• Applied Biological Chemistry
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• v.31 no.1
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• pp.26-32
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• 1988

This study was performed to construct killer wine yeasts which might suppress the growth of wild yeasts, reduce the consumption of starter and condense the fermentation period. Saccharomyces cerevisiae M524, a commercial wine yeast, was treated with N-methyl-N'-nitro-N-nitrosoguanidine to induce auxotrophic mutants, i.e., CHM $2(thr^-)$, CHM 3 $(asp^-)$ and CHM 6 $(tyr^-)$. These auxotrophs were fused successfully with a killer yeast, S. cerevisiae $1368R({\alpha}\;his\;4\;kar\;1-1(kil-k)\;(k_0)$, respiratory deficient) using sphoroplast techniques and the fusants were designated as CHF 21$(th^-\;kil^+)$, CHF 22$(thr^-\;kil^+)$, CHF 31$(asp^-\;kil^+)$ and GHF 61$(tyr^-\;kil^+)$. Combined cultivation of CHF 31 with 1368R or S. cerevisiae $5{\times}47$ (killer sensitive) proved out that CHF 31 had the characteristic of killing and produced the same amount of ethanol as the prototroph, M524.

• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.80-84
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• 1994

In order to induce the rapid alcohol fermentation through the increases of the cell density in a continuous alcohol fermentation of naked barley, the single-cultivation with S. cerevisiae IS-019(SCM, ordinary control), mixed-cultivation with Saccharomyces uvarum IS-026 having a flocculent ability and S. cerevisiae IS-019(MCM), and mash recirculation by single-cultivation of S. cerevisiae IS-019(MRM) modes were investigated. The cell mass in the mixed-cultivation mode was about 10% higher than that of ordinary control but the final alcohol yield was slightlyl decreased. When recycled the mash with the flow rate of 7 l/h from V$_{6}$ to V$_{5}$ fermentors under the ordinary control, the cell density was distributed at 140~170$\times $10$^{6}$ cell/ml depending upon the fermentorsorders, higher about 20% than that of the ordinary control. Under these conditions the alcohol productivity of the maximum and the overall was 12.16 g/l$\cdot $h with an alcohol of 7.6% at the V$_{5}$ fermentor and 1.19 g/l$\cdot $h with an alcohol of 8.94%, respectively. For higher cell mass it was more effective to apply the mash recirculation mode with the single-cultivation of S. cerevisiae IS-019 in a pilot scale multi-stage CSTR.

• Journal of Microbiology and Biotechnology
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• v.9 no.5
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• pp.679-682
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• 1999

When the human parathyroid hormone (hPTH) is expressed as a secretory product in S. cerevisiae, most of the secreted hPTH is internally cleaved by endoproteolytic processing. To investigate whether the yeast endoproteases such as Kex2p, Yap3p, and Mkc7p are involved in the endoproteolytic processing of hPTH in S. cerevisiae, hPTH was expressed in S. cerevisiae mutants deficient in one or two of the following well-known endoproteases such as Kex2p, Mkc7p, and Yap3p. Among these mutants, the yap3-disrupted(yap3$\Delta$) and yap3/mkc7-disrupted (yap3Δmkc7$\Delta$) yeasts showed a significant reduction in the extent of hPTH proteolysis. In contrast, the mkc7-disrupted (mkc7$\Delta$) yeast did not reduce the proteolysis of hPTH as compared to the wild type. This suggests that Mkc7p is not involved in the endoproteolytic processing of hPTH. It was also found that the kex2-disrupted (kex2$\Delta$) mutant was not able to secrete a detectable amount of hPTH.

