fermented grains
Choose DNA samples of good quality and used the universal primers of bacterial 16S rRNA gene to amplified the V3-V4 regions. The PCR amplification was conducted in a TransStart Fastpfu DNA Polymerase.AxyPrepDNA gel recovery kit (AXYGEN) was used to cut the gel to recover the PCR product. Then Tris-HCl eluted, 2% Agarose electrophoresis detection. According to the preliminary quantitative results of electrophoresis, the PCR products were detected and quantified by QuantiFluor  -ST blue fluorescence quantitative system (Promega), and the corresponding proportions were mixed according to the sequencing volume requirements of each sample, then the library was constructed. Finally, the library was sequenced on the Illumina MiSeq platform.