Utilization of Bacillus ‐Derived Secondary Metabolites in Sustainable Agriculture

Fungal phytopathogens represent a major challenge to global agriculture, leading to substantial yield losses. In recent decades, synthetic fungicides have dominated phytopathogen control, but rising environmental concerns are driving a shift toward sustainable, eco-friendly solutions to combat diseases in plants. Bacillus species have emerged as sustainable and eco-friendly solutions due to their ability to produce diverse secondary metabolites that exhibit strong antifungal activity while simultaneously enhancing plant growth. Secondary metabolites, including lipopeptides (e.g. Bacillus subtilis , Bacillus amyloliquefaciens ), ribosomal peptides (e.g. Bacillus coagulans ), polyketides (e.g. Bacillus subtilis , Bacillus velezensis ), volatile organic compounds (e.g. Bacillus pumilus , Bacillus thuringiensis ), siderophores (e.g. Bacillus megaterium , Bacillus subtilis ), hydrolytic enzymes (e.g. Bacillus mojavensis , Bacillus thuringiensis ), alkaloids ( Bacillus subtilis , Bacillus safensis ), dihydroisocoumarins (e.g. Bacillus subtilis ) effectively inhibit fungal growth by disrupting cellular structures, preventing spore germination, and interfering with fungal metabolism. At the same time, these metabolites boost plant health by enhancing root growth, improving nutrient uptake, and triggering plant defense mechanisms. The synthesis of these metabolites is regulated by complex biosynthetic gene clusters, enabling Bacillus species to thrive under environmental stresses and gain a competitive advantage in the rhizosphere. Recently, numerous studies from Gujarat reported the effectiveness of secondary metabolites produced by Bacillus species in inhibiting fungal phytopathogens. Given the growing importance of Bacillus species in agriculture, this chapter delves into their secondary metabolites, emphasizing their antifungal mechanisms and their role in inducing systemic resistance (ISR) in plants. Furthermore, it explores their potential applications in sustainable agriculture and addresses future prospects for enhancing their efficacy.