Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China.
Department of Environmental Engineering, College of Biology and the Environment, Nanjing Forestry University, Nanjing 210037, China.
Sci Total Environ. 2022 Feb 1;806(Pt 4):151403. doi: 10.1016/j.scitotenv.2021.151403. Epub 2021 Nov 4.
Quorum sensing signal molecules can be used to regulate the formation of biofilm, but it has not been reported that outer membrane vesicles (OMVs) can package and mediate signal molecules to regulate biofilm. We isolated and purified OMVs packaged with Pseudomonas quinolone signal (PQS) released by Pseudomonas aeruginosa and studied the effects of OMV-mediated PQS on the formation and structure of biofilms. OMV-mediated PQS promoted the growth of biofilm, and the cells in the biofilm were stretched, deformed and "bridged" with the surrounding cells. Raman spectrometry showed that the structure and components of the extracellular polymeric substances of P. aeruginosa changed; moreover extracellular proteins rather than polysaccharides played the dominant role in the formation of P. aeruginosa biofilms when regulated by OMV-mediated PQS. In the combination biofilm formed by P. aeruginosa and Staphylococcus aureus, the mediation of OMVs enhanced the inhibitory effect of PQS to the growth of S. aureus, resulting a decrease in EPS produced by the two bacteria. OMV-mediated PQS led to changes in the biodiversity, richness and structure of the microbial community in biofilms formed by active sludge. This work reveals the mechanism of OMVs mediated signal molecules regulating biofilm, which lays a new theoretical and practical foundation for guiding the operation of low-level of biofouling MBRs.
群体感应信号分子可用于调控生物膜的形成，但尚未有报道表明外膜囊泡（OMVs）可以包装并介导信号分子来调控生物膜。我们分离和纯化了由铜绿假单胞菌释放的假喹诺酮信号（PQS）包裹的 OMVs，并研究了 OMV 介导的 PQS 对生物膜形成和结构的影响。OMV 介导的 PQS 促进了生物膜的生长，生物膜中的细胞被拉伸、变形，并与周围细胞“桥接”。拉曼光谱表明，铜绿假单胞菌细胞外聚合物的结构和组成发生了变化；而且，当被 OMV 介导的 PQS 调控时，细胞外蛋白质而不是多糖在铜绿假单胞菌生物膜的形成中起主导作用。在铜绿假单胞菌和金黄色葡萄球菌形成的组合生物膜中，OMVs 的介导增强了 PQS 对金黄色葡萄球菌生长的抑制作用，导致两种细菌产生的 EPS 减少。OMV 介导的 PQS 导致活性污泥形成的生物膜中微生物群落的多样性、丰富度和结构发生变化。这项工作揭示了 OMVs 介导的信号分子调控生物膜的机制，为指导低生物污染 MBR 的运行奠定了新的理论和实践基础。
