Evaluation of non-encapsulated and microencapsulated lactic acid bacteria

Abstract

A total of 15 strains of lactic acid bacteria (LAB) were isolated from the broiler chicken’s gastrointestinal tract. All isolates were phenotypical and genetically identified. Among these isolates, only six were biochemical (API 50 CHL and ABIS soft) and genetically (16S rRNA sequencing) confirmed as Lactobacillus acidophilus, Limosilactobacillus fermentum, Levilactobacillus brevis, and Ligilac-tobacillus salivarius. Probiotic properties, including tolerance to pH (pH 2.0 and 3.0), bile salts (0.3% oxgall), hemolysis activity, and antibiotic susceptibility, were evaluated. Three isolates of the latter isolates showed high resistance at low pH values (73.74% to 98.20%) and bile salt concentrations (77.89% to 99.49%). The antibiotic test presented 100% resistance of LAB to gentamicin, lincomycin, enrofloxacin, and streptomycin lower than the 0.5 mm inhibition zone diameter. Selected strains (L. acidophilus IBNA 64, L. salivarius IBNA 33, and L. salivarius IBNA 41) were exposed to the spray-drying process based on observable probiotic potential. A maltodextrin-glucose solution was used as a thermoprotectant. After spray drying, a reduction in strain viability was noted (108 to 104 CFU/g). In conclusion, only L. salivarius (IBNA 33 and IBNA 41) could be used as a possible probiotic, and further studies are needed to ensure their safe application in the animal nutrition field with beneficial effects for improving performance and pathogen microorganism control from intestines equilibrating the microbiota composition.