Department of Chemical Engineering, McGill University, Montreal, Canada.
Energy, Mining and Environment Research Center, National Research Council Canada, Montreal, Canada.
Environ Microbiol Rep. 2020 Apr;12(2):203-213. doi: 10.1111/1758-2229.12824. Epub 2020 Feb 6.
The world's oceans are becoming increasingly polluted by plastic waste. In the marine environment, larger plastic pieces may degrade into nanoscale (<100 nm in at least one dimension) plastic particles due to natural weathering effects. We observe that the presence of 20 nm plastic nanoparticles at concentrations below 200 ppm had no impact on planktonic growth of a panel of heterotrophic marine bacteria. However, the presence of plastic nanoparticles significantly impacted the formation of biofilms in a species-specific manner. While carboxylated nanoparticles increased the amount of biofilm formed by several species, amidine-functionalized nanoparticles decreased the amount of biofilm of many but not all bacteria. Further experiments suggested that the aggregation dynamics of bacteria and nanoparticles were strongly impacted by the surface properties of the nanoparticles. The community structure of an artificially constructed community of marine bacteria was significantly altered by exposure to plastic nanoparticles, with differently functionalized nanoparticles selecting for unique and reproducible community abundance patterns. These results suggest that surface properties and concentration of plastic nanoparticles, as well as species interactions, are important factors determining how plastic nanoparticles impact biofilm formation by marine bacteria.
世界海洋正受到越来越多的塑料垃圾污染。在海洋环境中，较大的塑料碎片可能由于自然风化作用而降解成纳米级（至少在一个维度上小于 100nm）的塑料颗粒。我们观察到，浓度低于 200ppm 的 20nm 塑料纳米颗粒的存在对一组异养海洋细菌的浮游生物生长没有影响。然而，纳米颗粒的存在以特定于物种的方式显著影响生物膜的形成。虽然羧基化纳米颗粒增加了几种细菌形成的生物膜量，但 amidine 功能化纳米颗粒减少了许多但不是所有细菌形成的生物膜量。进一步的实验表明，细菌和纳米颗粒的聚集动力学受到纳米颗粒表面性质的强烈影响。暴露于塑料纳米颗粒显著改变了人工构建的海洋细菌群落的结构，不同功能化的纳米颗粒选择出独特且可重复的群落丰度模式。这些结果表明，纳米颗粒的表面性质和浓度以及物种相互作用是决定塑料纳米颗粒如何影响海洋细菌生物膜形成的重要因素。
