Abstract: Four strains of lactic acid bacteria, designated as L1, L2, L3 and L4 respectively, were isolated and preliminarily identified from six types of traditional Xinjiang yoghurt by Gram′s staining, contact enzyme test and rennet test. The 16S rDNA sequence analysis results demonstrated that the strains of L1 and L2 were Lactobacillus casei, and the strains of L3 and L4 were Lactobacillus plantarum; the content of exopolysaccharides produced by the lactic acid bacteria strains of L1, L2, L3 and L4 was 176 mg/L, 248 mg/L, 205 mg/L and 294 mg/L respectively, indicating that the highest and lowest exopolysaccharides was obtained in the strains of L4 and L1, respectively. Our study enriched the available types of exopolysaccharides producing fermentation starter of lactic acid bacteria.

Key words: traditional Xinjiang yogurt, exopolysaccharides, lactic acid bacteria, screening, identification