• 한국미생물·생명공학회지
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• 제51권2호
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• pp.184-190
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• 2023

Bioethanol has recently attracted much attention as a sustainable and environmentally friendly alternative energy source. This study aimed to develop a potential process for bioethanol production by fed-batch fermentation using instant dry yeast. To obtain the highest cell growth, we studied the influence of the initial sugar concentrations and pH of sugarcane molasses in batch fermentation. The batch system employed three levels of sugar concentrations, viz. 10%, 15%, 20% (w/v), and two levels of pH, 5.0 and 5.5. The highest cell growth was achieved at 20% (w/v) and pH 5.5 of molasses. The fed-batch system was then performed using the best batch fermentation conditions, with a molasses concentration of 13% (w/v) which resulted in high ethanol concentration and fermentation efficiency of 15.96% and 89%, respectively.

• 한국식품영양학회지
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• 제16권3호
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• pp.203-208
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• 2003

포도주 양조에 있어서 가장 중요한 효모배양을 효과적으로 하기 위하여 대표적인 활성건조효모 5종을 선정하여 포도주 특성과 제조공정에 적합한 활성건조 효모를 찾는 기준을 연구한 결과는 다음과 같다. 활성건조효모의 내성시험으로, 17% 에탄올 용액에서 72시간 후에 Lalvin W15 균주의 생존율이 0.007%로 가장 높았고, 1% 구연산 용액에서 72시간 후에 Pasteur Champagne 균주의 생존율은 2.85%로 가장 높았고, 또한 아황산 200ppm 용액에서 72시간 후에 Lalvin W15 >Prise de Mousse > Epernay II > Pasteur champagne > Montrachet 균주 순으로 생존율이 높았고 41.1%, 12.3%, 5.15%, 4.38%, 0.11%이었다. 적포도 Campbell Early 양조시험으로, 총산은 Lalvin W15 균주로 발효중인 must가 가장 높은 0.93g/100ml 이었으며, 에탄올 함량은 Epernay II 균주로 발효중인 must가 13.8%로 가장 높았다. 또한 유기산 함량은 주석산 > 사과산 > 구연산 순으로 많았고, Prise de Mousse 균주로 발효된 포도주가 주석산 1,897mg/l, 사과산 2,204mg/l로 가장 많았다.

• 한국미생물·생명공학회지
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• 제25권5호
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• pp.512-519
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• 1997

RNA accumulating strain of Torulopsis versatilis MT-1 was cultured in molasses medium for higher contents of RNA in cell. Yeast cells were harvested at logarithmic phase on synchronous culture. Yield of cells on dry base to input sugar was 59.5%. Crude protein content was 55.1% in cell. RNA content was 13.9%. Some problems found in the process for the preparation of yeast extracts were improved by the addition of culture broth of Streptomyces faecalis MSF which secrete RNase (5' nuclease and 5' adenylic acid deaminase). When the culture broth of S. faecalis MSF was added in autolysis process 46% of RNA in cell was converted to I and G(5' inosinic acid and 5' guanylic acid) in extract. By addition of 3-7% culture broth of S.faecalis MSF in autolysis or enzymolysis process at the start or early stage, RNA in extract was converted easily to I and G and protein in cells was easily extracted and hydrolyzed to amino acid. Taste of those yeast extracts was delicious. The yeasty smell in yeast extracts was removed. And cell debris was easily removed from extract.

• 한국미생물·생명공학회지
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• 제21권3호
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• pp.281-287
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• 1993

Rye stillage was adopted as a substrate for the production of yeast biomass by a thermotolerant yeast Candida rugosa isolated from East Africa. In the batch fermentation, the yield of biomass and crude protein reached 4.9-8.4g/l and 2.2-3.5g/l, respectively, the rate of COD reduction was about 20%. Over 90% amount of main components such as glycerol and lactic acid were assimilated, but protein assimilation reached only to 38-45% of the initial content. Crude protein content of the dry yeast biomass produced was 42-47% and sulfur-containing amino acid was revealed as limiting essential amino acid.

• 미생물학회지
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• 제16권3호
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• pp.103-110
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• 1978

Saccharomyces cerevisiae strain M. was cultured in a molasses-containing media with different amounts of phosphorous and nitrogen sources. The effects of constituents of the cell on the functional activity as well as sensitivity of it were investigated, the results obtained being summarised as follows : Both the thermotolerance and dry tolerance of the yeast cell were higher when the more carbohydrate and thehalose were present in the yeast cell. During the drying, the rate of dead cell was noted increasing and the fermentability decreasing, but it was more remarkable at early stage of the decreasing rate of drying, and at the same time increasing rate of dead cell and decrease of fermentability were more remarkable in the yeast cell containing much protein. In this case the speed of drying was slower. The trehalose content in the yeast cell increased during early stage of the drying and this increase was higher when content of trehalose and carbohydrate in the initial yeast cell was relatively high.

