• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1139-1146
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• 2007

Cultures of Saccharomyces cerevisiae were subjected to the effect of PEF (pulse electric field) and a source of selenium. The culture period after which yeast cells were subjected to PEF treatment was optimized, as was the duration of the exposure. Optimization of the nutrient medium composition in S. cerevisiae cultures resulted in an over 1.8-fold increase in selenium accumulation with relation to cultures on the initial substrate. Optimization of the pH value and of culture duration resulted in selenium accumulation increase by approximately 78%. A significant correlation was found between the accumulation of selenium in yeast cells and its concentration in the culture substrate. The highest accumulation of selenium in the biomass of yeast, approx. $240\;{\mu}g/g$ d.m., was obtained after 15-min exposure to PEF on a 20-h culture. An approx. 50% higher content of selenium in cells was recorded, as compared with the control culture without the application of PEF.

• Journal of Animal Science and Technology
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• 제54권6호
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• pp.427-433
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• 2012

The present study was performed to investigate long-term effects of the low-crude protein and lysine (low CP/lys) diet and a yeast culture supplemented to the low CP/lys diet on growth and carcass characteristics in growing-finishing pigs. Forty-five gilts and 45 barrows weighing approximately 25 kg born to Yorkshire ${\times}$ Landrace dams and Duroc sires were allocated to nine pens, with five gilts and five barrows assigned per pen. Every three pens received CP/lys-rich grower and finisher diets (control), low CP/lys grower and finisher (basal), or the low CP/lys grower and finisher supplemented (2%) with a yeast culture providing $3.2{\times}10^8$ Saccharomyces cerevisiae cells/kg diet (yeast) for 31 and 79 days, respectively. The ADG was less in the low CP/lys (basal + yeast) group than in the control group (P<0.01) during both grower (0.59 vs. 0.70 kg) and finisher (0.75 vs. 0.89 kg) phases. However, marbling score was greater (P<0.05) in the low CP/lys group vs. control (3.86 vs. 3.12) at slaughter, which resulted in a twice percentage of the $1^+$-quality grade carcasses in the former compared with that for the latter. Supplementation of the yeast culture to the basal diet caused a decrease in ADG during the grower phase (P<0.01), but not during the finisher phase (0.64 vs. 0.53 kg and 0.73 vs. 0.77 kg for the basal vs. yeast group during the grower and finisher phases, respectively), without influencing the marbling score or percentage of the $1^+$-quality grade carcasses. In conclusion, results indicate that long-term provision of the low CP/lys diet has a beneficial effect on marbling and carcass quality grade as well as a negative effect on weight gain and that the yeast culture supplemented to the low CP/lys diet has no beneficial effect on weight gain or carcass quality.

• 한국버섯학회지
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• 제14권1호
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• pp.6-13
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• 2016

This study was carried out to determine the basic mycelial culture conditions for Poria cocos growth. According to colony diameter and mycelial density, suitable media for mycelial growth were Malt yeast extract, Potato dextrose agar, Yeast extract agar, and Yeast malt agar. The optimum temperature for mycelial growth was between 25 and $35^{\circ}C$, and the optimum pH value was between 4 and 7. Carbon and nitrogen sources were fructose and yeast extract. The optimum C/N ratio was about 10 to 1 with 2% glucose. Other minor components for optimal growth were thiamine-HCl and nicotinamide as vitamins, acetic and lactic acid as organic acids, and $MgSO_4{\cdot}7H_2O$ and $FeSO_4{\cdot}7H_2O$ as mineral salts.

• 미생물학회지
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• 제16권3호
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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.

