Evaluación del potencial probiótico de la cepa Bacillus velezensis SNR14-4 de branquias de tilapia del Nilo mediante un enfoque genómico e in vitro

Introduction: The current investigation assessed a novel strain of Bacillus velezensis SNR14-4, isolated from the gills of Nile tilapia intending to consider it as a promising probiotic contender. Methods: Initially, an extensive analysis of the genome of the particular isolate was carried out employing bioinformatics tools to anticipate its characteristics and potential probiotic attributes. The total genome of SNR14-4, recognized as B. velezensis via 16S rRNA and whole-genome sequencing and phylogenetic analysis, is composed of a singular circular chromosome with a genome size of 4.1 Mb, a total length of 4183910 bp, and an average guanine-cytosine (GC) content of 46.52 %. Valuable insights were acquired utilizing AntiSMASH to detect secondary metabolite biosynthetic gene clusters, and functional gene annotation relevant to probiotic traits was accomplished by utilizing RASTtk and PROKKA. The absence of virulence elements, ascertained via genomic analysis, facilitated a targeted in vitro exploration. Results: SNR14-4 displayed notable probiotic characteristics and exhibited antimicrobial efficacy against common fish pathogens. HR-LCMS QTOF analysis of the microbial extract unveiled several potent antimicrobial compounds synthesized by the strain. Conclusions: B. velezensis SNR14-4 showcases promise as a probiotic candidate, either as a single point of source or as a part of probiotic consortia made of similar strains.