Abstract:

In the present study, changes in the bacteria composition of sweet potato sour liquid during the natural
fermentation process were investigated by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE).
Total bacterial DNA was extracted from the samples, and the touch down PCR was applied to amplify the V3 region of 16S
rDNA for identification based on DGGE fingerprints. The specific gel bands were excised, then sequenced and analyzed
by comparison with the GenBank database. Results showed that the representative bacteria during the fermentation process
of sour liquid were identified as Leuconostoc, Acinetobacter, Reyranella, Pantoea, Cronobacter, Spiriiium which belong
to Firmicutes and Proteobacteria, respectively. Flavobacterium belonging to the phylum Bacteroidetes and Chroococci
belonging to the phylum Cyanobacteria were also involved. The coefficient of similarity showed that the similarity of
bacterial community in sweet potato sour liquid ranged from 88.5% to 71.4%.

Key words: sweet potato sour liquid, denaturing gradient gel electrophoresis (DGGE), dominant bacteria, phylogenetic tree, flocculent microorganisms