• 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.

• Journal of Microbiology
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• 제35권2호
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• pp.149-151
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• 1997

A plasmid vector with combined features of yeast shuttle vector and mammalian expression vector was constructed to facilitate expression of cloned gene in both cell-types. All necessary elements required for plasmid maintenance and selection in E. coli, yeast and mammalian cells were size-economically arranged in this plasmid. The numan cytomegalovirus (CMV) immediate early promoter and yeast GAL1 promoter were sequentially placed in front of the gene to be expressed. The synthetic splicing donor and acceptor sequences were inserted into the immediate upstream and downstream of the GAL1 promotor, allowing the CMV promotor to direct the expression of a given gene in mammalian cell environment by splicing out the interfering GAL1 promotor sequence. When the resulting vector containing LacZ as a gene was introduced into yeast and mammalian cells, both cells efficiently produced .betha.-galactosidase, dimonstrating its dual host usage.

• 생명과학회지
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• 제13권5호
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• pp.712-717
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• 2003

박테리오신의 일종인 leucocin A를 생산하는 효모의 제작을 위하여 117 bp 길이의 개시코돈과 종지코돈을 포함하는 leucocin A 유전자를 합성하여 효모운반체인 pAUR123에 클로닝하였다. 형질전환된 효모는 부패균의 일종인 고초균(Bacillus subtilis)에 대해 항균활성을 나타냈다. 형질전환 효모로부터 분리한 플라스미드를 주형으로 하고 leucocin A에 특이적인 primer들을 이용하여 PCR 반응을 행한 결과, 효모에 도입된 leucocin A 유전자를 확인할 수 있었다. 이 연구의 결과로 부패하기 쉬운 식품들의 보존성을 향상시키거나, 내성이 생긴 병원균의 생육을 저해하기 위한 항생제로 사용할 수 있는 박테리오신을 산업적으로 생산할 수 있는 효모세포를 제작하였다.

• 한국미생물·생명공학회지
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• 제24권2호
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• pp.143-148
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• 1996

Thousand actinomycetes and 50 soil samples were used for the isolation of microorganisms producing yeast cell wall lytic enzymes. Among 493 strains producing large clear zones on autolysed washed yeast (AWY), 117 strains were selected on living yeast cell agar plates. With the method of lytic activity, one strain (St-1702) was selected, which was temporarily identified as Streptomyces eurythermus. The optimal condition for enzyme production of this strain was partially determined as follows: incubation of the strain for 3 days at 30$\circ$C in the medium containing 2% freeze dried yeast cell, 1% glucose, 1% K$_{2}$HPO$_{4}$, 0.01% MgSO$_{4}$'7H$_{2}$O, 0.5% peptone, and 0.2% (NH$_{4}$)$_{2}$CO$_{3}$ with pH 7.0. The protoplast formation of yeast by using the enzyme produced by this strain was compared with commercial enzymes.

• 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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• 제30권5호
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• pp.355-359
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• 1992

Yeast cells of a fusant strain constructed by protoplast fusion of Saccharomyces cerevisiae and Kluyveromyces frugilis were immobilized on calcium alginate beads. The increment of the ethanol tolerance of this strain to 8.0%, when compared with the parent K, fragilis, was confirmed. Based on the results from jar fermentation, a packed-bed reactor of theh immobilized yeast cells was operated. The optimal performance of the immobilized yeast reactor for ethanol production was achieved when supplying 10% lactose (suplemented 1.0% yeast extract) at a temperature of 30.deg.C. The maximal ethanol productivity was obtained as 13.3 g/I/hr at a dilution rate of $0.76 hr^{-1}$.

• 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.

• 한국식품영양학회지
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• 제12권4호
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• pp.339-343
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• 1999

A strain of gas-producing and volume-expanding yeast was isolated from Gochujang made in Sunchang by the traditional ways and was identified to be a Saccharomyces sp. This yeast was detected only in malt among the several ingrediants of Gochujang which means that the volume-expanding yeast comes into Gochujang at the time of making products through malt one of the major ingredients. However boiling of the malt-saccharified rice could not prevent the occurrence of the volume-expanding yeast in Gochuj-ang. This yeast was contained in the range of 5.67∼7.75 log10CFU/g in products made and aged between 1 monty and 3 year in Sunchang area.