• Journal of Species Research
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• 제9권3호
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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.

• 한국산학기술학회논문지
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• 제16권5호
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• pp.3361-3369
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• 2015

본 연구의 목적은 효모균주와 발효조건 등을 달리하여 머루를 첨가하여 복분자 와인의 품질을 향상시키는데 있다. 효모별 복분자 와인 술덧 품질에 미치는 영향 연구에서는 Y1(Lalvin 71B)효모가 젖산, 퓨젤유 성분을 발효후에 타 효모에 비해 유의적으로 높게 생성하였으며, 술덧의 산도를 낮추고 복분자 와인의 아로마를 강화하는데 효과가 있는 것으로 분석되었다. 또한 발효온도가 복분자 와인 술덧에 미치는 영향 연구에서는 고온발효($25^{\circ}C$)에서 Y1 효모를 이용하여 발효한 술덧에서 낮은 온도($15^{\circ}C$)에서 발효한 술덧에서보다 아로마 성분(에틸 아세테이트 및 고급알코올)이 유의적으로 높게 생성되었다. 본 연구를 통해 머루를 첨가한 복분자 와인제조시 Y1 효모를 이용하고 고온에서 발효하는 것이 복분자 와인의 맛과 아로마를 강화하는데 효과가 있는 것으로 나타났다.

• Journal of Species Research
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• 제13권1호
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• pp.105-110
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• 2024

The purpose of this study was to isolate and identify wild yeasts from soil samples collected in Seoul and Daejeon, Republic of Korea. To identify wild yeast strains, pairwise sequence comparisons of D1/D2 region of the 26S rRNA gene sequence were done using Basic Local Alignment Search Tool (BLAST). The cell morphologies were observed by phase contrast microscope and carbon source assimilation test were done using API 20C AUX kit. Among the 13 isolated strains, 11 strains were previously reported, but two strains have never been reported from Republic of Korea. The 13 strains were assigned to the phylum Basidiomycota. The two unrecorded yeast strains B2UV-201 and DJ1-5-B-10C belong to the genera Rhodotorula and Rhodosporidiobolus, respectively. The two unrecorded yeast strains are oval shaped and polar budding cells. This research focuses on the morphological and biochemical properties of the two unreported yeast species that have not officially been reported in Korea.

• Journal of Species Research
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• 제13권2호
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• pp.136-141
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• 2024

The purpose of this study is to isolate and identify wild yeasts from the soil samples collected in Daegu and Daejeon City, Republic of Korea. Among 15 strains isolated in this study, 13 strains were previously reported and two strains had not been reported in Republic of Korea. To identify wild yeast strains, pairwise sequence comparisons of D1/D2 region of the 26S rRNA gene sequence were done using Basic Local Alignment Search Tool (BLAST). The cell morphologies were observed by phase contrast microscope and assimilation tests were done using API 20C AUX kit. All strains were assigned to the phylum Basidiomycota. The two unrecorded yeast strains, PG2-2-10C and DJ2-14-10C, belong to the genus Holtermanniella (family Holtermanniaceae, order Holtermanniales, class Tremellomycetes) and Goffeauzyma (family Filobasidiaceae, order Filobasidiales, class Tremellomycetes), respectively. The two unrecorded yeast strains had oval shape and polar budding cells. This research describers the morphological and biochemical properties of the two unreported yeast species that had not officially reported in Korea.

• Mycobiology
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• 제42권2호
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• pp.198-202
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• 2014

Two new yeast records, Cryptococcus adeliensis YJ19-2 and Cryptococcus uzbekistanensis YJ10-4 were screened from 60 yeasts strains that were isolated and identified from wild flowers in Yokjido, Gyeongsangnam-do, Korea. The morphological and cultural characteristics of the newly recorded yeasts and the physiological functionalities of the supernatants and cell-free extracts obtained from their cultures were investigated. The two newly recorded yeasts did not form ascospores and pseudomycelia. They also grew well in yeast extract-peptone-dextrose broth. C. uzbekistanensis YJ10-4 grew in a vitamin-free medium and was also tolerant to sugar and salt. Antihypertensive angiotensin I-converting enzyme inhibitory activity of the supernatant from C. adeliensis YJ19-2 was high (71.8%) and its cell-free extract also showed very high (81.2%) antidiabetic $\acute{a}$-glucosidase inhibitory activity.

• 한국균학회지
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• 제51권4호
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• pp.373-381
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• 2023

This study aimed to isolate and characterize wild yeast strains from the vineyard soil in Korea. Twenty yeast strains were isolated from vineyard soil in Gimpo-si, Gyeonggi-do, Korea, where Vitis labrusca cv. Campbell Early is grown. Eighteen strains were previously recorded in Korea. The remaining two, Cyberlindnera mrakii VG-21-10C and Starmerella bacillaris GR9 were not previously recorded in Korea. The mycological characteristics of VG-21-10C and GR9 were investigated. Both were oval-shaped, convex, and smooth. However, differences were evident in colony color and carbon assimilation activities. Strain VG-21-10C is white-colored and assimilates glucose, glycerol, D-xylose, D-cellobiose, D-saccharose, and D-raffinose as carbon sources. Strain GR9 is cream-colored and assimilates glucose, D-saccharose, and D-raffinose as carbon sources.

