• Korean Journal of Microbiology
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• v.19 no.4
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• pp.163-173
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• 1981

The distribution of methanol-assimilating yeasts on three different sources (elm bark, soil and fresh-water mud) and the growth conditions of a new strain of Candidaboidinii (SIO) wereexamines. From 150 samples, 91 methanol yeasts were isolated through enrichment culture ; they were identified as 77 strains of Candida boidinii including four new strains, 5 isolates of Torulopsis pinus, 3 strains of Hansenula polymorpha and one sstrain of Pichia pastoris respectively. The comparison of these yeasts with three sources indicated that decaying bark of elm tree other two, and that Gandida boidinii was most frequently distributed in all three sources. Four new strains of Candida boidinii were freshly isolated and their taxonomical properties were discussed. Of them, SIO strain was selected and characterized for its growth on methanol. This yeast could grow well on less than 1%(v/v) methanol. However, its growth was inhibited at 10% methanol. The cell yield was 3.1g (dry weight) per 1000ml of mineral mediurr, containing 1%(v/v) methanol as well as 01.% yeast extract as additive. The concentration of 0.1% yeast extract appears to be effective for the biomass production. Optimum conditions for growth on methanol was found to be : $28^{\circ}C,\;NH_4^+$ as nitrogen sources, thiamine as vitamin, and pH 4.5 to 6.0. The cell composition was as follows : crude protein and nucleic acids were 54% and 7% respectively. The amino acids were also described.

• Journal of Species Research
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• v.9 no.3
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• pp.198-203
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• 2020

The goal of this study was to isolate and identify wild yeasts from soil samples. The 15 wild yeast strains were isolated from the soil samples collected in Pocheon city, Gyeonggi Province, Korea. Among them, four yeast stains were unrecorded, and 11 yeast stains were previously recorded in Korea. To identify wild yeasts, microbiological characteristics were observed by API 20C AUX kit. Pairwise sequence comparisons of the D1/D2 domain of the 26S rRNA were performed using Basic Local Alignment Search Tool(BLAST). Cell morphology of yeast strains was examined by phase contrast microscope. All strains were oval-shaped and polar budding and positive for assimilation of glucose, 2-keto-ᴅ-gluconate, N-acetyl-ᴅ-glucosamine, ᴅ-maltose and ᴅ-saccharose (sucrose). There is no official report that describes these four yeast species: one strain of the genus Kodamaea in the family Metschnikowiaceae and three strains of the Hannaella in the family Bulleribasidiaceae. Kodamaea ohmeri YI7, Hannaella kunmingensis YP355, Hannaella luteola YP230 and Hannaella oryzae YP366 were recorded in Korea, for the first time.

• The Korean Journal of Mycology
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• v.49 no.4
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• pp.545-553
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• 2021

In 2021, seven yeast strains were isolated from earthworm (Eisenia andrei) gut samples collected from the Nanji Water Regeneration Center in Goyang City, Gyeonggi Province, Korea. A total of seven yeasts were isolated, of which three strains have not been previously reported in Korea. To identify the yeasts, pairwise sequence comparisons of large subunit (LSU) rDNA sequences were performed using the basic local alignment search tool (BLAST). Assimilation test and cell morphology analysis were performed using the API 20C AUX kit and phase contrast microscope, respectively. Five of the seven strains were assigned to the genus Candida of the order Saccharomycetales of the class Saccharomycetes, and two to the genus Apiotrichum of the order Trichosporonales of the class Tremellomycetes. The yeast strain Candida sojae E2 belongs to the family Debaryomycetaceae, and Apiotrichum laibachii E8 and A. laibachii E9 belong to the family Trichosporonaceae. All strains were cultured in yeast mold agar for three days and showed different colony forms. C. sojae E2 was round and entire shaped, while A. laibachii E8 and A. laibachii E9 was round and convex shaped. This study focuses on the description of the three yeast strains that have not been officially reported in Korea.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.4
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• pp.547-553
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• 2008

