Metabolic shift of polyphosphate-accumulating organisms with different levels of polyphosphate storage

WATER RESEARCH

卷:46

Article

Acevedo, B.¹  Oehmen, A.²  Carvalho, G.²  Seco, A.³  Borras, L.³  Barat, R.¹ 

[1] Univ Politecn Valencia, Inst Ingn Agua & Medio Ambiente, Valencia 46022, Spain

[2] Univ Nova Lisboa, Fac Ciencias & Tecnol, Dept Chem, REQUIMTE CQFB, P-2829516 Caparica, Portugal

[3] Univ Valencia, Dept Ingn Quim, E-46100 Valencia, Spain

关键词: Polyphosphate-accumulating organisms (PAO);    Glycogen-accumulating organisms (GAO);    Accumulibacter Type I;    Accumulibacter Type II;    Polyphosphate (poly-P);    Polyphosphate-accumulating metabolism (PAM);    Glycogen-accumulating metabolism (GAM);    Wastewater;   

DOI  :  10.1016/j.watres.2012.01.003

来源: Elsevier

【 摘 要 】

Previous studies have shown that polyphosphate-accumulating organisms (PAOs) are able to behave as glycogen-accumulating organisms (GAOs) under different conditions. In this study we investigated the behavior of a culture enriched with Accumulibacter at different levels of polyphosphate (poly-P) storage. The results of stoichiometric ratios Gly(degraded)/HAC(uptake), PHBsynthesized/HAC(uptake), PHVsynthesized/HAC(uptake) and P-release/HAC(uptake) confirmed a metabolic shift from PAO metabolism to GAO metabolism: PAOs with high poly-P content used the poly-P to obtain adenosine tri-phosphate (ATP), and glycogen (Gly) to obtain nicotinamide adenine dinucleotide (NADH) and some ATP. In a test where poly-P depletion was imposed on the culture, all the acetate (HAc) added in each cycle was transformed into polyhydroxyalkanoate (PHA) despite the decrease of poly-P inside the cells. This led to an increase of the Gly(degraded)/HAcuptake ratio that resulted from a shift towards the glycolytic pathway in order to compensate for the lack of ATP formed from poly-P hydrolysis. The shift from PAO to GAO metabolism was also reflected in the change in the PHA composition as the poly-P availability decreased, suggesting that polyhydroxyvalerate (PHV) is obtained due to the consumption of excess reducing equivalents to balance the internal NADH, similarly to GAO metabolism. Fluorescence in situ hybridization analysis showed a significant PAO population change from Type I to Type II Accumulibacter as the poly-P availability decreased in short term experiments. This work suggests that poly-P storage levels and GAO-like metabolism are important factors affecting the competition between different PAO Types in enhanced biological phosphorus removal systems. (C) 2012 Elsevier Ltd. All rights reserved.

【 授权许可】

Free