Screening of the Antibacterial Potential of Marine Actinobacteria from the Bangka Belitung Island

Abstract

Marine Actinobacteria are a veritable cornucopia of marine natural products with strong potential in medicine and biotechnology, which generally serves as an invaluable resource for novel antimicrobial compounds. The ever-rising prevalence of multidrug-resistant bacteria has heightened the necessity for new antibiotics to challenge this threat. The marine environment has been widely known to yield chemically diverse and biologically active compounds from bacteria. In this study, the antibacterial potential of 5 isolates acquired from coastal sediment samples from Bangka Belitung was elucidated. It was found that all the samples were suspected of belonging to the genus Streptomyces, with a broad spectrum of antagonistic activity but with an added potency towards Gram-positive pathogens, especially Mycobacterium smegmatis, indicating the potential for antimycobacterial agents. Furthermore, the compounds produced by the isolates were subjected to a gas chromatography – mass spectrometry (GC-MS) analysis and were found to be antibacterial in nature when compared with literature. This antibacterial activity was further supported by molecular screening analysis of the isolates that showed the presence of both non-ribosomal peptides synthases (NRPS) and type I polyketide synthases (PKS-I) genes clusters in the majority of the isolates. Hence, this study demonstrated that Actinobacteria isolates from coastal marine sediments in Bangka Belitung was found to possess high antibacterial potential, especially towards M. smegmatis, where only a few studies using Streptomyces have shown similar potency.