Antimicrobial Compounds Biosynthesis and Biocontrol Mechanisms of Lysobacter enzymogenes

Biocontrol of plant pathogens is considered an environmentally friendly strategy and it is preferred over the use of chemicals which cause environmental pollution. Lysobacter enzymogenes is a bacterium that has been identified as an agriculturally important biocontrol agent. L. enzymogenes possess antagonistic activity against numerous phytopathogens such as fungi, oomycetes, bacteria and nematodes. Its antagonistic activity is conferred by its ability to produce bioactive secondary metabolites such as the Heat-Stable Anti-Fungal Factor (HSAF), Heat-Stable Degrading Metabolite (HSDM) and WAP-8294A2. It can also produce abundant lytic enzymes such as; chitinases, proteases, glucanases and cellulases that can degrade fungal cell walls and therefore inhibit their growth. To design effective biocontrol strategies employing L. enzymogenes, it is important to understand its antagonistic mechanisms. This review crystalizes information on the biosynthesis mechanisms and biocontrol mechanisms of various antimicrobial compounds produced by L. enzymogenes, this information is essential in designing biocontrol strategies against phytopathogens. Further, this review highlights the uncharacterized HSDM and proposes the need for its future characterization, determination of its biosynthetic gene cluster and characterization of its antagonistic mechanisms against various phytopathogens. Also, the mechanism of clp regulation of lytic enzymes biosynthesis needs to be further studied.