• 한국균학회지
• /
• 제46권4호
• /
• pp.415-425
• /
• 2018

다양한 Aureobaisidum속을 발굴하여 흑효모의 유용한 특성을 활용하기 위해 전라도 지역 꽃에서 효모 433균주를 분리하고 분자계통학 및 형태학적 분석을 통해 다양성을 확인하였다. large subunit (LSU) rDNA 염기서열 분석을 기준으로 전라도 지역의 Aureobasidium속을 6그룹으로 분류한 후, LSU와 ITS rDNA 염기서열 분석을 통해 전라도 지역 꽃에서 유래한 효모의 주요 우점종이 Group A와 Group D임을 확인할 수 있었다. GroupB, E, F는 전라남도에만 분포하는 것으로 보아 전라북도에 비해 전라남도에서 다양한 Aureobasidium종이 분포하는 것으로 생각된다. Group A는 A. pullulans, Group B는 A. melanogenum, Group F는 Aureobasidium 신종 후보군으로 분류할 수 있었다. Group C, D, E는 LSU와 ITS rDNA 분석에서 A. leucospermi, A. namibiae, A. subglaciale 사이의 명확하게 분류되지 않았으나 콜로니 형태에서 구분 가능한 특성을 보인 것으로 보아, Aureobasidium은 분자계 통학적 분석방법과 형태적 동정을 병행하여 종 수준 동정을 보완할 수 있을 것으로 생각된다.

• 한국균학회지
• /
• 제50권3호
• /
• pp.217-224
• /
• 2022

본 연구는 광주광역시와 전라남도 여수시의 담수환경으로부터 야생효모를 분리하여 특성 분석을 하였다. 분리된 효모의 동정을 위하여 26S rDNA의 D1/D2부위염기서열을이용하였다. 결과적으로 Apiotrichum chiropterorum (NNIBRFG36995), A. domesticum (NNIBRFG32938), A. dulcitum (NNIBRFG33144), A. laibachii(NNIBRFG36991), S. quercus (NNIBRFG33183), Tausonia pullulans (NNIBRFG33181)등 6종의 야생효모들을 동정하였다. 이들 6종의 효모는 국내에 기록된 바가 없으며, 본 논문이 최초보고이다. 미기록 효모 모두 PD, YM 배지에서 잘 자랐으며, 15-30℃ 온도 범위에서 생육하였다. A. domesticum (NNIBRFG32938), A. laibachii (NNIBRFG36991), Tausonia pullulans (NNIBRFG33181) 균주들은 20% glucose를 함유한 YPD 배지에서 생육하는 내당성을 보였으며A. domesticum (NNIBRFG32938)과 A. laibachii (NNIBRFG36991)는 5% NaCl을 함유한 YPD 배지에서도 생육하여 내염성을 가졌다.

• 한국균학회지
• /
• 제50권1호
• /
• pp.31-40
• /
• 2022

비병원성 야생효모로부터 대장에서의 독성물질 활성화에 관여하여 대장암을 유발시키는 효소 중의 하나인 β-glucuronidase를 저해하는 물질을 생산하기 위하여 대전광역시 월평공원으로부터 분리 동정한 야생효모들 중 비병원성 야생효모들을 선별하여 배양 상등액과 무세포 추출물을 각각 제조한 후 β-glucuronidase 저해활성을 측정하였다. 133균주의 비병원성 야생효모들 중 C. oleophila WP5-19-1의 무세포추출물이 49.0%의 가장 높은 저해활성을 보여 우수 균주로 최종 선발하였다. β-Glucuronidase 저해물질 최적 생산 조건은 C. oleophila WP5-19-1를 초기 pH를 6.0으로 조정한 dextrose 5% 함유한 potato dextrose 배지에 접종하여 30℃에서 24시간 배양하였을 때였고 이때 IC₅₀값; 8.4 mg으로 가장 높은 저해활성을 보였다. C. oleophila WP5-19-1의 β-glucuronidase 저해물질을 한외여과와 Sephadex G-50으로 gel 여과를 실시하여 부분 정제하였고 이들은 30-60℃, pH 6.0-9.0에서 80% 이상의 잔존 저해활성을 보여 안정하였다. 또한 철, 구리, 아연과 같은 중금속 이온들은 저해활성을 활성화시켰다.

