Comparative Genome Analysis and Characterization of Lacticaseibacillus Paracasei NKN344 Strain Isolated from Curd of Buffalo Milk Reared on Brackish Water Lagoons of the Eastern Indian Coast.

Ethnic fermented foods represent a significant repository for discovering novel probiotic entities. These fermented foods, entrenched in indigenous practices, have conserved a distinct microbiota through generations. Exploration of these fermented foods could yield microbial consortia capable of transforming human health. However, comprehensive research into the probiotic attributes and quality analysis is necessary before its usage as biotherapeutics. In the current study, Chilika curd - an ethnic fermented curd originating from Odisha was explored to isolate novel probiotic strains. A detailed phenotypic and genomic characterization of a novel Lacticaseibacillus paracasei strain was conducted. Host-probiotic interactions were assessed using the Caenorhabditis elegans model. Lacticaseibacillus paracasei NKN344 exhibited robust survival under various physiochemical stresses, such as in vitro simulated gut environment and in vivo Caenorhabditis elegans intestinal model. Additionally, an in-depth bioinformatic analysis revealed the metabolic prowess of Lacticaseibacillus paracasei NKN344, including a few bacteriocin-encoding operons. Lastly, the production of active bacteriocin by Lacticaseibacillus paracasei NKN344 was validated, showing inhibitory activity against Bacillus cereus, a major food spoilage bacterium. Results of the current study proved that Lacticaseibacillus paracasei NKN344 isolated from Chilika curd has promising probiotic properties and seems favorable for its use in functional fermented foods.