In Vitro Assessment of Probiotic Potential of an Autochthonous Bacterial Isolate, Pseudomonas mosselii COFCAU_PMP5

Microbiota of the fish gut contains many beneficial bacteria that can be used as probiotics in aquaculture. In this study, several in vitro assays along with an in vivo safety assessment were performed to decipher the probiotic potential of an autochthonous bacterial strain Pseudomonas mosselii COFCAU_PMP5, isolated from the gut of Labeo rohita . The isolate was antagonistic to 14 pathogenic bacteria, survived a wide range of pH (2–9) and tolerated high bile concentration (up to 10%). The strain COFCAU_PMP5 showed significant in vitro mucosal adherence, auto-aggregation capacity, and cell surface hydrophobicity. As a measure of safety prerequisites, the strain was found, besides being non-pathogenic to L. rohita , to be non-hemolytic and sensitive to several antibiotics. Moreover, the strain could produce extracellular enzymes and showed significant free radical scavenging activity, indicating additional beneficial properties. The probiotic potential of the strain Pseudomonas entomophila COFCAU_PEP4, isolated from an autochthonous source, was established by in vitro and safety assessments.