• Journal of Microbiology and Biotechnology
• /
• 제30권12호
• /
• pp.1876-1884
• /
• 2020

Ethanol often accumulates during the process of wine fermentation, and mitophagy has critical role in ethanol output. However, the relationship between mitophagy and ethanol stress is still unclear. In this study, the expression of ATG11 and ATG32 genes exposed to ethanol stress was accessed by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR). The result indicated that ethanol stress induced expression of the ATG11 and ATG32 genes. The colony sizes and the alcohol yield of atg11 and atg32 were also smaller and lower than those of wild type strain under ethanol whereas the mortality of mutants is higher. Furthermore, compared with wild type, the membrane integrity and the mitochondrial membrane potential of atg11 and atg32 exhibited greater damage following ethanol stress. In addition, a greater proportion of mutant cells were arrested at the G1/G0 cell cycle. There was more aggregation of peroxide hydrogen (H2O2) and superoxide anion (O2•-) in mutants. These changes in H2O2 and O2•- in yeasts were altered by reductants or inhibitors of scavenging enzyme by means of regulating the expression of ATG11 and ATG32 genes. Inhibitors of the mitochondrial electron transport chain (mtETC) also increased production of H2O2 and O2•- by enhancing expression of the ATG11 and ATG32 genes. Further results showed that activator or inhibitor of autophagy also activated or inhibited mitophagy by altering production of H2O2 and O2•. Therefore, ethanol stress induces mitophagy which improves yeast the tolerance to ethanol and the level of mitophagy during ethanol stress is regulated by ROS derived from mtETC.

• 한국미생물·생명공학회지
• /
• 제27권3호
• /
• pp.236-245
• /
• 1999

Andong Soju is a Korean traditional distilled liquor brewed with Nuruk which is cultured with wild microorganisms. To provide useful information for scientific production and systematic quality control of traditional distilled liquor, the effects of mixed culture of the alcoholic yeasts and saccharifying molds isolated from the Nuruk, and mashes on the flavor and sensory characteristics were investigated. Distillate from mashes cocultured with Saccharomyces cerevisiae and Hansenula anomala using Mucor Nuruk was compared with distillate from mashes brewed with Andong Nuruk and with distillate from plant fermented mashes to analyze their flavor characteristics. The volatile flavor compounds in distillates were analyzed by GC and GC-MS using direct injection, solvent extraction, and purge & trap methods. Alcohols such as 3-methyl-1-butanol, 2-methyl-1-propanol, 1-propanol, and 2-phenyl ethanol; aldehydes such as acetaldehyde and 2-furancar-boxaldehyde; esters such as ethyl ester of acetic acid, hexanoic acid, octanoic acid, decanoic acid; alkanes, alkenes, ketone, sulfur, and pyrone compounds were detected. Alcohols were chief components of flavor compounds. No significant difference in overall acceptability test was shown among three experimental groups(p<0.05), but Nuruk-like aroma, Kaoliangchiew-like aroma, sweet taste, and well rounded mouthfeel showed significant differences among them(p<0.05).

• 한국균학회소식:학술대회논문집
• /
• 한국균학회 2015년도 추계학술대회 및 정기총회
• /
• pp.39-39
• /
• 2015

Korean traditional Nuruk has been developed with various materials and shapes according to geographical environments and climates of their origins. Nuruk is also known as kokja in Korea, reflecting the understanding that microorganisms such as wild fungi, yeasts, and lactobacillus bacteria are naturally inoculated and reproduced. The objective of this study is to identify the characteristics of traditional Nuruk through recreating traditional production methods detailed in ancient Korean documents. In the present study, a total of 58 different kinds of Korean traditional Nuruk were prepared, including 46 kinds of recreated products. Each Nuruk sample was evaluated for its enzymatic activities, including glucoamylase, protease, and glucanase. Their suitability for alcoholic beverage production were compared to each other. To isolate valuable microorganisms from Nuruk samples, alcoholic beverages produced using each sample were subjected to sensory evaluation to determine their taste. In addition, metabolite changes in traditional alcoholic beverages fermented with different kinds of Nuruk were analyzed through mass-based metabolomics approach. This study presents, for the first time, the traditional production methods written in ancient Korean documents using workable production methods supported by modern technologies. In addition, this study analyzed the characteristics of reproduced Nuruk. It could be utilized as a basis for studying traditional Korean traditional alcoholic beverages and their valuable microorganisms.

