Isolation and molecular characterization of lactic acid bacteria isolated from selected fermented food condiments

This study investigated the isolation and molecular characterization of lactic acid bacteria (LAB) from four samples of fermented food condiments in Nigerian; Samples are fermented unsoften locust beans (iru woro), fermented soften locust beans (Iru pete), fermented African oil bean seeds (Ugba), fermented melon seed (Cirulus colocynthis) (Ogiri). Samples were obtained from Sabo market in Ogbomosho, Oyo State, and processed according to standard microbiological techniques on MRS medium under anaerobic conditions. Total LAB counts ranged from 1.2 × 10⁶ to 1.9 × 10⁶ CFU/g, with the highest count in the fermented unsoften locust beans (iru woro). Five distinct LAB isolates were obtained and molecularly characterized via 16S rRNA gene sequencing. From the BLAST analysis, with a similarity of 99-100% to the reference strains, the isolates were identified as Lactobacillus acidophilus IR1, Lactobacillus delbrueckii UG1, Lactobacillus johnsonii OG1, Lactococcus garvieae OG2, and and Lactococcus lactis IW1. All the isolates have been deposited in NCBI GenBank under accession numbers PQ758599, PQ758600, PQ555637, PQ555638, and PQ555639, respectively. The phylogenetic analysis showed that the isolates clustered within the Lactobacillaceae family and had a close relationship to other known probiotic strains. This shows the very high diversity that exists among the beneficial LAB in traditional Nigerian fermented foods and their availability for further studies in food biotechnology and probiotic development.