• Journal of Microbiology and Biotechnology
• /
• 제17권4호
• /
• pp.685-690
• /
• 2007

The deoxysugar biosynthetic gene cluster of Sch 47554/Sch 47555 was cloned from Streptomyces sp. SCC-2136. One of the ORFs, schS6, appeared to encode glucose-1-phosphate thymidylyltransferase, which converts dTTP and glucose-1-phosphate to TDP-D-glucose and pyrophosphate. The dTDP-D-glucose is a key metabolite in prokaryotics as a precursor for a large number of modified deoxysugars, and these deoxysugars are a maj or part of various antibiotics, ranging from glycosides to macrolides. SchS6 was expressed in E. coli vector pSCHS6 and the expressed protein was purified to apparent homogeneity by ammonium sulfate precipitation and Ni-NTA affinity column chromatography. The specific activity of the purified enzyme increased 4.7-fold with 17.5% recovery. It migrated as a single band on SDS-PAGE with an apparent molecular mass of 56kDa. The purified protein showed glucose-1-phosphate thymidylyltransferase activity, catalyzing a reversible bimolecular group transfer reaction. In the forward reaction, the highest activity was obtained with combination of dTTP and ${\alpha}-D-glucose-1-phosphate$, and only 12% of that activity was obtained with the substrates $UTP/{\alpha}-D-glucose-1-phosphate$. In the opposite direction, the purified protein was highly specific for dTDP-D-glucose and pyrophosphate.

• 한국연초학회지
• /
• 제20권2호
• /
• pp.172-177
• /
• 1998

The culture filtrate of Streptomyces sp. B25, which was identified in this experiment, was tested for the control of tobacco mosaic virus (TMV) with the susceptible tobacco cultivar, NC 82, under the field conditions following the preliminary examination of its characters for TMV control. Control efficacy of the culture filtrate against TMV infection continued over 50% up to 6 days after treatment, and its systemic effect was about 30% of the direct effect. In field conditions control efficacy of the culture filtrate against TMV infection was 95.3 % at 2 weeks after TMV inoculation, and decreased to 58.3 % at 3 weeks after inoculation. Five fold-dilution of the culture filtrate showed about half of the control efficacy by the stock culture filtrate. Analysis of the antibiotic material responsible for the inhibition of TMV infection through nuclear magnetic resonance experiments revealed that the antibiotic is antimycin $A_1$, which is firstly reported as an anti-phytoviral antibiotic in this experiment.

• Journal of Microbiology and Biotechnology
• /
• 제32권3호
• /
• pp.302-306
• /
• 2022

A chemical investigation of a culture extract from Streptomyces sp. RK85-270 led to the isolation and characterization of two new oxindoles, RK-270D (1) and E (2). The structures of 1 and 2 were determined by analyzing spectroscopic and spectrometric data from 1D and 2D NMR and High-resolution electrospray ionization mass spectrometry (HRESIMS) experiments. Compound 1 exhibited anti-angiogenic activities against human umbilical vein endothelial cells (HUVECs) without cytotoxicity. Results of Western blot analysis revealed that 1 inhibits VEGF-induced angiogenesis in the HUVECs via VEGFR2/ p38 MAPK-mediated pathway.

• The Plant Pathology Journal
• /
• 제39권6호
• /
• pp.566-574
• /
• 2023

The aim of this study was to investigate the regulation of lantipeptide production in Streptomyces globisporus SP6C4, which produces the novel antifungal lantipeptides conprimycin and grisin, and to identify the role of cytochrome P450 (P450) in tis regulation. To investigate the regulation of lantipeptide production, we created gene deletion mutants, including ΔP450, ΔtsrD, ΔlanM, ΔP450ΔtsrD, and ΔP450ΔlanM. These mutants were characterized in terms of their morphology, sporulation, attachment, and antifungal activity against Fusarium oxysporum. The gene deletion mutants showed distinct characteristics compared to the wild-type strain. Among them, the ΔP450ΔlanM double mutant exhibited a recovery of antifungal activity against F. oxysporum, indicating that P450 plays a significant role in regulating lantipeptide production in S. globisporus SP6C4. Our findings highlight the significant role of P450 in the regulation of lantipeptide production and morphological processes in S. globisporus. The results suggest a potential link between P450-mediated metabolic pathways and the regulation of growth and secondary metabolism in SP6C4, thereby highlighting P450 as a putative target for the development of new antifungal agents.

• Journal of Microbiology and Biotechnology
• /
• 제12권2호
• /
• pp.204-208
• /
• 2002

A Streptomyces sp. isolated from a soil sample collected in Taejeon, Korea has previously been found to produce two new polyene antibiotics. The two new antibiotics were named "16-methyloxazolomycin (antibacterial)" and "tetrin C (antifungal)", and their chemical structures are presented elsewhere [10, 11]. In the current study, chemotaxonomy, numerical taxonomy, and ISP methods were all employed for the taxonomic study. The spore chains were spirales and the spore surface was smooth. The spore mass was a gray series and no melanin pigment was produced. On the basis of the morphological and physiological properties, the microorganism was identified to be Streptomyces erumpens, belonging to the gray series of category IV, as defined by Bergey′s Manual. Tetrin C at the concentration of 20 ${\mu}g$/ml demonstrated a potent in vivo (pot test) preventive effect against rice blast, rice sheath blight, cucumber gray mold, wheat powdery mildew, and barley leaf rust.

