• The Korean Journal of Mycology
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• v.45 no.3
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• pp.234-240
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• 2017

The goal of this study was to isolate wild yeasts from reed fields in the Seocheon-gun county in Chungcheongnam-do, South Korea. Molecular analysis of the D1/D2 domain of the 26S rDNA of the yeasts isolated from soil samples was performed using Basic Local Alignment Search Tool (BLAST). In total, 20 yeast strains from 11 species were isolated from 20 different soil samples. Candida species were observed to be the most common yeasts. Of these 20 strains, Candida subhashii (6 strains), Candida tropicalis (3 strains), Candida boleticola MS008, and Lachancea thermotolerans (2 strains) were identified as alcohol-fermenting yeasts. Further, Bullera japonica YJ10-1, Candida subhashii J7-1, Kluyveromyces yarrowii YJ11-1, and Ustilago shanxiensis Y10-1 were newly recorded yeast strains in Korea, and therefore, their microbiological characteristics were investigated further. All of these unrecorded yeast strains had oval cells; only Candida subhashii J7-1 formed ascospores and pseudomycelia. Kluyveromyces yarrowii YJ11-1 grew in vitamin-free medium, and all of these strains, except Candida subhashii J7-1, grew in 5% NaCl-containing YPD broth.

• Microbiology and Biotechnology Letters
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• v.14 no.2
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• pp.125-131
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• 1986

In order to obtain the optimum conditions for intact yeast cell transformation in the various yeast host-vector systems, 3 yeast plasmid vectors, YRp7, YEpl3 and YIp5 were introduced into 5 yeast hosts, Saccaromyces cervisiae Dl3-1A, DKD-5D, DBY-746, MC-16 and S2022D with various transformation conditions, and plasmid stabilities in all the transformants were also observed. The highest transformation frequencies in all the host-vector system were obtained in the 16 hour Cultured cell (5.4 $\times$ 10$^6$ - 2.4 $\times$ 10$^8$cells/$m{\ell}$) treated with 0.1-0.2 M lithium chloride in 0.1 M tris-HCl (pH 7.6), 35% polyethylene glycol 4000, and heat-shocked at 42$^{\circ}C$ for 5 minutes after 60 minutes of induction. The intact cell transformation got more transformation frequency in DKD-5D (YRp7) and DBY-746 (YEpl3) than protoplast transformation, but reverse tendency was observed in DKD-5D (YEp13) and Dl3-lA (YRp7). The transformants, D13-1A (YRp7) and DKD-5D (YRp7) were very unstable in selective medium, with 80 to 85% of the transformants losing the plasmid after 70 generations, but the transformants, DKD-5D (YEpl3) and DBY-746 (YEpl3) were quite stable, with 35% of the transformants losing the plasmid.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.246-251
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• 2005

The aim of this study was to evaluate an efficacy about activation on macrophage, using model that measured cell viability, nitric oxide (NO), iNOS (inducible nitric oxide synthase) expression and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) on Raw 264.7 cells following treatment of Germanium-fortified Yeast in 0, 5, 10, 25, 50, 100, $200\;{\mu}g/ml$ and the same concentration of dried yeast without germanium. Cell viability (%) and NO produced in activated-macrophage were dose-dependant, a significant increase of the cell viability (132.5%) and NO in $10\;{\mu}g/ml$ (p < 0.05). Increase in iNOS level was in $10\;{\mu}g/ml$. $TNF-{\alpha}$ was produced dose-dependant, e.g. in activated-macrophage with a significant increase of the $TNF-{\alpha}$ in 5 and $10\;{\mu}g/ml$ (p < 0.05). Therefore, Germanium-fortified Yeast had an efficacy of NO mediated iNOS and $TNF-{\alpha}$ production by activated macrophage. This result showed that Germanium-fortified Yeast induced activation of cellular immunity, returned to normalcy on injured immune system and procured anticancer system by activation of macrophage, which was important in immune and anticancer function.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.9-15
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• 1996

