Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
Chemosphere. 2021 Feb;265:129030. doi: 10.1016/j.chemosphere.2020.129030. Epub 2020 Nov 19.
Microplastics with different sizes exist widely in fresh waters, which may affect the interspecific dynamics between predator and prey. The flagellate Ochromonas gloeopara can efficiently eliminate Microcystis aeruginosa and degrade microcystins, which shows great potential for controlling harmful Microcystis. In order to evaluate the effects of microplastics on O. gloeopara eliminating Microcystis, we designed an experiment of O. gloeopara feeding on Microcystis under different sizes (0.07 and 3 μm) and concentrations (0, 0.4, 0.8, 1.6, and 2.0 mg L) of microplastics. The results showed that maximum abundance of M. aeruginosa decreased significantly with addition of microplastics, regardless of the size and concentration. O. gloeopara can ingest the microplastics and suffer from their adverse effects. The maximum abundance of O. gloeopara decreased with enhancing concentrations of 3 μm microplastics during the process of O. gloeopara eliminating M. aeruginosa, whereas 0.07 μm microplastics did not affect the growth of O. gloeopara obviously. During the period of exposure under microplastics, clearance rate of O. gloeopara on M. aeruginosa decreased with the increasing concentrations of microplastics. Specially, 3 μm microplastics had a stronger reduction on clearance rate of O. gloeopara. The time to M. aeruginosa extinction was prolonged with the increasing concentrations of microplastics in both sizes. Comparatively speaking, 3 μm microplastics had a stronger delayed effect on the removal of Microcystis. These findings suggest that microplastics can interfere with protozoa eliminating toxic Microcystis, which may aggravate their adverse impacts on aquatic ecosystem.
微塑料广泛存在于淡水中，其大小不同，可能会影响捕食者和猎物之间的种间动态。鞭毛藻眼虫能够有效地消除铜绿微囊藻并降解微囊藻毒素，在控制有害微囊藻方面具有很大的潜力。为了评估微塑料对眼虫消除铜绿微囊藻的影响，我们设计了一个在不同大小（0.07 和 3 μm）和浓度（0、0.4、0.8、1.6 和 2.0 mg/L）的微塑料存在下，眼虫摄食铜绿微囊藻的实验。结果表明，添加微塑料后，铜绿微囊藻的最大丰度显著降低，与微塑料的大小和浓度无关。眼虫可以摄取微塑料并受到其不利影响。在眼虫消除铜绿微囊藻的过程中，3 μm 微塑料的浓度增加会导致眼虫的最大丰度降低，而 0.07 μm 微塑料对眼虫的生长没有明显影响。在暴露于微塑料期间，眼虫对铜绿微囊藻的清除率随着微塑料浓度的增加而降低。特别是，3 μm 微塑料对眼虫清除率的降低作用更强。在两种尺寸的微塑料浓度增加的情况下，铜绿微囊藻灭绝的时间延长。相比之下，3 μm 微塑料对微囊藻去除的延迟作用更强。这些发现表明，微塑料可以干扰原生动物消除有毒微囊藻，这可能会加重它们对水生生态系统的不利影响。
