Probiotic activities of lactic acid bacteria from Cassava and Ogi effluents

The Cassava and Ogi effluents include substantial quantities of bacteria, particularly lactic acid (LABs), which has garnered much attention as probiotics to improve human health. The potential desirable characteristics of the LAB as a probiotic have necessitated the screening of various fermentative compounds to identify a good source of LAB for probiotic use. This was designed to evaluate the probiotic activities of 10 Lactic Acid Bacteria (LAB) strains previously isolated from Cassava and Ogi effluents. Probiotic activities, including pH, titratable acidity, bile salt tolerance, and safety (DNase, hemolysis, and antibacterial activity) were examined using standard laboratory techniques. The pH and total titratable acidity (TTA) of last stage effluents samples generated during Ogi, and Cassava fufu production revealed that the pH of the samples ranges from 3.1 to 5.3 and the TTA ranges from 0.21 to 0.26 %. The pH and TTA of the samples clearly showed that they were acidic. It revealed that the maximum optical density values at 0.2% and 0.3% bile tolerance were 2.40±0.75 and 3.62±0.11 for LAB 9. All the isolates showed appropriate growth in the presence of bile and acid tolerance pH₃-pH₇. The safety evaluation of the LAB strains revealed negative hemolysis (Gamma hemolysis) and negative DNase activity. Results of antibacterial activity indicate that the LAB strains from Ogi and Cassava last stage effluent samples were found to inhibit the growth of most of the pathogenic clinical strains of S. aureus, E. coli, K. pneumoniae, and B. subtilis with the highest inhibition zones exhibited from the LAB strains was 23 mm. LAB1, LAB 2, LAB 3, LAB5, LAB6, LAB9, and LAB10 showed no inhibition activity against E. coli. Our overall findings indicate that 10 LAB strains displayed varying species-specific inhibition and their varying in vitro bioassay should not undermine the potential probiotics' desirable characteristics but rather substantiate their role in vivo evaluation of the strain for their potential as desirable probiotics that could be harnessed and used for the formulation of nutriceutical supplement to improve human wellbeing.