• Journal of Microbiology and Biotechnology
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• 제31권12호
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• pp.1722-1731
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• 2021

The genus Streptomyces is intensively studied due to its excellent ability to produce secondary metabolites with diverse bioactivities. In particular, adequate precursors of secondary metabolites as well as sophisticated post modification systems make some high-yield industrial strains of Streptomyces the promising chassis for the heterologous production of natural products. However, lack of efficient genetic tools for the manipulation of industrial strains, especially the episomal vector independent tools suitable for large DNA fragment deletion, makes it difficult to remold the metabolic pathways and streamline the genomes in these strains. In this respect, we developed an efficient deletion system independent of the episomal vector for large DNA fragment deletion. Based on this system, four large segments of DNA, ranging in length from 10 kb to 200 kb, were knocked out successfully from three industrial Streptomyces strains without any marker left. Notably, compared to the classical deletion system used in Streptomyces, this deletion system takes about 25% less time in our cases. This work provides a very effective tool for further genetic engineering of the industrial Streptomyces.

• 산업기술연구
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• 제2권
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• pp.21-25
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• 1982

This study was to investigate the basic research about Adriamycin production from Streptomyces peucetius var. caesius. Streptococcus pyogenes(YUFE 2204) was sensitive against Adriamycin and its MIC value was $3.125{\mu}g/ml$. Several mutants were isolated by UV-light. Among 325 mutants, Streptomyces peucetius var. caesius YS-107 was showed highest productivity of Adriamycin.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2001년도 춘계학술대회 발표논문집
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• pp.292-294
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• 2001

Cystocin을 생산하는 Streptomyces sp GCA0001균주를 screenig하였으며, Streptomyces sp GCA0001를 배양하고 분리 정제를 통하여 흰색 분말의 Cystocin을 얻을 수 있었다. Cystocin은 Streptomyces alboniger에서 생산되는 Puromycin과 매우 유사한 구조의 항생물질로 확인되었다. Cystocin은 Puromycin과 마찬가지로 단백질 합성시 폴리펩티드 사슬의 elongation을 조기 종결함으로써 생체내에서 항박테리아, 항종양 및 항바이러스 활성을 나타낸다

• Journal of Microbiology and Biotechnology
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• 제29권5호
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• pp.667-686
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• 2019

Streptomyces are attractive microbial cell factories that have industrial capability to produce a wide array of bioactive secondary metabolites. However, the genetic potential of the Streptomyces species has not been fully utilized because most of their secondary metabolite biosynthetic gene clusters (SM-BGCs) are silent under laboratory culture conditions. In an effort to activate SM-BGCs encoded in Streptomyces genomes, synthetic biology has emerged as a robust strategy to understand, design, and engineer the biosynthetic capability of Streptomyces secondary metabolites. In this regard, diverse synthetic biology tools have been developed for Streptomyces species with technical advances in DNA synthesis, sequencing, and editing. Here, we review recent progress in the development of synthetic biology tools for the production of novel secondary metabolites in Streptomyces, including genomic elements and genome engineering tools for Streptomyces, the heterologous gene expression strategy of designed biosynthetic gene clusters in the Streptomyces chassis strain, and future directions to expand diversity of novel secondary metabolites.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1672-1676
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• 2010

The Actinomycete strain KH29 is antagonistic to the multidrug-resistant Acinetobacter baumannii. Based on the diaminopimelic acid (DAP) type, and the morphological and physiological characteristics observed through the use of scanning electron microscopy (SEM), KH29 was confirmed as belonging to the genus Streptomyces. By way of its noted 16S rDNA nucleotide sequences, KH29 was found to have a relationship with Streptomyces cinnamonensis. The production of an antibiotic from this strain was found to be most favorable when cultured with glucose, polypeptone, and yeast extract (PY) medium for 6 days at $27^{\circ}C$. The antibiotic produced was identified, through comparisons with reported spectral data including MS and NMR as a cyclo(L-tryptophanyl-L-tryptophanyl). Cyclo(L-Trp-L-Trp), from the PY cultures of KH29, was seen to be highly effective against 41 of 49 multidrug-resistant Acinetobacter baumannii. Furthermore, cyclo(L-Trp-L-Trp) had antimicrobial activity against Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus, Saccharomyces cerevisiae, Aspergillus niger, and Candida albicans, However, it was ineffective against Streptomyces murinus.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.82-85
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• 2005

Doxorubicin is a highly-valuable anthracycline-family polyketide drug with a very potent anticancer activity, typically produced by a Gram-positive soil bacterium called Streptomyces peucetius. Thanks to the recent development of Streptomyces genomics-based technologies, the random mutagenesis approach for Streptomyces strain improvement has been switched toward the genomics-based technologies including the application of DNA microarray systems. In order to identify and characterize the genomics-driven potential target genes critical for doxorubincin overproduction, three different types of doxorubicin overproducing strains, a dnrI(doxorubicin-specific positive regulatory gene)-overexpressor, a doxA (gene involved in the conversion from daunorubicin to doxorubicin)-overexpressor, and a recursively-mutated industrial strain, were generated and examined their genomic transcription profiles using Streptomyces DNA microarray systems. The DNA microarray results revealed several potential target genes in S. peucetius genome, whose expressions were significantly either up- or down-regulated comparing with the wild-type strain. A systematic understanding of doxorubicin overproduction at the genomic level presented in this research should lead us a rational design of molecular genetic strain improvement strategy.

