Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
State Key Laboratory of Lake and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing 210008, China.
Environ Sci Technol. 2020 Apr 7;54(7):4609-4620. doi: 10.1021/acs.est.9b06438. Epub 2020 Mar 11.
Driven by global warming and eutrophication, outbreaks of cyanobacterial blooms have severely impacted ecosystem stability and water safety. Of the organisms used to control cyanobacteria, protozoa can highly resist cyanotoxins, efficiently control cyanobacterial populations, and show considerably different feeding strategies from those of metazoans. Thus, protozoa have great potential to control harmful cyanobacteria and improve phytoplankton composition in eutrophic waters. To evaluate the actual effects of protozoa in controlling cyanobacteria and improving the phytoplankton community structure in the field, an microcosm study was performed using a flagellate that ingests . Results showed that adding reduced the cyanobacterial populations and increased the chlorophyte and diatom proportions. Furthermore, the species richness and diversity of the phytoplankton community were enhanced in microcosms with . Additionally, there was a gradual increase in the chlorophyte population in the unicellular control, while addition significantly accelerated the replacement of dominant species. This study was the first to show the practical effects of protozoa on controlling cyanobacteria in the field, highlighting that a reduction in cyanobacteria via protozoa can improve the phytoplankton community structure, dredge the toxic cyanobacteria-dominated microbial food web, and mitigate harmful cyanobacteria risks in fresh waters.
受全球变暖与水体富营养化的驱动，蓝藻水华的爆发严重影响了生态系统稳定性和饮水安全。在用于控制蓝藻的生物中，原生动物能够高度抵抗蓝藻毒素，高效控制蓝藻种群，且摄食策略与后生动物有很大不同。因此，原生动物在控制有害蓝藻和改善富营养化水体中浮游植物组成方面具有巨大的潜力。为了评估原生动物在控制蓝藻和改善浮游植物群落结构方面的实际效果，本研究采用一种能摄食 的鞭毛虫在微宇宙中进行了实验。结果表明，添加 可降低蓝藻的数量，增加绿藻和硅藻的比例。此外，添加 还可增加微宇宙中浮游植物群落的物种丰富度和多样性。此外，在单细胞 的对照组中，绿藻的数量逐渐增加，而 添加则显著加速了优势种的更替。本研究首次表明原生动物在野外控制蓝藻方面具有实际效果，突出了原生动物通过减少 蓝藻来改善浮游植物群落结构，疏通以有毒蓝藻为主的微生物食物网，减轻淡水系统中有害蓝藻的风险。
