Multifunctional Bioactivity of Bacillus amyloliquefaciens SH-53: Analysis of Multiple Antagonistic and Synergistic Growth Promotion Mechanisms Based on Whole Genome

Bacillus amyloliquefaciens is an important agricultural microbial resource. This study focuses on the whole genome analysis and functional characterization of B. amyloliquefaciens SH-53, isolated from the Wuliang Mountain National Nature Reserve in Dali, Yunnan. The genomic feature analysis revealed that the genome of SH-53 contains 27 ribosomal RNA operons, 4078 protein-coding genes, and 250 prophage-related genes. Additionally, 12 biosynthetic gene clusters (BGCs) for secondary metabolites were predicted, of which 7 are novel gene clusters with unknown functions, showing significant differences compared to the known BGCs of conventional biocontrol strains. Functional potential analysis indicates that SH-53 possesses potential antagonistic activity against plant pathogenic bacteria and can colonize the plant rhizosphere through various mechanisms to exert growth-promoting effects. It is capable of synthesizing multiple antibacterial secondary metabolites, indole-3-acetic acid (IAA), iron carriers, secreting amylase, and efficiently utilizing sulfur sources. The genome also harbors a complete core gene network related to the induced systemic resistance (ISR) and supporting genes that maintain secondary metabolism homeostasis. In conclusion, B. amyloliquefaciens SH-53 exhibits rich biocontrol-related characteristics and unique secondary metabolic potential, indicating promising prospects for its development as an excellent biocontrol agent.