Lopez-Vazquez Carlos M, Oehmen Adrian, Hooijmans Christine M, Brdjanovic Damir, Gijzen Huub J, Yuan Zhiguo, van Loosdrecht Mark C M
Department of Environmental Resources, UNESCO-IHE Institute for Water Education, Wesvest 7, 2611 AX Delft, The Netherlands.
Water Res. 2009 Feb;43(2):450-62. doi: 10.1016/j.watres.2008.10.032. Epub 2008 Nov 1.
The influence of different carbon sources (acetate to propionate ratios), temperature and pH levels on the competition between polyphosphate- and glycogen-accumulating organisms (PAO and GAO, respectively) was evaluated using a metabolic model that incorporated the carbon source, temperature and pH dependences of these microorganisms. The model satisfactorily described the bacterial activity of PAO (Accumulibacter) and GAO (Competibacter and Alphaproteobacteria-GAO) laboratory-enriched cultures cultivated on propionate (HPr) and acetate (HAc) at standard conditions (20 degrees C and pH 7.0). Using the calibrated model, the effects of different influent HAc to HPr ratios (100-0, 75-25, 50-50 and 0-100%), temperatures (10, 20 and 30 degrees C) and pH levels (6.0, 7.0 and 7.5) on the competition among Accumulibacter, Competibacter and Alphaproteobacteria-GAO were evaluated. The main aim was to assess which conditions were favorable for the existence of PAO and, therefore, beneficial for the biological phosphorus removal process in sewage treatment plants. At low temperature (10 degrees C), PAO were the dominant microorganisms regardless of the used influent carbon source or pH. At moderate temperature (20 degrees C), PAO dominated the competition when HAc and HPr were simultaneously supplied (75-25 and 50-50% HAc to HPr ratios). However, the use of either HAc or HPr as sole carbon source at 20 degrees C was not favorable for PAO unless a high pH was used (7.5). Meanwhile, at higher temperature (30 degrees C), GAO tended to be the dominant microorganisms. Nevertheless, the combined presence of acetate and propionate in the influent (75-25 and 50-50% HAc to HPr ratios) as well as a high pH (7.5) appear to be potential factors to favor the metabolism of PAO over GAO at higher sewage temperature (30 degrees C).
使用一个纳入了这些微生物对碳源、温度和pH依赖性的代谢模型，评估了不同碳源（乙酸盐与丙酸盐比例）、温度和pH水平对聚磷菌和糖原积累菌（分别为PAO和GAO）之间竞争的影响。该模型令人满意地描述了在标准条件（20℃和pH 7.0）下，在丙酸盐（HPr）和乙酸盐（HAc）上培养的PAO（聚磷菌属）和GAO（竞争杆菌属和α-变形菌纲-GAO）实验室富集培养物的细菌活性。使用校准后的模型，评估了不同进水HAc与HPr比例（100 - 0、75 - 25、50 - 50和0 - 100%）、温度（10、20和30℃）和pH水平（6.0、7.0和7.5）对聚磷菌属、竞争杆菌属和α-变形菌纲-GAO之间竞争的影响。主要目的是评估哪些条件有利于PAO的存在，从而有利于污水处理厂的生物除磷过程。在低温（10℃）下，无论使用何种进水碳源或pH，PAO都是优势微生物。在中等温度（20℃）下，当同时供应HAc和HPr（HAc与HPr比例为75 - 25和50 - 50%）时，PAO在竞争中占主导地位。然而，在20℃下，除非使用高pH（7.5），否则单独使用HAc或HPr作为唯一碳源对PAO不利。同时，在较高温度（30℃）下，GAO倾向于成为优势微生物。尽管如此，进水乙酸盐和丙酸盐同时存在（HAc与HPr比例为75 - 25和50 - 50%）以及高pH（7.5）似乎是在较高污水温度（30℃）下有利于PAO而非GAO代谢的潜在因素。
