Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China; Department of Marine Biology, College of Oceanography, Hohai University, 1 Xikang Road, Nanjing 210098, China.
Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
Environ Pollut. 2020 Jun;261:114131. doi: 10.1016/j.envpol.2020.114131. Epub 2020 Feb 11.
The ecotoxicology of surfactants is attracting wide attention due to the rapidly expanding global application. As interspecific relationships play one of the central roles in structuring biological communities, it is necessary to take it into risk assessments on surfactants. With this aim, our study investigated the interference of three common surfactants on the inducible defense of a freshwater phytoplankton Scenedesmus obliquus. Nonlethal environmentally relevant concentrations (10 and 100 μg L) of several surfactants were set up. Results showed that growth and photosynthetic efficiency of Scenedesmus were inhibited during first 96 h, but recovered in the later stage. Surfactants interfered inducible defense of Scenedesmus against Daphnia grazing, and the interference was related to chemical characteristics of surfactants. The anionic surfactant sodium dodecyl sulfate (SDS) enhanced the colony formation even without grazing cues, whereas fewer defensive colonies were formed under the effects of cationic surfactant benzalkonium bromide (BZK) and nonionic surfactant polyoxyethylene (40) nonylphenol ether (NPE). These findings highlighted the sensitivity of grazer-induced morphological defense of Scenedesmus to surfactants even at nonlethal concentrations, which potentially affects the energy and information flow between trophic levels. This study appeals for more attention to take interspecific relationships into consideration in assessing the potential ecological risk of pollutants.
由于表面活性剂在全球范围内的应用迅速扩大，其对生态的毒性作用引起了广泛关注。种间关系在生物群落的结构中起着核心作用之一，因此有必要将其纳入表面活性剂的风险评估中。为此，本研究调查了三种常见表面活性剂对淡水浮游植物斜生栅藻（Scenedesmus obliquus）诱导防御的干扰作用。设置了非致死的、环境相关浓度（10 和 100μg/L）的几种表面活性剂。结果表明，表面活性剂在最初的 96 小时内抑制了斜生栅藻的生长和光合作用效率，但在后期恢复。表面活性剂干扰了斜生栅藻对水蚤摄食的诱导防御，这种干扰与表面活性剂的化学特性有关。阴离子表面活性剂十二烷基硫酸钠（SDS）即使在没有摄食信号的情况下也能增强群体形成，而阳离子表面活性剂苯扎氯铵（BZK）和非离子表面活性剂聚氧乙烯（40）壬基酚醚（NPE）的作用下则形成了较少的防御群体。这些发现强调了即使在非致死浓度下，食草动物诱导的斜生栅藻形态防御对表面活性剂的敏感性，这可能会影响营养级之间的能量和信息流。本研究呼吁更多地关注种间关系，以评估污染物的潜在生态风险。