• 한국미생물·생명공학회지
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• 제46권4호
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• pp.390-394
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• 2018

Endoxylanase와 endoglucanase 유전자가 ADH1 프로모터 하류에 따로따로 삽입된 pAGX3 플라스미드를 함유한 Saccharomyces cerevisiae에서 endoxylanase와 endoglucanase 유전자는 성공적으로 발현되었으며, YPD 배지에서의 회분배양 결과, endoxylanase는 7.91 units/ml, endoglucanase는 0.43 units/ml에 달하는 총활성을 보였다. Yeast extract와 포도당을 간헐적으로 공급하는 유가배양에서 endoxylanase와 endoglucanase의 총활성은 24.9 units/ml과 0.84 units/ml을 각각 보였으며, 이는 회분배양에서 발현된 각각 활성의 3.1배와 2배에 해당되었다. 또한, 대부분의 endoxylanase와 endoglucanase 활성은 세포밖 배지에서 측정되어, 향후 이 재조합 효모는 섬유소(cellulose)와 xylan 혼합물의 동시당화 바이오공정 개발에 활용될 가능성이 높다 하겠다.

• 한국응용과학기술학회지
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• 제32권1호
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• pp.93-99
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• 2015

본 연구는 유채 꽃가루 분말의 영양성분 분석과 파쇄한 꽃가루 분말을 이용하여 효모 배양용 액체배지와 고체배지를 제조하여 효모 배양효율을 분석하였다. 유채 꽃가루 분말(100 g)은 탄수화물 58.9 g, 단백질 20.8 g, 지방 4.1 g, 회분 2.5 g 및 수분 13.7 g으로 구성되었다. 당질 중에서는 Fructose(13.7 g), Glucose(11.1 g)와 Sucrose(6.6 g), 미네랄 중에서는 K(606.7 mg)와 P(603.3 mg) 함향이 높았다. 유리 아미노산은 Glutamic acid(2,482.4 mg), Aspartic acid(2,136.5 mg), Lysine(1,648.3 mg), 및 Leucine(1,631.1 mg) 순으로 많았다. 유채 꽃가루 분말을 단독 또는 NaCl을 첨가하여 액체배지 및 고체배지 제조하고 효모를 배양한 결과, 꽃가루 분말이 15 g/L 이상 함유된 액체배지는 효모 배양 후 건물중이 YPD 배지(대조구)에 비해 많았고, 꽃가루 분말의 농도 의존적으로 효모 건물중이 증가하였다. 또한 액체배지에 NaCl을 1~20 g/L 추가 시 배양된 효모의 건물중이 한층 더 증가하였다. 유채 꽃가루로 제조한 고체배지를 이용하여 효모를 배양(48시간)한 결과, 콜로니(colonies) YPD 배지와 유사하게 잘 자랐다.

• 한국식생활문화학회지
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• 제5권3호
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• pp.349-359
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• 1990

This study was carried out to understand and analyze the cooking and processing methods presented in CHE MIN YO SUL, Chinese books of husbandary was written in sixth century. This book was composed of two parts-part I is Agricultural production and part II is product-Utilization. Especially, wines and yeast(NU RUK) written in part II were studied at this study paper. Most of yeast was made of barley and wheat. These materials had been prepared as raw, steamed, and roasted state by proper ratio with kinds of yeast and then fermented as dough state. Occasionally, various kinds of soup made from cocklebur, leaves of mulberry tree, wormwood etc. put into yeast dough. Yeast doughs were shaped round and square with or without hole in the center, made in July of the lunar calendar and fermented for 3 or 4 weeks. There were 43 kinds of wines in this book. Most of them were made of all kinds of cereals grown at that time-rice, waxy rice, millet, waxy millet etc. These cereals had been steaming or cooking gruel with grain or powder state and then fermented with yeast. These wines were prepared by single or double brewing methods and the kinds of double brewing wines were more than single brewing wines by two times. There were none of wines made from fruit and distilled wines. Generally, single brewing wines were not made in Apr., Nov., Dec., of the lunar calendar and double brewing wines were not made in Aug., Oct., Nov., of the lunar calendar. And ripenning periods of wine brewing were various, from 1 day to 7 months for single brewing, from 2 days to 8 months for double brewing.

