Characterization of microbial communities in strong aromatic liquor fermentation pit muds of different ages assessed by combined DGGE and PLFA analyses

Abstract

The pit mud (PM), a specific fermented soil, is an essential material for the fermentation of strong aromatic liquor. The microbial diversities of PM from different ages of strong aromatic liquor fermentation pits (20-, 50-, 100-, 200- and 300-year old) were investigated using combined phospholipid fatty acids (PLFAs) and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) methods. The total PLFA content of 20-year-PM (477.32nmol/g) was significantly higher than that of other PMs (P<0.05), and G+ bacteria biomarkers' biomass dominated in PMs. Results of bacterial 16S rDNA gene fragment analysis suggested that a total of 31 bands belong to 8 families Clostridiaceae, Lactobacillaceae, Synergistaceae, Sphingomonadaceae, Ruminococcaceae, Clostridiales_Incertae Sedis XI, Lanchnospiraceae and Plannococcaceae) were identified, and Clostridiales (11 bands), Lacotobacillales (5 bands) and Bacillales (3 bands) were main microorganisms in PM. Fungal 18S rDNA gene fragment identification demonstrated that a total of 6 bands identified, and only 3 genus, Wickerhamomyces, Kluyveromyces and Pichia, were sequenced and Pichia anomala was the main yeast in PM. This is the first report about the microbial community structure and diversity in PMs of different ages by combined PLFA and PCR-DGGE analyses.