The principal objective of this study was to prepare watermelon wine with watermelon juice. For the manufacture of watermelon wine, we determined the contents of starting sugar content ($20^{\circ}Brix$, $25^{\circ}Brix$, $30^{\circ}Brix$, $35^{\circ}Brix$) and three different kinds of yeasts (EC-1118, K1-V1116, D-47). The main additives of the watermelon wine included $K_2S_2O_5$, $NH_4H_2PO_4$, bentonite, yeasts, sugar, mixed acid, and $C_6H_8O_2$. The watermelon wine was fermented at $15^{\circ}C$ until the remaining alcohol content was 5%. We assessed customers' preference regarding the manufactured watermelon wine via sensory evaluation. Three yeasts were shown to result in significantly different alcohol fermentation, among which K2-V1116 was selected for the preparation of the watermelon wine. In our sensory evaluation, the preference of the starting sugar contents was highest in the watermelon wine with $25^{\circ}Brix$ of sugar content. The preference of alcohol content was found to be higher in the watermelon wines prepared with sugar contents of 5% and 7%. The preference test between watermelon wines and purchased white wines demonstrated that the watermelon wine with an alcohol content of 5% was the most preferred wine, and the Chilean Late Harvest wine was the second most preferred.

• Applied Biological Chemistry
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• v.39 no.1
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• pp.16-19
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• 1996

The yeast strains isolated for Choungju brewing in the previous report were examined for their microbiological characteristics, together with some comparative tests with Japanese sake yeasts. The isolates KP-16, 21 and 54 were identified as the strains belong to Saccharomyces cerevisae according to the morphological and physiological properties described in Lodder's 'The Yeasts - A texanomic study'. The isolates were grouped into the pink-colored strains by 2,3,5-tripheny tetrazolium chloride over-lay method. The strains KP-16 and 21 were found to be distinguished from the strain KP-54 in aspects of fermentation of sugars, assimilation of carbon sources, and pellicle formation on malt extract broth. ${\alpha}-methyl-D-glucoside$ was not assimilated or fermented by the isolated yeast strains and this is one of the different characters from the Japanese sake yeasts. The isolated strains appeared to have the requirements for biotin and pantothenate, and to have higher tolerance to ethanol than the Japanese sake yeasts. The biotin requirement was not found in the sake yeasts.

• Korean Journal of Veterinary Research
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• v.28 no.2
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• pp.361-363
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• 1988

The prevalence of yeasts in mammary glands of dairy cows and teat cups of milking machines was studied in Chinju area. The rate of subclinical yeast infection in 330 quarters was 3.6%. Of 12 isolates from the milk, 4 Candida pseudotropicalis, 3 C tropicalis, 2 C krusei, 2 C albicans and 1 Rhodotorula spp were identified. The 91.7% of the isolates belonged to the genus Candida and C pseudotropicalis was the predominant species. From 20.5% of 200 teat cups tested, 51 strains of yeasts were isolated. These were 13 C pseudotropicalis, 9 C guilliermondii, 7 C tropicalis, 5 C krusei, 5 C parapsilosis, 3 C albicans, 2 Torulopsis glabrata, 2 Geotrichum candidum and 5 unidentified yeasts. C pseudotropicalis was most frequently encountcred.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.74-80
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• 2013

Fourteen new records of yeasts were screened from one hundred thirty-three yeasts strains which were isolated from wild flowers in east, west and south coast near areas and inland areas, Korea. Candida silvae, Cryptococcus terrestris and Auriculibuller fuscus were newly isolated from wild flowers collected at Donghae and Andong, respectively. Candida quercitrusa, Hanseniaspora opuntiae, Sporobolomyces carnicolor, Candida saopaulonensis and Sporobolomyces phaffii were newly isolated from wild flowers in Geumsan-gun and Taean-gun in Chungcheongnam-do, respectively. Candida oleophila and Jaminaea angkoriensis were newly identified from flowers in Yesan-gun and Hannaella zeae was also newly identified from flowers of Daecheon. Hanseniaspora vineae and two other yeast strains including Pseudozyma hubeiensis were newly isolated and identified from flowers collected at Gwangju and Wando-gun, respectively. Morphological and physiological characteristics of their new recorded yeasts were investigated.

