Institute of Microbiology of the Czech Academy of Sciences, Vídeská 1083, CZ-142 20, Prague 4, Czech Republic; Institute for Environmental Studies, Faculty of Science, Charles University, Benátská 2, CZ-128 01, Prague 2, Czech Republic.
Institute of Microbiology of the Czech Academy of Sciences, Vídeská 1083, CZ-142 20, Prague 4, Czech Republic.
Toxicon. 2021 May;195:69-77. doi: 10.1016/j.toxicon.2021.03.003. Epub 2021 Mar 9.
Secondary metabolites of cyanobacteria and algae released during algal blooms often exhibit toxic effects, but only a small number of the metabolites are the subject of routine analytical screenings. Alternatively, ecotoxicological assays offer a better representation of the overall negative effects. The aim of this work was to compare multiple assays in their sensitivity towards cellular algal organic matter (COM) of the toxin-producing cyanobacterium Microcystis aeruginosa. Multiple endpoints were investigated: mortality, growth inhibition, bioluminescence inhibition, genotoxicity, endocrine-disrupting effects, oxidative stress, and the induction of ethoxyresorufin-O-deethylase (EROD). Three rainbow trout (Oncorhynchus mykiss) cell lines as well as representatives of bacteria, yeasts, algae, vascular plants, and crustaceans were employed, and the results were expressed per mg of dissolved organic carbon (DOC) in the COM. M. aeruginosa COM was toxic to the RTgill-W1, RTG-2, and RTL-W1 cell lines (EC values ranging from 0.48 ± 0.02 to 1.9 ± 0.1 mg/L), to the crustacean Thamnocephalus platyurus (LC = 20 ± 1 mg/L), and to Lepidium sativum (IC = 241 ± 13 mg/L). In contrast, no effect was observed for bacteria and yeasts, and the growth of the alga Desmodesmus subspicatus was even stimulated. No genotoxicity, endocrine-disrupting effects or increase in oxidative stress or EROD activity was detected. The content of six microcystins (MC-LR, MC-RR, MC-YR, MC-LY, MC-LW, and MC-LF), anatoxin-a, cylindrospermopsin, and nodularin in the M. aeruginosa COM was determined by liquid chromatography-tandem mass spectrometry. An artificially prepared mixture of the detected cyanotoxins in the corresponding concentrations did not induce response in the O. mykiss cell lines and T. platyurus, suggesting that other cyanobacterial metabolites are responsible for the toxicity of M. aeruginosa.
微囊藻和藻类在水华期间释放的次生代谢物通常具有毒性作用，但只有少数代谢物是常规分析筛选的对象。相比之下，生态毒理学测定能更好地反映整体的负面影响。本研究的目的是比较多种测定方法对产毒微囊藻（Microcystis aeruginosa）细胞有机物质（COM）的敏感性。研究了多个终点：死亡率、生长抑制、生物发光抑制、遗传毒性、内分泌干扰效应、氧化应激和乙氧基荧蒽-O-脱乙基酶（EROD）的诱导。采用了三种虹鳟（Oncorhynchus mykiss）细胞系，以及细菌、酵母、藻类、维管束植物和甲壳类动物的代表，结果以 COM 中每毫克溶解有机碳（DOC）的形式表示。M. aeruginosa COM 对 RTgill-W1、RTG-2 和 RTL-W1 细胞系（EC 值范围为 0.48±0.02 至 1.9±0.1 mg/L）、甲壳类动物 T. platyurus（LC=20±1 mg/L）和生菜（IC=241±13 mg/L）有毒。然而，细菌和酵母没有观察到效果，藻类 Desmodesmus subspicatus 的生长甚至受到刺激。没有检测到遗传毒性、内分泌干扰效应或氧化应激或 EROD 活性的增加。通过液相色谱-串联质谱法测定了 M. aeruginosa COM 中六种微囊藻毒素（MC-LR、MC-RR、MC-YR、MC-LY、MC-LW 和 MC-LF）、鱼腥藻毒素-a、柱孢藻毒素和节球藻毒素的含量。在相应浓度下人工制备的检测到的蓝藻毒素混合物没有在虹鳟细胞系和 T. platyurus 中引起反应，这表明其他蓝藻代谢物是 M. aeruginosa 毒性的原因。
