Evaluation of probiotic and antimicrobial properties of Lactobacillus species isolated from decaying Musa acuminata

The increasing interest in probiotics has heightened the need to explore natural sources of beneficial microorganisms. While dairy products have long been a staple for probiotic isolation, plant sources offer a diverse array of novel strains of probiotics with antimicrobial properties. This study aimed to evaluate the probiotic potentials and antimicrobial activity of Lactobacillus species isolated from decaying Musa acuminate (banana). Ten different decaying banana samples were obtained from different banana vendors. Lactobacillus was isolated in deMan Rogosa Sharpe (MRS) agar containing 0.5% CaCO₃ and was identified based on cultural, biochemical and molecular characteristics. The isolated Lactobacillus species were screened for their probiotic properties using different parameters. The antibacterial activity of the effective Lactobacillus species was evaluated using agar well diffusion. The analyses of their probiotic properties showed that the isolated Lactobacillus species exhibited good tolerance to acidic pH, high tolerance to sodium chloride and 0.3 bile salt concentration and were sensitive to proteolytic enzymes. The result of antibacterial activity showed that the isolates exhibited a wide spectrum of antimicrobial activity against gram-positive and negative bacteria in the agar well diffusion test. The gene sequence analysis identified the isolates as Lactobacillus plantarum, Lactobacillus casei, Lactobacillus fermentum and Lactobacillus rhamnosus. This study has shown that the banana is a potential source of probiotic Lactobacillus species with broad-spectrum antimicrobial properties.