• Journal of Microbiology and Biotechnology
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• v.1 no.3
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• pp.207-211
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• 1991

Yeast fermentation at $40^{\circ}C$ was conducted for microbial protein production and COD reduction in three different sugar beet stiIlages by a thermo- and acid-tolerant yeast Candida rugosa isolated from East Africa. The assimilation proceedings of some main components such as protein, carbohydrate, total titrable acids and glycerol in stillages were observed with growth kinetics of the yeast. Most of glycerol and organic acids were rapidly assimilated at the beginning of the fermentation. Protein assimilation was slowly accelerated with the proceeding of fermentation time and its assimilation rate reached only 14.2%-28.4%. Though Candida rugosa was a flocculent yeast, the flocculation characteristics of the yeasts grown in three stillages were different from each other.

• Microbiology and Biotechnology Letters
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• v.23 no.6
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• pp.723-729
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• 1995

A flocculating sugar tolerant yeast strain was isolated from fermenting Takju. This strain was identified as Saccharomyces cerevisiae CA-1 according to the Lodder's yeast taxonomic studies. The isolated yeast could grow in 50% glucose and in 7% ethanol in the YPD medium. It's optimal growth temperature, initial pH, shaking rate and initial glucose concentration for ethanol fermentation showed 35$\circ$C, 4.5, 150 rpm, 15%, respectively. Ethanol concentration was 63 g/l in 20% glucose after 24 hours, fermentation yield was 0.49 g-ethanol/g-glucose in 10% glucose after 24 hours and ethanol productivity was 3.09 g/l$\cdot $h in 10% glucose after 12 hours in batch fermentation. Repeated batch fermentation was possible for over 50 days and ethanol yield, ethanol productivity and substrate conversion rate were 0.39-0.50 g/g, 1.63-2.08 g/l$\cdot $h and more than 99%, respectively during these periods.

• Mycobiology
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• v.42 no.2
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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.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1160-1164
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• 2008

An novel amylolytic yeast, Saccharomyces cerevisiae HA 27, isolated from nuruk, displayed resistance against high sugar (50% glucose) and alcohol (15%). Maximal production of amylolytic enzyme by S. cerevisiae HA 27 was achieved on 9 days of cultivation at the optimal temperature $20^{\circ}C$ and pH 6.0. The activity of amylolytic enzyme produced by S. cerevisiae HA 27 was stable, even at $70^{\circ}C$, and over a broad pH range (4.0-11.0). Also, the amylolytic enzyme of S. cerevisiae HA 27 showed optimal activity in pH 5.0 at $50^{\circ}C$. S. cerevisiae HA 27 exhibited 6.2%(v/v) alcohol fermentation ability using starch as a carbon source.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.307-314
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• 2018

The goal of this study was to investigate the microbiological characteristics of the ethanol-producing wild yeast, Aureobasidium pullulans P-1, isolated from flowers growing near the Yedang reservoir, Chungnam province, Korea, and in addition, to optimize its fermentation ability for the production of Makgeolli. A. pullulans P-1 was oval-shaped, and formed ascospores and pseudomycelium. The P-1 strain was a halophilic and sugar tolerant yeast which grew in 15% NaCl and 50% glucose-containing yeast extract-peptone-dextrose media. The P-1 strain was also resistant to 20% ethanol. Changes of the physicochemical properties during Makgeolli fermentation by A. pullulans P-1 were investigated. A maximum of 8.45% ethanol was obtained when a mixture of cooked rice, 150% water, and 35% ipguk per cooked rice was fermented by 5% A. pullulans P-1 culture broth at $25^{\circ}C$ for 10 days. Antihypertensive angiotensin I-converting enzyme inhibitory activity in the Makgeolli ferment produced by A. pullulans P-1 reached a high of 71.1% after 10 days.

• Food Science and Preservation
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• v.19 no.3
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• pp.413-419
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• 2012

Fermentation of ice apple wine from freeze-concentrated Fuji apple juice to 36 $^{\circ}Brix$ was carried out using Saccharomyces cerevisiae SS89, a sugar-tolerant wine yeast strain. The characteristics of the fermentation and the properties of ice apple wine were compared with those of S. cerevisiae W-3, an industrial wine yeast that was used as a control in this study. During the fermentation, the alcohol content increased more rapidly by S. cerevisiae SS89 together with the decrease of the soluble solid content, compared to S. cerevisiae W-3. It reached 12% (v/v) after 15 days of fermentation by S. cerevisiae SS89 (12.4%, v/v) and 21 days by S. cerevisiae W-3 (12.6%, v/v). The soluble solid contents of the SS89 and W-3 wines were 24.0 and 23.6 $^{\circ}Brix$, respectively. Lactic acid was detected at the highest level, followed by malic aid, among the organic acids in both wines. No big differences in the organic acid contents were observed based on the strains. In the SS89 wine, higher levels of methanol, propanol, butanol, and isoamyl alcohol were detected, together with a lower isobutanol content, compared with the W-3 wine. The SS89 wine showed higher level of intensity as well as higher Hunter's L and b color values compared to the W-3 wine. In the sensory evaluation, similar scores in color, flavor, taste, and overall preference were obtained in the two wines. Therefore, S. cerevisiae SS89 was thought to be useful for the rapid fermentation of ice apple wine.

