• Journal of Microbiology and Biotechnology
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• v.32 no.1
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• pp.117-125
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• 2022

Until recently, four types of cellobiose-fermenting Saccharomyces cerevisiae strains have been developed by introduction of a cellobiose metabolic pathway based on either intracellular β-glucosidase (GH1-1) or cellobiose phosphorylase (CBP), along with either an energy-consuming active cellodextrin transporter (CDT-1) or a non-energy-consuming passive cellodextrin facilitator (CDT-2). In this study, the ethanol production performance of two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-2 (N306I) with GH1-1 or CBP were compared with two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-1 (F213L) with GH1-1 or CBP in the simultaneous saccharification and fermentation (SSF) of cellulose under various conditions. It was found that, regardless of the SSF conditions, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the best ethanol production among the four strains. In addition, during SSF contaminated by lactic acid bacteria, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the highest ethanol production and the lowest lactate formation compared with those of other strains, such as the hydrolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-1 with GH1-1, and the glucose-fermenting S. cerevisiae with extracellular β-glucosidase. These results suggest that the cellobiose-fermenting yeast strain exhibiting low energy consumption can enhance the efficiency of the SSF of cellulosic biomass.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.285-296
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• 2020

The goal of this study and potent whitening tyrosinase inhibitor-producing wild yeasts and further optimiz production of tyrosinase. Among non-pathogenic wild yeasts obtained from soils in Daejeon city and spice field of Geumsan in Chungcheongnam-do, Korea, we selected Saccharomyces cerevisiae(S. cerevisiae) WJSL0191 and Papiliotrema laurentii (P. laurentii) ON30 show 33.2% and 27.3% respectively. These selected strains formed and not pseudomycelium. S. cerevisiae WJSL0191 was sugar-tolerant as well as halophilic in 20% glucose-containing yeast (YPD) medium and 15% NaCl-containing YPD medium. S. cerevisiae WJSL0191 and P. laurentii ON30 showed 26.2% and 18.6% anti-wrinkle elastase inhibitory activities, respectively. aximal production of tyrosinase inhibitors obtained when S. cerevisiae WJSL0191 was cultured at 30 for 72h in YPD medium and P. laurentii ON30 was incubated at 20℃ for 24hr.

• Applied Biological Chemistry
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• v.38 no.3
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• pp.278-282
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• 1995

The effect of Schizandrae fructus extract on the physiological properties of Saccharomyces cerevisiae was investigated. S. cerevisiae was inoculated into glucose broth, added with Schizandrae fructus extract, 0, 0.01, 0.1, 0.5 and 1%(w/v), respectively. And a 96 hours incubation was followed to investigate the changes in the growth, alcohol production, alcohol dehydrogenase and pyruvate decarboxylase activities of S. cerevisiae. The growth of S. cerevisiae was more pronounced in the broth containing 0.1 and 0.OlfS Schizandrae fructus extract than in the control. The growth was, however, inhibited in the broth containing 0.5 and 1% of the extract. The content of alcohol produced by S. cerevisiae also showed very similiar results with those of the yeast growth by addition of Schizandrae fructus extract. Alcohol dehydrogenase activities of S. cerevisiae cultured in broth treated with the extract of 0.1% and 0.01% increased by 25% and 18% than those in control group. Pyruvate decarboxylase activities in 0.1% and 0.01% treatments increased to 1.32 and 1.26 times. The activities in 0.5% and 1% treatments, however, decreased by 30% and 44%.

• Journal of Microbiology
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• v.38 no.1
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• pp.48-51
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• 2000

In liquid cultures using sucrose media, the coculture of Monascus with recombinant Saccharomyces cerevisiae expressing the glucoamylase gene from Aspergillus niger enhanced red pigment production by approx. 19％, compared with the coculture of wild type S. cerevisiae. Coculture with recombinant S. cerevisiae was more effective than with wild type S. cerevisiae for Monascus red pigment production. Cocultures of Monascus with commercial amylases of Aspergillus also induced high production of pigment and morphological changes in a solid culture using sucrose media.

• Journal of Microbiology and Biotechnology
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• v.23 no.9
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• pp.1253-1259
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• 2013

The influences of glucose concentration, initial medium acidity (pH), and temperature on the growth and ethanol production of Saccharomyces cerevisiae NK28, which was isolated from kiwi fruit, were examined in shake flask cultures. The optimal glucose concentration, initial medium pH, and temperature for ethanol production were 200 g/l, pH 6.0, and $35^{\circ}C$, respectively. Under this growth condition, S. cerevisiae NK28 produced $98.9{\pm}5.67$ g/l ethanol in 24 h with a volumetric ethanol production rate of $4.12{\pm}0.24g/l{\cdot}h$. S. cerevisiae NK28 was more tolerant to heat and ethanol than laboratory strain S. cerevisiae BY4742, and its tolerance to ethanol and fermentation inhibitors was comparable to that of an ethanologen, S. cerevisiae D5A.

