Wang Chao, Liu Sitong, Xu Xiaochen, Zhao Chuanqi, Yang Fenglin, Wang Dong
Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environment Science and Technology, Dalian University of Technology, Linggong Road 2, Dalian, 116024, China.
Department of Environmental Engineering, Peking University, Beijing, 100871, China.
Appl Microbiol Biotechnol. 2017 May;101(9):3821-3828. doi: 10.1007/s00253-016-7981-y. Epub 2017 Jan 11.
The objective of this study was to investigate the influence of extracellular polymeric substance (EPS) on the coupling effects between ammonia-oxidizing bacteria (AOB) and anaerobic ammonium-oxidizing (anammox) bacteria for the completely autotrophic nitrogen removal over nitrite (CANON) biofilm formation in a moving bed biofilm reactor (MBBR). Analysis of the quantity of EPS and cyclic diguanylate (c-di-GMP) confirmed that the contents of polysaccharides and c-di-GMP were correlated in the AOB sludge, anammox sludge, and CANON biofilm. The anammox sludge secreted more EPS (especially polysaccharides) than AOB with a markedly higher c-di-GMP content, which could be used by the bacteria to regulate the synthesis of exopolysaccharides that are ultimately used as a fixation matrix, for the adhesion of biomass. Indeed, increased intracellular c-di-GMP concentrations in the anammox sludge enhanced the regulation of polysaccharides to promote the adhesion of AOB and formation of the CANON biofilm. Overall, the results of this study provide new comprehensive information regarding the coupling effects of AOB and anammox bacteria for the nitrogen removal process.
本研究的目的是调查胞外聚合物（EPS）对移动床生物膜反应器（MBBR）中氨氧化细菌（AOB）与厌氧氨氧化（anammox）细菌之间耦合效应的影响，以实现亚硝酸盐完全自养脱氮（CANON）生物膜的形成。对EPS和环二鸟苷酸（c-di-GMP）含量的分析证实，AOB污泥、anammox污泥和CANON生物膜中多糖和c-di-GMP的含量具有相关性。anammox污泥比AOB分泌更多的EPS（尤其是多糖），其c-di-GMP含量明显更高，细菌可利用这些物质调节胞外多糖的合成，最终将其用作固定基质以实现生物质的附着。事实上，anammox污泥中细胞内c-di-GMP浓度的增加增强了多糖的调节作用，促进了AOB的附着和CANON生物膜的形成。总体而言，本研究结果为AOB和anammox细菌在氮去除过程中的耦合效应提供了新的全面信息。
