ABSTRACT
Anaerobic ammonium oxidation is an important part of the biological nitrogen removal process, and the performance of the process is determined by the microbial community structure. Low-temperature anaerobic ammonium oxidation technology has good prospects for saving a lot of energy, and anaerobic ammonium oxidation bacteria play a vital role in the removal of total nitrogen from waste water. To explore the microbial community structure changes of anammox reactor in sewage treatment during the cooling process (from 30 degrees C to 20 degrees), the total amount of the microbial, the quantity of anaerobic ammonium oxidation and the change of functional microbial community were investigated in a sewage treatment process using the phospholipid fatty acid method (PLFA), quantitative PCR and the clone library of bacterial 16S rRNA. The PLFAs results showed that the total amount of microbial was first decreased and then gradually increased with the running time, when the temperature dropped from 30 degrees C to 20 degrees C, and the NH4+ -N content in the effluent of the system was decreased. The quantitative PCR results showed that 16S rRNA gene copies of anammox bacteria increased from 1.19 x 10(8) copies x mL(-1) to 1.86 x 10(8) copies x mL(-1) in the wastewater. The PCR-DGGE results showed that when the temperature decreased, the anammox bacteria were further enriched. A shift of anammox bacteria community from single Candidatus Kuenenia sp. to a combination of Candidatus Brocadia sp. and Candidatus Kuenenia sp. was observed.
