Microbial community structure in a membrane bioreactor determined using PCR-DGGE
利用PCR-DGGE研究膜生物反应器中微生物的群落结构

The microbial community structure of an MBR (membrane bioreactor) in a reclaimed water treatment plant of Tianjin was investigated using PCR-denaturing gradient gel electrophoresis (PCR-DGGE). Investigations on the succession of the total bacterial community in the cultivation and domestication process showed that the microbial community of the inoculated traditional activated sludge changed greatly after a few days in the MBR system. The wastewater inflow had a significant impact on the microbial community during the domestication process. However, it finally stabilized as certain bacteria gradually became the dominant species in the reactor. And a unique microbial community ecosystem was gradually formed in the reactor. Part of the microbial community of dominant bacteria was analyzed through cloning, sequencing and phylogenetic analysis. Ten bacterial 16S rDNA sequences were identified. The homology of these bacteria was more than 97% compared with Aeromonas, Pseudomonas, Nitrosomas, Comamonas and Bacillus. These dominant microorganisms played key roles in the removal of organic pollutants in the MBR system.