• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.340-344
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• 2002

A gene, npl, encoding neopullulanase from Paenibacillus sp. KCTC 8848P was cloned and expressed in Escherichia coli. It consisted of an open reading frame of 1,530 bp for a protein that consisted of 510 amino acids with a molecular weight of 58,075 Da. The deduced amino acid sequence of the neopullulanase gene had $92\%$ identity with the neopullulanase of Bacillus polymyxa. The npl gene was also expressed in Saccharomyces cerevisiae secreting Schwanniomyces occidentalis glucoamylase (GAM1) under the control of the yeast actin gene (ACT1) promoter. Secretion of the neopullulanase was directed by the yeast mating pheromone ${\alpha}$ -factor ($MF{\alpha}1$) prepro region. Enzyme assays confirmed that co-expression of npl and GAM1 enhanced starch and pullulan degradation by S. cerevisiae.

• 한국균학회지
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• 제45권1호
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• pp.31-42
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• 2017

충청남도와 전라북도에 걸쳐있는 대둔산과 충청남도 청양군 칠갑산의 각종 나뭇잎 87점을 수집하여 야생효모들을 분리, 동정하였다. 대둔산 나뭇잎들에서는 Cryptococcus tephrensis JSL0131를 포함하는 Cryptococcus속 균이 18균주로 가장 많이 분리되었고 Aureobasidium pullulans도 16균주가 분리되었다. 이들 중에서 Asterotremella humicola JSL502, Barnettozyma californica JSL503, Bullera unica JSL501, Bulleromyces albus JSL505와 Candida vaccinia JSL507이 국내 희귀 효모들이었고 Bulleromyces albus JSL505와 Bullera unica JSL501은 10%의 NaCl을 함유한 배지에서도 생육하는 호염성 효모였다. 칠갑산 나뭇잎에서는 Pseudozyma aphidis JSL614를 포함하는 Pseudozyma속 균이 가장 많이 분리 되었다. Rhodotorula phylloplana JSL515, Rhodotorula pinicola JSL516과 Schwanniomyces vanrijiae JSL517과 Sporisorium loudetiae JSL518 등 4균주들이 국내 희귀 종이었고 Sporisorium loudetiae JSL518은 포자와 의균사를 형성하였으며 Rhodotorula pinicola JSL516과 Schwanniomyces vanrijiae JSL517은 5% NaCl을 함유한 YPD 배지에서 생육하는 호염성 효모이었다.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1998년도 한국생물과학협회 학술발표대회
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• pp.323.2-323
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• 1998

No Abstract, See Full Text

• 한국균학회지
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• 제48권4호
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• pp.523-531
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• 2020

This study focused on the isolation and characterization of wild yeasts in Korea. The yeasts were identified by phylogenetically analyzing the D1/D2 domains of the 26S rDNA regions. Consequently, we identified seven strains, NNIBRFG856, NNIBRFG3732, NNIBRFG3734, NNIBRFG3738, NNIBRFG3739, NNIBRFG5497, and NNIBRFG6049, which were confirmed to be Kabatiella microsticta, Pichia membranifaciens, Candida vartiovaarae, Candida sake, Debaryomyces hansenii, Candida railenensis, and Schwanniomyces polymorphus, respectively, all of them being new in Korea. Morphological and cultural characteristics of these yeast species were investigated. None of the strains formed ascospores or pseudomycelia. Moreover, these yeasts grew in a pH range of 4-8. NNIBRFG3732, NNIBRFG3738, NNIBRFG3739, NNIBRFG5497, and NNIBRFG6049 were halotolerant or halophilic, and NNIBRFG3732, NNIBRFG3734, and NNIBRFG6049 grew in vitamin-free medium. NNIBRFG3732, NIBRFG3739, and NNIBRFG6049 grew at 35 ℃, but not at 40 ℃.

• Applied Biological Chemistry
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• 제32권4호
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• pp.408-415
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• 1989

전국 각지로부터 수집한 30개 누룩 시료로부터 27균주의 전분자화성효모를 분리하여 이들 균주를 Hansenula anomala(6균주), Hansenula sydowiorum(2균주), Saccharomycopsis fibuligera (4균주), Schwanniomyces occidentalis(2균주), Candida fabianii(2균주), Candida famata(1균주), Candida hydrocarbofumarica(3균주), Candida silvicola(1균주), Candida steatolytica(4균주), Candida tropicalis(2균주)의 4속 10종으로 동정하였다. 분리효모균주 중 Saccharomycopsis fibuligera Nu-01, Nu-08, Nu-12 및 Nu-27은 높은 amylase활성을 나타내고 이들 균주중 Nu-12는 가장 높은 amylase 활성 (16.9 IU/ml)을 나타내었다. 분리효모균주의 비증식속도는 starch를 탄소원으로 한 배지에서 Hansenula anomala의 균주가 일반적으로 높았고 ethanol 발효에 있어서는 Candida hydrocarbofumarica Nu-15, Nu-22 및 Nu-25를 제외한 모든 분리균주가 알콜을 생성하였다.

