Biosynthetic Gene Clusters in Bacteria: A Review

Abstract

Soil is a nutrient-rich environment that harbors billions of microbial species. The diversity of microbes in an environment varies with the change in edaphic factors. To survive these environmental changes, microbes produce secondary metabolites which are not directly associated with their growth and reproduction. Bacterial genomes possess biosynthetic gene clusters (BGC) which regulate the synthesis of these secondary metabolites. These BGCs encode for megasynthases such as nonribosomal peptide synthases (NRPS) and polyketide synthases (PKS) which produce metabolites such as antimicrobial compounds, which are the most common metabolites produced by these megasynthases. They help bacteria to survive in the competitive environment by killing surrounding microbes. As chemical drugs may pose immense damage to human health and the environment, so antibiotics produced by natural sources are of major attention these days. The extraction of antimicrobial compounds from bacterial sources also provides scaffolds for new synthetic drugs. Bacteria maintain strict genetic control over antibiotic production. They have particular quorum sensing pathways that help to trigger the surrounding cells to produce antibiotics when required. Biosynthetic gene clusters need to be explored widely under various culture conditions so that more useful products can be extracted from a single type of bacterium. This review focuses on the secondary metabolite production, extraction, and biosynthetic gene clusters which encode megasynthases responsible for the production of antimicrobial compounds.