Marine College, Shandong University, Weihai 264209, PR China.
Marine College, Shandong University, Weihai 264209, PR China; Marine Bioresource and Environment Research Center, Key Laboratory of Marine Eco-Environmental Science and Technology, The First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, PR China.
J Hazard Mater. 2022 Jun 5;431:128627. doi: 10.1016/j.jhazmat.2022.128627. Epub 2022 Mar 3.
Ocean acidification caused by increasing emission of carbon dioxide (CO) is expected to have profound impacts on marine ecological processes, including the formation and evolution of harmful algal blooms (HABs). We designed a set of experiments in the laboratory to examine the effects of increasing CO on the growth and toxicity of a toxic dinoflagellate Alexandrium minutum producing paralytic shellfish toxins (PSTs). It was found that high levels of CO (800 and 1200 ppm) significantly promoted the growth of A. minutum compared to the group (400 ppm) representing the current CO level. The total yields of PSTs by A. minutum, including both intracellular and extracellular toxins, were significantly enhanced, probably due to the induction of core enzyme activity and key amino acids synthesis for PST production. More interestingly, high level of CO promoted the transformation from gonyautoxin2&3 to gonyautoxin1&4 and depressed the release of PSTs from inside to outside of the cells. All these processes collectively led to an apparent increase of A. minutum toxicity. Our study demonstrated that rising CO would increase the risk of toxic A. minutum based on the comprehensive analyses of different processes including algal growth and toxin synthesis, transformation and release.
由于二氧化碳（CO）排放量的增加，海洋酸化预计将对海洋生态过程产生深远影响，包括有害藻类大量繁殖（HABs）的形成和演变。我们在实验室设计了一系列实验，以研究增加 CO 对产生麻痹性贝类毒素（PSTs）的有毒甲藻亚历山大藻生长和毒性的影响。结果发现，与代表当前 CO 水平的 400 ppm 组相比，高浓度 CO（800 和 1200 ppm）显著促进了亚历山大藻的生长。亚历山大藻产生的 PST 总量，包括细胞内和细胞外毒素，均显著增强，这可能是由于 PST 产生的核心酶活性和关键氨基酸合成的诱导。更有趣的是，高水平的 CO 促进了 GTX2&3 向 GTX1&4 的转化，并抑制了 PST 从细胞内到细胞外的释放。所有这些过程共同导致亚历山大藻毒性的明显增加。我们的研究表明，基于对藻类生长和毒素合成、转化和释放等不同过程的综合分析，上升的 CO 将增加有毒亚历山大藻的风险。
