Characterization and comparison of microbial community of different typical Chinese liquor Daqus by PCR-DGGE

Abstract

To identify and compare microbiota in Chinese liquor Daqu, which were produced in the different regions using different production process. The DNA exacted from Daqu samples was used as a template for PCR with universal primers of 16S rRNA, 26S rRNA and 18S rRNA, respectively. The amplicons were analysed using denaturing gradient gel electrophoresis (DGGE). It was observed that the bacterial DGGE profile indicated high diversity and predominance of lactic acid bacteria. The results showed that Saccharomycopsis fibuligera and Pichia anomal were dominant yeast species and that several non-Saccharomyces yeasts including Hanseniaspora guilliermondii, Debaryomyces hansenii, Issatchenkia orientalis and Trichosporon asahii were also detected. As for fungal DGGE, Aspergillus oryzae and Absidia blakesleeana were the most common species amongst different samples. Based on the DGGE analysis, a few differences in community structure were found between Daqu samples. A variety of bacteria, yeast and moulds were identified in Daqu samples, in addition to the present knowledge obtained mainly through the traditional culture-dependent methods. Moreover, production temperature played a more decisive role on the formation of micro-organism composition in Daqu than geographical region. PCR-DGGE technique was used in this study to fully observe and asses all microbial community (including bacteria, yeast and mould) in Chinese liquor Daqu for the first time and proved to be effective in profiling Daqu microbial diversity.