• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 추계학술대회 및 정기총회
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• pp.23-23
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• 2014

There are many yeast strains have been discovered for industrial usage in global scale. In the point of view for the alcoholic fermentation performance and producing alcoholic beverage products, recently many countries have known about the importance of microorganisms as a valuable resource. Discovered with well performed yeasts have potential industrial application in diverse ways such as foods, beverages, cosmetics, pharmaceutical functions, and so on. In Korea, the yeast research has not been sufficiently performed especially for distilled spirits industry. As a result, not so little manufacturers use exotic yeasts from overseas even included the expensive royalties. Besides of those, to produce distilled spirits, many manufacturers do not use specialized yeast for distilled spirits. Distiller's characterized yeasts such as whisky, brandy, vodka, Japanese shochu and awamori, are all well-known industrialized. For decades, the distillers, except us, have selected, developed, and practised yeasts in accordance with distilled spirits characters. This study is about selection and industrial application of yeasts for the Korean pot distilled spirits. Finally 7 yeast strains were selected among over 1,000 yeasts from the traditional Nuruks, through the essential related tests based on brewing and distilling science. The selected yeasts show the appropriate characteristics of distilled spirits. The result of this study could help our distilled spirits industry be activated and stand independent from the exotic microbes.

• Mycobiology
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• 제42권4호
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• pp.361-367
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• 2014

Makgeolli, also known as Takju, is a non-filtered traditional Korean alcoholic beverage that contains various floating matter, including yeast cells, which contributes to its high physiological functionality. In the present study, we assessed the levels of ${\beta}$-glucan and glutathione in various yeast strains isolated from traditional Korean Nuruk and selected a ${\beta}$-glucan- and glutathione-rich yeast strain to add value to Makgeolli by enhancing its physiological functionality through increased levels of these compounds. Yeast ${\beta}$-glucan levels ranged from 6.26% to 32.69% (dry basis) and were strongly species-dependent. Dried Saccharomyces cerevisiae isolated from Nuruk contained $25.53{\mu}g/mg$ glutathione, $0.70{\mu}g/mg$ oxidized glutathione, and $11.69{\mu}g/g$ and $47.85{\mu}g/g$ spermidine and L-ornithine monohydrochloride, respectively. To produce functional Makgeolli, a ${\beta}$-glucan- and glutathione-rich yeast strain was selected in a screening analysis. Makgeolli fermented with the selected yeast strain contained higher ${\beta}$-glucan and glutathione levels than commercial Makgeolli. Using the selected yeast strain to produce Makgeolli with high ${\beta}$-glucan and glutathione content may enable the production of functional Makgeolli.

• 한국균학회지
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• 제40권4호
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• pp.204-209
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• 2012

전통누룩으로부터 분리한 효모 중 입국을 발효제로 사용하여 담금 막걸리의 양조적성을 확인하였다. 그 첫 단계로 본 연구원에서 보유하고 있는 알코올 발효 효모로 입국과 막걸리를 담근 결과 관능 및 이화학 분석에서 Y111-5 균주가 선별 되었다. 선별된 균주의 최적 배양 조건으로 기본 YPD배지 중 탄소원으로 sucrose 9%와 질소원으로 yeast extract 5%대체하여 사용 시, 기본 YPD배지에서 6.33 g/L로 생산되었던 균체가 최적배지에서 13.82 g/L로 증가한 것을 확인하였다. 최적배지 선정에 이어 최적배양 시간 탐색을 위해 control배지와 최적배지를 함께 배양하여 생육곡선을 확인한 결과 최대 균체생산량은 15시간임을 확인하였다.

• Journal of Ginseng Research
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• 제5권2호
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• pp.139-147
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• 1981

The effect of ginseng extract and ginseng saponins on alcoholic fermentation was studied 1. Alcoholic fermentation on gllicose medium at 30$^{\circ}C$. by Saccharomyces coveanus and Saccharomyces uvavum was stimulated when the media contained 5% and 10 % of ginseng extract, respectively. But that of Saccharomyces cerevisiae was inhibites by the addition of 10% of ginseng extract. 2. Saponin did not stimulate the alcoholic fermentation by Saccharomyces uvarum. 3. The yeast cell counts was increased remarkably by addition of ginseng extract while that of ginseng saponins was increased slightly. Dried cell weight of the broth which Contained 5% of ginseng extract was 3 times than that of control.

• 한국식품과학회지
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• 제21권6호
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• pp.832-837
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• 1989

포도주 발효에 사용되는 호모균주 12종을 Murphy배지에 배양하여 중간크기의 지방산(MCFA)의 생성을 분석하였고 발효조건에 따라 그 생성량을 관찰하였다. 특히 발효력이 강한 Saccharomyces cerevisiae에 속하는 균주들은 발효초기에 decanoic acid를 약 21-26mg/1 생성하였고 발효 후기에는 약 5-10mg/1로 감소하였다. 발효조건에서 볼 때 MCFA의 생성은 온도가 높을수록 감소하였고 당함량이 클수록 증가하였으며 또한 탄산가스의 존재 하에서도 증가하였다.

