MICROBIAL COMMUNITY STRUCTURE OF THERMOPHILIC ANAEROBIC DIGESTER SLUDGE AS REVEALED BY PMA-PCR

Abstract

 Dead microbial cells derived from sewage sludge (the mixutre of primary sludge and waste activated sludge) cause serious problems on microbial community analysis of anaerobic sludge digesting sewage sludge. In this study, PMA-PCR was employed to inhibit the amplification of DNA derived from dead microbial cells, and microbial community of an anaerobic thermophilic sludge digester was investigated. The results revealed that conventional DNA-based microbial community analysis overestimates the richness and diversity of the anaerobic digester sludge. Microbial members eliminated by PMA-PCR were mainly belonging to Alphaproteobacteria, Gammaproteobacteria (mostly Betaproteobacteriales) and Actinobacteria. Microbial community of the anaerobic thermophilic digester revealed by PMA-PCR was characterized by abundant 15 OTUs (≥1% relative abundance), occupying more than 80% of the community.