微板吸光法测定9种农药对斜生栅藻的抑制毒性

Microplate Algae Toxicity of 9 Pesticides to Scenedesmus obliquus Based on Absorbance

以斜生栅藻(Scenedesmus obliquus)为指示生物,96微孔板为暴露反应载体,SpectraMax M5酶标仪为吸光度测试设备,建立了测定毒物对藻生长抑制毒性的微板吸光法.论文系统研究了微板吸光法中斜生栅藻的可见吸收光谱和生长曲线以及pH和暴露时间对藻生长的影响,同时应用该方法成功测定了环嗪酮、阿特拉津、西草净、扑灭通、苯嗪草酮、敌草快、草甘膦7种除草剂和磷胺、甲胺磷2种杀虫剂对斜生栅藻的剂量-效应曲线(DRC).通过对剂量-效应数据进行非线性最小二乘模拟,获得了这些农药的半数效应浓度EC50及置信区间.对比标准锥形瓶栅藻毒性试验,微板吸光法具有测试简便快速,所需样品体积少,便于多次平行毒性测试等优点.

A microplate algae toxicity assay was developed using the multifunctional microplate reader（SpectraMax M5）to measure the absorbance of Scenedesmus obliquus and taking the 96-well microplate as exposure reaction carder. The visible absorption spectra and growth curve of Scenedesmus obliquus, effects of pH and exposure time on algae growth in the microplate algae toxicity assay were systematically investigated. The method was successfully employed in dose-response curve （DRC） tests of seven herbicides （hexazinone, atrazine, simetryn, prometon, metamitron, diquat, glyphosate ） and two insecticides （phosphamidon, methamidophos） to Scenedesmus obliquus. The median effect concentration （EC50）and its confidence intervals （CI） of these pesticides were computed from the nonlinear least square modeling of dose-response data. Compared with the standard flask assay of Scenedesmus algae, microplate absorbance assay has some advantages such as fast easy-operating, requiring low sample volumes, easy to perform more parallel tests of toxicity and so on.