• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.227-235
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• 2015

The objective of this study was to improve the quality of Korean rice wine with wild type yeast strains isolated from various traditional Korean fermented foods. Herein the fermentation and sensory characterization of wild yeast, for the purposes of brewing Korean rice wine, was investigated. 12 yeast strains were examined for their ethanol and glucose tolerance. In addition, the pH, soluble solids, acidity, amino acidity, ethanol content, organic acids, and volatile compounds were also studied for the alcoholic beverages made with the wild yeasts. Almost all Saccharomyces genera yeasts were showed to have a tolerance at 10% ethanol, but non-Saccharomyces genera yeasts displayed a low tolerance. The alcoholic beverages fermented by non-Saccharomyces yeasts demonstrated higher levels of soluble solids, titratable acidity, amino acids, and lower ethanol content, when compared with the alcoholic beverages fermented by Saccharomyces genera yeasts. The organic acid content, such as malic acid, acetic acid, and succinic acid, was seen to also be higher. The electronic nose was analyzed, and discriminant function analysis (DFA) was used for discriminating wild yeast strains. The DFA plots indicated a significant separation of Saccharomyces genera and non-Saccharomyces yeast strains. For volatile compounds, ethyl acetate from non-Saccharomyces yeasts, and ethanol from Saccharomyces genera yeast, a high area ratio was observed.

• The Korean Journal of Mycology
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• v.49 no.3
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• pp.337-349
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• 2021

This study aimed to isolate wild yeasts from water and soil sample of the Nonsan stream and Sapgyoho (lake) in Chungcheonnam-do, Korea, and to further characterize previously unrecorded wild yeast strains. In total, 102 strains, representing 55 different species of wild yeast were isolated from 95 samples collected from the Jangseoncheon and Ipchoncheon of Nonsan stream in Jellabuk-do and Chungcheonnam-do. Among these, 33 strains were isolated from alkalophilic yeast extract-peptone-dextrose (YPD) medium (pH 9.0), and 9 strains were isolated concurrently on general YPD medium (pH 6.5) and alkalophilic medium. Seventeen strains of Cryptococcus laurentii were predominantly isolated. Additionally, 65 strains, representing 27 different species of wild yeast were isolated from 58 samples obtained from Sapgyoho (lake). Among the 82 isolated wild yeast strains, 8 strains, including Candida fructus JSC 72-1(JSL-GGU 015), had not previously been recorded. All 8 previously unrecorded yeasts were oval in shape except C. fructus JSC72-1(JSL-GGU-015), and only the Filobasidium chernovii JSC39-1(JSL-GGU-013) strain formed spores. All strains except Pseudosydowia eucalypti JSC23-6(JSL-GGU-012) grew well in yeast extract-peptone-dextrose (YPD) and yeast extract-malt extract media and grew in vitamin-free medium. Four strains, including P.eucalypti JSC23-6(JSL-GGU-012) grew well in 15% NaCl-containing YPD medium. F.chernovii JSC39-1(JSL-GGU-013) and Sirobasidium intermedium JSC7-3(JSL-GGU-014) assimilated lactose, and five strains, including F. chernovii JSC39-1(JSL-GGU-013) also assimilated starch. All strains were resistant to 800 ppm of Ca, Cu, Li, and Mg ions.

• 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.

• The Korean Journal of Mycology
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• v.41 no.1
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• pp.47-51
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• 2013

Yeasts isolated from wild flowers of Gyejoksan in Daejeon city, Oseosan in Chungchungnamdo, and Baekamsan in Jeollabukdo, Korea were identified by comparison of nucleotide sequences for PCR-amplified D1/D2 region of 26S rDNA or internal transcribed spacer (ITS) 1 and 2 including 5.8S rDNA using BLAST. Twelve yeast strains of ten species and seventeen yeast strains of ten species were isolated from wild flowers of Gyejoksan and Oseosan, respectively. And thirty seven yeast strains of twenty four species were isolated from wild flowers of Baekamsan. Total thirty four yeast species were isolated from three different sample collection areas, but only nine species were overlapped from the at least two different sampling areas: Cryptococcus sp., Cryptococcus aureus, Cryptococcus flavescens, Cryptococcus flavus, Metschnikowia sp., Pseudozyma aphidis, Rhodotorula glutinis, Sporobolomyces carnicolor, and Sporobolomyces ruberrimus. Among them only Cryptococcus aureus was occurred from all three different collection sites. Other twenty five species were restricted to specific collection site suggesting that each area has distinctive yeast flora.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3361-3369
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• 2015

The objective of this study was to improve the quality of black raspberry wine added with wild grape, based on selection of yeast strains and fermentation conditions. The Y1 yeast(Lalvin 71B) indicated significantly higher lactic acid, ester, fusel oil content after fermented mashing than other samples tested and had an effect on the reduction of acidity and enhanced aroma of black raspberry wine. In addition, the high fermentation temperature($25^{\circ}C$) using Y1 yeast showed much higher tendency to retain components of aroma (ethyl acetate, higher alcohols) and the highest overall preference including sensory evaluation than that of low fermentation temperture($15^{\circ}C$). Thus, the fermentation using Y1 yeast at $25^{\circ}C$ can be applied to positively improve the taste and flavor of production of black raspberry wine added wild grape.

