Probiotic Potential of Lactic Acid Bacteria Isolated from Local Foods in Ado-Ekiti, South West Nigeria

Abstract

Probiotics are live microorganisms acclaimed to provide health benefits when consumed and are generally considered safe for  consumption. The lactic acid bacteria (LAB) are common groups of bacteria with certain health benefits, including the ability of some  strains to play probiotic roles. Some indigenous fermented foods localized in Ado-Ekiti carry LAB that may have some probiotic  properties. The aim of this study was to determine the probiotic potential of some LAB isolated from some local fermented foods in Ado- Ekiti. Samples of locally fermented foods: “garri”, “iru”, “ogi”, and “fura de nono” were obtained from the local market in Ado-Ekiti for  isolation of LAB. All samples were cultured using standard methods. A total of sixteen (16) isolates were recovered from the samples and  screened for their antibacterial activity against four human pathogenic bacterial strains which were Escherichia coli, Pseudomonas  aeruginosa, Salmonella typhi, and Staphylococcus aureus. The LAB with enhanced antibacterial activity were further screened for  potential probiotic characteristics using pH tolerance test, bile salt tolerance test, NaCl tolerance test, temperature sensitivity, and lactose  utilization. The LAB isolates identified from the local food samples included: Lactobacillus fermentum, Acetobacter spp., Bacillus  subtilis, Lactobacillus plantarum, and Lactococcus lactis. Out of the 16 strains obtained, five strains that showed considerable  antibacterial activity were evaluated for their probiotic potential. The five strains were susceptible to conventional antibiotics. It was also  shown that the five strains were able to grow at the selected range of pH 4.0 – 7.0, they were able to survive at the temperature ranges  between 20 oC and 45 oC, they were lactose-tolerant, and they were able to tolerate 1 – 5% sodium chloride (NaCl) concentration. Some  isolated LAB exhibited excellent probiotic characteristics and thus can be recommended as a potential use as probiotics. The findings of  this study suggest that popular local foods in Ado Ekiti, such as “garri”, “iru”, “ogi”, and “fura de nono”, harbor some LAB with potential  probiotic properties, and can be explored for possible health benefits.