• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1242-1251
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• 2016

The ethanol production of Trichoderma reesei was improved by genome shuffling in our previous work. Using RNA-Seq, the transcriptomes of T. reesei wild-type CICC40360 and recombinant strain HJ48 were compared under fermentation conditions. Based on this analysis, we defined a set of T. reesei genes involved in ethanol production. Further expression analysis identified a series of glycolysis enzymes, which are upregulated in the recombinant strain HJ48 under fermentation conditions. The differentially expressed genes were further validated by qPCR. The present study will be helpful for future studies on ethanol fermentation as well as the roles of the involved genes. This research reveals several major differences in metabolic pathways between recombinant strain HJ48 and wild-type CICC40360, which relates to the higher ethanol production on the former, and their further research could promote the development of techniques for increasing ethanol production.

• 한국식품과학회지
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• 제23권2호
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• pp.161-166
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• 1991

미생물을 이용한 유용물질 생산연구의 일환으로 토양으로부터 생물고분자 생산균주를 분리하고, 이 분리균에 대한 균학적 성질 및 생성 생물고분자의 이화학적 성상을 검토하였다. 분리균주는 Bacillus속의 한 균종으로 동정 하였으며, 알칼리 내성균주의 특징을 나타내었다. 이 균주로부터 생성된 생물고분자는 성분분석, 정색반응 및 I.R. spectrum 분석결과 단백질 함량이 높고, 일부 amino sugar가 존재하나 uronic acid는 함유하지 않았다. 그러나 cetyl pyridinium chloride에는 침전되어 산성의 생물고분자인 것으로 추정되었다.

• Journal of Microbiology and Biotechnology
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• 제23권7호
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• pp.959-965
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• 2013

Monascus species have been used to produce fermented rice called Monascus-fermented rice (MFR). To improve a Monascus strain via activation of secondary metabolite (SM) gene clusters for use in the production of MFR, we overexpressed an ortholog of the laeA gene, which encodes a global positive regulator of secondary metabolism under the control of the strong heterologous Aspergillus nidulans alcA promoter in Monascus pilosus. The OE::laeA transformant produced more SMs, including those not detected under uninduced conditions. MFR produced using the M. pilosus OE::laeA strain contained 4 times more monacolin K, a cholesterol-lowering agent, than MFR produced using the wild-type strain. In addition, pigment production was remarkably increased, and the antioxidant activity was increased as well. The results from this study suggest that Monascus species, which are important industrial fermentative fungi in Asia, can be improved for the production of functional foods by overexpressing the laeA gene.

• 미생물학회지
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• 제54권4호
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• pp.453-455
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• 2018

된장으로부터 콩발효 종균후보 Bacillus licheniformis 0DA23-1가 분리되었다. 0DA23-1 균주는 GC 함량 45.96%, 약 4.4 Mb 크기의 단일 chromosome을 보유하고 있었고, 식중독균 Bacillus cereus 및 Staphylococcus aureus가 보유한 위해성 유전자는 유전체로부터 확인되지 않았다. 또한, 8종의 항생물질(chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, tetracycline, vancomycin) 저항성 및 혈청분해 활성, 바이오필름 생성 관련 유전자도 확인되지 않았다.

• 한국식품과학회지
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• 제28권1호
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• pp.137-145
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• 1996

기업적으로 생산하는 공장의 김치를 시료로 하여 5, 15, $25^{\circ}C$에서 발효하면서 화학적 성분과 함께 젖산균과 효모의 변화를 관찰하였다. 발효온도에 따른 숙성김치의 적정 pH인 4.2에 도달하는 시간은 $25^{\circ}C$의 경우 2일, $15^{\circ}C$의 경우 3일, $5^{\circ}C$의 경우 23일 소요되었다. 젖산량으로 산출한 최적 산도는 pH와 정확하게 일치하지는 않았다. 총균수는 발효온도 $25^{\circ}C$의 경우 2일, $15^{\circ}C$는 6일, $5^{\circ}C$는 12일에 최고 수준에 달하였다. 김치 발효동안 동정된 Lactobacilli 종은 L. brevis, L. plantarum, L. acidophilus와 3종의 미확인 균종이었다. L. brevis, L. plantarum은 $15^{\circ}C$, $25^{\circ}C$ 발효 온도에서 발효 시작에서부터 종결까지 일정수준을 유지하면서 나타났다. Leuconostoc종은 L. mesenteroides subsp. mesenteroides로 동정되었다. L. mesenteroides subsp. mesenteroides는 발효 초기에는 균수가 증가하였다가 모든 발효온도에서 발효 후기에는 급격하게 감소하였다. Pediococcus종은 P. pentosaceus와 1종의 미확인종으로 밝혀졌으며 발효 초기에는 증가하였다가 후에 감소하였다. 발효 중기에 나타난 Streptococcus faecium subsp. casseliflavus와 Aerococcus viridans 또한 김치 발효중에 동정된 균이다. Crytococcus laurenti는 모든 발효온도에서 동정되었고 발효초기에 나타난 후 사라졌다가 $25^{\circ}C$ 발효온도에서만 10일 후에 다시 나타났다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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• pp.185-188
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• 2003

