Wang Shuai, Su Xiangyu, Qin Jianmei, He Lei, Tong Meiping
The Key Laboratory of Water and Sediment Sciences, Ministry of Education; State Environmental Protection Key Laboratory of All Material Fluxes in River Ecosystems; College of Environmental Sciences and Engineering, Peking University, Beijing 100871, PR China.
National Base of International S&T Collaboration on Water Environmental Monitoring and Simulation in TGR Region; College of Resources and Environment, Southwest University, Chongqing 400715, PR China.
Environ Sci Technol. 2025 Jul 1;59(25):13012-13021. doi: 10.1021/acs.est.5c04426. Epub 2025 Jun 17.
The initial adhesion of microbes onto plastics is crucial for the subsequent formation of the plastisphere, which might be affected by signal molecules commonly present in bacteria-related environments that regulate cell-to-cell communication. Herein, the initial retention performance of onto six types of plastics, both without and with -acyl-homoserine lactones (AHLs, a common signal molecule) at concentrations ranging from 10 ng/L to 100 μg/L in suspension, was determined to reveal the influence of signal molecules on the formation of the plastisphere. We found that AHLs coexisting in suspensions significantly enhanced bacterial adhesion performance onto plastics, regardless of plastic types and AHL types, with a more pronounced enhancement observed at higher AHL concentrations. This enhanced bacterial adhesion induced by AHLs also held true in solutions containing humic acid, in river water, and in sewage. AHLs stimulated the synthesis of EPS, enhanced EPS hydrophobicity by altering the protein/polysaccharide ratio and its secondary structures, and upregulated pathways related to flagellar assembly, quorum sensing, protein production, and biofilm formation, thereby enhancing bacterial adhesion capability onto plastics. Moreover, AHLs adsorbed onto plastic surfaces could induce chemoattraction effects, further promoting bacterial adhesion performance. Obviously, through various mechanisms, the signal molecules greatly influence the initial adhesion of bacteria onto plastics in aquatic systems.
微生物在塑料上的初始粘附对于随后塑料球的形成至关重要，而这可能会受到细菌相关环境中常见的调节细胞间通讯的信号分子的影响。在此，测定了在悬浮液中浓度范围为10 ng/L至100 μg/L的六种类型塑料在有无N-酰基高丝氨酸内酯（AHLs，一种常见信号分子）情况下的初始滞留性能，以揭示信号分子对塑料球形成的影响。我们发现，悬浮液中共存的AHLs显著增强了细菌在塑料上的粘附性能，无论塑料类型和AHL类型如何，在较高AHL浓度下观察到的增强更为明显。由AHLs诱导的这种增强的细菌粘附在含有腐殖酸的溶液、河水和污水中也成立。AHLs刺激了胞外聚合物（EPS）的合成，通过改变蛋白质/多糖比例及其二级结构增强了EPS的疏水性，并上调了与鞭毛组装、群体感应、蛋白质产生和生物膜形成相关的途径，从而增强了细菌在塑料上的粘附能力。此外，吸附在塑料表面的AHLs可诱导化学吸引作用，进一步促进细菌的粘附性能。显然，通过各种机制，信号分子极大地影响了水生系统中细菌在塑料上的初始粘附。
