Bis-(3′ -5′ )-cyclic dimeric guanosine monophosphate (c-di-GMP) mediated membrane fouling in membrane bioreactor
Bis-(3′ -5′ )-cyclic dimeric guanosine monophosphate (c-di-GMP) mediated membrane fouling in membrane bioreactor
复制标题
膜生物反应器中双-(3--5-)-环状二聚鸟苷酸 (c-di-GMP) 介导的膜污染
DOI：
10.1016/j.memsci.2021.120224
复制
发表时间：
2022
影响因子：
9.5
通讯作者：
Song Yonghui
中科院分区：
文献类型：
--
作者：
Chen Hang;Tian Yucheng;Hu Zekun;Wang Cenchao;Xie Peiran;Liping Chen;Yang Fan;Liang Yunyao;Mu Chunyan;Wei Chaohai;Ting Yen-Peng;Qiu Guanglei;Song Yonghui
本研究揭示了双-(3 ' -5 ')-环二聚鸟苷单磷酸（c-di-GMP）在膜生物反应器（MBR）中膜生物污染过程中的关键作用。两个实验室规模的mbr并联运行，不同的污泥滞留时间（R1为30 d， R2为10 d）。在两个反应器中，膜污染物中检测到的细胞内c-二gmp水平明显高于活性污泥。与R1相比，R2的膜污染率要高得多，这与该反应器中活性污泥和膜污染物中细胞内c-二gmp水平的升高相对应。胞外聚合物质（EPS）含量与胞内c-di-GMP水平密切相关，表明细菌细胞中c-di-GMP水平的升高刺激了EPS的产生，导致膜污染速率加快。16S rRNA基因元条形码分析显示，膜污染物中含有不动杆菌、假黄毒单胞菌、谷氨酰胺杆菌和链球菌相关操作分类单位（OTUs）。它们的相对丰度与c-di-GMP水平高度相关，表明这些微生物在c-di-GMP介导的生物膜形成和膜污染中起主要作用。Sloan中性群落模型表明，这些关键细菌的富集和沉积不是由它们在膜表面生长的固有倾向决定的，而是由c-di-GMP驱动的它们的生活方式改变。对这些关键细菌的全基因组分析以及全社区PICRUSt2调查表明，富含膜污染物的细菌比活性污泥中的细菌具有更强的c-di-GMP代谢能力，突出了c-di-GMP第二信使途径在调节EPS产生从而控制膜生物污染过程中的关键作用。
This work reveals the key role of bis-(3’-5’)-cyclic dimeric guanosine monophosphate (c-di-GMP) in the membrane biofouling process in membrane bioreactor (MBR). Two lab-scale MBRs were operated in parallel with different sludge retention times (30 d for R1 and 10 d for R2). Significantly high intracellular c-di-GMP levels were detected in membrane foulants than in the activated sludge in both reactors. Compared to R1, R2 showed much higher membrane fouling rates, corresponding to elevated intracellular c-di-GMP levels in both the activated sludge and membrane foulants in this reactor. The extracellular polymeric substances (EPS) contents were strongly correlated to the levels of intracellular c-di-GMP, suggesting that elevated c-di-GMP levels in bacterial cells stimulated increased production of EPS, leading to accelerated membrane fouling rates. 16S rRNA gene metabarcoding showed the enrichment of Acinetobacter, Pseudofulvimonas, Glutamicibacter, and Streptococcus related operational taxonomic units (OTUs) in the membrane foulants. Their relative abundances were highly correlated to the c-di-GMP level, showing the mainstay role of these microorganisms in c-di-GMP mediated biofilm formation and membrane fouling. Sloan neutral community modeling suggested that the enrichment and deposition of these key bacteria were not determined by their inherent tendency to grow on the membrane surface but their lifestyle change was driven by c-di-GMP. Genome-wide analysis of these key bacteria together with a community-wide PICRUSt2 survey suggested stronger c-di-GMP metabolic abilities of bacteria enriched in membrane foulants than those in the activated sludge, highlighting the key role of c-di-GMP second-messenger pathway in regulating EPS production thus governing the membrane biofouling process.