The possible inhibitory effect of wood hydrolyzate in lactic acid fermentation was partially decreased by adaptation of Enterococcus faecalis RKY1 to wood hydrolyzate-based medium. The strain RKY1 grown on wood hydrolyzate-based medium was tolerant to wood hydrolyzate medium with fermentation efficiency being improved to approximately 20% higher than that obtained with the strain RKY1 grown on glucose-based medium.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.338-342
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• 1994

The bacterium producing EPA was isolated from the intestines of the marine fishes. The strains were studied for their identification and their culture conditions. The selected strain was gram negative, rod(0.7 $\times$ 2.4 $\mu m$ in size) and motile with a single polar flagellum. This strain was identified as a Pseudomonas sp. on the basis of its morphological, cultural and physiological characteristics. The strain showed a maximum productivity of phospholipid at $20^{\circ}C$ after 48 hours of culture time with an initia1 pH of 7.0 in the PYM-glucose medium. Under these culture conditions, the production of phospholipid was about 0.3 mg/ml and 0.06 mg/mg dry cell weight.

• KSBB Journal
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• 제9권4호
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• pp.378-384
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• 1994

KRF-OOI의 대량생산에 관한 연구를 수행하여 산 업화연구에 연결할 수 있는 자외선을 이용한 변이주 개발을 통해 모균주보다 약 2배 이상의 생산능이 높 은 lN4균주를 개발하였으며, 또한 10배까지 scale up한 발효를 통해 안정된 돌연변이주염을 확인할 수 있었다. HPLC를 이용한 KRF -001의 정성정량분석 방법을 개발함으로써 발효 중 harvest 시기를 정확 히 결정할 수 있였으며 대량발효에 따른 대량 분리 정제 방법의 전략을 수립할 수 있었다.

• 한국식품영양학회지
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• 제12권1호
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• pp.1-6
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• 1999

The strain isolated for making chungkuk-jang was Bacillus subtilis which formed sport with 98% ratio. Logarithmical culture was inoculated(1,000 CF/g) to the steamed soybeans and at th optimum fer-mentation conditions(4$0^{\circ}C$, RH 90%) fermentation progressed very rapidly and synchronously. Fermen-tation time was 24 hours on the optimum fermentation conditions. During activated fermentation chun-gkuk-jang's aroma and flavor created. After finishing the fermentation the spore forming ratio was 95% and replenishment was not occured easily during aging at the below 5$^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• 제3권2호
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• pp.95-98
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• 1993

This study was carried out to isolate and characterize the mutant strains of Schwanniomyces castellii NRRL Y-2477. Mutants were prepared with the treatment of ethyl methane sulfonate. 2-deoxy-D-glucose resistant mutants were isolated and two mutants were selected based on their high production of amylolytic enzymes and their ability to ferment starch. The mutants selected had higher a-amylase and glucoamylase activities than the wild type strain from several other carbon sources. Especially, it was revealed that mutant strain M-9, when cultured in the presence of glucose as a sole carbon source, shows relatively high activities of a-amylase and glucoamylase compared to those of the wild type strain. In result, this mutant strain can be considered as a constitutive producer of amylolytic enzymes. To compare the ethanol production ability of wild type strain and of mutant strains selected, an alcohol fermentation was carried out using 100 g/l soluble starch. Mutant strain M-9 did not improve the direct alcohol fermentation of starch, despite its excellent amylolytic activities performance. On the other hand, mutant strain M-6 produced 37.9 g/l (4.8%, v/v) ethanol by utilizing about 82% of substrate.