Evaluation of antimicrobial activity of new Streptomyces species isolated from marine sediments of eastern Gilan province, Iran

Streptomyces have the ability to produce bioactive metabolites such as antibacterial compounds. This study aimed to isolate and evaluate the production of  antibacterial compounds from marine sediments by Streptomyces of eastern Gilan province. 

Marine sediments were collected and Streptomyces species were identified based on morphological, physiological, biochemical methods and molecular identification was used by 16SrRNA gene sequencing and phylogenetic analysis. Antimicrobial activity was evaluated against pathogenic microorganisms such as Micrococcus luteus PTCC 1408, Bacillus cereus PTCC 1154, Staphylococcus aureus PTCC 1189, Pseudomonas aeruginosa PTCC 1310, Salmonella typhi PTCC 1609 and Proteus mirabilis PTCC 1776 by using primary (Cross streak) and secondary (Well diffusion agar) methods were investigated.                                                                         

The isolate SN7 was collected from marine sediments of eastern Gilan province, Iran and the results of 16SrRNA gene sequencing and phylogenetic analysis revealed that the isolate belonged to Streptomyces genus with the highest similarity (90.17%) to uncultured Streptomyces sp. and it can be introduced as a new species. This isolate showed significant antimicrobial activity against pathogenic microorganisms and P. aeruginosa was the most resistant microorganism against antimicrobial activity of this isolate.

The results showed that the marine sediments of the eastern regions of Gilan province, Iran can be significant for producing antimicrobial compounds and these regions can be valuable for pharmaceutical application.