Microbial Ecology Group (MEG), National Research Council - Institute of Ecosystem Study (CNR-ISE), Largo Tonolli, 50, 28922 Verbania, Italy.
Microbial Ecology Group (MEG), National Research Council - Institute of Ecosystem Study (CNR-ISE), Largo Tonolli, 50, 28922 Verbania, Italy; Department of Earth, Environmental and Life Sciences (DISTAV), University of Genoa, Corso Europa 26, 16132 Genoa, Italy.
Environ Pollut. 2018 Mar;234:495-502. doi: 10.1016/j.envpol.2017.11.070. Epub 2017 Dec 21.
Plastic pollution is a major global concern with several million microplastic particles entering every day freshwater ecosystems via wastewater discharge. Microplastic particles stimulate biofilm formation (plastisphere) throughout the water column and have the potential to affect microbial community structure if they accumulate in pelagic waters, especially enhancing the proliferation of biohazardous bacteria. To test this scenario, we simulated the inflow of treated wastewater into a temperate lake using a continuous culture system with a gradient of concentration of microplastic particles. We followed the effect of microplastics on the microbial community structure and on the occurrence of integrase 1 (int1), a marker associated with mobile genetic elements known as a proxy for anthropogenic effects on the spread of antimicrobial resistance genes. The abundance of int1 increased in the plastisphere with increasing microplastic particle concentration, but not in the water surrounding the microplastic particles. Likewise, the microbial community on microplastic was more similar to the original wastewater community with increasing microplastic concentrations. Our results show that microplastic particles indeed promote persistence of typical indicators of microbial anthropogenic pollution in natural waters, and substantiate that their removal from treated wastewater should be prioritised.
塑料污染是一个全球性的主要问题，每天有数百万个微塑料颗粒通过废水排放进入淡水生态系统。微塑料颗粒刺激整个水柱中的生物膜形成（塑料球层），如果它们在远洋水域中积累，有可能影响微生物群落结构，特别是增强了生物危害细菌的增殖。为了验证这种情况，我们使用连续培养系统模拟了经处理的废水流入温带湖泊的情况，该系统具有微塑料颗粒浓度梯度。我们跟踪了微塑料对微生物群落结构的影响，以及整合酶 1（int1）的出现，后者是与移动遗传元件相关的标记，被用作人类活动对抗生素耐药基因传播影响的替代指标。随着微塑料颗粒浓度的增加，int1 在塑料球层中的丰度增加，但在微塑料颗粒周围的水中没有增加。同样，随着微塑料浓度的增加，微塑料上的微生物群落与原始废水群落更加相似。我们的结果表明，微塑料颗粒确实促进了天然水中微生物人为污染的典型指标的持续存在，并证实了应优先从经处理的废水中去除微塑料颗粒。
