Probiotic characterization of Bacillus sp. strains from fermented palm wine and investigation of cellulolytic potential in regards to application as animal feed additive

Abstract The main objective of this study was to assess cellulolytic probiotic strains from traditional fermented beverages such as palm wine in order to supplement the animal feed and strengthen the gut health of the animal for better digestibility and absorption. In the present study, different types of microbes were isolated from traditionally prepared palm wine and analyzed for their probiotic nature. For any microbe to be probiotic in nature, it has to sustain the harsh conditions of human gastrointestinal tract such as acid tolerance, bile tolerance at lower range of pH and other properties like auto aggregation test, cell surface hydrophobicity test with non-polar hydrocarbons for evaluating its capabilities to adhere to the intestinal cells and antimicrobial nature against pathogens. Bacillus mycoides strain PR04 and Bacillus subtilis strain PR21 were found to be resistant to acid and bile in simulated artificial gastrointestinal tract model, found to be greater than 55% hydrophobic with xylene and n-hexadecane and also showed antimicrobial activity towards pathogenic strains like Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Salmonella typhimurium respectively. The cellulolytic activity of the isolates PR04 and PR21 was evaluated in (0.2-2) % CMC (carboxymethyl cellulose) plate. Bacillus mycoides PR04 and Bacillus subtilisPR21 could degrade carboxymethyl cellulose, filter paper and sugarcane bagasse. The degradation of sugarcane bagasse was confirmed by Scanning electron microscopy and filter paper degradation after 4 days of incubation at 37°C. Cellulase gene of the identified Bacillussp. strains was amplified by primers CF5’-‘ACAGGATCCGATGAAAACGGTCAATTTCTATTTT-3’and CR5’-ACTCTCGAGATTGGGTTCTGTTCCCAAT-3’. This study proposes potential probiotic Bacillus mycoides PR04 (Accession no. OR625070) and Bacillus subtilis PR21 (Accession no.OR625072) in application as animal feed additive to assist in its digestibility and encourage the gut health.