Abstrait

Quantitative Analysis of the Composition and Abundance of Nitrifying Bacteria on Simultaneous Nitrification and Denitrification in SBBR

Hongwei Rong, Jingyin Wang, Chaosheng Zhang and Guanhua Gao

To reveal the effect of dissolved oxygen (DO) on microorganism community structure during simultaneous nitrification and denitrification (SND) in sequencing biofilm batch reactor (SBBR), the molecular biological techniques of denaturing gradient gel electrophoresis (DGGE), cloning and real-time PCR were applied. DGGE sequence analysis showed some kinds of populations had been highly preponderance consistently, and cloning and phylogenetic tree of AOB gene revealed Nitrsospira was dominant species. The real-time PCR analysis indicated that the amount of the AOB and NOB both had most copy number in the lower surface, and the quantity relation of AOB and NOB population between three samples was “lower surfaceï¼�?upper surfaceï¼�?internal layer”. The result proved that DO concentration directly affected the proportion of aerobic fraction and anoxia fraction in the biofilm, which led to an effect on efficiency of SND.