Biochemical and molecular identification of lactic acid bacteria isolated from camel milk in Tunisia

Abstract

This study aimed to compare biochemical vs. molecular methods for identification of Lactic Acid Bacteria (LAB) isolated from camel milk. Ten strains among 62 LAB isolates were chosen for identification using API50CHL and 16S rDNA sequencing. Only Gram-positive and catalase-negative isolates were considered. Citrate utilization, in the presence of carbohydrates, was studied. These strains were tested from the growth in NaCl (4, 6.5%), growth at different temperature (10-45°C) and growth at different pH values (4.2, 9.6). Results indicated that ten (10) strains were identified as: Lactococcus lactis, Lactobacillus pentosus, Lactobacillus plantarum, Lactobacillus brevis and Pediococcus pentosaceus by using biochemical method. However by molecular methods, all strains were identified as Enterococcus faecium. It was, thereby, concluded that each technique had its limitations but the molecular analysis is the most reliable.