Antifungal Activity and Genome Mining Reveal Potentiality of Streptomyces sp. VNUA24 as a Biocontrol Agent.

Fungi are major phytopathogens that have a strong impact on agricultural productivity. Recently, biological control has gained attention for managing plant pathogenic fungi due to its eco-friendly characteristics. Hence, using biological agents to replace chemical fungicides is a viable alternative approach in sustainable agriculture systems. In this study, we demonstrated the potentiality of Streptomyces sp. VNUA24 as a promising biocontrol agent. The strain strongly inhibited mycelial growth of several common pathogenic fungi. Its culture filtrate also altered fungal morphology, restricted hyphal elongation, inhibited spore germination, and suppressed fungal virulence. Biochemical assays and genomic analysis revealed the productions and encoding genes for several hydrolytic enzymes. The antiSMASH analysis identified 38 biosynthetic gene clusters in the genome. Interestingly, many of these exhibited strong homologies to clusters responsible for producing established antifungal metabolites such as ε-poly-L-lysine, concanamycin A, informatipeptin, and humidimycin. These findings highlight the strong antifungal potential of Streptomyces sp. VNUA24 and suggest that it is a promising candidate for developing microbial control agents in sustainable fungal disease management.