| 摘要: |
| 通过实验室构建不同氮磷比条件下的酸化海水环境，培养麻痹性贝毒（paralytic shellfish toxin，PST）产毒藻微小亚历山大藻（Alexandrium minutum），采用藻细胞计数法、分光光度法、高效液相色谱-质谱法等分析方法，探讨了不同氮磷比条件下的酸化海水对微小亚历山大藻的生长、氮磷营养盐吸收、产毒等参数的影响。结果表明，在一定程度上，酸化环境对A.minutum的生长、PST的胞内累积和胞外释放有促进作用，且胞外培养液中PST含量增加的程度更高；同时，酸化海水促进胞内毒性较低的N-H类膝沟藻毒素（GTX2和GTX3）被氧化成毒性较高的N-OH类膝沟藻毒素（GTX1和GTX4），导致A.minutum的细胞毒性和培养液毒性增加。而海水中氮磷比的进一步升高，在一定程度上促进了微小亚历山大藻细胞毒素含量和毒性的增加，但并未促进其生长，且降低了藻细胞内的磷储量。 |
| 关键词: 氮磷比 酸化环境 微小亚历山大藻 麻痹性贝毒素 |
| DOI：10.11759/hykx20200909002 |
| 分类号:P734 |
| 基金项目:山东省自然科学基金（ZR2019MD026）；国家基金委-山东省联合基金（U1806202）；中国科学院海洋生态与环境科学重点实验室（中国科学院海洋研究所）开放基金（KLMEES202003） |
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| Effects of acidification and high N/P ratios on toxin production in Alexandrium minutum |
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HAO Shuang1,2, LIU Li-jun1, CHEN Jun-hui2, HE Xiu-ping2, LIAN Zi-ru1
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1.Marine College, Shandong University, Weihai 264209, China;2.Key Laboratory of Marine Eco-Environmental Science and Technology, The First Institute of Oceanography, Ministry of Natural Resources, Qingdao 266061, China
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| Abstract: |
| In this paper, paralytic shellfish toxin (PST)-producing algae were cultivated under laboratory-simulated seawater eutrophication and acidification conditions, using the algae cell counting method, spectrophotometry, HPLC-MS, and other analytical methods, to explore the effects of an acidified seawater environment under different N/P ratios on Alexandrium minutum growth, nitrogen and phosphorus nutrient absorption, toxicity, and other parameters. The results showed that acidified seawater promoted, to a certain extent, the growth and intracellular accumulation and extracellular release of PST in A. minutum and, to a greater extent, the extracellular PST content. Meanwhile, acidification promoted the oxidation of less toxic N-H gonyautoxin (GTX2 and GTX3) into more toxic N-OH gonyautoxin (GTX1 and GTX4), leading to increased cytotoxicity of A. minutum and toxicity in the culture medium. The increased N/P ratio in seawater had the benefit of elevating the toxin content and toxicity of A. minutum to a certain extent but did not promote the growth of A. minutum and decreased the intracellular phosphorus reserves. |
| Key words: N/P ratios acidification Alexandrium minutum PST |