• Journal of Species Research
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• 제13권2호
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• pp.142-146
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• 2024

The purpose of this study was to isolate and identify wild yeasts from soil collected in Daegu City and Cheongyang County, Republic of Korea. Among 11 strains isolated in this study, nine strains were previously reported and two strains were unreported in Republic of Korea. To identify wild yeast strains, pairwise sequence comparisons of the D1/D2 region of the 26S rRNA gene sequence were done using Basic Local Alignment Search Tool (BLAST). The cell morphologies were observed by phase contrast microscope and assimilation test are done using API 20C AUX kit. All strains were assigned to the phylum Basidiomycota. Of the two unrecorded yeast strains, CY-9-10C belongs to the genus Mrakia (family Mrakiaceae, order Cystofilobasidiales, class Tremellomycetes) and PG3-4-10C belongs to the genus Slooffia (family Chrysozymaceae, order Microbotryomycetes incertae sedis, class Microbotryomycetes). Both strains had oval-shaped and polar budding cells. This research described the morphological and biochemical properties of the two unreported yeast species that had not officially reported in Korea.

• 한국가금학회지
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• 제33권2호
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• pp.113-119
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• 2006

본 연구는 유기태 철과 효모철의 첨가가 육계의 생산성 및 체조성에 미치는 영향에 대하여 연구하였다. 공시동물은 Ross broiler 252수로 7처리 6반복 반복당 6수씩 사양시험을 실시하였다. 처리구는 1) 대조구, 2) YM03 0.1%, 3) YM03 1.0%, 4) YF04 0.1%, 5) YF04 1.0%, 6) 유기태 Fe 0.01% 및 7) 유기태 Fe 0.1%로 총 7처리로 나누어 실시하였다. 증체량은 대조구가 2,087 g으로 낮게 나타났으며, 유기태 Fe 0.01% 첨가구가 2.121 g으로 나타나 대조구보다 높은 경향을 보였으나 통계적인 유의차는 보이지 않았다(P>0.05). 사료섭취량은 대조구는 3,797 g으로 낮게 나타났으며, YM03 1.0% 첨가구가 3,827 g으로 높게 나타나 대조구보다 높은 경향을 보였으나 통계적인 유의차는 보이지 않았다(P>0.05). 도체 Fe 함량은 대조구가 30.51 mg/dL 로 낮게 나타났으며, YF04 0.1 % 첨가구가 41.58 mg/dL 로 높게 나타나 대조구보다 높은 경향을 보였으나 통계적인 유의차는 보이지 않았다(P>0.05). 육계에서 사료내 유기태 철 또는 효모철의 첨가는 도체내 철의 함량을 강화시키고 철분이 강화된 축산물 생산이 가능할 것으로 사료되나 사업화하기 위해서는 추후에 더욱 체계적인 연구가 요구된다.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1702-1710
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• 2010

Korean traditional rice wines yakju and takju are generally brewed with nuruk as the source of the saccharogenic enzymes by natural fermentation. To improve the quality of Korean rice wine, the microorganisms in the nuruk need to be studied. The objective of this research was to improve the quality of Korean wine with the wild-type yeast strains isolated from the fermentation starter, nuruk. Only strain YA-6 showed high activity in 20% ethanol. Precipitation of Y89-5-3 was similar to that of very flocculent yeast (>80%) at 75.95%. Using 18S rRNA sequencing, all 10 strains were identified as Saccharomyces cerevisiae. Volatile compounds present in yakju were analyzed by gas chromatography-mass selective detector. The principal component analysis (PCA) of the volatile compounds grouped long-chain esters on the right side of the first principal component, PC1; these compounds were found in yakju that was made with strains YA-6, Y89-5-3, Y89-5-2, Y90-9, and Y89-1-1. On the other side of PC1 were short-chain esters; these compounds were found in wines that were brewed with strains Y183-2, Y268-3, Y54-3, Y98-4, and Y88-4. Overall, the results indicated that using different wild-type yeast strains in the fermentation process significantly affects the chemical characteristics of the glutinous rice wine.

• 한국미생물·생명공학회지
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• 제47권4호
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• pp.555-564
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• 2019

Biodiesel is produced through the transesterification process in the presence of alcohol and a catalyst that catalyzes the conversion of triglycerides to esters and glycerol compounds. A more optimal product conversion can be achieved using enzymes, such as lipase. Lipase is reported to be produced in osmophilic yeasts due to the low water content in their natural habitats. Wild forest honey is one of the osmophilic natural habitats in Indonesia. However, lipase-producing yeast has not been reported in the Indonesian honey. In this study, we screened the lipase-producing yeasts isolated from wild forest honey collected from Central Sulawesi. The production profile and activity of lipase were determined at different pH values and temperatures. One promising yeast was isolated from the honey, which was identified as Zygosaccharomyces mellis SG 1.2 based on ITS sequence. The maximum lipase production (24.56 ± 1.30 U/mg biomass) was achieved by culturing the strain in a medium containing 2% olive oil as a carbon source at pH 7 and 30℃ for 40 h. The optimum pH and temperature for lipase activity were 6 and 55℃, respectively. The enzyme maintained 80% of its activity upon incubation at 25℃ for 4 h. However, the enzyme activity decreased by more than 50% upon incubation at 35 and 40℃ for 2 h. This is the first study to report the lipase producing capability of Z. mellis. Further studies are needed to optimize the enzyme production.