Probiogenômica de lacticaseibacillus paracasei UFTM 2.9: revelando o potencial probiótico por meio de abordagens in silico e in vitro

Abstract

Probiotics are microorganisms capable of colonizing the gastrointestinal tract (GIT) and promoting host well-being through molecular interactions with the immune and digestive systems. Lactic Acid Bacteria (LAB) comprise a group of Gram-positive bacteria that produce lactic acid as the end product of fermentation and hold significant industrial relevance. Several LAB strains are recognized as probiotics due to their ability to withstand the physicochemical conditions of the gastrointestinal tract (GIT), adhere to the intestinal mucosa, and confer benefits to the host through immunomodulatory and pathogen-antagonistic activities. L. paracasei UFTM 2.9 was previously isolated from cow’s milk in the region of the Federal University of Triângulo Mineiro and showed satisfactory in vitro results regarding resistance to acidic pH and bile salts. Although different probiotic species have already been identified, the molecular mechanisms promoting probiotic effects are not yet fully understood. This study aimed to use probiogenomic strategies associated with in vitro validations to broaden the knowledge of L. paracasei UFTM 2.9 and characterize its probiotic potential. The genome of L. paracasei UFTM 2.9 consists of 127 contigs, 321,652 base pairs (bp), and has a GC content of 46.20%. No virulence genes or CRISPR elements were detected. Two phages were identified in the genome of L. paracasei UFTM 2.9. Antimicrobial activity was confirmed in vitro by identifying genes encoding carnocin, enterocin, and salivaricin. The bacterium exhibits metabolic versatility, growing on four carbon sources in addition to glucose. Furthermore, the functional annotation of genes associated with probiotic effects identified the presence of 170 genes responsible for probiotic traits in L. paracasei UFTM 2.9. The results indicate the potential use of L. paracasei UFTM 2.9 as a probiotic, considering its ability to inhibit pathogenic microorganisms and its genetic potential to express traits of interest and survive in the gastrointestinal tract.