Taxonomic characterization of Streptomyces strain CH54-4 isolated from mangrove sediment

Abstract

An actinobacterium, designated as strain CH54-4, was isolated from mangrove sediment on the east coast of the Gulf of Thailand using starch casein agar. This isolate was found to contain chemical markers typical of members of the genus Streptomyces: This strain possessed a broad spectrum of antimicrobial activity against Gram-positive, Gram-negative bacteria and fungi. In addition, this strain also showed strong activity against breast cancer cells with an IC50 value of 2.91 µg ml−1. Phylogenetic analysis of a 16S rRNA gene sequence showed that strain CH54-4 forms a distinct clade within the Streptomyces 16S rRNA gene tree and closely related to Streptomyces thermocarboxydus.