To improve the quality of Choungju. a kind of rice wine, two different types of koji were prepared and compared : one from wheat bran with Aspergillus usamii mut. shirousami Y-79 and the other from rice with A. oryzae, and yeast strains from cereal wine mashes were newly isolated and applied for the brewing method. Levels of the related enzymes such as glucoamylase, ${\alpha}-amylase$ and acid protease in the wheat bran koji were higher than those in the rice koji, whereas vice versa in the case of acid carboxypeptidase. An amount of $2{\sim}3%$ wheat bran koji to the weight of total rice was adequate for saccharification of the mash and resulted in improved duality of the fermented mash, accompanied by decrease in koji ordor and amino acidity. When the solution of wheat bran koji and the isolated yeast strains were employed, the better Choungju taste was obtained in comparison with those fermented with Japanese sake yeasts, the strain K-7 and 9, due to the lower content of organic acids especially succinic acid. The amino acidity of the fermented mash was able to be controlled to some extent, when the rico types of koji and the isolated strains were employed, by changing the ratio of the two koji types. However, the application of the rice koji with the isolated strains was not desirable for the brewing process because organic acids were produced in excess and ethanol fermentation was retarded.

• Applied Biological Chemistry
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• v.27 no.4
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• pp.217-224
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• 1984

Effect of a thermophilic yeast (strain T-71) on the ethanol fermentation of raw starchy materials was investigated. The maximum temperature of the thermophilic yeast for the growing and fermentation was a little higher than that of ordinary yeasts and their resistance to ethanol was also high. Even though the optimum temperature of the thermophilic yeast for fermenting ethanol of several raw starchy materials was different depending upon the concentration of mashing, their optimum fermentation temperature was higher than the ordinary yeasts in all cases studied, and their fermentation efficiency was good enough to use. It was also found from the study that the period of fermentation could be shortened for about one to two days by using the thermophilic yeast.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.4
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• pp.87-94
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• 2014

Objective of this study was to investigate characteristics of inorganic components contained in liquid fertilizer produced using bone powder and rice bran by adding dry yeast and molasses. Addition of dry yeast to liquid fertilizer resulted in little change in pH, considerable increase in EC, and it showed high EC value compared to the control which has no additives. Also, it was appeared that the dry yeast-added treatment had higher at $2,936mg{\cdot}L^{-1}$ of $NH_4$-N concentration than the control which had $1,782mg{\cdot}L^{-1}$. In the other hand, addition of molasses resulted in low pH and slightly low EC, as compared to the control. $NH_4$-N concentration in the no added molasses treatment was $2,936mg{\cdot}L^{-1}$ higher than its molasses added treatment which had $2,378mg{\cdot}L^{-1}$. In conclusion, it was shown that addition of dry yeast to liquid fertilizer increased ammonium nitrogen concentration by accelerating nitrogen mineralization, while molasses has an effect of inhibiting nitrogen mineralization and enhancing the characteristics of fermentation. With application of organic liquid fertilizer containing bone powder and rice bran increased the fresh weight of Allium tuberosum.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.383-390
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• 2013

Several yeasts were isolated from flowers found in Gyonggi-do Province and Jeju island in Korea. They were then identified by a comparison of their PCR-amplified D1/D2 regions of 26S rDNA, internal transcribed spacer 1 and 2 inclusive of 5.8S rDNA, using the BLAST database. A total of fifty four yeast strains were isolated from wild flowers in Gyonggi-do and the genus Pseudozyma was noted as being dominant. A total of thirty two strains were isolated from Songaksan and Seongsan-ilchulbong in Jeju island and Sporobolomyces ruberrimus was seen to be dominant. The anti-gout xanthine oxidase inhibitory activities of the culture broths and cell-free extracts from eighty six yeast strains were then determined. The cell-free extracts of Pseudozyma hubeiensis 228-S-1 exhibited the highest xanthine oxidase inhibitory activity of 19.6%. The XOD inhibitor was also maximally produced when Pseudozyma hubeiensis 228-S-1 was cultured at $30^{\circ}C$ for 36h in YEPD medium.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.448-452
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• 2015