• 한국미생물·생명공학회지
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• 제40권1호
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• pp.10-16
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• 2012

방선균 Streptomyces peucetius OIM ($\underline{O}$verproducing $\underline{I}$ndustrial $\underline{M}$utant)은 반복적인 돌연변이를 통하여 폴리케타이드 항생제인 독소루비신(DXR)의 생산성이 최적화 된 고생산성 산업균주이다. 이 S. peucetius OIM 변이종을 대리의 숙주로 이용하여, 생합경로 크기가 작은 모델 폴리케타이드인 알로에사포나린 II(액티노로딘의 합성경로 유도체)의 생합성 유전자군을 고복제수 플라스미드에 클로닝하여 알로에사포나린 II의 기능적 발현을 확인하여 정량분석을 수행하였다. OIM 균주의 알로에사포나린 II의 생산량은 조절 네트워크가 극대화된 S. coelicolor 변이종 뿐만 아니라 야생형S. peucetius 보다 매우 높은 수준으로 생산되는 것으로 확인되었다. 또한 알로에사포나린 II의 생산 수준은 다운-조절자 $wblA_{spe}$가 제거된 S. peucetius OIM 균주에서 가장 높은것으로 측정되었으며, 이는 합리적으로 유전체를 재설계한 S. peucetius OIM 변이종 균주가 이종의 폴리케타이드 생합성을 높은 수준으로 발현할 수 있는 대리의 숙주로서 충분히 활용 가능함을 보여준다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2001년도 춘계학술대회 발표논문집
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• pp.295-297
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• 2001

본 발명의 Puromycin 유도체인 Cystocin 화합물은 유기 합성에 의해 제조된 물질이 아니라 방선균 계열의 신균주인 Streptamyces sp GCA0001로부터 추출된 신규 물질로서, 항박테리아, 항종양 및 항바이러스 활성 등의 생물학적 미생물 활성면에서 종래의 Puromycin 화합물에 비해 현저히 뛰어난 효과를 지니고 있고 Streptomyces sp GCA0001로부터 추출, 분리 및 정제 과정을 통해 제조된 자연의 선택의 과정을 거친 화합물이므로, Puromycin을 대체할 수 있는 획기적인 물질로 볼 수 있다.

• KSBB Journal
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• 제18권4호
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• pp.289-293
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• 2003

독소루비신 고 생산성 산업균주인 BR-Dox의 충분한 양의 세포를 얻어내기 위해 R2YE 배지를 사용하였으며, 방선균의 포자형성이 잘 일어나는 R2YE 배지의 각 성분별로 첨가한 결과, CaCO$_3$를 첨가하였을 때 인위적인 원형질체 유도에 적합한 양의 세포를 얻어낼 수 있었다. 독소루비신 생합성 능력이 향상된 균주를 선별하기 위해 BR-Dox를 배양하여 세포를 인위적으로 원형질체로 유도하여 세포벽을 재생시킨 결과, 특이적으로 독소루비신 색소로 추정되는 붉은 색을 많이 내는 콜로니를 선별하여 정성 및 정량분석을 수행하였다. 선별된 파생균주 BR-Dox4와 BR-Dox6의 경우 TLC 정성분석 및 HPLC 정량분석 결과, BR-Dox에 비해 각각 25.2%, 12.2%의 생산성이 향상되었다. 본 연구결과는 인위적 원형질체 도입과 세포벽 재생을 통한 새로운 개념의 방선균 균주개량 방법을 제시하고, 이를 이용한 독소루비신 고생산성 균주개발의 가능성을 제시하였다.

• Journal of Applied Biological Chemistry
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• 제56권2호
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• pp.119-129
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• 2013

Thirteen different Streptomyces isolates were evaluated for their ability to produce keratinase using chicken feather as a sole carbon and nitrogen sources under solid state fermentation (SSF). Streptomyces sp. NRC 13S produced the highest keratinase activity [1,792 U/g fermented substrate (fs)]. The phenotypic characterization and analysis of 16S rDNA sequencing of the isolate were studied. Optimization of SSF medium for keratinase production by the local isolate, Streptomyces sp. NRC13S, was carried out using the one-variable-at-a-time and the statistical approaches. In the first optimization step, the effect of incubation period, initial moisture content, initial pH value of the fermentation medium, and supplementation of some agro-industrial by-products on keratinase production were evaluated. The strain produced about 2,310 U/gfs when it grew on chicken feather with moisture content of 75% (w/w), feather: fodder yeast ratio of 70:30 (w/w), and initial pH 7 using phosphate buffer after 8 days. Based on these results, the Box-Behnken design and response surface methodology were applied to find out the optimal conditions for the enzyme production. The corresponding maximal production of keratinase was about 2,569.38 U/gfs.