• 한국가금학회지
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• 제18권3호
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• pp.167-181
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• 1991

효모(Saccharomyces cerevisiae)제품의 첨가가 육계의 생산성에 미치는 영향을 알아보기 위하여 Arbor Acres종으로 2차에 걸친 사양시험을 실시하였다. 실험 1은 육계 숫 병아리 200수를 무첨가 대조구, yeast culture 0.25%구(YC-0.25%) 및 2.5%구(YC-2.5%), 활성효모 0.05%구(LY-0.05%) 및 0.1%구(LY-0.1%)의 5처리에 4반복으로 반복당 10수씩 battery에 완전임의배치하여 6주간의 사양시험을 실시하였다. 실험 2는 육계 감별추 암, 수 각 120수씩을 성별로 무첨가대조구, 후기(4~6주)에만 0.1% 활성효모첨가구 그리고 전기간 0.1% 활성효모첨가구를 2$\times$3 요인 배치하고 각 처리당 4반복, 반복당 10수씩 공시하여 7주간 사양하였다 실험 1의 결과는 증체율과 사료섭취량 및 폐사율에 있어서 처리간에 유의한 차이가 없었으나 YC-0.25%와 LY-0.1%가 대조구나 타처리구에 비해 3주 이후부터 증체율이 높아지는 경향이 있었다. 사료효율은 LY-0.05%가 대조구, YC-0.25% 및 LY-0 1%에 비해 유의하게 낮았다. 영양소 이용율은 처러간에 유의한 차이가 없었으나 Ca 및 P의 이용율은 첨가구들이 대조구에 비하여 높은 경향을 보여주었다. 소장내의 미생물총균은 Lactobacilli spp., Streptococcus spp. 그리고 yeast 수는 첨가구들에서 높고 Coliforms세균수는 대조구에서 높은 경향을 보였다. 실험 2의 결과는 사료, 성별, 사료$\times$성별 상호작용이 증체량에 모두 유의한 영향을 미쳤는데 특히 숫 육계에서는 활성효모를 전기간 첨가한 구가 증체량이 가장 높은 반면 암 육계에서는 후기만 첨가한 구가 가장 높았다 사료섭취량과 폐사율은 숫 육계가 유의하게 높았으며 사료효율은 사료$\times$성별 상호작용이 유의하여 숫 육계에서는 활성효모 전기간 첨가구가 그리고 암 육계에서는 후기만 첨가한 구가 가장 높았다. 영양소 이용율에 있어서 숫 육계는 암 육계보다 건물, Ca및 P의 이용율이 유의하게 높았고 활성효모 첨가구들은 Ca및 P의 이용율이 대조구에 비하여 유의하게 높았다. 근위, 소장 상, 하부 및 맹장의 세균수를 조사한 결과 Lactobacillus spp.와 yeast는 소장 상, 하부 그리고 Streptococcus spp는 소장과 맹장에서 활성효모첨가구가 대조구에 비하여 높은 경향이 있었으며 Coliforms 세균수는 소장 상, 하부에서 대조구가 첨가구보다 높은 경향이 있었다. 또한 소장의 pH는 활성효모첨가구들이 대조구에 비하여 높은 경향이 있었다.

• 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.

• KSBB Journal
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• 제26권1호
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• pp.87-91
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• 2011

Automatic counting of yeast cells in baker's yeast culture was tried using a conventional light microscope equipped with a pc camera. Relatively good binary image was obtained by using white LED as microscope light source, but uneven brightness distribution in original image hindered counting accuracy. A block binarization method using local thresholds proportional to local brightnesses was used to get improved binary images. The brightnesses of the blocks were expressed as the value component in HSV color model. Good quality binary images were obtained by binarization on $8{\times}6$ blocks of original images and connected-component labelling of the binarized images produced reliable counting results in the concentration range $1.4{\times}10^5/mL{\sim}1.4{\times}10^7\;cells/mL$.