• 미생물학회지
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• 제14권1호
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• pp.1-7
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• 1976

Effect of some nutrients on the growth of 3 yeast strains in the pulp mill waste liquor was determined during an attempt to lower the BOD content of the waste liquor and to produce the fodder yeast. The strains applied were Debaryomyces castelli Capriotti, D.phoffi Capriotti, and Cryptococcus luteolus (Saito)Skinner. The necessity of the addition of 0.2% ${NH_4}2SO_4$ 0.5% yeast extract, 0.2% $NH_2SO_4$, and 0.1% $MgSO_4$.$7H_2$O for the best growth of all three strains in the waste liquor was ascertained as a result. After 3-day treatment of the yeast cells on the waste liquor, the BOD content was lowered by about 60-70%. Harvested yeast cells contained ca. 75% water with 1.5-3% lipid, 40-46% protein, 50% carbohydrate and 3-5% ash on the dry weight basis, indicating the possibility of being utilized as the fodder yeast.

• 한국균학회지
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• 제26권3호통권86호
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• pp.361-364
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• 1998

시험한 유기 질소원 중 yeast extract와 soytone이 Tricholoma matsutake DGUM 26001의 균사생장에 가장 우수한 질소원이었다. Yeast extract를 starch-pyridoxine 배지에 1.0% 농도까지 첨가하였을 때, 균사생장이 증가하였다. $24^{\circ}C$에서 30일간 yeast extract가 첨가된 배지에서 배양하였을 때, 50 ml 배양액에서 518 mg의 건조 균사체를 얻을 수 있었다.

• KSBB Journal
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• 제19권4호
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• pp.245-249
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• 2004

천연 식품 소재로 널리 사용되는 효모 추출물을 제조하는 공정의 개선을 위하여 제빵용 효모를 이용하여 자기소화법과 효소처리법을 병용하여 효모 추출물을 제조하였다. NaCl과 에탄올이 효모의 자기소화에 영향을 미치는 인자이었으며 최적 첨가량은 각각 3%와 1%이었다. 효모의 열처리와 효모 세포벽 분해효소의 사용은 유의하지 않았다. 효모를 자기소화 시킨 후 단백질 분해효소와 핵산 분해효소를 처리하고 Maillard 반응과 debittering 공정을 거쳐 효모 추출물을 제조하였다. 최종적으로 얻어진 효모 추출물의 수율은 고형분 기준으로 76%, 총 질소 기준으로 59%이었다. 맥주 효모를 이용한 결과와 비교하면 제빵용 효모를 이용하는 것이 맥주 효모를 이용하는 것보다 수율면에서도 유리하였다.

• 농업과학연구
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• 제46권2호
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• pp.229-237
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• 2019

The influence of dietary supplementation with a yeast culture on growth performance, fecal score and nutrient digestibility was evaluated in weaned pigs in a 6-week feeding trial. A total of 50 weaning pigs with an initial average body weight (BW) of $7.46{\pm}1.60kg$ were randomly allotted into 1 of 2 dietary treatments according to the initial BW. There were 5 replicate pens in each treatment with 5 pigs per pen. The dietary treatments were as follows: 1) control, basal diet (CON) and 2) 0.10% yeast culture, basal diet supplemented with 0.1% yeast culture (YC). The average daily feed intake was significantly improved with the dietary supplementation of the yeast culture compared with the control during phases 1 and 3. Overall (0 to 6 weeks), dietary supplementation with the 0.1% yeast culture had a significant effect on the feed conversion ratio (FCR). There was no significant difference in the fecal score between the CON and YC dietary treatments. In addition, no difference in the apparent total tract digestibility was observed between the CON and YC dietary treatments. Collectively, the results of this study indicate that dietary supplementation of 0.1% yeast only improved the feed intake of weaning pigs; however, yeast culture supplementation did not affect the average daily gain, feed efficiency, total tract digestibility of dry matter, and nitrogen and energy levels as well as the fecal scores.

• 한국식품과학회지
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• 제24권3호
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• pp.221-225
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• 1992

국내에서 대량생산될 수 있는 자생가능한 자원인 배추의 비전통적 이용을 위해 배추즙액에 효모 Candida utilis를 배양하여 단세포단백을 생산하는 연구를 하였다. 배추의 당함량은 $2.1{\sim}4.0%$의 범위에 있었고 배추원액을 그대로 사용하여 C. utilis를 배양했을 때보다는 배추즙액을 적절히 희석하여 배양하였을 때 증식속도가 빨라졌고 소비된 당에 대한 건조균체생산율도 17%에서 약 50% 정도로 향상되었다. 배추즙액에 C. utilis를 배양하여 단세포단백을 생산하고자 할 때는 당의 함량이 1.0% 정도로 희석하는 것이 적절하였고 당함량을 1.0%되게 조정한 배추희석액에 영양원을 첨가하여 그 영향을 평가해 보았을 때 glucose, $KH_2PO_4$나 $(NH_4)_2SO_4$는 첨가효과가 없거나 오히려 균체생산량을 감소시킨데 비하여 yeast extract나 peptone은 건조균체 생산 및 균체의 단백질 함량을 $10{\sim}20%$씩 증가시키는 효과가 있었으나 yeast extract나 peptone의 첨가량에 비해 건조균체생산량의 증가가 적어서 배추즙희석액 자체로만도 효모배양을 위한 좋은 기질임이 확인되었다.