In vitro evaluation of probiotic potential of Lactobacillus paracasei BIOTECH 10363 strain isolated from Tapuy

Fermented foods can be a source of potentially probiotic microorganisms as they contain different types of lactic acid bacteria. In the Philippines, there are a variety of traditional fermented food products that may harbor probiotics. This study determined the probiotic properties of Lactobacillus paracasei BIOTECH 10363 isolated from Tapuy, an indigenous alcoholic beverage made from fermented glutinous white rice. The acid and bile resistance, antibacterial, cell surface hydrophobicity, auto-aggregation, NaCl tolerance, hemolytic, and antibiotic sensitivity properties of L. paracasei BIOTECH 10363 were evaluated in vitro. The isolate displayed resistance to acid (pH 3 to 5) and bile (0.1 to 0.5%). Its cell-free supernatant exhibited strong inhibitory activity against Escherichia coli. Higher affinity to xylene and chloroform was observed in L. paracasei BIOTECH 10363. This suggests that the cell surface of the isolate has hydrophobic and electron donor (basic) properties. Moreover, the isolate had a strong auto-aggregating phenotype. Cell surface hydrophobicity and strong auto-aggregation activity could enable the isolate to adhere, colonize and survive in the gastrointestinal tract. The isolate could withstand MRS broth with 9% NaCl. It also displayed γ-hemolytic activity in blood agar plates indicating the non-hemolytic nature of the isolate. L. paracasei BIOTECH 10363 expressed sensitivity against various cell wall synthesis inhibitors (amoxicillin, ampicillin, augmentin, penicillin, and cefaclor) and protein synthesis inhibitors (streptomycin, chloramphenicol, clindamycin, erythromycin, and tetracycline). However, it displayed intrinsic resistance toward kanamycin. The findings of this study showed the promising potential of L. paracasei BIOTECH 10363 as a candidate probiotic strain as it exhibited desirable attributes in vitro.