In Silico and In Vitro Analysis of Antifungal Compounds of Ten New Bacillus and Paenibacillus Strains

This study investigates the range of secondary metabolites with antifungal activity produced by bacterial strains that have been previously characterised as antagonistic strains to phytopathogenic fungi. The properties of ten strains were analyzed in silico through functional genomic analysis and in vitro by mass spectrometry. The research has demonstrated that Bacillus and Paenibacillus strains possess diverse gene clusters for biosynthesis of secondary metabolites, including peptides and polyketides. Mass spectrometry analysis confirmed the synthesis of key antimicrobial peptides, such as surfactin, fengycin, macrolactin, and fusaricidin, which are associated with antifungal activity. These strains have been observed to exhibit robust antagonism against phytopathogenic fungi—the diameter of the inhibition zones for the presented strains was at least 20 mm. This feature highlights their potential as biocontrol agents. The presence of numerous uncharacterized gene clusters suggests the possibility of discovering previously undescribed bioactive compounds.