Evaluation of Probiotic Quality of Lactic Acid Bacteria Isolated from Locally Fermented Palm Wine and Kunu from Sellers in Oluku and Oba Markets in Benin City, Edo State, Nigeria

Abstract

Commonly used probiotics bacteria are the lactic acid bacteria (LAB) from the gastro intestinal tract. However, other LAB from exogenous origin having similar functional properties can also confer health benefit to the host. The objective of this work is to evaluate the probiotic quality of lactic acid bacteria isolated from locally fermented palm wine and kunu from sellers in Oluku and Oba markets in Benin City, Edo State, Nigeria using standard microbiological methods. Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus acidophilus and Lactobacillus casei were isolated from palm wine and kunu, and they were assessed for the following: resistance to simulated gastric and intestinal fluids, resistance to bile salt and low pH, haemolytic activity and their antimicrobial characteristic against some bacteria pathogens, mainly; Staphylococcus aureus, Klebsiella pneumonia, Pseudomonas aeruginosa and Escherichia coli. Results showed resistance/tolerance and cell viability of all LAB isolates to simulated gastric and intestinal fluids, and low pH resistance of all isolates were negative at pH 2 but positive with viable cell growth at pH 3. The L. fermentum, L. plantarum, and L. acidophilus were not haemolytic while L. casei was haemolytic (alpha haemolysis). The LAB isolates were more resistance to bile salt (with viable cell growth) at 0.1% and 0.3% concentration compared to 0.5% concentration. Antibacterial activity testing showed that L. acidophilus and L. casei had antibacterial property against Pseudomonas aeruginosa, while L. plantarum and L. fermentum had antibacterial property against Staphylococcus aureus and Klebsiella pneumonia respectively. While all lactic acid bacteria (Lactobacillus species) isolated from the locally fermented food/product samples demonstrated strong probiotic characteristic properties, further in-vivo study to establish their probiotic potential is recommended.