Purification of the antimicrobial compounds from Streptomyces xinghaiensis

Abstract:

Streptomyces xinghaiensis is a novel Streptomyces species isolated from marine sediment sample collected in Xinghai Bay, Dalian, China, and wide spectrum of antimicrobial activities of its fermentation broth has been observed. In this study, the antibacterial activities of the fermentation broth of S. xinghaiensis against drug-resistant clinical isolates were investigated, and inhibitory activities against Acinetobacter baumannii and Staphylococcus aureus (MRSA) strains were revealed. Purification of the active compound (s) against methicillin-resistant Staphylococcus aureus (MRSA) clinical isolates was performed and the properties of the active compounds were studied. Active fractions were obtained after treatments of the broth with macroporous adsorptive resin HP-20 and Sephadex LH-20. The active components were weak alkaloid compounds with no specific UV adsorption, and ninhydrin coloration further supported the hypothesis that the active compounds likely belong to aminoglycoside antibiotics. The draft genomic sequence of S. xinghaiensis was searched and a ribostamycin-related gene cluster was identified. However, Thin Layer Chromatography (TLC) analysis indicated that the major components of the active compounds are different from ribostamycin.