Unveiling the probiotic potential of the genus Geobacillus through comparative genomics and in silico analysis

Pursuing new probiotic targets has surged, driven by next-generation sequencing, facilitating a thorough exploration of bacterial traits. The genus Geobacillus stands out as a promising candidate for probiotics. The study explored the genetic attributes of the genus Geobacillus for their resilience to gastrointestinal conditions, nutrient production, and immunomodulatory compound creation, revealing potential probiotic traits. Predictive analyses of genomic elements like prophages, CRISPR-Cas systems, insertion sequences, genomic islands, antibiotic resistance genes, and CAZymes were conducted to assess safety. Comparative genomic analysis was performed using 18 published Geobacillus genomes and a few Lactobacillus and Bifidobacterium genomes as controls. Genes associated with probiotic traits, such as adhesion, stress tolerance (acid/bile, osmotic, oxidative), immune modulation, and molecular chaperones, were uniformly detected in Geobacillus. Mobile genetic elements (such as plasmids, prophages, and insertion sequences), virulence factors, toxins, and antibiotic resistance genes were absent, while CRISPR-Cas systems and CAZymes were present. The pan-genome comprised 25,284 protein-coding genes. Comparative genomic analysis revealed an open pan-genome for Geobacillus. Pan-genome exhibited variability, particularly in genes linked to environmental interaction and secondary metabolite synthesis. Geobacillus appears potentially safe and well-suited for the gut habitat. However, further in vitro studies are essential to confirm its probiotic potential.