• 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.

• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.776-783
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• 2000

Various alcohol yeast strains have been isolated from main mashes of Korean traditional liquors, and their genetic diversities were previously reported [23]. In this study, the strain SHY111, showing the highest alcohol production, was tested for its fermentation and sporulation characteristics. Additionally, its haploid cells were isolated and tested for their growth and fermentation patterns. The strain was identified as Saccharomyces cerevisiae based on its morphological and physiological characteristics. The sequences of the ITS(internal transcribed spacer) and 5.8S rDNA regions of S. cerevisiae SHY111 were found to be identical to those of S. cerevisiae that was obtained from through the yeast genome project. The maximum fermentation ratio obtained by the strain SHY111 (96.7%) was almost the same as that by S. cerevisiae Balyun No. 1 (96.5%) that was a little higher than that by S. cerevisiae KCCM11215(95.8%). The strain was induced for sporulation in a sporulation liquid medium using log phase cells grown in different types of pre-sporulation media, and its haploid cells were obtained by spore dissection using a micromanipulator. The majority of the spores formed a small colony on a YPD agar plate, and the haploid yeast cells derived from the strain SHY111 showed a variety of growth and alcohol fermentation patterns. It was proposed that the fermentation patterns were related to their growth phenotypes in the most haploid strains, but possible not in some strains.

• Microbiology and Biotechnology Letters
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• v.14 no.5
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• pp.359-363
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• 1986

S. diastaticus hydrolysised $\alpha$-1.4 linkage of the starch and was known fermenting yeast strain, but poorly hydrolized $\alpha$-1.6 linkage of the starch. To improve the starch fermentation ability of yeast, we tried that protoplast fusion between S. diastaticus and C. tropicalis and finally two starins of fusant (FPDC42, FPDC43) were obtained. C. tropicalis well hydrolysis both $\alpha$-1.4 and $\alpha$-1.6 linkanges in the starch. The protoplast of parental auxotrophic cells were fused in the presence of 10mM CaCl$_2$ and 35% of polyethylene glycol (M. W. 4,000). The fusion frequency was 10$^{-5}$ to 10$^{-6}$. Properties of the fusants(genetic stability, assimilation of carbon sources, random spore formation, copper resistance, NaCl tolerance, DNA content, cell size and growth rate) were investigated.

• Food Science and Preservation
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• v.10 no.3
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• pp.417-420
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• 2003

In order to study optimum culture condition of yeast medium added deep seawater, we examed samples with 9 yeast strains. The growth rate were measured for Saccharomyces cerevisiae 10, 11, 12, 901 and RCY and Saccharomyces kluyvery DJ97, Saccharomyces cerevisiae YJK, JK99, CMY-28 etc.. The growth of S. cerevisiae 12 was found most active in the deep seawater(hardness 500). The growth rate of S. cerevisiae 901 on medium containing deep seawater(hardness 1000) was faster than that of the yeast on medium without deep seawater. The use of deep seawater on the growth of Sacch.cerevisiae kluyvery DJ97 revealed maximum growth under the condition of hardness 200 of deep seawater and 10％ of sugar concentration.

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.744-750
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• 1999

Forty alcohol yeast strains were isolated from the main mashes (10 strains from each mash) for brewing of 4 different kinds of Korean traditional liquor (3 different types of Yakju and 1 Takju). Thirty-eight out of 40 strains were identified to be the same strain, Saccharomyces boulardii, by the Automated Bacteria, Yeast, and Fungi Identification System (Biolog Co., U.S.A.) based on the metabolic fingerprints. One strain that showed the highest ethanol production among the 38 strains in YPD medium, designated SHY 111, was selected and used for differentiating from other yeast type strains using the polymerase chain reaction (PCR). Amplified DNA, from transcribed internal spacers of SHY 111 chromosomal DNA, was found to be the same in both size and sequence as those of S. cerevisiae KCCM 11215 (formerly S. coreanus) and S. boulardii along with that of S. cerevisiae AB 972, which was used as a type strain for the yeast genome project. However, when PCR was carried out with the intron splice site primer, it resulted in the amplification of the SHY 111-specific DNA fragment which was about 200 bp in size. When PCR was carried out using the primer to test diversity of 40 isolated yeast strains, it was found that the PCR patterns were similar to each other except for the 200 bp bands derived from all the 10 strains from one Yakju, and 2 strains from another Yakju. These results suggest the strain identified as S. boulardii by the Automated Identification System to be a dominant strain for the fermentation of Korean traditional liquors.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.376-385
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• 2019

This study was undertaken is to isolate brewing yeast suitable for rice beer fermentation from the traditional Nuruk, and to identify the brewing ability of the isolated yeast. After 6 months of research, four brewing yeast isolated from traditional Nuruk showed a normal fermentation pattern in terms of physicochemical data (pH, brix, alcohol content) and higher vitality, as compared to commercial brewing yeast. The concentrations of higher alcohol and ester, that impart the aroma to beer, were 78.4 to 106.5 ppm and 15.1 to 29.3 ppm, respectively. In particular, S. cerevisiae (KCCM 90313) bestowed significantly higher contents of higher alcohol and ester concentrations than rice beer prepared from commercial yeast. We conclude that the four variants of yeast isolated from traditional Nuruk are potentially suitable for manufacturing rice beer. Especially, the S. cevisiae (KCCM 90313) yeast shows excellent yeast activity and aroma production, thereby displaying potential application for manufacturing rice beer in the future.

