Bacteriocin-Producing Rhizosphere Bacteria and Their Potential as a Biocontrol Agent

Abstract

An alarming rise in environmental pollution due to unsafe use of chemically toxic pesticides and fertilizers in agriculture industry has stimulated researchers to search for alternative control agents with wide spectrum of actions and lesser side effects. In this context, the antimicrobial polypeptide bacteriocins produced by rhizosphere bacteria have been evaluated as potential bio-stimulants of plant growth and as biocontrol agents. Bacteriocins are ribosomally synthesized peptides demonstrating bacteriostatic or bactericidal activity against other related and unrelated microorganisms. A wide range of rhizosphere- and plant-associated bacteria have been identified as potential bacteriocin producers demonstrating wide range of inhibitory spectrum toward economically important plant pathogens. To date, approximately 500 bacteriocins have been identified and characterized of which majority are produced by rhizosphere bacteria. These antimicrobials characterized as highly potent toxins with powerful killing action, high stability, and low toxicity to humans have been considered as a viable option and a suitable alternative to chemically toxic agents used in many industrial applications. The importance of bacteriocins is well recognized in agriculture industry for their role in reducing the use of fertilizers and chemical inputs such as fungicides and insecticides. This review presents an overview of bacteriocins, their nature, mode of action, resistance, and genetics with special emphasis on bacteriocin-producing rhizosphere bacteria and their possible potential as biocontrol agents for combating bacterial plant diseases.