Comparison of Microbial Community Structures of Kefir and Tibetan Kefir Grain

Microbial community structures of Tibetan kefir and Kefir were compared by using PCR-DGGE.Through clustering analysis of microbe DGGE,bacteria community showed a 78%-84% similarity among different Tibetan kefir,and 50%-70% among kefir from different regions.DGGE profiles of yeast indicated 80%-92% similarity of yeast community among 3 Tibetan kefirs,and a 50%-75% similarity among kefir from different regions.The comparison analysis showed that Tibetan kefir is likely to be one of the Kefir series.The results of sequence alignment exhibited that V3 region in 16SrDNA was highly similar between bacteria from Tibetan kefir and lactic acid bacteria,and the sequence data of the strongest band showed a 100% homology to Lactococcus lactis,others to Lactobacillus kefiranofaciens,Leuconostoc mesenteroides,Lactobacillus acidophilus,Lactobacillus casei.The sequence analysis of yeast showed that there existed Saccharomyces unisporus and Candida humi in Tibetan kefir.