• Biotechnology and Bioprocess Engineering:BBE
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• v.3 no.1
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• pp.15-18
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• 1998

The entanol productivity of superoxide dismutase (SOD)-deficient mutants of Saccharo-Myces cerevisiae was examined under the oxidative stress by Paraquat. It was observed that MnSOD-deficient mutant of S. cerevisiae had higher ethanol productivity than wild type or CuZnSOD-deficient yeast both in aerobic and in anaerobic culture condition. Pyruvated dehydrogenase activity decreased by 35% and alcohol dehydrogenase activity increased by 32% were observed in MnSOD-deficient yeast grown aerobically. When generating oxygen radicals by Paraquat, the ehanol productivity was increased by 40% in CuZnSOD-deficient or wild strain, resulting from increased activity of alcohol dehydrogenase and decreased a activity of pyruvate dehydrogenase. However, the addition of ascorbic acid with Paraquat returned the enzyme activities at the level of control. These results imply that SOD-deficiency in yeast strains may cause the metabolic flux to shift into anaerobic ethanol fermentation in order to avoid their oxidative damages by Paraquat.

• Journal of the East Asian Society of Dietary Life
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• v.1 no.1
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• pp.99-111
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• 1991

In each nuruk using today, effect of pH on glucoamylase activity and viable cell count of yeast and bacteria was measured. Common components during fermentation, alcohol, acetaldehyde and acetone, amino acid composition, and total sugars and mineral content were determined in yakju(korean wine) brewed from different ingredients and by different methods. Results are summarized as follows ; 1. The lower the pH, the lower the glucoamylase activity in JK, BK, JK-S BK-S and JN. But the higher the glucoamylase activity ratio in Koji and KN. 2. Yeast and bacteria cell count could not determined in nuruk inoculated of seed. In JK, BK and JN, yeast cell count was 50${\times}$104∼80${\times}$104, bacteria cell count was 5${\times}$106∼24${\times}$106. 3. In yakju during fermentation, pH was higher in RU, total acidity content was higher in ST-N, ST-K, RU and ST-RUPO and alcohol content was lower in RUPO and ST-RUPO. 4. Ethanol and acetaldehyde content were highest in dukyunju. Trace amount of acetone was determined only in ST-K, RUPO and ST-RUPO . n-Propyl alcohol content was higher in ST-K, ST-RUPO and ST-N, iso-butyl alcohol content was higher in L-RUPO, Dukyunju and Songyupju and iso-amyl alcohol content was higher in Songyupju, RU, L-RUPO and Dukyunju. 5. In amino acids composition of each yakju, Pro, Ala and Val content was higher than other amino acids. Total amino acids content was the highest in Dukyunju and second highest in ST-N, NH3 was higher in ST-N, Dukyunju, RUPO than other samples. 6. Total sugars content was the highest in ST-N and second highest in RU. 7. P, K and Mg content were higher in Dukyunju and ST-N than in other samples. In Dukyunju, Ca and P ratio was 0.075 because of low Ca content and high P content.

• Archives of Pharmacal Research
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• v.16 no.3
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• pp.231-236
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• 1993

Gly-224 residue of yeast alcohol dehydrogenase was mutated by site-directed mufagenesis to isoleucine, which is the corresponding amino acid residue of horse liver alcohol dehydrogenase. The mutated gene on M13 vector was subcloned in YEp13 and used to transform Saccharomyces cerevisiae 302-21 #2 strain, and the expressed protein was purified. The tumover numbers of mutant enzyme for ethanol and acetaldehyde were decreased copared to wild-type enzyme. The results of product inhibition studies indicated that the reaction mechanism was changed to Iso Theorell-Chance from Ordered Bi Bi. We supposed that Gly-224 was related to the enzyme reaction mechanism.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.348-355
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• 1991

DNA segment encoding $\beta$-1, 4-glucanase of Bacillus subtilis was fused in frame to mouse $\alpha$-amylase signal sequence behind the alcohol dehydrogenase isoenzyme I gene (ADHI) promoter of the yeast expression vector pMS12. To enhance the expression level of the $\beta$glucanase gene in yeast, transcription terminator sequence iso-1-cytochrome c gene (CYCI) was inserted into the recombinant plasmid. The transformants harbouring such recombinant plasmids secreted $\beta$-glucanase into the culture medium. The expresstion level of the $\beta$-glucanase gene was increased about 2-fold caused by inserting the terminator. The amount of the secreted $\beta$-glucanase in culture medium was approximately 60% of the total quantity synthesized.