• 미생물학회지
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• 제8권2호
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• pp.69-76
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• 1970

1. The yeasts in the two samples of Nuruk (mold wheat) which one prepared at the College of Agriculture, Choong-Nam University (S) and the other purchased at a market(T), were examined and counted. The yeasts were differe entiated by the market (T), were examined and counted. The yeasts were differe entiated by the TTC(2,3,5-triphenyltetrazolium chloride)agar overlay technique that yields a varied shade of color. The results were : the population of yeasts in 1g of Nuruk S was about $6{\times}10^4$, 56.5% of which were TTC-pink yeasts, 16% TTC-red pink yeasts, 8% were TTC-red yeasts, and 16.5% TTC-white yeasts. In Nuruk T(1g), the number of yeasts accounted for $14{\times}10^4$ and constituted of 42% TTC0pink, 21% TTC-red pink, 23% TTC-red and 9% TTC-white. 2. During the fermentation of Takju (Korean Sake) employing the Nuruk S and T the yeast flora throughout the brewing were observed in 12 hour intervals. TTC pink and red yeasts considered to be the major yeasts were isolated all cultured. The strains ($1{\times}10^5$/ml) were added to the mashes S and T in which pH was adjusted to 4.2 and the change of yeast flora was examined during fermentation.

• Applied Biological Chemistry
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• 제13권1호
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• pp.97-103
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• 1970

간장국제조과정중에 생육하는 효모들을 계수 및 분리 동정하고 TTC 정색에 의하여 유발한 결과는 다음과 같다. 1. 간장국 1g 중의 효모수는 3일국에 $97{\times}10^3$, 4일국에 $135{\times}10^3$, 5일국에 $179{\times}10^3$개로서 제국일수의 경과에 따라 효모수가 증가하였다. 2. 이들 효모의 TTC 정색에 었어서 White가 53.6${\sim}$71.9%, Red가 5.6${\sim}$11.1%, Red pink가 6.8${\sim}$1905 pink가 11.1${\sim}$22.6%로서 white 효모가 가장 많았고 Red 효모가 가장 적었다. 3. 30주를 임의 분리하여 동정한 결과 Saccharomyces rouxii 5주, Saccharomyces fermentati 2주, Saccharomyces rosei 1주, Hansenula suaveolens 1주, Hansenula anomala 6주, Pichia polymorpha 6주, Debaryomyces nicotianae 2주, Debaryomyces hansenii 2주, Torulopsis candida 2주, Torulopsis sake 2주, Candida pelliculosa 1주등 6속 11종으로 동정되었다. 4. 등정한 이들 효모를 TTC 정색에 따라 유별한 결과 Hansenula suaveolens, Hansenula anomala, Candida pelliculosa, Debaryomyces nicotianae, Pichia polymorpha 등은 국중에 생육하는 전체 효모의 약 60%를 차지하는 TTC white 효모구에 속하였으며 Saccharomyces rouxii와Saccharomyces rosei는 Red 로 Saccharomyces fermentati와 Debaryomyces hansenii는 Red pink로 Torulopsis candida와 Torulopsis sake는 pink로 나타났다. 5. 분리된 효모의 대부분이 무염 또는 식염10% 합유배지에서 잘 생육하나 15-18% 식염 합유배지에서는 생육이 거이 억제되었다.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1236-1239
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• 2006

Allyl alcohol (2-propen-l-ol), found in considerable amounts in heated garlic, was able to discriminate yeasts from bacteria and was approximately three orders of magnitude more inhibitory towards yeasts than bacteria. The average minimum inhibitory concentration (MIC) of allyl alcohol for bacteria and yeasts was 5.0% and 0.0056%, respectively. The unsaturated primary alcohols, including allyl alcohol and 2-buten-l-ol, seemed to work differently from all the other saturated alcohols and unsaturated secondary alcohols in inhibiting various yeasts. An alcohol dehydrogenase-negative (ADH$^-$) strain of Saccharomyces cerevisiae was as resistant to allyl alcohol as various bacteria, exhibiting an MIC of 5.0%. The unsaturated primary alcohols were apparently oxidized into the corresponding unsaturated aldehydes before they inhibited the yeasts.

• Molecular & Cellular Toxicology
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• 제3권1호
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• pp.19-22
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• 2007

Optic tweezer is powerful tool to investigate biologic cells. Of eukaryotic cells, it was poorly documented regarding to optic trapping to manipulate yeasts. In preliminary experiment to explore yeast biology, interferometric optical tweezers was exploited to trap and manipulate budding yeasts. Successfully, several budding yeasts are trapped simultaneously. We found that the budding direction of the daughter cell was almost outward and the daughter cell surrounded by other yeasts grows slowly or fail to grow. Thus it was assumed that neighboring cells around budding yeast may be critical in budding and the growth of daughter cells. This is first report pertaining to the pattern of yeast budding under the optical trap when multiple yeasts were trapped.

