Abstract:

Samples of koumiss during the fermentation period were taken for the extraction of metagenomic DNA. PCR
amplification of the 16S rRNA gene sequence was conducted followed by 454 pyrosequencing to analyze the succession of
bacterial community structure. The main findings were as follows: 1) The highest diversity of bacteria occurred at the early
stage of fermentation, while bacterial abundance showed the maximum value at 72 h. 2) Firmicutes and Proteobacteria were
the dominant phyla in koumiss fermentation. Lactobacillus and Lactococcus were the dominant bacterial genera. 3) With the
extension of fermentation time, there were rising or falling trends in bacterial counts at phylum and genus levels. This study
has provided a new understanding of dynamic changes in bacterial community structure during koumiss fermentation, which
may offer some references for exploring bacterial community structure in other fermented dairy products.

Key words: koumiss, traditional fermentation, bacterial community structure, 16S rRNA