The bacterial strain that was isolated from chinese cabbage rhizosphere, showed inhibition of yeast growth. This strain was identified as Pseudomonas fluorescens BB2 by API 20NE test and 16S rRNA gene sequence analysis. P. fluorescens BB2 strain produced antibiotics against yeast as a secondary metabolite effectively when the culture was carried out in YM medium with 3% glucose at $20^{\circ}C$. The protein antibiotic of BB2 strain which was concentrated by ammonium sulfate precipitation and n-butanol extraction inhibited the growth of yeast with the minimal inhibitory concentration of $10{\mu}g/ml$ against Candida albicans KCTC 7965, and the growth of yeast was completely inhibited at $80{\mu}g/ml$. The hydrophilic fraction of n-butanol extraction inhibited the growth of Bacillus cereus ATCC 21366, showed orange halo on chrome azurol S plate, which means the fraction contained iron chelating siderophore. The results of crystal violet uptake through the cell membrane showed that membrane permeability was increased about 9% than control, when the concentration of hydrophobic antibiotic against yeast C. albicans was $60{\mu}g/ml$. As a result, the antibiotic produced by P. fluorescens BB2 against yeast Candida is considered antimicrobial peptide, and this is the first report in the genus Pseudomonas.

• Journal of Aquaculture
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• v.9 no.4
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• pp.345-351
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• 1996

Mass production of resting egg of the rotifer, Brachionus plicatilis was carried out in 1 $m^3$ tank for L-type rotifer and in 1 $m^3$ and 4 $m^3$ tank for S-type rotifer. L-type rotifer was fed on concentrated Chlorella + baker's yeast and only baker's yeast for 15 days. S-type rotifer was fed on concentrated Chlorella in 1 $m^3$ tank for 7 days and frozen Chlorella + baker's yeast in 4 $m^3$ for $6\~8$ days. Total number of resting egg and number of resting egg from $10^8$ rotifers and 1 g dry weight diet for L-type rotifer fed on Chlorella + baker's yeast were $54.5{\times}10^6$ eggs, $30.5{\times}10^6$ eggs and $100{\times}10^3$ eggs, respectively. These were higher than those of rotifer fed on baker's yeast only. Total number of resting egg and number of resting egg from $10^8$ rotifers and 1 g dry weight diet for S-type rotifer fed on concentrated Chlorella in 1 $m^3$ tank were $50\~104{\times}10^6$ eggs, $47\~82{\times}10^6$ eggs and $136\~260{\times}10^3$ eggs, respectively. In 4 $m^3$ tank with frozen Chlorella + baker's yeast, these were $149\~567{\times}10^6$ eggs, $36\~123{\times}10^6$ eggs and $131\~338{\times}10^3$ eggs, respectively. This result suggests that S-type rotifer are better than L-type rotifer for the mass production of resting egg of the Korean rotifer.

• Journal of Animal Environmental Science
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• v.10 no.1
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• pp.59-66
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• 2004

This study was conducted for a period for 5 weeks in order to evaluate effects of brewer's yeast slurry(BYS) on the growth performance, organ development and blood composition of broiler chicks. A total number of 84 one day old broiler chicks were allocated to one of three supplemented diets: 0%(control), 2% and 4% BYS. Body weight gain and feed efficiency of chicks fed the diet supplemented with 4% BYS significantly was increased by 9% and 8%, respectively, compared to the control diet(P<0.05). The BYS supplements did not affect weights of liver, heart and abdominal fat, and their ratios per body weight. However, in 4% BYS supplement group, ratio of liver to body weight significantly decreased(P<0.05) by 12%, compared to the control. The supplement of 4% BYS decreased the concentration of triglyceride by 31%, and increased the concentration of high density lipoprotein(HDL) by 26%, compared to the control(P<0.05). These results indicated that the supplementation of 4% BYS in diet can improve body weight gain as well as feed efficiency, and increased the concentration of blood HDL, and ratio of HDL to total-cholesterol of broiler chicks.