• Journal of the FoodService Safety
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• v.4 no.1
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• pp.21-28
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• 2023

Saccharomyces cerevisiae and Zygosaccharomyces rouxii are known to produce alcohol in gochujang. To reduce alcohol production, garlic and chives were applied to gochujang solution to find their inhibitory effect on S. cerevisiae and Z. rouxii. The 70% ethanol extract of garlic and chives showed significant inhibition activity against S. cerevisiae and Z. rouxii, showing growth inhibition zone of 14.00±0.00~25.33±0.58 mm by disc diffusion method. In addition, the addition of 70% ethanol extract of garlic and chives in 10% gochujang solution spiked with S. cerevisiae and Z. rouxii reduced the numbers of total aerobic bacteria (below 7 Log CFU/g) and yeast (below 4 Log CFU/g), alcohol content (below 0.30%), respectively. In conclusion, the addition of garlic ethanol (70%) extract or chives ethanol (70%) extract to gochujang inhibited the growth of S. cerevisiae and Z. rouxii, resulting in reduced alcohol content in gochujang. For further study, it is necessary to conduct food application experiments by using real gochujang paste.

• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.52-58
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• 1987

The yeast S. cerevisiae DBY747 was transformed with E. C - S. C shuttle vector YIp5, YEp13 and YRp7 by the method of spheroplast. The transformation frequency of YEp13 and YRp7 in S. cerevisiae DBY747 was $1.2{\times}10^3$ and $1.0{\times}10^2$ per $10{\mu}g$ of DNA, respectively. The transformants with YIp5 plasmid incapable of autonomous replication in S. cerevisiae were not detected in the condition of this experiment, but YIpS plasmid expressed the gene carried on it when cotransformed with a helper plasmid such as YEp13 or YRp7 : autonomously replicating plasmid. When plasmids were used in covalently closed circular form, cotransformation frequency of Ylp5-YEpl3 and Ylp5-YRp7 was 210 and 95 per $10{\mu}g$ of DNA, respectively. In cotransformation of linear plasmids, transformation frequency of the same cohesive ends was similar to that of noncomplementary cohesive ends. Transformants by the cotransformation with circular plasmids have been shown much higher frequency than with linear plasmids in S. cerevisiae DBY 747. The mitotic segregation stability test suggested that the cotransformant of YIpS-YEp13 was more stable than that of YIpS-YRp7.

• Food Science and Preservation
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• v.23 no.5
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• pp.666-672
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• 2016

The objective of this study was to evaluate the effects of low temperature-adapted Saccharomyces cerevisiae Y297 and fermentation temperatures on the quality of Yakju brewed. Physicochemical properties of Yakju brewed were compared pH, total acidity, ethanol, free amino acid, organic acid contents, and volatile flavor compounds in S. cerevisiae Y297 with control treatment. Cooked non-glutinous rice and saccharogenic amylase in koji were mixed with ethanol-producing yeasts and then fermented at $15^{\circ}C$, $20^{\circ}C$, and $25^{\circ}C$ for 20 days. Yakju brewed using the Y297 treatment showed the highest ethanol yield (17.9%) at $20^{\circ}C$. Expression of heat shock protein (HSP) 104 was evaluated by immunoblotting as an indication of adaptation to low temperatures ($15^{\circ}C$); levels of the HSP104 protein were higher in the Y297 treatment than in the control. Organic acid analysis showed that the lactic acid content of Yakju brewed using the control was the highest at $25^{\circ}C$. Finally, free amino acid analysis showed that the Y297 treatment had a higher proportion of essential amino acids than the control. Overall, these results indicate that S. cerevisiae Y297 could be used as a suitable yeast for Yakju brewed under low temperature ($15^{\circ}C$) condition.

• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.209-212
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• 1986

$\alpha$-Amylase gene of Bacillus amyloliquetaciens was cloned on plasmid YEp13, S. cerevisiae-E. coli shuttle vector. Hybrid plasmid pTG17, carrying $\alpha$-amylase gene of B. amyloliquefaciens, was transformed to E. coli and the expression of it in yeast was investigated. This plasmid was unstable in E. coli and produced two minor plasmids, pTG17-1 and PTG17-2, which resulted from the segregation of it. Transformant of S. cerevisiae MC16 with pTG17-1 plasmid was not appeared on SD medium because of the Leu2 gene defection. S. cerevisiae could be transformed by the hybrid plasmid, and $\alpha$-amylase activity of the yeast transformant was detected by somogyi-Nelson method and agar diffusion method.

