• 한국식생활문화학회지
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• 제26권2호
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• pp.190-197
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• 2011

Chungtaejeon is a traditional tea introduced in the age of the Three States and is the only "Don-cha" culture in the world that survived on the southwestern shore of Korea. To restore Chungtaejeon and to make the tea with consistent quality, the microorganisms involved in traditional type fermentation of Chungtaejeon were isolated, and the tea was prepared with high fermentation ability starters. The sensuous characteristics of Chungtaejeon were also examined. Only Bacilli were found in 3 and 5 year aged Chungtaejeon samples. The Lactobacilli were isolated from properly fermented kimchi and one of them showed high growth capability in media containing green tea extract and also showed strong antagonistic activity against methicillin-resistant Staphylococcus aureus, S. aureus, Salmonella, and E. coli. It was identified and named Lactobacillus plantarum CHO25. Chungtaejeon was fermented with a single starter of L. plantarum CHO25 and with a mixed starter (L. plantarum CHO25, Saccharomyces cerevisiae and Bacillus amyloliquefaciens CHO104). The single fermented sample had the highest cell growth after 5 days of inoculation and the level decreased slowly thereafter. The mixed fermented sample showed strong growth of S. cerevisiae. The highest hunter values were the a value of the single fermented sample and the b value of the mixed sample. The single fermented tea showed the best incense score.

• 한국식품저장유통학회지
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• 제30권6호
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• pp.1043-1055
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• 2023

본 연구에서는 항산화와 항균 활성 등이 우수한 녹차 잎을 대상으로 관련 물질 회수에 적합한 추출 용매의 농도 설정과 세포벽 분해 효소 처리 및 효모 발효가 활성을 높이는데 도움을 줄 수 있는지 살펴보았다. 입도 약 4-10 ㎛의 녹차 분말을 사용하여 추출물을 제조할 때, 다양한 에탄올 농도 가운데 50% 에탄올을 추출 용매로 하고 가열 처리 (121℃, 15 min)를 진행할 경우 높은 수율과 DPPH 라디칼 소거능 및 항균 활성을 나타내었다. 이 추출물은 B. cereus, B. licheniformis, S. aureus subsp. aureus 및 A. hydrophila subsp. hydrophila 에서 항균 활성을 나타내었다. 녹차 잎 분말에 효소 처리 및 효모 발효 진행 시 최종 녹차 잎 추출물의 항산화와 항균 활성에 미치는 영향을 조사하기 위해, 효소 처리에는 cellulase와 pectinase를 혼합(2.5% + 2.5%)하여 사용하였고, 효모 발효에는 S. cerevisiae 가 사용되었다. 녹차 잎을 효소 처리할 경우 추출물의 수율은 증가되었으나, 50% 에탄올 추출물(대조구)에 비해 항산화와 항균 활성은 유의적으로 감소되었다(p<0.05). 그에 반해 효모 발효를 단독으로 진행할 경우 최종 추출물의 수율 증가는 없었지만, 총페놀화합물과 플라보노이드 함량을 높여 항산화와 항균 활성을 높이는데 긍정적으로 작용하였다.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.479-484
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• 1995

The effect of initial cell concentration on the characteristics of ethanol fermentation was investigated in the batch fermentation of Saccharomyces cerevisiae ATCC 24858. The characteristics were investigated in the range of 60 to 230 g/l of the initial sugar concentrations and 0.5 to 85 g/l of the initial cell concentrations. When the initial cell concentrations were 27 g/l for 60 g/l of the initial sugar and 85 g/l for 230 g/l, the fermentation time required for the complete consumption of the initial sugar was one hour, respectively. The ethanol productivity increased with the initial cell concentration so that, in the case of 100 g/l of initial sugar, the productivity rose up to 55 g/l/hr at 55 g/l of the initial cell concentration. The specific growth rate decreased according to the increase in the initial biomass concentration and finally became zero at around 25 g/l of the cell concentration regardless of the initial sugar concentration. The specific ethanol production rate was constant as 1.02 g/l/hr up to 150 g/l of the initial sugar. However, the rates decreased sharply with the augmentation of concentration of the initial sugar above 160 g/l. The overall ethanol yield represented a constant value, 0.475 g/g irrespective of the initial cell and sugar concentrations. The overall biomass yietd showed a trend to diminish in values with the biomass and ultimately to reach zero more than 25 g/l of the initial cell concentration.

