强化生物除磷系统的功能微生物研究进展

Research Progress on the Functional Microorganisms in Enhanced Biological Phosphorus Removal (EBPR) Systems

人类活动过程中排放的磷是导致水体富营养化的重要原因之一,因此,采取强化生物除磷(Enhanced biological phosphorus removal,EBPR)技术去除污水中磷,减轻对环境不利影响。由于具有经济、可持续的优点,EBPR系统在污水除磷中得到广泛应用,而体系中微生物群落组成合理、功能完整是EBPR系统高效稳定运行的关键所在。为了深入了解EBPR系统除磷机理和实现高效稳定运行,对系统中微生物群落结构和主要功能微生物进行了大量研究。EBPR系统中除了具有聚磷能力的聚磷菌(Polyphosphate-accumulating organisms,PAOs)外,还包括没有聚磷能力的非聚磷菌(non-PAOs),主要为聚糖菌(Glycogen-accumulating organisms,GAOs)和一些辅助细菌等。目前,发现与聚磷相关的功能微生物种类越来越多,研究最多的PAOs和GAOs分别为Accumulibacter和Defluviicoccus。PAOs和GAOs在不同的环境条件下存在竞争或合作关系,但是PAOs在特定条件下是否能够表现出GAOs的代谢特性这一问题还存在争论。除传统碳源、p H和温度等因素影响生物除磷外,外源污染物(如抗生素和重金属)对EBPR系统中功能微生物也产生影响。为了获得高效PAOs,传统分离方法、蓝白斑筛选法和人工构建工程菌的方法先后得到应用。现代分子生物学技术的发展为EBPR系统中功能微生物研究提供了先进可靠的技术手段,通过高效聚磷菌的构建实现高效除磷是未来提高实际污水中生物除磷效率的一个重要发展方向。

Phosphorus emission from human activities is one of the major causes of water eutrophication. The technology of enhancedbiological phosphorus removal（EBPR）has been widely applied for removing phosphorus from wastewater due to its advantages of economyand sustainability. The key to the efficient and stable operation of EBPR system is that the microbial community in the system is reasonableand functional. For deeply understanding the mechanism of phosphorus removal and the efficient and stable operation of EBPR system,alarge number of studies were conducted on the microbial community structure and main functional microorganisms in the system. In addition topolyphosphate-accumulating organisms（PAOs）,the EBPR system also includes non-PAOs,mainly glycogen-accumulating organisms（GAOs）and some auxiliary bacteria. Nowadays,more and more types of functional polyphosphate-accumulating microorganisms were identified,andthe most studied PAOs and GAOs were Accumulibacter and Defluviicoccus respectively. PAOs and GAOs compete or cooperate under differentenvironmental conditions,but it is still controversial whether PAOs may exhibit the metabolic properties of GAOs under certain conditions.Besides the traditional factors such as carbon source,p H and temperature,the effects of exogenous pollutants,like antibiotics and heavymetals,on functional microorganisms in EBPR system also exist. The traditional separation methods,blue/white screening and the method ofartificial construction of gene engineering bacteria have been applied for acquiring efficient PAOs. The development of modern molecular biologytechnology provides advanced and reliable technical means for the research of functional microorganisms in EBPR system,and the efficientremoval of phosphorous by constructing high-performance polyphosphate-accumulating microorganisms will be an important trend in futureincreasing bio-removal phosphorus efficiency from actual wastewater.