• Journal of Species Research
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• 제10권4호
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• pp.336-343
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• 2021

In 2020, as a subset study to discover indigenous yeast species in Korea, a total of 22 yeast species were isolated from soil samples collected in Gwangju-si, Gyeonggi-do. Among them, 10 strains were unreported species. From the high 26S rRNA gene sequence similarity and formation of a robust phylogenetic clade with the closest species, it was determined that each strain belonged independent and predefined yeast species. The 22 strains were assigned to the genera Dothiora (1 strain), Sarocladium (1 strain), Tetrapisispora (1 strain) and Torulaspora (2 strains) of the phylum Ascomycota; the genera Erythrobasidium (1 strain), Leucosporidium (4 strains), Ustilentyloma (2 strains), Fellozyma (1 strain), Sampaiozyma (2 strains), Filobasidium (1 strain), Solicoccozyma (2 strains) and Vishniacozyma (4 strains) of the phylum Basidiomycota. This is the first official report of the following species in Korea: Dothiora cannabinae (1 strain), Sarocladium strictum (1 strain), Fellozyma inositophila (1 strain), Filobasidium magnum (1 strain), Solicoccozyma phenolicus (1 strain), Solicoccozyma terreus(1 strain), Vishniacozyma tephrensis(1 strain) and Vishniacozyma victoriae (3 strains). Cell morphology, phenotypic features and biochemical features are described in the Species Description section.

• KSBB Journal
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• 제19권4호
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• pp.245-249
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• 2004

천연 식품 소재로 널리 사용되는 효모 추출물을 제조하는 공정의 개선을 위하여 제빵용 효모를 이용하여 자기소화법과 효소처리법을 병용하여 효모 추출물을 제조하였다. NaCl과 에탄올이 효모의 자기소화에 영향을 미치는 인자이었으며 최적 첨가량은 각각 3%와 1%이었다. 효모의 열처리와 효모 세포벽 분해효소의 사용은 유의하지 않았다. 효모를 자기소화 시킨 후 단백질 분해효소와 핵산 분해효소를 처리하고 Maillard 반응과 debittering 공정을 거쳐 효모 추출물을 제조하였다. 최종적으로 얻어진 효모 추출물의 수율은 고형분 기준으로 76%, 총 질소 기준으로 59%이었다. 맥주 효모를 이용한 결과와 비교하면 제빵용 효모를 이용하는 것이 맥주 효모를 이용하는 것보다 수율면에서도 유리하였다.

• 유기물자원화
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• 제8권4호
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• pp.147-152
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• 2000

남은 음식물을 기질로 생균효모사료를 만들기 위해 Kluyveromyces marxianus 효모의 호기적 액상발효가 $35^{\circ}C$에서 시도되었다. 먼저 액상으로 시료를 충분히 마쇄시킨 시료의 효모 생균수를 증가시키기 위한 적정발효조건이 진탕배양을 통해 연구되었다. 시료로 사용된 남은 음식물의 고형분 함량을 수분첨가로 5%, 10%와 15%로 다르게 조정하여 발효시킨 결과 고형분 함량 10%에서 생균수가 가장 높은 것으로 나타났다. 효모의 생균농도를 증가시키기 위하여 Aspersillus oryzae를 2리터용 jar fermenter를 이용하여 혼합배양한 결과 증식속도를 증가시켜 주었으나 최고 생균수는 $3.5{\times}10^9/ml$로서 단독 배양시보다 근소하게 높은 결과를 보여주었다.

• Journal of Microbiology
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• 제37권2호
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• pp.51-58
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• 1999

Using yeast, Saccharomyces cerevisiae, and the integrate vector system, we have isolated and characterized an autonomously replicating sequence (ARS) from Aspergillus nidulans. The DNA fragment, designated ANR1, is 5.0 kb in size and maintained free from the chromosome in S. cerevisiae. The YIplac211-ANR1 recombinant plasmid, which consists of sequences derived from the yeast integrative vector YIplac211 and 5.0 kb ANR1 fragment, showed a 104-fold enhancement in transformation efficiency over that found for YIplac211, and was easily recovered from the transformed yeast. Genetic analysis of transformants showed that YIplac21-ANR1 could be over 96% cured when cultured over 20 generations in complete medium and thus suggests that this sequence is mitotically unstable. In A. nidulans, recombinant plasmid PILJ16-4.5 which carries the 4.5 kb EcoRI fragment of ANR1 showed a 170-fold enhancement in transformation efficiency compared to that of the integrative vector PILJ16.

• 자연과학논문집
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• 제4권
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• pp.1-10
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• 1991

발현 Vector인 pKK223-3를 이용하여 효모 Thiol-Specific Antioxidant단백질 유전자를 대장균에 도입시켜 이 단백질을 발현시켰다. 이 단백질은 대장균 단백질의 약 1% 정도로 발현되었으며, 물리 및 화학적 특성은 효모의 것과 동일한 특성을 보였다.

• Applied Biological Chemistry
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• 제37권5호
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• pp.397-401
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• 1994

활성 빵효모를 이용한 생물학적 환원은 n-hexane, pentane과 석유에테르와 같은 유기용매에서 순조롭게 진행되어, ethyl(1)과 octyl 3-oxohexanoate(2)는 높은 %ee로 환원되었다. 활성 빵효모에 의한 생물학적 환원은 물보다 유기용매에서 생성물의 정제가 간편하고 경제적 효과가 크다는 이점이 있었다. 이러한 생물학적 환원방법은 광학활성 천연물의 합성에 이용할 수 있으리라 생각되어 진다.

• 한국균학회지
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• 제51권4호
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• pp.361-371
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• 2023

The study was undertaken to isolate and characterize wild yeast strains from soil samples collected in Seoul, Korea. Among the 19 yeast strains obtained, 17 were previously recorded species. The remaining two strains, Wickerhamomyces sp. GW1-4 and Archaeorhizomyces sp. YB4-103 were new species candidates. The genomic and microbiological characteristics of GW1-4 and YB4-103 were investigated. Phylogenetic analyses based on the 26S rRNA gene sequences and internal transcribed sequences, GW1-4 and YB4-103, represent a distinct lineage within the family Phaffomycetaceae and Archaeorhizomycetaceae, respectively. The GW1-4 and YB4-103 strains had the highest sequence homology with Wickerhamomyces xylosivorus NBRC 111553^T (88.97%) and Archaeorhizomyces finlayi CBS 128710^T (87.55%), respectively.

• 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.

• 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.