• 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.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.707-712
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• 1994

Yeast screening for effective production of alcohol from Jerusalem artichoke tubers as an alternative energy source was performed. Inulin assimilative strains with high alcohol tolera- nce were isolated from wild sources and cultured in the liquid media of Jerusalem artichoke powder varying its concentraion from 15 to 30%. As a result, four strains of 2,445 isolates showing the inulin assimilation were selected as alcohol fermentative and alcohol tolerant yeasts. These strains were assignated to be Kluyveromyces marxianus F043 and Kluyveromyces sp. F173, E040, and F334, respectively, by their cultural and physiological characteristics. The F043 strain produced ethanol of 98.1 g/l in the 25% Jerusalem artichoke medium for 3 days.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.237-249
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• 2020

The goal of this study was to isolate wild yeasts from waters and soils in Sangjubo of Nakdong river and Daechung dam in Daejeon city, Korea and investigate characteristics of previously unrecorded novel wild yeasts. In total, 94 strains from 39 different species of wild yeasts were isolated from 47 soils and waters samples obtained from Sangjubo in Nakdong river. Among these, 3 strains, including Rhodosporidium azoricum JSL-GRU-009, represented novel yeast strains which were previous recorded. Two hundred nine strains from 105 different species of wild yeasts were isolated from 130 soils and water samples obtained from Daechungdaegyo and Daechung dam of Shintanjin in Daejeon city, Korea. Ten strains including Bullera pseudoalba JSL-GRU-005 also represented newly recorded strains in Korea. All the 13 previously unrecorded yeasts were oval or global in shape, and nine strains, including R. azoricum JSL-GRU-009, formed ascospores. Ten strains grew well in vitamin-free medium. R. azoricum JSL-GRU-009 grew well in 20% glucose-containing yeast extract-peptone-dextrose (YPD) medium and 3 strains, including Rhodotorula oryzicola JSL-GRU-003, grew well in 5% NaCl-containing YPD medium.

• Korean Journal of Environmental Agriculture
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• v.34 no.2
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• pp.149-154
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• 2015

BACKGROUND: Yeast isolates associated with the leaves, stems, and flowers of the tiger lily needed to be identified using isolation methods that have previously been used effectively in yeast biotechnology. A culture-based approach was necessary for the isolation of many yeast strains associated with tiger lily. METHODS AND RESULTS: In this study, the homogenized leaves, stems, and flowers of tiger lily were spreaded onto GPY medium containing chloramphenicol, streptomycin, Triton X-100, and L-sorbose. A total of 82 yeast strains from the leaves, 94 and 97 yeast strains from the stems and flowers were isolated, respectively. Yeast isolates were identified by phylogenetic analysis based on internal transcribed spacer region sequencing. The yeast species isolated from the leaves comprised of 31 isolates of the genus Pseudozyma, 28 of Aureobasidium pullulans, and 11 of the genus Cryptococcus. Those isolated from the stems comprised of 40 of A. pullulans and 11 of Cryptococcus, and 95 of A. pullulans While, 1 isolate each of the genera Rhodotorula and Metschnikowia were isolated from the flowers. CONCLUSION: We identified site-specific yeast communities associated with tiger lily. These yeast isolates may have high potential for application in the field of biotechnology.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.177-182
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• 2016

Malodor emitted while producing fertilizer from hatchery egg waste treated with microorganism is an important limiting factor. To reduce this problem, we attempted to use two yeast strains, Saccharomyces cerevisiae, KACC 30008 and KACC 30068. Both yeast strains reduce ammonia gas emission 35.4% than only treated with bacterium, Bacillus amyloliquefaciens. When both strains were used together, that was reduced as 57.1%. KACC 30008 and 30068 strains reduced hydrogen sulfide 42 and 90.4%, respectively. Both strains together reduced hydrogen sulfide gas as 98.5%. KACC 30008 did not decrease methyl mercaptan emission. However KACC 30068 decreased 40% and both strains together decreased the gas emission as 66.7%. Overall, this study showed that yeast treatment could enhance the effect of B. amyloliquefaciens treatment in the reduction of malodorous gas emission.