Identification of lactic acid bacteria isolated from traditional drinking yoghurt in tribes of Fars province

Abstract

Morphological, cultural, physiological and biochemical characteristics were employed to identify lactic acid bacteria (LAB), isolated from drinking yoghurt in different areas in Fars province, Iran. From 18 drinking yoghurt samples a total of 673 LAB positives were determined, in which 117 (17.38%) and 556 (82.62%) were identified as lactic acid cocci and lactic acid bacilli, respectively. Additionally, our biochemical tests showed the occurence of 52 (44.44%) Lactococcus lactis subsp. cremoris and 65 (55.56%) Leuconostoc mesenteroides subsp. cremoris among lactic acid cocci, and in the case of lactic acid bacilli, Lactobacillus helveticus 85 (15.3%); Lactobacillus plantarum 124 (22.3%); Lactobacillus brevis 117 (21%); Lactobacillus casei subsp. casei 86 (15.5%) and Lactobacillus delbrueckii subsp. bulgaricus 144 (25.9%).Among lactic acid cocci and bacilli, Leuconostoc mesenteroides subsp. cremoris and Lactobacillus delbrueckii subsp. bulgaricus were found to be the more dominant species, respectively. The current study constitutes the first step in the designing process of LAB starter cultures, in order to protect the typical organoleptic characteristics of traditional drinking yoghurt. However, in the future we can consider genetical characterization and selection of the most desirable strains which can assess their potential as starter cultures for commercial use.