Streptomyces have been reported as a remarkable source for bioactive secondary metabolites with complex structural and functional diversity. In this study, 35 isolates of genus Streptomyces were purified from rhizospheric and marine soils collected from previously unexplored habitats and screened for antimicrobial activities. One of these isolates, G1, when tested in vitro, was found highly active against wide range of microbes including Gram-positive, Gram-negative bacteria, and different fungal pathogens. It was identified as mesophilic, alkaliphilic, and moderately halotolerant as it showed optimum growth at temperature 30 °C, pH 8.0 in casein-starch-peptone-yeast extract-malt extract medium supplemented with 5% NaCl. Sequence analysis of the 16S rRNA gene indicated 100% identity of this isolate to Streptomyces fimbriatus. Moreover, maximum antimicrobial activity was achieved in starch nitrate medium supplemented with 1% glycerol as carbon and 0.03% soy meal as nitrogen source. The antimicrobial compounds produced by this isolate were extracted in methanol. Bioassay-guided fractionation through thin layer chromatography of methanolic extract resulted in the separation of a most active fraction with an R_f value of 0.46. This active fraction was characterized by FTIR and LCMS analysis and found similar to streptothricin D like antibiotic with m/z 758.42.

据报道，链霉菌是具有复杂结构和功能多样性的生物活性次级代谢物的重要来源。在本研究中，35 株链霉菌属从以前未开发的栖息地收集的根际和海洋土壤中纯化，并筛选抗菌活性。其中一种分离株 G1 在体外测试时被发现对多种微生物具有高度活性，包括革兰氏阳性菌、革兰氏阴性菌和不同的真菌病原体。它被鉴定为嗜温、嗜碱和中等耐盐，因为它在 30 °C 的温度、pH 8.0 下在酪蛋白-淀粉-蛋白胨-酵母提取物-麦芽提取物培养基中显示出最佳生长，并辅以 5% NaCl。16S rRNA 基因的序列分析表明该分离株与Streptomyces fimbriatus 100% 同一性. 此外，在补充有 1% 甘油作为碳和 0.03% 豆粕作为氮源的硝酸淀粉培养基中实现了最大的抗菌活性。由该分离物产生的抗微生物化合物在甲醇中提取。通过甲醇提取物的薄层色谱法进行生物测定引导的分馏导致分离出R _f值为 0.46的最具活性的部分。该活性部分通过 FTIR 和 LCMS 分析表征，发现与 m/z 758.42 的链丝菌素 D 样抗生素相似。