• Mycobiology
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• 제48권6호
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• pp.501-511
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• 2020

Xylophagous termites are capable of degrading lignocellulose by symbiotic gut microorganisms along with the host's indigenous enzymes. Therefore, the termite gut might be a potential niche to obtain natural yeasts with celluloytic, xylanolytic and ethanologenic traits required for bioethanol production from lignocellulosic biomass. In this study, we cultured 79 yeasts from three different termites viz. Coptotermes heimi, Odontotermes javanicus and Odontotermes obesus. After suitable screening methods, we identified 53 yeasts, which belonged to 10 genera and 16 different species of both ascomycetous and basidiomycetous yeasts. Most yeasts in the present study represent their first-ever isolation from the termite gut. Representative strains of identified yeasts were evaluated for their cellulolytic, xylanolytic, and ethanologenic abilities. None of the isolates showed cellulase activity; 22 showed xylanolytic activity, while six produced substantial quantities of ethanol. Among xylanolytic cultures, Pseudozyma hubeiensis STAG 1.7 and Hannaella pagnoccae STAG 1.14 produced 1.31 and 1.17 IU of xylanase. Among ethanologenic yeasts, the strains belonging to genera Candida and Kodamaea produced high amount of ethanol. Overall, highest ethanol level of 4.42 g/L was produced by Candida tropicalis TS32 using 1% glucose, which increased up to 22.92 g/L at 35 ℃, pH 4.5 with 5% glucose. Fermentation of rice straw hydrolysate gave 8.95 g/l of ethanol with a yield of 0.42 g/g using the strain TS32. Our study highlights the gut of wood-feeding termites as a potential source of diverse yeasts that would be useful in the production of xylanase and bioethanol.

• 한국균학회지
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• 제42권2호
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• pp.170-173
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• 2014

Two unrecorded yeasts, Meyerozyma caribbica UL5-1 and Pichia silvicola UL6-1 were screened from 58 yeasts which were isolated from wild flowers in Ulleungdo in Gyeongsangbuk-do, Korea. The morphological and cultural characteristics of these unrecorded yeasts were investigated. Both yeasts were oval in shape and formed pseudomycelia. P. silvicola UL6-1 formed ascospore, but M. UL5-1 did not. P. silvicola UL6-1 and M. caribbica UL5-1 also grew in vitamin-free medium and 5% NaCl-containing yeast extract-peptone-dextrose medium. The two unrecorded yeasts assimilated glucose, galactose, xylose, cellobiose, trehalose, glycerol and sorbitol, and also fermented glucose, fructose and mannose. The supernatant of both M. caribbica UL5-1 and P. silvicola UL6-1 showed high antihypertensive angiotensin I-converting enzyme inhibitory activity of 84.2% and 82.6%, respectively. Cell-free extract of P. silvicola UL6-1 also showed very high anti-diabetic ${\alpha}$-glucosidase inhibitory activity (85.8%).

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.23-23
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• 2014

There are many yeast strains have been discovered for industrial usage in global scale. In the point of view for the alcoholic fermentation performance and producing alcoholic beverage products, recently many countries have known about the importance of microorganisms as a valuable resource. Discovered with well performed yeasts have potential industrial application in diverse ways such as foods, beverages, cosmetics, pharmaceutical functions, and so on. In Korea, the yeast research has not been sufficiently performed especially for distilled spirits industry. As a result, not so little manufacturers use exotic yeasts from overseas even included the expensive royalties. Besides of those, to produce distilled spirits, many manufacturers do not use specialized yeast for distilled spirits. Distiller's characterized yeasts such as whisky, brandy, vodka, Japanese shochu and awamori, are all well-known industrialized. For decades, the distillers, except us, have selected, developed, and practised yeasts in accordance with distilled spirits characters. This study is about selection and industrial application of yeasts for the Korean pot distilled spirits. Finally 7 yeast strains were selected among over 1,000 yeasts from the traditional Nuruks, through the essential related tests based on brewing and distilling science. The selected yeasts show the appropriate characteristics of distilled spirits. The result of this study could help our distilled spirits industry be activated and stand independent from the exotic microbes.

• Journal of Microbiology
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• 제40권1호
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• pp.55-62
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• 2002

Biodiversity af yeasts in various natural environments including soils, swamps and plants was investigated. By molecular identification methods based on the partial sequences of 265 rDNA, 69 isolates were assigned to 44 taxa including 27 known species. The remaining 17 taxa could potentially form new species. All of them were classified into Ascomycota, Hymenomycetes, Urediniomycetes and Ustilaginomycetes. Ascomycetous and ustilaginomycetous yeasts were generally isolated from flower samples, and hymenomycetous and urediniomycetous yeasts were generally isolated from soil samples. Distribution of yeast groups exhibited geographical variation. Yeast biodiversity of root sail also varied according to the associated plant species.

• 미생물학회지
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• 제13권4호
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• pp.157-164
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• 1975

The distribution and population densities of yeasts including their epiflora on seaweeds were estimated over two months in inshore waters of Mok-po, Korea. Nine species of 48 isolates were obtained from this area. Rhodotorula, Torulopsis and Debaryomyces that are widespread in estuaries were of common occurrence in this water body. The highest counts belonged to Torulopsis candida which was predominated in temperate estuarine zone. The distribution of sea weeds seems to be correlated with the population densities of yeasts. Two species of marine algae harbored yeasts during May and July, 1975. Among seaweeds isolates, the highest numbers werre of the species Rhodotorula glutinis var. glutinis. A dominant colonization of this strain on Chlorophyceae and Phaeophyta and a role of water temperature for the growth of yeasts are discussed.

• 한국미생물·생명공학회지
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• 제31권3호
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• pp.297-300
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• 2003

In order to select probiotics with a high survival rate in gut and the growth inhibition of virulent pathogens to human beings or animals, we have screened lactic acid bacteria and yeasts from Jeot-gal to assess resistance against the artificial gastric acid and bile juice. Lactic acid bacteria and yeasts isolated were incubated for 24 h in artificial bile juice after incubation for 2 h in artificial gastric acid. Especially, strain HW 161 and strain NK 181 showed the higher survival for 2 h incubation in artificial gastric acid. All of 3 strains of lactic acid bacteria and 2 strains of yeast were showed higher growth rate than the control in artificial bile. The antimicrobial activity of lactic acid bacteria and yeasts was also investigated to prove efficacy as probiotic organisms. Lactic acid bacteria were shown the inhibition of Gram positive and negative bacteria, but yeasts narrow inhibition.