Assessment of Probiotic Activities of Lactic Acid Bacteria Isolated from Cassava Mill Effluent in Awka Metropolis

Abstract

Lactic Acid Bacteria (LAB) are renowned for their probiotic benefits, including immune function enhancement, gut microbiota balance, and prevention of gastrointestinal disorders. While traditionally sourced from fermented foods and dairy products, environmental niches have emerged as potential reservoirs for novel LAB strains. This study assessed the probiotic potential of LAB strains isolated from Cassava Mill Effluent (CME) in Awka metropolis. LAB strains were isolated from CME samples using MRS agar supplemented with 1.0% CaCO3 and incubated micro-aerophilically at 37oC for 48 hours. The isolates were identified based on microscopic, macroscopic, biochemical, and molecular characteristics. Probiotic properties, including acid tolerance, bile salt tolerance, phenol tolerance, salt concentration tolerance, temperature tolerance, and antimicrobial activities, were evaluated. The LAB counts ranged from 5.45 x 104 ± 1.11 cfu/ml to 9.93 x 107 ± 1.87 cfu/ml. The isolates were identified as Lactococcus lactis, Lactobacillus acidophilus, and Lactobacillus gallinarum. L. lactis and L. acidophilus exhibited acid tolerance, remaining viable for 3 h, while L. gallinarum was sensitive to acid conditions. All isolates showed bile salt tolerance, phenol tolerance, and temperature tolerance. The LAB strains demonstrated antimicrobial activities, attributed to bacteriocin production, against E. coli, K. pneumonia, S. aureus, E. aerogenes, and E. faecalis. The findings suggest that CMF can serve as a natural reservoir for LAB strains with probiotic potential, useful for reclamation of microbiota balance in the human gut and intestines, promoting health and preventing diseases.