• 미생물학회지
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• 제49권2호
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• pp.195-199
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• 2013

멧돼지 대장에서 MPL-01 균주를 분리하여 균주의 형태학적, 생리 생화적 특성 및 지방산 조성을 분석하여 Bacillus임을 확인하였다. 16S rRNA 유전자 서열 분석 결과 MPL-01 균주는 Bacillus atrophaeus와 거의 일치하므로(99.99%) B. atrophaeus MPL-01로 명명하였다. MPL-01 균주는 고추 탄저병을 일으키는 Colletotrichum acutatum에 대하여 가장 강한 항진균 활성을 나타내었다. 배양액의 ethyl acetate 추출액에서 항진균 활성은 물론이고 계면활성도 확인하였다. 그러므로 B. atrophaeus MPL-01은 농작물 병원성 곰팡이 제어를 위한 bio-control 개발에서 유용하게 사용될 것이다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.195-198
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• 2000

Production of eight avermectin components was improved in Streptomyces avermitilis wild type strain (ATCC31267) and high producing mutant strain (ATCC31780) when transformed with a foreign regulatory gene, afsR2 of Streptomyces lividans. Wild type and the high producing strain of S. avermitilis transformed with multiple copies of afsR2 improved total avermectin productions by 2.3 fold and 1.5 fold, respectively. In both of wild type and the high producing transformants carrying afsR2, glycerol was proved to be the best carbon source for the stimulation of avermectin production.

• 대한수의학회지
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• 제39권5호
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• pp.896-907
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• 1999

The morphometrical characteristics such as external measurements and mandible size assessment in mice and rats have to be highly heritable and sufficiently variable between strains in order to calculate a strain specific profiles. The coat color of Korean wild rats were observed and morphometric analysis of external measurements were carried out on Korean wild rats compared to laboratory strains in order to clarify the genetic characteristics of Korean wild rats and to establish background data as a domestication of Korean wild rats for new laboratory strain. Korean wild rats were captured from Chunchon and Hoengsong. 4 inbred and 1 outbred strains of rats were used in this study for the comparison of genetic characteristic of Korean wild rats. Total body length, head length, tail length, hind foot length and ear length were measured and then statistical analysis were carried out by discrimiant analysis. The coat color of Korean wild rat showed golden white in ventral portion and dark agouti in dorsal portion. Korean wild rats could be distinguished from the other laboratory strains distinctly by morphogenetical analysis. There was significant variations among Korean wild rat compared to those of the other laboratory strains of rat. This study may provide that Korean wild rats have a unique genetic characterization compared to those of other inbred strains of rats based on morphogenetical characteristics by external measurements.

• KSBB Journal
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• 제17권3호
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• pp.290-294
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• 2002

경제적으로 에리스리톨을 대량 생산하기 위해 Moniliella suaveolens var. nigra의 wild type을 mutation시켜 변이주를 선별하였다. 선별된 변이주는 400 g/L 포도당배지 플라스크 배양에서 에리스리톨 172 g/L, 글리세롤 20 g/L를 생산하였는데 wild-type의 배양결과와 비교하면 에리스리롤의 생산성은 비슷하고 부산물인 글리세롤의 생성은 50% 적다. 변이주는 wild type 배양시 발생하는 다량의 foam을 적게 발생시킴이 관찰되었다. 배양기 5 L 배양에서 변이주는 에리스리톨의 생산과 부산물 글리세롤의 생성이 wild-type의 것들과 비슷하였다. 이의 원인은 아직 규명되지 않았으나 배양 중 부적절한 산소전달이나 배양 중 발생하는 거품에 세포가 응집하였기 때문인 것으로 추측된다. 균주의 대사를 조사한 결과, 글리세롤은 에리스리톨로 변환되나 에리스리톨은 글리세롤로 변환되지 않음이 관찰되었다. 새로운 고생산성 Moniliella 변이주는 분리.정제 비용이 절감된 순도 놀은 에리스리톨 생성을 가능 하게 할 것이다.

• 미생물학회지
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• 제29권3호
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• pp.160-166
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• 1991

The regulatory mechanism of tubercidin biosynthesis in Streptomyces tubercidicus was studied. In a wild type strain, addition of adenine and histidine into the medium decreased the tubercidin production by 60-65% and 40%, respectively. The effects of adenine and histidine were alleviated by the addition of inosine monophosphate and 5-aminoimidazole-4-carboxamide ribotide. The production of tubercidin in S. tubercidicus K115 strain ($ade^{-}$ ) was nearly shut off by histidine. In contrast with K115 strain, adenine inhibited the tubercidin biosynthesis in S. tubercidicus K412 strain ($his^{-}$. In S. tubercidicus F667 strain ($ade^{-}$ , $his^{-}$ ), tubercidin production was increased by adenine and histidine. From the effects of adenine and histidine on tubercidin biosynthesis in S. tubercidicus wild type and mutant strains, it became known that feedback control by adenine and histidine of biosynthetic pathwat for purine ribonucleotide and histidine are involved in the regulation of tubercidin biosynthesis.