• Microbiology and Biotechnology Letters
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• v.13 no.2
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• pp.145-149
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• 1985

Studies were conducted on the conditions for yeast protoplast regeneration in Hansenula anomala var.anomala FRI YO-32 and Saccharomyces cerevisiae. Protoplasts lysed when suspended in hypotonic solutions of KCI, and the least degree of osmolysis was shown in the hypertonic solution containing 1.4M KCI for the strain FRI YO-32 or 0.8M KCI for S. cerevisiae. It was considered that the concentration of agrar and KCI, and protoplast plating method were the main factors influencing regeneration of yeast protoplasts. Yeast protoplasts were regenerated very favorably when embedded in the complete protoplast regeneration media containing 3％ agar as well as 0.4M KCI for the strain FRI YO-32 or 1.0M KCI for S. cerevisiae. It was shown from the relationship between protoplast formation and regeneration that the higher extent of protoplast formation, the lower extent of protoplast regeneration.

• KSBB Journal
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• v.14 no.1
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• pp.66-70
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• 1999

Comparison of lead removal characteristics between two strains, Aureobasidium pullulans and Saccharomyces cerevisiae, and effects of extracellular polymeric substances(EPS) excreted by microorganisms on the removal of lead were investigated. The capacity of lead biosorption to A. pullulans which had EPS was increased as the storage time of the cells increased, due to the increased amounts of excreted EPS. When the EPS were removed from A. pullulans cells, the amounts of adsorbed lead were very small(10% of the cell with EPS). In the case of s. cerevisiae which had no EPS, the lead removal capacity was nearly constant with storage time except early stage, but the spending time to reach an equilibrium state decreased with increasing storage time because of lowering the function of cell membrane. Therefore, it seems that the phenomena of lead biosorption were remarkably affected by the presence of extracellular polymeric substances.

• Food Science and Preservation
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• v.22 no.5
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• pp.768-777
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• 2015

Persimmon contains high levels of vitamins and phenolic compounds, as well as soluble solids, necessary for the fermentation of persimmon wine. Co-fermentation of persimmon wine was carried out using a mixed culture of Pichia anomala JK04, a Korean indigenous yeast that improves wine quality and flavor, and Saccharomyces cerevisiae Fermivin, an industrial wine yeast, in the following ratios: 9:1 (v/v), 5:5 (v/v), 1:9 (v/v) and 0:10 (v/v). During fermentation, the alcohol contents increased more slowly in samples of mixed culture than in samples of the single culture of S. cerevisiae Fermivin. The alcohol contents of all samples reached 12~13% (v/v) after 15 days. All samples of the mixed culture showed greater variety in flavor and taste than S. cerevisiae Fermivin only. In the sensory evaluation, mixed culture samples had higher scores in terms of flavor and overall preference than the single culture samples. Therefore, P. anomala JK04 is thought to improve the wine flavor of Korean domestic persimmon wine.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.131-137
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• 1995

The alkaline phosphatase (K-ALPase) gene of Kluyveromyces fragilis has been cloned (1) and determined its base sequences (2) previously in our laboratory. When the K-ALPase gene was expressed in Escherichia coli and Saccharomyces cerevisiae, it showed a constitutive activity in E. coli, and a derepressed activity in S. cerevisiae in phosphate-limited medium. Northem hybridization experiment was performed to elucidate the transcription level of the K-ALPase gene. Northern experiment showed that transcription level of K-ALPase gene in S. cerevisiae was higher in phosphate depletion, but it was higher in high phosphate medium than in phosphate limited medium in K. fragilis. The transcription initiation site of the K-ALPase gene was determined by primer extension analysis. It matched nucleotide position - 169 in relation to the putative trnslational start site.

• Microbiology and Biotechnology Letters
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• v.25 no.3
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• pp.266-270
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• 1997

From persimmon fruits, about 40 yeast strains were isolated and tested for their ability of alcohol fermentation were tested. Among them, two strains, RCY14 and RCY15, showing the highest alcohol fermentibility were selected for further investigations. They were identified as Saccharomyces cerevisiae and Saccharomyces kluyveri based on their morphological, cultural and physiological properties. Their optimum condition for the alcohol fermentation in YPD-15% glucose was pH 6.0, 30$circ$C and 120 rpm of shaking speed. The alcohol yields of S. cerevisiae RCY14 and S. kluyveri RCY15 in a persimmon juice were 94.54 and 96.81%, respectively. Although the alcohol yields of both strains were not very high in YPD-15% glucose, they were much higher in a persimmon juice as compared to those of S. cerevisiae Balyon-1, S. cerevisiae 701 and S. cerevisiaein W3 which are being used in the industrial alcohol fermentation.