Conventional procedures of identification are laborious and time consuming because they depend on growth of microorganism in that particular environment and hence, sometimes, give misleading results while molecular methods relies upon generating a large number of copies of a specific part of its genome for identification of unknown isolates and enables the problem of poor identification. The identification of a microbial isolate to genus level imparts a partial characterization of the isolate revealing a lot of information about that organism. Lactic acid bacteria are very significant to human health due to their probiotic attributes, production of antimicrobial substances and subsequently to inhibit pathogenic bacteria. Bile tolerance has been one of the major probiotic criterion while selecting the isolate for probiotic properties. This work aims at looking directly at the genome of bile tolerant Lactobacillus isolates using genotypic and phenotypic characteristics. The isolates were identified by sequencing specific region of 16 S r DNA segment, after amplification by PCR, and then comparing the results to sequences from related database. The results from both conventional and molecular methods were then compared. Twenty five isolates (25) of Lactobacillus fermentum were isolated from fecal samples and identified using API- 50 CH. The isolates were further identified using molecular methods using polymerase chain reaction (PCR) for amplification of 16S rRNA gene to confirm their identities. The genotypic characterization however showed that 84% of the organisms identified using conventional method as L. fermentum correlated, while 16% did not correlate; 2 were identified as Lactobacillus planterum, 01 as L. delbrueckiiand 01 as L.paraplanterum.
Characterization of a Lactobacillus brevis strain with potential oral probiotic properties