• Journal of Microbiology and Biotechnology
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• 제3권4호
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• pp.232-237
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• 1993

A strain of yeast which can convert starch directly to ethanol was developed by the intergeneric protoplast fusion between Schwanniomyces alluvius possessing $\alpha$ amylase as well as glucoamylase with debranching activity and FSC-14-75 which previously had been formed from a heterologous transformation and subsequent intergeneric protoplast fusion. Fusants were selected on minimal medium after protoplasts of auxotrophic mutant of S. alluvius fused with heat-treated protoplasts of FSC-14-75 in the presence of 30%(w/v) PEG and 20 mM $CaCl_2$. The fusion frequency was in the range of $10^{-6}$ order. All fusants tested were intermediate types of parental strains for carbon compound assimilation, and their cell volumes were approximately 1.1 times larger than FSC-14-75 and 1.8 times larger than S. alluvius. The fusants were unable to sporulate like FSC-14-75, while S. alluvius could sporulate. In flask scale the most promising fusant, FSCSa-R10-6, produced 7.83%(v/v) and 10.17%(v/v) ethanol from 15% and 20% of liquefied potato starch, respectively, indicating that the fermetation efficiency of each case increased 1.2 times and 1.6 times than that of FSC-14-75. The elution pattern on DEAE-cellulose chromatography showed that FSCSa-R10-6 has four distinct amylase peaks of which two peaks originated from S. alluvius and the other two from FSC-14-75. These results suggest that the enhanced fermentation efficiency of the fusant might be due to almost-complemented parental amylases.

• 한국균학회지
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• 제27권6호
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• pp.386-393
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• 1999

대체에너지 생산을 위한 우수발효효모를 선별하기 위하여 전국 지역에서 전분, 전분박 및 전분 공장의 주변 토양과 폐수 등 시료를 채취하여 glucoamylase를 분비하는 효모균 64분리주를 얻었으며 이중 비교적 높은 activity를 보여주는 분리주를 선별하였다. 분리주를 동정한 결과 A1-5, D1, E3, G1과 J20은 Saccharomyces diastaticus로 동정되었으며 Saccharomycopsis fibuligera와 Schwanniomyces occidentalis는 각각 두 분리주, Ambrosiozyma monospora와 Lypomyces kononenkoae로 각각 한 분리주색 동정되었다. 그 중 높은 효소활성을 보여주는 S. diastaticus A1-5, J20과 E3을 선택하여 분비되는 glucoamylase의 일반적인 특성을 조사하였다. 배양액내의 효소의 생성을 측정한 결과 glucose나 saccharose, 그리고 4탄당과 3탄당보다 수용성녹말에 의하여 현저하게 증가하였다. Glucoamylase활성의 반응 최적 온도는 $50^{\circ}C{\sim}60^{\circ}C$였고, 최적 pH는 $5{\sim}6$이었으며, 열에 대해서는 $60^{\circ}C$ 이상에서는 불안정한 활성을 보며주었다. 금속이온에 따른 효소의 활성은 $Na^+,\;Mg^{2+}$에 의해 약간 증가하였으나, $H^{2+},\;Ag^{2+}$에 의해 현저하게 감소되는 현상을 보여주었다. 효소의 기질 특이성은 수용성녹말이 쌀 전분, 옥수수전분과 밀 전분에 비하여 현저하게 좋은 기질임을 알 수 있었다.

• 미생물학회지
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• 제29권2호
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• pp.136-142
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• 1991

The selection of ethanol-tolerant strains was applied to enrichment culture of YPD broth medium containing various concentrations of ethanol. Isolates were identified to be Saccharomyces cerevisiae, the others as S. dairensis, S. exiguus, S. telluris, Saccharomycodes ludwigii, Schwanniomyces occidentalis var. occidentalis and Zygosaccharomyces florentinus. Among isolates S. cerevisiae YO-1 was screened as having the highest ethanol tolerance and produced 18% (v/v) ethanol after 4 days fermentation. The change of fatty-acyl residues represents that a progressive decrease in fatty-acyl unsaturation and a proportional increase in saturation in phospholipids of yeast cells during fermentation affected the yeast viability. Supplementation ethanol to the cultures led to an increase of unsaturated fatty-acyl residues, especially $C_{16}$ or $C_{18}$ residues, along with a decrease in the proportion of saturated residues in cellular phospholipids. Increasing the amount of soy flour led to an increase in the maximum number of viable yeast cells and ethanol production. It was possible in 4 days to reach 21% (v/v) ethanol by adding 4% soy flour as source of unsaturated fatty-acyl residues to the fermentation medium. Soy flour not only increased yeast population but also enhanced the physiological properties of yeast cells to be ethanol tolerant in the anaerobic culture.