The growth and metabolism of polyphosphate accumulating organisms (PAOs) affect the phosphorus (P) removal performance of the biofilm sequencing batch reactor (BSBR). A novel strain PAO Acinetobacter lwoffii (P5) was isolated and identified from the BSBR. The growth conditions of P5 in BSBR were simulated with alternate aerobic (9 h)/anaerobic (6 h) cycles for 10 days. The orthogonal experiment showed that P and carbon (C) sources had significant interactions with the growth and P metabolism of P5 (P >0.05). The growth of P5 was mainly affected by the C source, but its P metabolism was mainly affected by the P source. Metabolism model, enzyme activity, and P recovery efficiency tests showed that when the sludge loading was 0.15 g P/(gMLSS·d), the P recovery efficiency was the highest (82.07 %). When the P/C ratio was ≥1/40, the P removal activity was activated, and the P removal performance of P5 was improved by the polyphosphate-accumulating metabolism (PAM). When the P/C ratio was ≤1/100, the P removal activity was inhibited, and the P removal performance of P5 was decreased by the glycogen-accumulating metabolism (GAM). Our research on the P mechanism of P5 provided valuable in-depth insights into the P removal performance of PAOs.

聚磷酸盐积累生物 (PAO) 的生长和代谢影响生物膜序批式反应器 (BSBR) 的磷 (P) 去除性能。从 BSBR 中分离并鉴定出一株新菌株 PAO Acinetobacter lwoffii (P5)。P5 在 BSBR 中的生长条件用交替的有氧（9 小时）/厌氧（6 小时）循环模拟 10 天。正交试验表明，P和碳（C）源与P5（P>0.05）。P5的生长主要受C源的影响，但其P代谢主要受P源的影响。代谢模型、酶活性和P回收效率测试表明，当污泥负荷为0.15 g P/(gMLSS·d)时，P回收效率最高(82.07 %)。当P/C比≥1/40时，除磷活性被激活，P5的除磷性能通过聚磷酸盐积累代谢（PAM）得到提高。当P/C比≤1/100时，除磷活性受到抑制，糖原累积代谢(GAM)降低了P5的除磷性能。我们对 P5 的 P 机制的研究为 PAO 的 P 去除性能提供了有价值的深入见解。