Bacillus spp. – A Potential Probiotic

Aim: To determine the probiotic characteristics for selected Bacillus spp.

Study Design: The study was aimed for evaluating the in vitro probiotic properties such as acid and bile tolerance, adhesion ability and antibacterial activity of four strains of Bacillus spp. such as Bacillus cereus, Bacillus subtilis, Bacillus tropicus and Bacillus licheniformis.

Place and Duration of Study: Department of Dairy Microbiology, Dairy Science College, Hebbal, Bengaluru, Karnataka, India, study conducted between June 2023 to April 2024.

Methodology: Probiotic nature was evaluated by determining the percentage survivability of four strains of Bacillus spp. at pH 2.0 and 0.3 % ox bile concentration. Percentage adhesion was determined using xylene hydrocarbon and antibacterial activity of four Bacillus spp. against test organisms like Escherichia coli, Salmonella spp. and Staphylococcus aureus was tested using agar well diffusion method.

Results: In this present study four strains of Bacillus spp. that is B. cereus, B. subtilis, B. tropicus and B. licheniformis exhibited good probiotic characteristics such as acid, bile tolerance, adhesion ability and antibacterial activity against test organisms. Among all the strains B. subtilis have exhibited highest survival rate of 88.01 and 74.86 % at pH 2.0 and 0.3% ox bile concentration respectively, whereas B. tropicus showed 14.5% adhesion ability to xylene hydrocarbon. Regarding antibacterial activity B. subtilis exhibited highest inhibitory zone of 7.1, 6.2 and 4.0 mm against E. coli, Salmonella spp. and Stap. aureus respectively.

Conclusion: In conclusion, the results of present study suggested that B. subtilis showed good in vitro probiotic characteristics.