Shi Yahui, Huang Jinhui, Zeng Guangming, Gu Yanling, Chen Yaoning, Hu Yi, Tang Bi, Zhou Jianxin, Yang Ying, Shi Lixiu
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
College of Environmental Science and Engineering, Hunan University, Changsha, 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha, 410082, PR China.
Chemosphere. 2017 Aug;180:396-411. doi: 10.1016/j.chemosphere.2017.04.042. Epub 2017 Apr 12.
Extracellular polymeric substances (EPS) are present both outside of the cells and in the interior of microbial aggregates, and account for a main component in microbial aggregates. EPS can influence the properties and functions of microbial aggregates in biological wastewater treatment systems, and specifically EPS are involved in biofilm formation and stability, sludge behaviors as well as sequencing batch reactors (SBRs) granulation whereas they are also responsible for membrane fouling in membrane bioreactors (MBRs). EPS exhibit dual roles in biological wastewater treatments, and hence the control of available EPS can be expected to lead to changes in microbial aggregate properties, thereby improving system performance. In this review, current updated knowledge with regard to EPS basics including their formation mechanisms, important properties, key component functions as well as sub-fraction differentiation is given. EPS roles in biological wastewater treatments are also briefly summarized. Special emphasis is laid on EPS controlling strategies which would have the great potential in promoting microbial aggregates performance and in alleviating membrane fouling, including limitation strategies (inhibition of quorum sensing (QS) systems, regulation of environmental conditions, enzymatic degradation of key components, energy uncoupling etc.) and elevation strategies (enhancement of QS systems, addition of exogenous agents etc.). Those strategies have been confirmed to be feasible and promising to enhance system performance, and they would be a research niche that deserves further study.
胞外聚合物（EPS）存在于细胞外部以及微生物聚集体内部，是微生物聚集体的主要组成部分。EPS会影响生物废水处理系统中微生物聚集体的性质和功能，具体而言，EPS参与生物膜的形成与稳定、污泥行为以及序批式反应器（SBR）的颗粒化过程，同时它们也是膜生物反应器（MBR）中膜污染的成因。EPS在生物废水处理中具有双重作用，因此，控制EPS的含量有望改变微生物聚集体的性质，从而提升系统性能。在这篇综述中，给出了关于EPS基础知识的最新信息，包括其形成机制、重要性质、关键组分功能以及亚组分区分。还简要总结了EPS在生物废水处理中的作用。特别强调了EPS控制策略，这些策略在提升微生物聚集体性能和减轻膜污染方面具有巨大潜力，包括限制策略（抑制群体感应（QS）系统、调节环境条件、对关键组分进行酶解、能量解偶联等）和提升策略（增强QS系统、添加外源剂等）。这些策略已被证实可行且有望提升系统性能，将是一个值得深入研究的细分领域。
