Effects of some carbon and nitrogen sources on antibacterial activity of sponge-derived Streptomyces sp. strain HM9

Abstract

Streptomyces has been known as a source of natural bioactive substances so far. In this present study, the sponge-derived Streptomyces HM9 was optimised with a number of different carbon (C) and nitrogen (N) sources to evaluate the broad-spectrum antibacterial ability. Starch and (NH₄)₂SO₄ were favourable carbon and nitrogen sources to the growth of the strain HM9. Starch and casein were suitable carbon and nitrogen sources for antibacterial activity of strain HM9 against Vibrio, whereas lactose and NH₄Cl were beneficial on the inhibition of standard indicator Bacillus subtilis ATCC 6633. There was no overlap of C and N sources for the antibacterial activity of the strain HM9 against Gram-positive and Gram-negative bacteria, indicating that strain HM9 used different sources of C and N to produce different antibiotics. This is the first report on a marine Streptomyces strain using C and N sources to produce antibiotics against Gram-positive bacteria and opportunistic Gram-negative Vibrio pathogen isolated from the ambient aquaculture. This result may pave the way for further research on exploiting antibiotics as medicine or using them for seafood preservation.