Isolation Of Streptomyces From Phu Quoc Island

Abstract

Streptomyces spp is a group of bacteria that is frequently found in water and soil. This group of bacteria is noticeable as antibiotic producers with their potential is estimated large and needs to be more investigated. So, the isolation and antimicrobial activity of Streptomyces species seemed to be crucial in to explore more favorable antibiotics. Various researches of isolation of Streptomyces in Vietnam have been carried out for years. Concurrently, some relevant reports indicated the Streptomyces strains isolated from marine sources would probably produce high yield of antimicrobial compounds. This study therefore aims to explore Streptomyces from Phu Quoc Island in Vietnam and screens for the strains that have potential to produce antimicrobial substances under different medium conditions. From twenty-one soil samples collected in different sites of Phu Quoc Island, Streptomyces spp were isolated by culturing on selective medium ISP4 agar plates. After continuous subcultures to pure microbes, Streptomyces isolates were finally observed and confirmed under microscope via morphology observation and biochemical tests. Seventy-eight Streptomyces isolates were collected. The preliminary tests for antimicrobial activities of collected isolates using well diffusion technique were performed against 6 microbes including S. aureus, E. coli, B. subtilis, P. aeruginosa, C. albicans, A. flavus. Antimicrobial testes from crude extracts of 78 isolates showed that, 22 exhibited activity against S. aureus, 10 displayed activity against P. aeruginosa, 17 presented the capability against C. albicans, and 1 strain revealed antimicrobial competence to B. Subtilis. Crude extracts of all 78 isolates are stored in glycerol 30% in -80oC for further research.