论文部分内容阅读
Candidatus Accumulibacter has been identified as dominant polyphosphate-accumulating organisms (PAOs) in enhanced biological phosphorus (P) removal (EBPR) from wastewater.This study revealed the relevance of community structure,abundance and seasonal population dynamics of Candidatus Accumulibacter to process operation of wastewater treatment plants (WWTPs) in China using ppk1 gene as phylogenetic marker.All sludge samples had properties of denitrifying P removal using nitrate as an electron acceptor.Accumulibacter abundance in the anaerobic-anoxic-oxic (A2O) process was the highest (26％ of total bacteria),and higher in winter than in summer with a better EBPR performance.Type-Ⅱ was the dominant Accumulibacter in all processes,and type-Ⅰ accounted for a small proportion of total Accumulibacter.The abundance of Clade-ⅡC as the most dominant clade reached 2.59 × 109 cells/g MLSS and accounted for 87.3％ of total Accumulibacter.Clade ⅡC mainly contributed to denitrifying P removal.Clades ⅡA,ⅡC and ⅡD were found in all processes,while clade-ⅡF was only found in oxidation ditch process through phylogenetic analysis.High proportion of clade ⅡD to total Accumulibacter led to poor performance of aerobic P-uptake in inverted A2O process.Therefore,Accumulibacter clades in WWTPs were diverse,and EBPR performance was closely related to the clade-level community structures and abundances of Accumulibacter.