• 한국토양비료학회지
• /
• 제21권2호
• /
• pp.129-134
• /
• 1988

토양(土壤)으로부터 분리(分離)한 Streptomyces sp. S-45 균주(菌株)의 효소학적(酵素學的) 성질(性質)을 검토(檢討)한 결과(結果)는 다음과 같다. 1. 분리균(分離菌) Streptomyces sp. S-45의 Chitinase activity는 $3.01({\mu}/m{\ell})$이고 ${\beta}$-1.3-Glucanase activity는 $2.49({\mu}/m{\ell})$이었다. 2. 탄소원(炭素原)으로서 Colloidal chitin 0.7%, Glucose 0.3%, 질소원(窒素原)으로서 Asparagine 0.5%, Peptone 0.2% 존재(存在)가 효소생산(酵素生産)에 효과적(效果的)이었다. 3. 최적(最適) 효소생성(酵素生成) 조건(條件)으로 pH 7.0, $30^{\circ}C$에서 6일간(日間) 진탕배양시(培養時) 최고(最高)의 효소생성(酵素生成)을 나타내었다. 4. 효소(酵素)의 활성(活性)에 미치는 최적(最適) 작용조건(作用條件)은 pH 6.5~7.0, 온도(溫度)는 $45{\sim}50^{\circ}C$였다. 5. 본(本) 효소(酵素)는 pH6.0~7.0에서 안정성(安定性)이 가장 높았고, $80^{\circ}C$로 10분(分) 처리시(處理時) Chitinase는 10%, ${\beta}$-1.3-Glucanase는 12%로 잔존활성(殘存活性)이 감소(減少)하였다. 6. 금속(金屬)이온에 대한 효소(酵素)의 영향(影響)은 $Co^{{+}{+}}$, $Cu^{{+}{+}}$, $Mn^{{+}{+}}$, $Al^{{+}{+}{+}}$의 $10^{-2}M$과 $Sn^{{+}{+}}\;10^{-3}M$에서 활성(活性)이 증대(增大)하였고, $Ag^{{+}{+}}$, $Hg^{{+}{+}}$는 현저(顯著)한 저해작용을 하였다.

• 식물병연구
• /
• 제11권1호
• /
• pp.66-71
• /
• 2005

본 연구는 감자 더뎅이병원균에 대한 항균활성을 갖는 Streptomyces sp. A020645 균주를 대상으로 최적의 고체 배양 및 항더뎅이병 활성증진 배지조성 조건을 검토하고자 실시하였다. 본 실험에 사용한 배지의 조성을 보면 밀기울, 쌀겨, 오트밀, 대두박을 기본 성분으로, 그리고 $KH_2PO_4$, 포도당, 당밀을 첨가물로 사용하였다. 연구결과 포자생성은 오트밀배지를 주성분으로 하고 glucose 0.1~0.01%, 당밀 1.1~0.01% 첨가배지에서 포자생성이 매우 양호하였다 그 외에도 $KH_2PO_4$ 2%를 첨가한 경우와 포도당과 당밀의 농도를 달리하였을 경우도 양호한 균체생성을 확인하였다. Streptomyces sp. A020645 균주의 배지소성별 항더뎅이병원균에 대한 활성을 조사한 결과 오트밀 및 쌀겨 배지를 주성분으로 사용할 경우 glucose 0.1~0.01%, 당밀 0.1% 첨가 조건에서 가장 높은 항균활성을 나타냈다. 이러한 연구결과는 생물제제 제형개발을 위한 기초자료로서 유용하게 활용될 수 있을 것이다.

• KSBB Journal
• /
• 제9권5호
• /
• pp.464-468
• /
• 1994

공업적 응용 가능성을 검토하기 위하여 한국의 근해 연얀저토에서 분리한 청색색소를 생성하는 Streptomyces sp.의 성질을 조사하였다. 탄 소원은 가용성 전분으로서 1% 였고, pH 7.0 이 상의 약 얄칼리성에셔 최대성장을 하였으며, 다량의 청색색소를 생생하였다.

• Journal of Microbiology and Biotechnology
• /
• 제7권5호
• /
• pp.333-340
• /
• 1997

An actinomycetes, KT-10 isolated from ginseng field in Kyongpook, Korea was selected based on its ability to produce a lysosomal cathepsin B inhibitor. The inhibitor purified from the culture supernatant of the isolate KT-10 showed strong inhibitory effects against cathepsin B as well as against papain when the activities were measured using synthetic substrate, ${\alpha}$-N-benzyloxycarbonyl-L-Iysine p-nitrophenyl ester (CLN) or ${\alpha}$-N-benzoyl-D,L-arginine 2-naphthylamide (BANA). The isolate KT-10 was identified as a species of Streptomyces based on its morphological characteristics and chemotaxonomic data. The TAXON program of Ward was used to identify Streptomyces sp. KT-10 as a strain of Streptomyces luteogriseus belong to cluster 18 of the genus Streptomyces with a Willcox probability 0.999388. The cathepsin B inhibitor was presumed to a novel material composed of a polyhydroxylamine.

• 한국미생물·생명공학회지
• /
• 제25권6호
• /
• pp.537-545
• /
• 1997

The aim of the present research program was to isolate a strain of actinomycetes producing antifungal substance. Soil samples were collected from various sites in Korea and a number of actinomycetes were isolated from the soil samples by applying selective agar for actinomycetes. Among isolates, a strain (NA -52) producing antifungal substance against Pyricularia oryzae was selected. Chemotaxonomic and numerical identification were carried out for the isolate. Fifty taxonomic unit characters were tested and the data were analyzed numerically using TAXON program. The isolate was identified as a synonym of streptomyces diastaticus belong to cluster No. 19 (Streptomyces diastaticus). But it showed a low similarity to S. diastaticus in simple matching coefficients, hence it was considered as one new species in Streptomyces.