• Korean Journal of Environmental Agriculture
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• v.36 no.2
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• pp.129-134
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• 2017

BACKGROUND: Yeasts are used in a variety of industries. However, most industries are biased toward Saccharomyces cerevisiae ; so we sought to explore non-conventional yeasts (NCY). This study aimed to isolate yeasts from seawater collected from the East Sea of Korea and to analyze the NCY. METHODS AND RESULTS: We first collected seawater and performed pure isolation using four kinds of medium (GPY, DOB + CSM, DG18, and SCG). In total, 314 strains and 17 genera were isolated by ITS sequencing, including Aureobasidum pullulans (236 strains), Cryptococcus (19 strains), Cystobasidium (18 strains), and Rhodotorula (9 strains). Upon in-depth analysis, A. pullulans, the most dominant genus (236 strains), was divided into Group II (147 strains), Unknown I (8 strains), and Unknown II (49 strains). CONCLUSION: In this study, a total of 314 strains were isolated from seawater; many of these yeasts have been found and reported in seawater previously. In-depth analysis of A. pullulans, showed the dominance of Group I (21 strains) and Group II (147 strains) We also discovered Unknown I (8 strains) and Unknown II (49 strains), which have not been reported previously.

• Journal of Microbiology and Biotechnology
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• v.24 no.4
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• pp.497-506
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• 2014

In this study, crude glycerol was used as a carbon source in the cultivation of wild yeasts, aiming at the production of microbial lipids and citric acid. Forty yeasts of different sources were tested concerning their growth in crude and commercial glycerol. Four yeasts (Lindnera saturnus UFLA CES-Y677, Yarrowia lipolytica UFLA CM-Y9.4, Rhodotorula glutinis NCYC 2439, and Cryptococcus curvatus NCYC 476) were then selected owing to their ability to grow in pure ($OD_{600}$ 2.133, 1.633, 2.055, and 2.049, respectively) and crude ($OD_{600}$ 2.354, 1.753, 2.316, and 2.281, respectively) glycerol (10%, 20%, and 30%). Y. lipolytica UFLA CM-Y9.4 was selected for its ability to maintain cell viability in concentrations of 30% of crude glycerol, and high glycerol intake (18.907 g/l). This yeast was submitted to lipid production in 30 g/l of crude glycerol, and therefore obtained 63.4% of microbial lipids. In the fatty acid profile, there was a predominance of stearic (C18:0) and palmitic (C16:0) acids in the concentrations of 87.64% and 74.67%, respectively. We also performed optimization of the parameters for the production of citric acid, which yielded a production of 0.19 g/l of citric acid in optimum conditions (38.4 g/l of crude glycerol, agitation of 184 rpm, and temperature of $30^{\circ}C$). Yarrowia lipolytica UFLA CM-Y9.4 presented good lipid production when in the concentration of 30 g/l of glycerol. These data may be used for production in large quantities for the application of industrial biodiesel.

• Archives of Pharmacal Research
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• v.19 no.3
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• pp.178-182
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• 1996

Using superoxide dismutase (SOD)-deficient mutants of Saccharomyces cerevisiae, the oxidative stresses induced by 0.1 mM of copper ion $(Cu^{++})$ was studied. In aerobic culture condition, yeasts lacking MnSOD (mitochondrial SOD) showed more significant growth retardation than CuZnSOD (cytoplasmic SOD)-deficient yeasts. However, not so big differences in growth pattern of those mutants compared withwild type were observed under anaerobic condition. It was found that, under aerobic condition, the supplementation of 0.1 mM copper ioh:(Cu") into culture medium caused the remarkable increase of CuZnSOD but not so significant change in MnSOD. It was also observed that catalase activities appeared to be relatively high in the presence of copper ion in spite of the remarkable reduction of glutathion peroxidase in CuZnSOD-deficient yeasts, but the slight increments of catalase and glutathion peroxidase were detected in MnSOD-deficient strains. It implies that the lack of cytoplasmic SOD could be compensated mainly by catalase. However, these phenomena resulted in the significantincrease of cellular lipid peroxides content in CuZnSOD-deficient yeasts and the slight increment of lipid peroxides in MNSOD-deficient cells. In anaerobic cultivation supplementing copper ion, the cellular enzyme activities of catalase and glutathion peroxidase in SOD-deficient yeasts were slightly increased without any significant changes of lipid peroxides in cell membrane. It suggests that a little amount of free radicals generated by copper ion under anaerobic condition could be sufficiently overcome by catalase as well as glutathion peroxidase.dase.