ISOLATION, BIOCHEMICAL AND MOLECULAR CHARACTERIZATION OF LACTIC ACID BACTERIA FROM WHEY OF A NIGERIAN TRADITIONALLY FERMENTED YOGHURT DRINK

Abstract

Lactic Acid Bacteria (LAB) have been identified as an essential group of microorganisms due to the health-promoting effects they exert on human and animal hosts. This research was conducted to, isolate LAB from whey obtained from kindirmo a locally fermented cow milk product in Nigeria, characterize the strains based on physiological and biochemical properties and  identify them using 16SrRNA sequencing.  A total of 32 samples were collected aseptically and the whey cultured on an MRS and M17 media. Physiological and biochemical results showed that the isolated organisms, which were mostly rod and cocci shaped, included gram positive and catalase negative species. The organisms did not only vary in their abilities to tolerate and grow at different concentrations of pH, temperature and NaCl, but were able to ferment twelve different sugars distinctively. The ten most desirable strains obtained were subsequently screened by molecular techniques using PCR and sequence analysis. The PCR results revealed that 98% of the identified organisms were Lactobacillus bulgaricus, Lactobacillus casei, Lactobacillus acidophilus, Streptococcus thermophilus, Lactobacillus gasseri and Lactobacillus plantarum. These findings showed that kindirmo could be an excellent and potential source of probiotic bacteria, which are often the main sources of probiotics. Further screening and identification processes were recommended to ascertain the functional, technological and probiotic properties of the strains.