• 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.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.

• The Korean Journal of Mycology
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• v.43 no.1
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• pp.64-67
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• 2015

Several kinds of wild yeasts were isolated and identified from some cereals. A total of twenty six yeast strains were isolated from eleven kinds of cereals. Among twenty six yeast strains, Saccharomyces cerevisiae were five strains and Pseudozyma antarctica were four strains. Five species of Cryptococcus including Cryptococcus magnus were also isolated. Pseudizyma aphidis were isolated from black bean, and Saccharomyces cerevisiae, Cryptococcus flavescens, Cryptococcus magnus and Hannaella zeae were also isolated from glutinous millet.

• Mycobiology
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• v.48 no.6
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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.

• The Korean Journal of Mycology
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• v.48 no.2
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• pp.151-160
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• 2020

The goal of this study was to investigate the diversity present among wild yeasts obtained from soils of spice fields and from mountain soils, and to further, characterize previously unrecorded novel wild yeast strains. In total, 36 strains from 17 different species of wild yeasts were isolated from 35 soil samples obtained from garlic fields of Geumsan, Chungcheongnam-do, Korea. Among these, six yeast strains of Trichosporon moniliiforme, and four strains each of Papiliotrema flavescens and Candida melibiosica species were isolated. Additionally, 22 strains of 18 different species of wild yeasts were isolated from 32 soil samples collected from the ballonflower and ginger fields of Geumsan, Korea. Finally, 46 strains of wild yeasts were isolated from 35 soil samples obtained from Mt. Daedun in Geumsan, Korea. Among the total of 106 isolated wild yeast strains, 10 strains, including Debaryomyces vindobonensis GHY31-3 represented novel yeast strains which were previously unrecorded. All the 10 previously unrecorded yeasts were oval or global in shape, and five strains, including Filobasidium stepposum SFG1-4 formed ascospores. Three strains, including Pseudozyma alboarmeniaca CD 23-5 grew well in vitamin-free medium. Cell-free extract obtained from Filobasidium magnum SFG1-3 indicated 28.6% of xanthine oxidase inhibitory activity.