• Mycobiology
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• 제41권3호
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• pp.139-144
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• 2013

Makgeolli is a traditional cloudy-white Korean rice wine with an alcohol content of 6~7%. The present study investigated the morphological characteristics, carbon-utilizing ability, fatty acid composition, alcohol resistance, glucose tolerance, and flocculence of Saccharomyces cerevisiae Y98-5 and Pichia anomala Y197-13, non-S. cerevisiae isolated from Nuruk, which is used in brewing Makgeolli. Similar morphological characteristics were observed for both isolated wild yeast strains; and the carbon source assimilation of Y197-13 differed from that of other P. anomala strains. Strain Y197-13 was negative for D-trehalose, mannitol, arbutin, I-erythritol, and succinic acid. The major cellular fatty acids of strain Y197-13 included C18:2n6c (33.94%), C18:1n9c (26.97%) and C16:0 (20.57%). Strain Y197-13 was Crabtree-negative, with 60% cell viability at 12% (v/v) ethanol. The flocculation level of strain Y197-13 was 8.38%, resulting in its classification as a non-flocculent yeast.

• Journal of Microbiology and Biotechnology
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• 제22권12호
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• pp.1749-1757
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• 2012

Makgeolli is a traditional rice wine favored by the general public in Korea. This study investigated the fermentation and sensory characteristics of using wild yeast strains for brewing makgeolli. A non-Saccharomyces cerevisiae strain was isolated from nuruk and termed Y197-13. It showed 98% similarity to Pichia anomala and had an optimal growth temperature of $25^{\circ}C$. Makgeolli was manufactured using koji, jinju nuruk, and improved nuruk as fermentation agents. Y197-13 makgeolli brewed with koji had alcohol and solids contents of 11.1% and 13.9%, respectively. Sweet sensory characteristics were attributed to residual sugars in makgeolli with 6% alcohol. The makgeolli had a fresh sour taste and carbonated taste. Volatile component analysis showed the isoamyl alcohol, phenylethyl alcohol, isoamyl acetate, and fatty acid, including ethyl oleate and ethyl linoleate, relative peak area was higher in Y197-13 makgeolli than in makgeolli with Saccharomyces cerevisiae. These results suggest the wild yeast, Y197-13, as a candidate for brewing makgeolli.

• 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.

• Mycobiology
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• 제42권4호
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• pp.353-360
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• 2014

Makgeolli is a traditional Korean alcoholic beverage. The flavor of makgeolli is primarily determined by metabolic products such as free sugars, amino acids, organic acids, and aromatic compounds, which are produced during the fermentation of raw materials by molds and yeasts present in nuruk, a Korean fermentation starter. In this study, makgeolli was brewed using the wild yeast strain Saccharomyces cerevisiae Y98-5, and temporal changes in the metabolites during fermentation were analyzed by ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry. The resultant data were analyzed by partial least squares-discriminant analysis (PLS-DA). Various metabolites, including amino acids, organic acids, sugar alcohols, small peptides, and nucleosides, were obviously altered by increasing the fermentation period. Changes in these metabolites allowed us to distinguish among makgeolli samples with different fermentation periods (1, 2, 3, 6, 7, and 8 days) on a PLS-DA score plot. In the makgeolli brewed in this study, the amounts of tyrosine ($463.13{\mu}g/mL$) and leucine ($362.77{\mu}g/mL$) were high. Therefore, our results indicate that monitoring the changes in metabolites during makgeolli fermentation might be important for brewing makgeolli with good nutritional quality.

• 한국식품영양과학회지
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• 제41권2호
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• pp.254-260
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• 2012

본 연구는 건조 오미자 추출액을 이용하여 오미자와인을 발효하였다. 건조 오미자를 YM배지에 분주하고 반복 배양하여 알코올 발효효모 OM-1 및 OM-2를 분리하였다. 분리균은 $10^{\circ}Brix$로 보당한 오미자 추출액배지에서 10% 이상의 알코올을 생성하였으며, OM-2로 발효한 오미자와인의 관능적 특성이 OM-1으로 발효한 와인보다 우수한 것으로 평가되었다. 분리균 OM-2는 0.1% urea, 0.02% mineral mixture를 첨가한 오미자 추출액배지에서 균체증식이 유의적으로 촉진되었으며 vitamin mixture는 urea가 첨가된 경우에만 약간의 증식촉진 효과를 나타내었다.