• KSBB Journal
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• v.26 no.5
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• pp.427-432
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• 2011

In this study, a EXGA gene code for exo-β-1,3-glucanase from Aspergillus oryzae was overexpressed and secretory produced in Saccharomyces cerevisiae. To overexpress the β-1,3-glucanase, pGInu-exgA and pAInu-exgA plasmids having GAL10 and ADH1 promoter, respectively, and exoinulinase signal sequence (Inu s.s) were constructed and introduced in S. cerevisiae SEY2102 and 2805. The recombinant β-1,3-glucanase was successfully expressed and secreted into the medium and the β--1,3-glucanase activity in 2102/pGInu-exgA and 2102/pAInu-exgA strain were 5.01 unit/mL and 4.09 unit/mL, respectively. In the 2805/pGInu-exgA and 2805/pAInu-exgA strain, the β-1,3-glucanase activity showed 3.23 unit/mL and 3.22 unit/mL, respectively. Secretory efficiency in each strain reached 95% to 98%. Subsequently, the recombinant β1,3-glucanase was used for ethanol production. Ethanol productivity in 2102/pAInu-exgA strain was 0.83 g/L when pre-treated Laminaria japonica which has initial reducing sugar of 1.4 g/L was used as substrate. It is assumed that the polysaccharides of Laminaria japonica was effectively saccharified by recombinant β-1,3-glucanase, resulting in increase of ethanol productivity. These results suggested that recombinant β-1,3-glucanase was efficiently overexpressed and secreted in S. cerevisiae SEY2102 as host strain by using ADH1 promoter-Inu s.s system.

• Microbiology and Biotechnology Letters
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• v.18 no.3
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• pp.305-308
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• 1990

In order to clone the gene coding for 3-isopropylmalate dehydrogenase of Muyveromyces fragilis, a shuttle plasmid vector pHNll4 was used. It can serve as a cloning vector in Saccharomyces cerevisiae DBY746 for other Sau3AI-cleaved DNA segment of Kluyveromyces fragilis. Two cloned fragments which complement the leu2 mutation of Saccharomyces cerevisiae and E, coli were obtained. Their length was 4.4 kb an 3.5 kb, and their orientation was opposite each other. From the fact that the two recombinant plasmids were expressed in Saccharomyces cerevisiae and E, coli, probably the two inserts had the promoter of Ktuyveromyces fi-agilis and that of Kluyveromyces fiagilis was efficiently assosiated with RNA polymerase of Saccharomyces cerevisiae and E. coli. According to the result of Southern hybridization, we thought that the cloned fragment has low homology with 3-isopropylmalate dehydrogenase coding region of E. coli and Saccharomyces cerevisiae.

• Environmental Mutagens and Carcinogens
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• v.16 no.2
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• pp.77-82
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• 1996

The RAD3 gene of Saccharomyces cerevisiae is required for excision repair and is essential for cell viability. RAD3 encoded protein possesses a single stranded DNA-dependent ATPase and DNA-RNA helicase activies. To examine the extent of conservation of structure and function of RAD3 during eukaryotic evolution, we have cloned the RAD3 homolog, HRD3, from the distantly related yeast Schizosaccharomyces pombe. Here, we report the partial cloning and characterization of HRD3 gene (Homologous of RAD3 gene) which was isolated by PCR amplification using conserved domain of Saccharomyces cerevisiae RAD3 gene. Chromosomal DNA isolated from S. pombe had similar restriction patterns to those from S. cerevisiae, as determined by Southern blot analysis. The 2. 8 kb transcript of mRNA was identified by Northern hybridization. The level of transcript did not increase upon UV-irradiation, suggesting that the HRD3 gene in S. pombe is not UV-inducible.