Abstract:The lipopeptide content and antifungal activity of Bacillus velezensis after mutagenesis were investigated.Bacillus velezensis A4 strain was screened for its high production of lipopeptides by atmospheric pressure and room temperature plasma （ARTP） mutagenesis,and the inhibitory effect of the mutated strain on 12 pathogenic fungi was assessed by plate confrontation and fruit inoculation.The results showed that the A4 strain had significant inhibitory effects on 12 pathogenic fungi,and the mutant strain treated with ARTP mutagenesis for 60 s performed better than the original strain in inhibiting the growth of pathogenic fungi and enhancing the post-harvest resistance of fruits,with the inhibitory effect on Penicillium expansum being particularly significant,which may be related to the increase in the production of lipopeptides.