consituents of cell mass on the functional activity and sensitivity of the cell were investigated. The results obtained were summarized as follows : 1. In the same culture condition of yeasts, the carbohydrates and trehaloses contents were more remarkably increased when small amounts of phosphate and nitrogen sources were added, then when alrge amounts were added, but yield percentage on assimilated sugars was lower. 2. The content of trehalose in yeast cells was reduced remarkably at the early stage in the culture, but this increased remarkably at later stage. When small amounts of nitrogen and phosphate were added to the culture medium, the amount of thehalose in the cells increased greasly. 3. The more protein content was present in the yeast cells, the smaller the carbohydrate and trehalose content, but more amino-N, RNA and moisture content were present in the cells. And in this case fermentability of the cells was stronger, but sugar tolerance was lower. 4. During the preservation period of compressed yeast cells at different temperature, the higher the temperature was, the more rapidly the amount of trehalose in the cells decreased. And in the cell where the amount of trehalose in the cells decreased. And in the cell where the amount of trehalose(carbohydrate) was large and the amount of protein was small, the amount of trehalose decreased at a slower rate during the preservation period.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.137-143
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• 1988

We studied suitable dough formula for yeast-raised breadmaking using frozen dough prepared by straight no-time method, centering around breadmaking quality. The most suitable dough formula based on 1,000 g of wheat flours was as follows : compressed yeast ; 30 g, sucrose ; 50 g, salt ; 20 g, shortening ; 40 g, potassium bromate ; 75mg, L-ascorbic acid ; 200mg, yeast food ; 3 g, vital wheat gluten ; 30 g, calcium phosphate, monobasic ; 400mg, sodium stearoyl-2-lactylate ; 8 g, water ; 680 g. Breadmaking test employing this formula showed that gassing power and fermentation time were suitable and higher specific loaf volume was obtainable. By using much emulsifiers and dough conditioners, frozen injury of dough was controlable in spite of the addition of more content of water(68%) than that of water (62%) obtained from the farinograph data.