• 미생물학회지
• /
• 제27권4호
• /
• pp.415-421
• /
• 1989

Ten strains out of about 1,000 yeast strains isolated from byproducts of alcoholic industries, milk products, fruits, greens, food-related industries and soils of nature, revealed the killer activities. Two strains which have excellent killer activities among them were isolated and identified with Saccharomyces cerevisiae B 15-1 and Hansenula anomala Y 33 by investigation of the morphological, cultural and physiological properties. The optimal conditions on these strains for the production of killer toxin were investigated. The strain B 15-1 showed the highest killer toxin activities when it was cultured up to the log phase of 48 hr in YPD medium (pH 4.7) at $25^{\circ}C$. On the other hand, the strain Y33 revealed the highest activities when it was cultured up to the stationary phase of 60 hr in YPD medium (pH 4.0) at $20^{\circ}C$. The sensitive strain Kyokai 7 was found to be killed entirely by the killer toxin produced from the wild killer yeast B 15-1 when B 15-1 was cocultured with the same cell concentration ($10^{6}$ cells/ml) of Kyokai 7 after cultivation of 36 hr, and with large concentration ($9\times 10^{7}$ cells/ml) after 48 hr.

• Journal of Microbiology and Biotechnology
• /
• 제9권5호
• /
• pp.679-682
• /
• 1999

When the human parathyroid hormone (hPTH) is expressed as a secretory product in S. cerevisiae, most of the secreted hPTH is internally cleaved by endoproteolytic processing. To investigate whether the yeast endoproteases such as Kex2p, Yap3p, and Mkc7p are involved in the endoproteolytic processing of hPTH in S. cerevisiae, hPTH was expressed in S. cerevisiae mutants deficient in one or two of the following well-known endoproteases such as Kex2p, Mkc7p, and Yap3p. Among these mutants, the yap3-disrupted(yap3$\Delta$) and yap3/mkc7-disrupted (yap3Δmkc7$\Delta$) yeasts showed a significant reduction in the extent of hPTH proteolysis. In contrast, the mkc7-disrupted (mkc7$\Delta$) yeast did not reduce the proteolysis of hPTH as compared to the wild type. This suggests that Mkc7p is not involved in the endoproteolytic processing of hPTH. It was also found that the kex2-disrupted (kex2$\Delta$) mutant was not able to secrete a detectable amount of hPTH.

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

• 한국식품과학회지
• /
• 제42권5호
• /
• pp.549-553
• /
• 2010

본 연구에서는 다양한 효모 배양액을 자가소화 시킨 후 관능검사를 통해 1차적으로 8종(S. cerevisiae 3종, C. utilis 4종 및 Z.rouxii 1종)을 선별하였다. 이 중 정미성과 균체 성장율을 고려하여 C. utilis인 SEM-Y8을 선정하여 고글루타치온 생산을 위한 균주 개량을 수행하였다. 두 번의 UV 처리를 통해 SEM-Y8보다 글루타치온 생성능이 2.0배 증가된 SY8-M2-1 개량 효모 균주를 얻었으며, 선택배지(4.0% yeast extract, 1.5% glucose, 0.04% $NH_4H_2PO_4$, 0.04% L-cystein)를 사용함으로써 글루타치온 함량을 1.5배 더 향상시킬 수 있었다. 이상의 조건에서 얻어진 고글루타치온 함유 효모추출물은 마늘과 양파엑기스보다 우수한 감칠맛과 부드럽고 깊은 맛을 나타내었으며, SEM-Y8 대비 3.2배 향상된 라디컬 소거능을 나타내었다.