• Journal of Microbiology and Biotechnology
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• 제14권2호
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• pp.243-249
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• 2004

The toxicity of inorganic sulfuric acid as a stressor was characterized in Saccharomyces cerevisiae KNU5377. In this work, we examined physiological responses to low extracellular pH $(pH_{ex})$ caused by inorganic $H_2SO_4$, which could not affect cell growth after pH was adjusted to an optimum with Trizma base. The major toxicity of sulfuric and was found to be reduction of environmental pH, resulting in stimulation of plasma membrane ${H^+}-ATPase$, which in turn contributed to intracellular alkalinization. Using a pH-dependent fluorescence probe, 5-(and-6)-carboxy SNARF-1, acetoxymethyl ester, acetate (carboxy SNARF-1 AM acetate), to determine $pH_{in}$, we found that color was dependent on the changes of intracellular pH which coincided with calculated $pH_{in}$ of alkalinization up to approximately pH 7.3. This alkalinization did not seem to affect survival of these cells exposed to 30 mM sulfuric acid, which lowered the $pH_{ex}$ of the glucose containing growth media up to approximately pH 3.0; however, the cells could grow only up to 70% of the maximum growth in the same media, when 30 mM sulfuric acid was added.

• Journal of Microbiology
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• 제37권4호
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• pp.248-255
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• 1999

We have analyzed the MRE3/REC114 gene of Saccharomyces cerevisiae, previously detected in isolation of mutants defective in meiotic recombination. We cloned the MRE3/REC114 gene by complementation of the meiotic recombination defect and it has been mapped to chormosome XIII. The DNA sequence analysis revealed that the MRE3 gene is identical to the REC114 gene. The upstream region of the MRE3/REC114 gene contains a T_4C site, a URS (upstream repression sequence) and a TR (T-rich) box-like sequence, which reside upstream of many meiotic genes. Coincidentally, northern blot analysis indicated that the three sizes of MRE3/REC114 transcripts, 3.4, 1.4 and 1.2 kb, are induced in meiosis. A less abundant transcript of 1.4 kb is detected in both mitotic and meiotic cells, suggesting that it is needed in mitosis as well as meiosis. To examine the role of the MRE3/REC114 gene, we constructed mre3 disruption mutants. Strains carrying an insertion or null deletion of the MRE3/REC114 gene showed slow growth in nutrient medium and the doubling time of these cells increased approximately by 2-fond compared to the wild-type strain. Moreover, the deletion mutant (${\delta}$mre3) displayed no meiotically induced recombination and no viable spores. The mre3/rec114 spore lethality can be suppressed by spo13, a mutation that causes cells to bypass reductional division. The double-stranded breaks (DSBs) which are involved in initiation of meiotic recombination were not detected in the analysis of meiotic chromosomal DNA from the mre3/rec114 disruptant. From these results we suggest that the MRE3/REC114 gene product is essential in normal growth and in early meiotic stages involved in meiotic recombination.

• 한국미생물·생명공학회지
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• 제30권1호
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• pp.68-72
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• 2002

RNA 함량이 증가되고, 증식속도가 더 빠른 효모 변이주를 선별하기 위해, 모균주 Saccharomyces cerevisiae MTY62 세포에 화학적 돌연변이제인 ethylmethane sulfonate를 처리하여, YPD 배지에서는 잘 자라고 KCl 함유 배지에서는 자라지 않는 변이주들을 선별하였다. 이 변이주들 중 시험관 및 플라스크 배양을 통해 균체농도와 RNA 함량이 모균주 MTY62에 비해 각각 1.5배, 1.3배 증가한 M40-10 변이주를 최종적으로 선별하였다. 변이주 M40-l0을 발효조 회분배양한 결과, 최대비증식속도는 $0.38 h^{-1}$ , RNA 농도는 3210 mg-RNA/1, RNA 함량은 183mg-RNA/g-DCW 값을 보여, 모균주에 비해 각각 23%, 15%, 12%씩 증가하였다. M40-10 변이주를 간헐적 유가배양한 결과, 최대 균체농도는 35.6 g-DCW/1을, 최대 RNA 농도는 5677mg-RNA/l을, RNA함량은 160 mg-RNA/g-DCW을 나타내어 모균주보다 우수하였다. 일정속도의 유가배양에서도 M40-10 변이주의 최대 균체농도는 46.4g-DCW/1, RNA 농도는 6270mg-RNA/1, RNA 함량은 135mg-RNA/g-DCW을 보였다. 이들 유가배양에서 배양 중반기인 20시간 전후에서는 모균주에 비해 변이주의 세포농도는 30%, RNA 농도는 10% 정도 증가되었다. 또한 유가배양 말기까지도 RNA 분해는 거의 일어나지 않아, M40-10 변이주는 산성 RNase 활성이 크게 감소한 변이주임을 알 수 있었다.

