Abstract:In order to ascertain the diversity of bacteria and lactic acid bacteria in the aged and aging pit mud from Guxiangyang distillery in Xiangyang city，Hubei province，the pit mud samples were collected and studied by denaturing gradient gel electrophoresis.The results showed that the microbial community structure in the aged pit and aging pit mud was much different.The bacterial community diversity in the aged pit mud was higher and could be divided into two phyla：Firmicutes and Bacteroidetes.Bacteria belonging to Firmicutes from the aged pit mud could be divided into 6 families，and could be further divided into 6 known genera，and 3 pending genera.Generally，the bacteria in aged pit mud are mainly composed of Firmicutes，which is represented by Clostridium.The bacterial diversity in aging pit mud was lower than that of aged pit mud，and mainly composed of Lactobacillus acidophilus.Further research indicated that the lactic acid bacteria in the aged pit mud are mainly lactic acid bacteria belonged to Enterococcus and Lactobacillus.From the perspective of vertical spatial distribution，the community structure of bacteria and lactic acid bacteria in the aging pit mud had not changed obviously.