链霉菌属也称链丝菌，是放线菌门一个大属，约有近千种。

链丝菌好气，绝大部分腐生，其基质菌丝不断裂，气生菌丝分化成直的、弯曲的或螺旋状的孢子丝，成熟的孢子丝生成链状的分生孢子，故名链丝菌。菌落较小而致密，不易挑取，表面呈粉状、绒状，并有多种颜色。

链霉菌属的不少菌种在代谢过程中，次级代谢产物为抗生素，如链霉素、四环霉素、红霉素、卡那霉素和春雷霉素等；有的菌种可生产蛋白酶、葡萄糖异构酶。

常见于土壤及腐烂植物中，一般闻起来有泥土味道。相较于其他菌种，链霉菌属繁殖较缓慢，但由于代谢过程的抗生素能抑制其他菌种的生长，所以时间一长，链霉菌属就会成为地盘上的优势菌种。

Streptomyces is the largest genus of Actinobacteria and the type genus of the family Streptomycetaceae. Over 500 species of Streptomyces bacteria have been described. As with the other Actinobacteria, streptomycetes are Gram-positive, and have genomes with high GC content. Found predominantly in soil and decaying vegetation, most streptomycetes produce spores, and are noted for their distinct "earthy" odor that results from production of a volatile metabolite, geosmin.