Klapes N A
Division of Environmental and Occupational Health, School of Public Health, University of Minnesota, Minneapolis 55455.
Ecotoxicol Environ Saf. 1990 Oct;20(2):167-74. doi: 10.1016/0147-6513(90)90055-a.
Cyanobacterin is a potent, photosynthetic inhibitor produced as a secondary metabolite by the filamentous, freshwater cyanobacterium Scytonema hofmanni. With a spectrum of activity encompassing species of cyanobacteria and eucaryotic algae as well as higher plants, cyanobacterin might be utilized as a commercial algicide for algae waterbloom control. As a component of the preliminary environmental risk/hazard evaluation of this proposed application, the acute toxicity of cyanobacterin to the planktonic crustacean, Daphnia magna, was assessed. Based on five trials, the 48-hr LC50 for D. magna was determined to be approximately 1.37 micrograms/ml (range: 0.78-2.58 micrograms/ml). In addition, a significant percentage of the surviving daphnids were completely immobile at the end of the 48-hr exposure period. These results give strong indication that cyanobacterin and/or its residues exhibit some nontarget organism lethality at projected use-concentration level. Furthermore, estimates of partition coefficients and bioconcentration factor, generated through quantitative structure-activity relationships, suggest that sediment, suspended particulates, and biota may serve as major compartments of cyanobacterin partitioning in an aquatic ecosystem. Before cyanobacterin should be further considered for application as a commercial algicide, a rigorous evaluation of nontarget organism lethality and environmental fate is required.
蓝藻素是一种由丝状淡水蓝藻霍氏伪枝藻作为次级代谢产物产生的强效光合抑制剂。蓝藻素的活性谱涵盖蓝藻、真核藻类以及高等植物物种，因此可作为一种用于控制藻类水华的商业除藻剂。作为对该拟议应用进行初步环境风险/危害评估的一部分，评估了蓝藻素对浮游甲壳类动物大型溞的急性毒性。基于五项试验，确定大型溞的48小时半数致死浓度约为1.37微克/毫升（范围：0.78 - 2.58微克/毫升）。此外，在48小时暴露期结束时，相当比例存活的溞完全无法活动。这些结果有力地表明，在预计使用浓度水平下，蓝藻素和/或其残留物对非目标生物具有一定的致死性。此外，通过定量构效关系得出的分配系数和生物富集因子估计表明，沉积物、悬浮颗粒物和生物群可能是蓝藻素在水生生态系统中分配的主要部分。在将蓝藻素进一步考虑用作商业除藻剂之前，需要对非目标生物致死性和环境归宿进行严格评估。
