Assessment of Probiotic Potentials of Lactic Acid Bacteria Isolated from some Locally Fermented Foods

Abstract

Some locally fermented foods were collected from different locations in Abakaliki, Nigeria, plated out on MRS agar and were analyzed using standard microbiological methods. Ten isolates were obtained which were of four major different species of lactic acid bacteria such as Lactococcus sp, Streptococcus sp, Pediococcus sp and Lactobacillus sp. The probiotic properties showed that the maximum cholesterol assimilation potential of 57.0% was for isolate G3 at 10% cholesterol concentration and 24.4% for G3 at a 20% cholesterol concentration while the least value of 17.3% for A2 at 10% cholesterol concentration and 10.9% for Y5 at 20% concentration of cholesterol. Isolates A1 and G2 showed maximum bile salt assimilation of 84.5% at 8% w/v concentration of cholesterol, 58.6% for OG4 at 12% w/v, 43.6% for F1 and Y5 at 20% w/v, 46.3% for F1, OG3 and Y5 at 40% w/v cholesterol respectively. The acid tolerance test on the isolates all showed positive results with growth at pH 3.0, pH 4.0 and pH 5.0. This implies that the lactic acid bacteria isolated were able to grow at different pH values. All the isolates were negative to alpha hemolysis and beta hemolysis. All other isolates were positive to gamma hemolysis except isolates A2 and G1. All the isolates had good probiotic properties at varying degrees except isolate A2 and G1 that were negative to gamma hemolysis. This result provided a baseline knowledge for the selection of probiotics in functional foods and starter cultures in industries.