Isolation and Molecular Characterization of Actinomycetes from Coastal Sediments of the Sundarbans

Abstract

Actinomycetes are unicellular organisms found in various environments across the world. It is a large order of bacteria and are potential source of a wide range of biologically active compounds. This study was conducted to isolate, identify and screen for potential antibacterial activity of Actinomycetes from coastal sediments of the Sundarbans. A total of nine isolates were screened which were subsequently subjected for 16s-rRNA gene subsequently. Eight isolates were found to be Actinomycetes (6 Streptomyces spp., I Nocardia spp., 1 Cellulosimicrobium spp.). C.funkei and S.labedae were selected for extraction of secondary metabolites to investigate the antibacterial and antioxidant potentials. Both isolates demonstrated moderate antioxidant potential in DPPH free radical scavenging assay compared to standard ascorbic acid. Extracts from both bacteria exhibited strong antibacterial activity against four pathogenic bacteria and their MIC value ranged from 0.25 to 2.0 mg/mL. C.funkei extract showed the highest antibacterial activity (MIC value of 0.0024mg/mL) against Vibrio cholerae. This study showed that the Sundarbans are rich in Actinomycetes specially Streptomycetes sp. Furthermore, Actinomycetes from coastal sediments of Sunderbans could be potential sources of antimicrobial agents.