Comparative genomics reveals conserved biosynthetic potential and structural diversification of biosynthetic gene clusters in Brazilian Lactiplantibacillus plantarum

Brazilian Lactiplantibacillus plantarum remains underexplored as a source of biosynthetic diversity with potential biotechnological applications. Although biosynthetic gene clusters (BGCs) are commonly compared based on class distribution, the extent of structural variation among homologous clusters in Brazilian lineages remains poorly understood. Here, we performed a comparative genomic analysis of nine publicly available Brazilian L. plantarum genomes to characterize the distribution, functional composition, and structural organization of predicted BGCs. Genomes were re-annotated and analyzed using antiSMASH and BiG-SCAPE, integrating class-level identification, local synteny, gene-content comparison, and similarity-based clustering. Five BGC classes were identified and were broadly conserved across genomes despite their phylogenomic and ecological diversity. In contrast, homologous clusters displayed distinct degrees of structural conservation. Terpene-precursor was the most conserved class in both gene composition and synteny, whereas terpene exhibited the greatest structural diversification and accessory-gene variation. RiPP-like and cyclic-lactone-autoinducer clusters showed relatively stable architectures, while T3PKS retained a conserved core with variable accessory regions. These findings demonstrate that biosynthetic diversity in Brazilian L. plantarum is driven primarily by internal variation within homologous BGCs rather than by differences in BGC class repertoire. This study provides a comparative genomic framework for prioritizing Brazilian L. plantarum strains for future functional characterization and highlights the value of genome mining for microbial bioprospecting.