Antimicrobial and antioxidant activities of Bacillus mojavensis I4 lipopeptides and their potential application against the potato dry rot causative Fusarium solani.

Lipopeptides are diverse metabolites produced by various bacterial and fungal genera. They are known for their antimicrobial and surfactant activities with diverse environmental, pharmaceutical, and also agronomic applications as biocontrol agents. In this study, a PCR was used to confirm the presence of NRPS genes in Bacillus mojavensis I4. This bacterial strain could produce diverse lipopeptides which belong to the fengycin, and surfactin families. The antioxidant activity of I4 biosurfactants was determined through four different in vitro assays. Furthermore, antimicrobial activity assays indicated that I4 lipopeptides exhibited marked inhibitory activity against several bacterial and fungal strains. Further treatment of potato dry rot causative pathogen Fusarium solani with I4 lipopeptides demonstrated a remarkable reduction in the fungal penetration by almost 80% after 15 days of incubation. The findings suggest that I4 lipopeptide is a potential biocontrol agent during potato tuber storage.