Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, 266237, China.
Frontiers Science Center for Deep Ocean Multispheres and Earth System, Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, 266100, China; Laboratory for Marine Ecology and Environmental Science, Qingdao Marine Science and Technology Center, Qingdao, 266237, China.
Environ Pollut. 2024 Nov 1;360:124649. doi: 10.1016/j.envpol.2024.124649. Epub 2024 Jul 31.
Dimethyl sulfide (DMS) is a prevalent volatile organic sulfur compound relevant to the global climate. Ecotoxicological effects of nano- and microplastics (NPs and MPs) on phytoplankton, zooplankton, and bacteria have been investigated by numerous studies. Yet, the influences of NPs/MPs on dimethylated sulfur compounds remains understudied. Herein, we investigated the impacts of polystyrene (PS) NPs/MPs (80 nm, 1 μm, and 10 μm) on zooplankton grazing, chlorophyll a (Chl a) concentration, bacterial community, dimethylsulfoniopropionate (DMSP), and DMS production in the microcosms. Our findings revealed that rotifer grazing increased the production of DMS in the absence of NPs/MPs but did not promote DMS production when exposed to NPs/MPs. The ingestion rates of the rotifer and copepod exposed to NPs/MPs at high concentrations were significantly reduced. NPs/MPs exposure significantly decreased DMS levels in the treatments with rotifers compared to the animal controls. In the bacterial microcosms, smaller NPs/MPs sizes were more detrimental to Chl a concentrations compared to larger sizes. The study revealed a stimulatory effect on Chl a concentrations, DMSP concentrations, and bacterial abundances when exposed to 10 μm MP with low concentrations. The effects of NPs/MPs on DMS concentrations were both dose- and size-dependent, with NPs showing greater toxicity compared to larger MPs. NPs/MPs led to changes in bacterial community compositions, dependent on both dosage and size. NPs caused a notable decrease in the alpha diversities and richness of bacteria compared to MPs. These results provide insights into the influences of NPs/MPs on food webs, and subsequently organic sulfur compounds cycles.
二甲基硫（DMS）是一种普遍存在的挥发性有机硫化合物，与全球气候有关。许多研究已经调查了纳米和微塑料（NPs 和 MPs）对浮游植物、浮游动物和细菌的生态毒理学影响。然而，NPs/MPs 对二甲硫基化合物的影响仍研究不足。在此，我们研究了聚苯乙烯（PS）NPs/MPs（80nm、1μm 和 10μm）对浮游动物摄食、叶绿素 a（Chl a）浓度、细菌群落、二甲基巯基丙酸（DMSP）和 DMS 产生的影响在微宇宙中。我们的研究结果表明，轮虫摄食在没有 NPs/MPs 的情况下增加了 DMS 的产生，但在暴露于 NPs/MPs 时并没有促进 DMS 的产生。在高浓度下暴露于 NPs/MPs 的轮虫和桡足类的摄食率显著降低。与动物对照相比，NPs/MPs 暴露显著降低了轮虫处理中 DMS 的水平。在细菌微宇宙中，与较大尺寸相比，较小的 NPs/MPs 尺寸对 Chl a 浓度的危害更大。当暴露于低浓度的 10μm MPs 时，研究发现对 Chl a 浓度、DMSP 浓度和细菌丰度有刺激作用。NPs/MPs 对 DMS 浓度的影响既依赖于剂量又依赖于尺寸，与较大 MPs 相比，NPs 表现出更大的毒性。NPs/MPs 导致细菌群落组成发生变化，这取决于剂量和大小。与 MPs 相比，NPs 导致细菌的 alpha 多样性和丰富度明显降低。这些结果深入了解了 NPs/MPs 对食物网的影响，进而影响有机硫化合物循环。
