Abstract:In the present study, three strains of high-efficiency phosphorus removal bacteria were screened and isolated from a stable anaerobic/aerobic/anoxic sequencing batch reactor (A/O/A-SBR). The species were identified by morphological observation, physiological and biochemical tests and 16S rRNA sequence analysis. The three strains of bacteria were identified as Acinetobacter, Klebsiella and Enterobacter.The NCBI preservation accession numbers are OL519151, OL519152, and OL519153, respectively. The effects of pH, temperature and the carbon source on cell grow and phosphorus removal were explored. Meanwhile, the distribution and transformation of inorganic phosphorus and organic phosphorus in bacterial cells, soluble microbial products (SMP) and extracellular polymers (EPS) were also investigated. According to the results, the highest phosphorus removal efficiencies of Acinetobacter sp. PK01,Klebsiella sp. PK02 and Enterobacter sp. PK03 were 89.4%, 85.43% and 76.95%, respectively, based on the optimal condition. The removal of phosphorus from the environment by Acinetobacter mainly relied on the absorption of extracellular inorganic phosphorus and stored in the body as polyphosphate, removing 54.93% of the phosphorus fromthe matrix. The removal of phosphorus by Klebsiella mainly relied on EPS synthesis and adsorption. This route removed 47.18% of the phosphorus from the matrix. Enterobacter removed 48.32% of the phosphorus, which was mainly depended on the synthesis of polyphosphate and EPS.