多因素对Accumulibacter代谢机制及分支水平的影响综述

Review on Metabolic Mechanism and Population Structure of Accumulibacter Under Different Influencing Factors

“Candidatus Accumulibacter phosphatis”(简称Accumulibacter)是污水处理系统中最常见的聚磷菌(PAOs)。该文从碳源、温度、电子受体及相关质子化产物——游离亚硝酸、磷源等方面综述了其对除磷效能、Accumulibacter分支水平以及代谢机制等的影响。综合不同的研究得出如下相似的结果:(1)碳源类型会改变胞内聚合物——聚羟基烷酸的种类和含量,影响强化生物除磷(EBPR)系统的脱氮除磷效能,且与其他碳源相比,以丙酸为碳源的系统中Accumulibacter的富集程度更高,除磷效率更好;(2)低温环境有利于Accumulibacter的生长,其天然竞争菌“Candidatus Competibacter phosphatis”(简称Competibacter)在高温环境中表现出竞争优势;(3)FNA抑制和磷匮乏条件下,Accumulibacter的TypeⅡ型表现出较强的耐受性与灵活的代谢机制转变等。然而,截至目前,尚未有研究建立EBPR系统中各功能菌属与除磷效能之间的关系。因此,对单一菌种及其进化枝的培养和对单一菌种与侧翼菌群之间关系的研究,有利于为进一步提高EBPR系统除磷效能及其稳定性提供理论支撑。

"Candidatus Accumulibacter phosphatis"(Accumulibacter)is the most common polyphosphate accumulating organisms(PAOs)in wastewater treatment systems.This review provides many aspects of the effects on phosphorus removal efficiency,Accumulibacter clade level and metabolic mechanism:carbon source,temperature,electron receptor and its protonation product-free nitrous acid(FNA),and phosphorus source.A summary of different studies provided similar results:(1)The type of carbon source could change the type and content of intracellular polymer-poly-β-hydroxyalkanoate(PHA),and affected the nitrogen and phosphorus removal efficiency of enhanced biological phosphorus removal(EBPR)system.Furthermore,compared to other carbon source,in the system with propionic acid as carbon source,Accumulibacter was more enriched and the phosphorus removal efficiency was higher.(2)Low temperature environment was conducive to the growth of Accumulibacter,while its natural rival bacteria"Candidatus Competibacter phosphatis"(Competibacter)showed competitive advantages in high temperature environment.(3)Under FNA inhibition and phosphorus deficiency conditions,Type II of Accumulibacter(PAO II)showed strong tolerance and flexible metabolic mechanism transformation.However,no study had established the relationship between functional bacteria and phosphorus removal efficiency in EBPR system yet.Therefore,cultivation of a single species and its clades,as well as study on the relationship between a single bacterial species and other bacterial groups,both are beneficial to provide theoretical support for the further improvement of the phosphorus removal efficiency and stability in EBPR system.