Institute of Hydrobiology, Jinan University, Guangzhou 510632, China.
Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China.
Int J Environ Res Public Health. 2021 Dec 30;19(1):404. doi: 10.3390/ijerph19010404.
The mixotrophic dinoflagellate frequently forms harmful algal blooms around the world and has caused massive deaths of shellfish, finfish and birds, yet its toxic mechanism is still unclear. In this study, toxic effects of on co-culturing phytoplankton and zooplankton were investigated. The results showed that sonicated cultures of JX13 and JX14, isolated from the Pearl River Estuary, had a significant lethal effect on the rotifer , with the highest mortality rate of 80%. The highest inhibition rates of cultures JX13 (90%) and JX14 (80%) on were much higher than that of AS2 (20%). Toxicity varied with the growth stage, during which cells in the exponential stage showed the highest toxicity (40%), while filtrate had the highest toxicity (10%) in the decline stage. The action mode of toxicity on plankton was explored through an osmotic membrane culture device. It was found that JX13 displayed an inhibitory effect on coexisting phytoplankton, whether they had contact or not, but the inhibition rate increased by 25% with contact. A lethal effect of JX13 on rotifer was observed only in contact treatment. This study suggests that direct contact is the key action mode to trigger the release of toxins and induce toxic effects of on co-occurring plankton.
混养甲藻经常在世界各地形成有害藻类水华，导致大量贝类、鱼类和鸟类死亡，但它的毒性机制仍不清楚。本研究调查了 对共培养浮游植物和浮游动物的毒性作用。结果表明，来自珠江口的JX13 和 JX14 声处理培养物对轮虫有显著的致死作用，最高死亡率为 80%。JX13（90%）和 JX14（80%）培养物对 的最高抑制率远高于 AS2（20%）。毒性随生长阶段而变化，其中指数期细胞毒性最高（40%），衰退期滤液毒性最高（10%）。通过渗透膜培养装置探索了 毒性对浮游生物的作用模式。结果发现，JX13 对共存的浮游植物表现出抑制作用，无论是否接触，接触时抑制率增加 25%。仅在接触处理中观察到 JX13 对轮虫的致死作用。本研究表明，直接接触是触发毒素释放并诱导 对共存浮游生物产生毒性作用的关键作用模式。