• 한국미생물·생명공학회지
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• 제22권5호
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• pp.477-484
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• 1994

Using a methylotrophic yeast Hansenula polymorpha, a heterologous gene expression and secretion system was developed for the production of hEGF(human Epidermal Growth Factor) which has been shown to promote epithelial cell proliferation and to inhibit gastric acid secretion. The hEGF gene was chemically synthesized according to the preferred codon usage in H. polymor- pha and expressed under the control of the strong and inducible methanol oxidase(MOX) promoter. The mating factor $\alpha$ pre-pro leader sequence of Saccharomyces cerevisiae was employed for hEGF to be secreted into the extracellular medium. This expression cassette was stably integrated into the host chromosomal DNA. Mature hEGF was efficiently expressed and secreted into the extracel- lular medium. About 24 mg/l of hEGF was detected in the cuture supernatant of a transformant with pA-EGF3 under the suboptimal culture conditions.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.99-102
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• 2001

본 연구에서는 히루딘을 생산할 수 있는 재조합 S. cerevisiae 에서 ‘히루딘 유전자의 copy number 와 히루딘 발현양과의 관계를 규명하였으며 , ${\delta}$ 서열을 이중으로 사용한 히루딘 발현벡터를 제조하여 히루딘 유전자의 효모염색체로의 도입효율을 증가시켰다. 숙주세포인 효모의 GALl 유전자를 파쇄하여 균체에 의한 갈락토스 소모를 방지하여 보다 경제적으로 히루딘을 생산할 수 있는 시스템을 개발하였으며, 재조합 H. polymorpha을 이용한 발효공정에서 히루딘 생산을 위한 최적의 메탄올 농도를 결정하였다.

• 한국미생물·생명공학회지
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• 제19권4호
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• pp.325-330
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• 1991

섬유성 당화액에서의 ethanol 생산에 적합한 균류를 개발할 목적으로 Candida sp. KM-09-135와 Saccharomyces cerevisiae SM-07의 이속간의 원형질체 융합을 행하여 우수한 융합체로 인정된 KMS-23 균주를 얻었다. 융합주 KMS-23은 37'C에서 생육 및 ethanol 생성능이 가장 좋았고, 발효당으로 xylose, cellobiose, maltose 및 raffinose도 이용하였다. 세포의 크기는 KM-09-135 및 SM-07에 비해 각각 1.2배, 1.5배 증가하였으나 DNA 함량은 약간의 증가만 보여 완전한 2배체의 융합주가 아닌 것으로 나타났다. 환원당으로서 6.44(w/v)의 당을 함유한 밀기울 당화액에서 융합주 KMS-23은 동일조건하에서 KM-09-135보다 약 1.3배 높은 2.57(v/v)의 ethanol을 생산하였다.

• International Journal of Oral Biology
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• 제30권1호
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• pp.17-22
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• 2005

In the previous studies of Saccharomyces cerevisiae, Abp140p (actin binding protein 140) fused to GFP has been only a protein that can label actin cables of yeast cells so far. However, the role of Abp140p in actin dynamics was remained elusive. In this study, the function of Abp140p was investigated with a deletion mutant and overexpression of GFP fused Abp140p. The deletion mutant was slightly more susceptible to Latrunculin-A (Lat-A), an actin-monomer sequestering agent, than wild type, although no significant deformation of actin structures was caused by ABP 140 deletion. Overexpression of Abp140p-GFP retarded cell growth, and produced thick and robust actin cables. Lat-A was not able to destabilize the thick actin cables, which suggests that actin dynamics was compromised in the cells with surplus of Abp140p. Therefore, Abp140p seems to stabilize actin cables together with other bundling proteins. Recently, actin cable dynamics of budding yeast was found to have a resemblance to that of filopodial tip of cultured mammalian cells. Retrograde movement of actin cables from buds to mother cells indicated local generation of the cable at bud sites. By using Abp140p-GFP, we traced the steps in the generation of a new actin cable after elimination of old cables by sodium azide. Before the appearance of a new actin cable, Abp140p-GFP concentrated in buds and disappeared, as mother cells became abundant in actin cables. Our observations provide a direct evidence of actin cable formation at buds of budding cells.