• 한국미생물·생명공학회지
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• 제18권6호
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• pp.624-632
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• 1990

새로운 phthalic acid 유도체 및 염기성 마크로라이드 항생물질을 생산하는 strain 88-GT-161은 numerical taxonomic data base에 의거 Streptomyces melanosporofaciens로 동정되었으나, 139 단위 특성 중 4가지 단위에 있어. S.violaceoniger 혹은 S.violaceusniger로 대표되는 cluster No.32에 속하는 6균주의 공통된 특성과 분명히 다른 특성을 나타냈다. 따라서 본 논문에서는 strain 88-GT-161의 분류. 동정학적 특성에 대하여 보고하고자 한다.

• Journal of Microbiology
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• 제45권3호
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• pp.262-267
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• 2007

During a screening program, an actinomycete strain isolated from the Egyptian soil was investigated for its potential to show antimicrobial activity. The identification of this isolate was performed according to spore morphology and cell wall chemo-type, which suggested that this strain is a streptomycete. Further cultural, physiological characteristics and the analysis of the nucleotide sequence of the 16S rRNA gene (1480 bp) of this isolate indicated that this strain is identical to Streptomyces violaceusniger (accession number EF063682) and then designated S. violaceusniger strain HAL64. In its culture supernatant, this organism could produce one major compound strongly inhibits the growth of Gram-positive but the inhibition of Gram-negative indicator bacteria was lower. The antibiotic was separated by silica gel column chromatography and then purified on a sephadex LH-20 column and finally the purity was checked by HPLC. The chemical structure of the purified compound was determined using spectroscopic analyses (molecular formula of $C_{33}H_{32}N_{2}O_{10}$ and molecular weight of 617.21) and found to be identical to the kosinostatin, a quinocycline antibiotic which is known to be produced by Micromonspora sp. TP-A0468 (Igarashi et al., 2002) and to quinocycline B isolated from Streptomyces aureofaciens (Celmer et al., 1958). Although the antibiotic is known, the newly isolated strain was able to produce the antibiotic as a major product providing an important biotechnological downstream advantage.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.96.2-97
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• 2003

More than 1200 microorganisms were isolated from soil samples collected from various sources and localities. Among the isolates, 2 actinomyces (TH-04 and BA313) and 1 Bacillus sp. (CJ3) were selected as antagonists to pepper anthracnose fungus Colletotrichum gloeosporioides. These 3 isolates inhibitied mycelial growth of C gloeosporioides and the inhibition rates were over 70％ on PDA. When the isolates were co-cultured with conidia of C. gloeosporioides in potato dextrose broth, conidial germination was severely inhibited and the inhibition rates of TH-04, BA313, and CJ3 at 24 hours were 75％, 72％, and 68％, respectively. The inhibition rates at n hours incubation were not much different from the rates at 24 hours. To check the activity on the plant, each isolate was mixed with equal volume of conidial suspension of C. gloeosporioides and wound-inoculated on green pepper fruit. After 6 days, the anthracnose lesions on the fruits inoculated with the mixture were much smaller than the lesions caused by the C. gloeosporioides itself. The lesion areas of TH-04 or BA313 treated pepper were less than 30％ of the check. TH-04 and BA313 also showed antagonistic activity to Phytophthora spp. and Botrytis cinerea. By scanning electron microscopy and fatty acid analyses (MIDI), TH-04 and BA313 were identified to Streptomyces halstedii and S. violaceusniger, repectively.

• 생명과학회지
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• 제21권1호
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• pp.96-101
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• 2011

ATP와 L-methionine으로부터 SAM synthetase (MetK)에 의해 생합성 되는 S-adenosylmethionine (SAM)은 세포내 메틸화에 필요한 메틸기를 제공하는 중심적인 공급체의 역할을 할뿐만 아니라 방선균에서는 일차 및 이차대사산물의 생산 조절에 관여하고 있다는 사실이 밝혀졌다. 이에 논 연구에서는 산업적으로 매우 중요한 항진균성 항생물질인 natamycin을 생산하는 S. natalensis로부터 SAM synthetase 코드하는 metK 유전자를 클로닝하고 동정하였다. S. natalensis에서 클로닝된 metK는 1,209 bp의 염기를 가진 유전자로써 아미노산서열에서 S. pristinaespiralis ATCC 25486과 S. peucetius ATCC 27952의 MetK와 96%, S. violaceusniger Tu 4113과 95% 일치하는 매우 높은 상동성을 보였다. 또 pSET152ET 벡터를 이용해 구축한 metK 고발현용 재조합 플라스미드 pCD1를 S. lividans TK24의 genomic DNA에 도입하여 actinorhodin 생산 유도를 시도해 본 결과 R5 고체배지에서 pCD1이 도입되지 않은 균주에서는 actinorhodin 생산을 전혀 확인할 수 없었지만 pCD1이 도입된 형질전환체에서는 actinorhodin 생산이 강하게 유도되었으며 R4 액체배지에서는 actinorhodin 생산량이 10배 증가되었다. 따라서 본 연구를 통해 클로닝된 S. natalensis 유래 metK 유전자는 방선균에서 이차대사산물의 생산을 유도할 수 있음을 확인할 수 있었다.