Lactic acid bacteria (LAB) are included in the groups of microbiota Beneficial; they are widely used in the field of biotechnology thanks to their technological and functional quality as well as nutritional. Accordingly, the objective of this study is the isolation of homolactic-type lactic acid bacteria from three different biotopes: barley with traditional lben, raw milk barley and fermented barley, having shown a technological property important including the ability to grow and adapt to different environments, this characterization is expressed by measuring the optical density at 600 nm using a spectrophotometer.

The isolated strains are purified on the solid MRS medium which is suitable for the specific search for lactobacilli. Initially, a pre-identification is carried out on the basis of the classic technique of microbiology which includes the study of morphological, physiological and biochemical character.

The phenotypic identification of the selected strains is then completed by the use of an API 50CHL Medium strip (Bio-Mérieux reference 50410) in the interest of making the results more reliable. Thus, the species is given automatically by the computer-aided database of "APIWEB" version (5.1).

The results obtained revealed that the five selected strains are identified as lactic acid bacteria that belong to the species: Lactobacillus plantarum, Pediococcus spp, and Lactococcus lactis ssp lactis.

Index Terms- Lactic acid bacteria, phenotypic identification, Lactobacillus plantarum, Lactococcus lactis ssp lactis, Pediococcus spp.