Genomic Insights into Antimicrobial Biosynthetic Potential of Bacillus velezensis Isolated from Traditional Peruvian Tocosh

Tocosh, a traditional Peruvian fermented potato product, is known for its health-promoting properties, including its antioxidant, anti-inflammatory, probiotic, and antibiotic effects, which have popularized its consumption, particularly in rural areas. To gain a better understanding of its antimicrobial properties, this study aimed to perform a comprehensive whole-genome analysis and functional assessment of the Bacillus velezensis TCSH0001 strain isolated from tocosh. The isolate was identified through whole-genome sequencing using the MinION nanopore platform. AntiSMASH analysis revealed nine biosynthetic gene clusters (BGCs) potentially responsible for producing secondary metabolites with antibiotic potential. Notably, seven BGCs showed a 100% similarity to known clusters involved in the biosynthesis of polyketide synthases (PKSs) and non-ribosomal peptides (NRPSs), including difficidin, bacillibactin, bacilysin, macrolactin H, bacillaene, fengycin, and bacillomycin D. In vitro analysis revealed antimicrobial activity against S. aureus strains. In addition, RT-qPCR indicated that the expression of the baeJ (bacillaene), bmyA (bacillomycin D), and pks2A (macrolactin H) occurs predominantly during the exponential growth phase. Our results suggest that this B. velezensis strain has the capacity to produce a diverse array of bioactive compounds, supporting the traditional use of tocosh as a natural antimicrobial agent, and revealing the potential of the strain as a high NRPS producer.