Evaluation of Probiotic Potential of Lactic Acid Bacteria Isolated from Raphia Palm Wine (Raffia mambillensis)

Aim: The present study was undertaken to assess the probiotic potential of lactic acid bacteria strains isolated from raphia palm wine (Raffia mambillensis O.) of the South West region of Cameroon.

Study Design: The study site and sample were randomly chosen and the responses assessed were submitted to analyses of variance.

Place and Duration of Study: The study was carried out in Ekona in the South West region of Cameroon, between February 2017 and October 2018.

Methodology: Physicochemical analyses were performed to characterize the Raphia palm wine samples. Lactic acid bacteria were isolated from these samples using pour plate method, and the isolates were tested for their antimicrobial activity, low pH and bile salts tolerance, antibiotic sensitivity, hemolytic activity and enzymes production. The active isolates were identified phenotypically using API 50 CHL.

Results: The results revealed that among the nine isolates, only three were active against Escherichia coli BL21, Escherichia coli, Salmonella typhi, Salmonella enterica and Staphylococcus aureus with inhibition diameters ranging from 10 to 25 mm. The three isolates which exhibited antimicrobial activity were able to survive at simulated stomach pH (pH 3.0) with survival rate above 80% and in the presence of bile salts at 1% with survival rates above 50%. All three isolates gave negative results for hemolytic activity and were resistant to most antibiotic treatments. These three isolates produced β-galactosidase, which is beneficial for lactose intolerance. They also produced some non-carcinogenic enzymes including leucine arylamidase, crystine arylamidase, acid phosphatase, α-galactosidase, α-glucosidase, β-glucosidase, and N-acetyl-β-glucosamidase. Identification of these three isolates with API kit 50 CHL reveals that they are Lactobacillus lactis, Lactobacillus plantarum and Lactobacillus brevis.

Conclusion: Our findings revealed that raphia palm wine can be an excellent source of
probiotic lactic acid bacteria.