Study On Identification And Fermentation Properties Of Dominant Lactic Acid Bacteria From Koumiss

Koumiss is a kind of unique dairy beverage, it is beneficial for health and with a better market development value. As a traditional drinks for centuries, microbial resources in koumiss are rich and it is an important source of the lactic acid bacteria. Therefore, this study combine the morphological,traditional physiological and biochemical characteristics analysis,16 S rRNA sequence analysis and PCR-DGGE, identificating the dominant lactic acid bacteria strains and analysis the biodiversity, and fermentation properties during fermentation were determinated to promote the industrialization process.The main conclusions are as follows:(1) 10 dominant species of lactic acid bacteria were identified from the samples by PCR-DGGE, including Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus kefiranofaciens, Lactobacillus fermentum, Lactobacillus jensenii, Lactobacillus brevis,Lactobacillus helveticus, Lactococcus lactis, Streptococcus thermophilus and Lactobacillus casei. Conclusion: Streptococcus thermophiles were appeared in all koumiss samples. The dominant species of koumiss in Xinjiang were Lactobacillus kefiranofaciens, Lactobacillus brevis and Lactobacillus helveticus while the dominant species in samples of Inner Mongolia were much different.(2) The results of isolation and identification of lactic acid bacteria in koumiss from Inner Mongolia were shown as 1 strain of Lactobacillus casei, 1 strain of Lactococcus lactis and 7 strains of Enterococcus durans. Besides, it may be used in the production of new-styles fermented dairy products as the isolates were growth in good condition.(3) Compared with single strain of Lactobacillus casei and Streptococcus thermophiles in mare’s milk, Lactobacillus casei has a better fermentation properties as the viable counts、the pH value and the titratable acidity were 2.37×1010 CFU?mL-1、3.81 and95.00 oT, while they were 4.85×108CFU?mL-1、 4.13 and 75.00 o T for streptococcus thermophiles. The volatile composition during fermentation progress of Lactobacillus casei and Streptococcus thermophiles in mare’s milk by SPME-GC-MS were all 44. They are same in composition, including the alcohols, aldehydes, ketones, esters, carboxylic acids,hydrocarbons and other categories, but much different in the content.