• Applied Biological Chemistry
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• v.34 no.1
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• pp.61-66
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• 1991

In order to improve the productivity of ethanol by sugar-alcohol-tolerant Saccharomyces cerevisiae D1, the effect of addition of soybean meal on the alcohol fermentation was investigated. The addition of soybean meal led tn the increase of the ethanol productivity and viable cell concentration. Increasing the mont of soybean meal increased the number of viable cells and the consumption percentage of glucose. The water-soluble fraction of soybean meal was nearly as effective as whole-soybean meal, whereas the lipidic fraction had no positive effect. The addition of 4% soybean meal increased the rate of ethanol production regardless of the initial concentrations of glucose. The rate of glucose consumption fermenting a soybean meal supplemented medium was higher than possible in a non-supplemented medium, either in the absence or in the presence of ethanol. But the percentage of ethanol inhibition of the glucose consumption rate was identical for supplemented md unsupplemented media. The increase of final ethanol concentration could not be attributed In an increase of ethanol tolerance of yeast cells but to the satisfaction of nutritional deficiencies.

• The Korean Journal of Mycology
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• v.47 no.3
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• pp.249-258
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• 2019

The goal of this study was to isolate and characterize the wild yeast strains in the soils of Hajodae and Gyungpodae Beaches, Gyungpo Lake in Kangwon-do, Korea and evaluate their anti-demential and tyrosinase inhibitory activities. Among the 27 yeast strains isolated from 30 soil samples from Hajodae Beach, Cyberlindnera culbertsonii HJ31-1, Dothichiza pithyophila HJ22-4, Metschnikowia bicuspidata HJ16-1, and Sakaguchia cladiensis HJ14-1 were recorded for the first time in Korea. Additionally, six of the 55 wild yeast strains isolated from 45 soil samples from Gyungpodae Beach and Gyungpo Lake had not previously been detected in Korea, such as Aureobasidium melanogenum JR3-1. The microbiological characteristics and anti-demential and tyrosinase inhibitory activities of these previously unrecorded yeasts were investigated. Almost all of them were oval-shaped and had ascospores except for Dothichiza pithyophila HJ22-4, Diutina siamensis JR37-5, and Canadida gelsemii DC 35-1. Furthermore, they were all sugar-tolerant and able to grow in 20% glucose-containing YPD broth, except for Cyberlindnera culbertsonii HJ31-1. Diutina siamensis JR37-5 had the highest tyrosinase inhibitory activity (30.9%).

• Food Science and Preservation
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• v.21 no.6
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• pp.917-924
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• 2014

Normal- and late-harvested Fuji apples were fermented using the rapid-fermenting yeast strain Saccharomyces cerevisiae SS89. The late-harvest apples showed a slightly higher soluble-solid content with a lower level of total-acid and moisture (p<0.05) contents as well as hardness (p<0.05) than the normal-harvest apples. During the fermentation, the apples had similar changes in the pH and total-acid content regardless of the harvest time, but the increases in the alcohol content and yeast viable count with the decrease of the soluble-solid content were more rapid in the late-harvest apples than in the normal-harvest apples. After the completion of the fermentation, the soluble-solid and alcohol contents became very similar. The late-harvest cider showed a high total phenolic-compound content and a high DPPH radical scavenging effect, although these were slightly lower than those of the normal-harvest cider. It also showed a higher malic-acid content and higher hue color (p<0.05), Hunter's L, and b (p<0.05) values than the normal-harvest cider. In the sensory evaluation, the late-harvest cider obtained a higher score in taste and a lower score in color compared to the normal-harvest cider.

• The Korean Journal of Mycology
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• v.41 no.3
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• pp.181-184
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• 2013

Rhodosporidium fluviale 201-C-1 and Kluyveromyces thermotolerans 150-JE-2(1) were isolated from wild flowers in Geumsan-gun, Chungcheongnam-do and Wando-gun, Jeollanam-do, respectively. Rhodosporidium paludigenum 86-J-1 and Candida sp. 80-J-3 were also isolated from flowers in Jeju island, Korea. Characteristics for these yeasts were not reported before. Therefore, morphological and physiological characteristics for these yeasts were investigated in this study. R. fluviale 201-C-1 was halophilic asporogenous yeast and formed pseudomycelium. It also grew at $30^{\circ}C$ and pH 4.0-6.0. K. thermotolerans 150-JE-2(1) was sugar-tolerant and halotolerant asporogenous yeast. It formed pseudomycelium and showed positive urease activity. Candida sp. 80-J-3 and R. paludigenum 86-J-1 were asporogenous yeasts, and grew well in yeast extract-peptone dextrose(YPD) medium, potato-dextrose medium as well as vitamin-free medium and YPD medium containing 5% NaCl.