Isolation, characterization and extraction of antimicrobial compound from marine actinomycete streptomyces hygroscopicus BDUS 49

Abstract

A total of eight actinomycetes colonies were isolated from near sea shore marine environment locations of Bigeum Island, South West coast of South Korea. Among them, 4 isolates were morphologically distinct on the basis of spore mass colour, reverse side colour, aerial and substrate mycelia formation and production of diffusible pigment. The majority of these isolates were assigned to the genus Streptomyces of which one isolate showing broad spectrum of antimicrobial was on the basis of their morphological, physiological and biochemical properties. Phylo genetic analysis of a 16S rRNA gene sequence showed that strain Streptomyces hygroscopicus BDUS 49 forms a distinct clade within the Streptomyces 16S rRNA gene tree and is closely related to Streptomyces hygroscpicus subsp sub species. This strain possessed a broad spectrum of antimicrobial activity against Gram-positive, Gram-negative bacteria and fungi. The UV spectra of the active compounds in ethyl acetate showed peaks between 200 to 295 nm. The bioactive region was detected on the TLC plate (Rf 0.40). The structure of the bioactive components was further determined using FTIR, MS, 13C NMR and 1H NMR. The molecular formula of the given compound was identified as 7, demethoxy rapamycin C50H 75NO12+NA (MW 905.12).