Production and Identification of Antifungal Compounds Produced by Bacillus subtilis B579

Biological control has become an important approach to suppress many pathogens. Bacillus subtilis is considered to be an excellent biocontrol agent not only due to its ability on inducing plant systematic resistance, but also on producing various hydrolytic enzymes and antibiotics. In this study, polymerase chain reaction (PCR) was used to detect the 12 genes related to the antifungal compounds biosynthesis. Six genes were detected that exist in the genome DNA of B579 by the sequence homology analysis. Five genes were related to biosynthesis of lipopeptide antifungal compounds, and one gene was related to biosynthesis of protein antifungal compounds. Lipopeptide antifungal compounds were obtained from the supernatant of B579 using the method of acid deposition and methanol extraction. Two homologies with the molecular weight of m/z 1043.59 and m/z 1057.35 were detected in the lipopeptide antifungal compounds, which had the similar molecular weight with iturin A. Three homologies with the molecular weight of m/z 1008.32, m/z 1022.06, and m/z 1036.13 were detected in the lipopeptide antifungal compounds, which had the similar molecular weight with surfactin. The antifungal compounds produced by B579 could be of a good prospect for being used as a new tool for biological control.