Application of PCR-DGGE to Analysis of Microbial Community Diversity in MBRs

In order to reveal microbial diversity of activated sludge in membrane bioreactor(MBR),sludges in MBRs treating different wastewater were sampled.The genomic DNA of microbial communities was extracted di-rectly by cell lysis.After the 16S rRNA genes(V3 region)were amplified by using the universal primerst,he po-lymerase chain reaction(PCR)products separated by denaturing gradient gel electrophoresis(DGGE)were about 240,bp.The denaturant gradient was from 30% to 60%.The profile of DGGE showed that different sludges had differ-ent DNA finger printingsT.here exist some common and specific bands in both MBRs.The amount of the common microorganisms were different in the two MBRs.The specific microorganisms were gradually become the predomi-nant communities after a long period of cultivation and acclimatization because of the different water quality.