Enhanced spoVF operon increases host attachment and biocontrol ability of Bacillus subtilis for the management of Ceratocystis fimbriata in sweet potato

Abstract

Bacillus subtilis is a ubiquitous environmental bacterium commonly used for the biological control of fungal plant diseases. The ability to form surface-attached microbial communities is essential for B. subtilis to colonize and protect plants from pathogen infection. In this work, it was found that enhanced spoVF operon altered the carbon metabolic pathways of B. subtilis 168, accelerating cell growth and glucose consumption, and inducing the production of antifungal metabolite dipicolinic acid (DPA). These metabolic effects significantly increased swimming motility and biofilm formation, enhancing the colonization ability and host attachment of B. subtilis. Mutant B. subtilis showed higher inhibitory activity in vivo against sweet potato pathogen Ceratocystis fimbriata in comparison with the wild-type strain. Collectively, novel insights on the key genes and pathways involved in biofilm formation and attachment of B. subtilis were revealed in this work.