Lysobacter enzymogenes: A fully armed biocontrol warrior

Lysobacter enzymogenes is less-studied, but emerging as a powerful biocontrol bacterium producing multiple antimicrobial weapons including lytic enzymes, toxins, secondary metabolites and protein secretion systems. The loss of surface-attached flagellum, production of heat-stable antifungal factor (HSAF, also named as Ningrongmycin) as a novel antifungal antibiotic, and the use of the type IV secretion system (T4SS) rather than the common type VI secretion system (T6SS) to kill competitor bacteria make this species unique. These distinct features set L. enzymogenes apart from well-studied plant beneficial biocontrol agents, such as Bacillus and Pseudomonas. This review describes what takes L. enzymogenes to be a unique biocontrol warrior by focusing to illustrate how the lack of flagellum governs morphological and functional co-adaptability, what adapted signaling transduction pathways are adopted to coordinate the biosynthesis of HSAF, and how to ecologically adapt plant rhizosphere by cell-to-cell interacting with microbiome members via the bacterial-killing T4SS.