• Mycobiology
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• 제46권4호
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• pp.382-387
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• 2018

The entomopathogenic fungus Cordyceps militaris is a valuable medicinal ascomycete, which degenerates frequently during subsequent culture. To avoid economic losses during industrialized production, scratching stimuli of mycelia was introduced to improve the fruiting body production. The present results indicated that higher yields and biological efficiency were obtained from two degenerate strains (YN1-14 and YN2-7) but not from g38 (an insertional mutant in Rhf1 gene with higher yields and shorter growth periods). Furthermore, the growth periods of the fruiting bodies were at least 5 days earlier when the mycelia were scratched before stromata differentiation. Three ROS-scavenging genes including Cu/Zn superoxide dismutase (CmSod1), Glutathione peroxidase (CmGpx), and Catalase A (CmCat A) were isolated and their expression profiles against scratching were determined in degenerate strain YN1-14 and mutant strain g38. At day 5 after scratching, the expression level of CmGpx significantly decreased for strain g38, but that of CmSod1 significantly increased for YN1-14. These results indicated that scratching is an effective way to promote fruiting body production of degenerate strain, which may be related at least with Rhf1 and active oxygen scavenging genes.

• The Plant Pathology Journal
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• 제30권2호
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• pp.215-219
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• 2014

The GacS/GacA two component system regulates various traits related to the biocontrol potential of plant-associated pseudomonads. The role of the sensor kinase, GacS, differs between strains in regulation of motility. In this study, we determined how a gacS mutation changed cell morphology and motility in Pseudomonas chlororaphis O6. The gacS mutant cells were elongated in stationary-phase compared to the wild type and the complemented gacS mutant, but cells did not differ in length in logarithmic phase. The gacS mutant had a two-fold increase in the number of flagella compared with the wild type strain; flagella number was restored to that of the wild type in the complemented gacS mutant. The more highly flagellated gacS mutant cells had greater swimming motilities than that of the wild type strain. Enhanced flagella formation in the gacS mutant correlated with increased expression of three genes, fleQ, fliQ and flhF, involved in flagellar formation. Expression of these genes in the complemented gacS mutant was similar to that of the wild type. These findings show that this root-colonizing pseudomonad adjusts flagella formation and cell morphology in stationary-phase using GacS as a major regulator.

• 생명과학회지
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• 제7권3호
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• pp.180-185
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• 1997

Methylelaiophylin은 gram양성균에 대하여 광범위한 항균활성을 보이며, 특히Bacillus subtilis에서 superoxide redicals을 발생하여 항균활성을 나타낸다. B. subtilis에 대한 항균활성은 wild type strain보다 mutant strain인 rec$^{-}$에 대하여 더민감하며, 이러한 항균력은 항산화제인 dithiothreito에 의하여 현저히 감소되었다. 또한 항균력은 세포내 RNA합성보다 DN합성에 효과적으로 작용하였다. 이러한 결과들은 methylelaiophylin의 항균활성이 세포내에서 발생한 활성산소에 의하여 기인한 것임을 나타낸다.

• Mycobiology
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• 제51권1호
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• pp.26-35
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• 2023

The diversity of A mating type in wild strains of Lentinula edodes was extensively analyzed to characterize and utilize them for developing new cultivars. One hundred twenty-three A mating type alleles, including 67 newly discovered alleles, were identified from 106 wild strains collected for the past four decades in Korea. Based on previous studies and current findings, a total of 130 A mating type alleles have been found, 124 of which were discovered from wild strains, indicating the hyper-variability of A mating type alleles of L. edodes. About half of the A mating type alleles in wild strains were found in more than two strains, whereas the other half of the alleles were found in only one strain. About 90% of A mating type combinations in dikaryotic wild strains showed a single occurrence. Geographically, diverse A mating type alleles were intensively located in the central region of the Korean peninsula, whereas only allele A17 was observed throughout Korea. We also found the conservation of the TCCCAC motif in addition to the previously reported motifs, including ATTGT, ACAAT, and GCGGAG, in the intergenic regions of A mating loci. Sequence comparison among some alleles indicated that accumulated mutation and recombination would contribute to the diversification of A mating type alleles in L. edodes. Our data support the rapid evolution of A mating locus in L. edodes, and would help to understand the characteristics of A mating loci of wild strains in Korea and help to utilize them for developing new cultivars.

• 한국미생물·생명공학회지
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• 제28권2호
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• pp.63-70
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• 2000

To determine an increased acid tolerance of an adipic acid-resistant mutant Leuconostoc mesenteroides(ANaM100) developed for use as a Kimchi starter, proton permeability of cytoplasm, activities of H+-ATPase, Mg++ release and fatty acid composition of cytoplasmic membranes of strain ANaM100 were studied and compared with those of its wild type (LMw). The value of protons permeability of LMw after an acid shock at pH 5.0 was 5.4 min., while the value of ANaM100 cells was 8.4 min. at the same pH. The pH of maximal specific activ-ities of ATPase originated from the LMw and ANaM100 were 0.87 unit/mg protein at pH 6.0 and 0.92 unit/mg pro-tein at pH 5.5, respectively. The release of magnesium ion from ANaM100 was observed about 12.8% at pH 4 after 2 hours, while the wild strains of LMw released Mg++ about 27.6% under the same conditions. The content of C19:0,cyclo and C18:1 in a membrane fatty acid of ANaM100 was higher and lower, respectively than that of LMw. These results indicated that acid tolerance of adipic acid-resistant strain, ANaM100 was significantly improved in comparison with that of its wild type, LMw. In addition, the strain ANaM100 was adipic resistance based on the result of growth of the strain in comparison with that of strain LMw in a broth containing adipic acid.