珠江口海域3种重要有害藻类的溶血毒性研究

从珠江口海域分离、鉴定出3种重要有害藻类小普林藻JX12(Prymnesium parvum)、剧毒卡尔藻JX24(Karlodinium veneficum)、红色赤潮藻JX14(Akashiwo sanguinea),在实验室条件下研究了不同反应温度和pH值对小普林藻溶血活性的影响,在此基础上对海洋微藻溶血活性的测定方法进行了优化,并进一步分析比较了不同藻株以及不同生长时期溶血毒性的变化特征。研究结果显示,在实验温度范围内(4~50°C),小普林藻的溶血活性随温度的升高而增大,37℃为其最佳反应温度,pH 8和50 min为其最佳反应条件。不同生长时期的小普林藻溶血毒性具有显著差异,对数期溶血活性(5.67×10~(-7)HU·cell~(-1))显著高于稳定期(2.32×10~(-7)HU·cell~(-1))和衰亡期(3.40×10~(-7)HU·cell~(-1))。分离自珠江口海域的3种微藻均检测出溶血毒性,单个细胞溶血活性由强到弱分别为红色赤潮藻(976.20×10~(-7)HU·cell~(-1))、小普林藻(5.67×10~(-7)HU·cell~(-1))、剧毒卡尔藻(2.58×10~(-7)HU·cell~(-1))。值得注意的是,红色赤潮藻中国株JX14的单位细胞溶血活性显著高于美国株AS2,是后者的2倍以上。本研究首次确认珠江口海域红色赤潮藻、小普林藻和剧毒卡尔藻均具有较强的溶血毒性,这些有害藻类一旦形成赤潮可能对河口生态系统安全以及水产养殖业造成严重危害。

Hemolytic Toxicity of Three Important Harmful Microalgae Isolated from Pearl River Estuary

Three important harmful algal bloom causative species, Prymnesium parvum ( strain number: JX12 ), Karlodiniumveneficum(strain number:JX24), and Akashiwosanguinea(strain number:JX14) were isolated and i-dentified from Pearl River Estuary. The effect of different temperature and pH value on the hemolytic activity of P. parvum were investigated under laboratory conditions. On the basis, the determination method of hemolytic activity of marine microalgae was optimized. Furthermore, the change character of hemolytic activity of different microalgal strains and different growth periods were compared. The results showed that hemolytic activity of P. parvum in-creased along with the rise of temperature between the experimental temperature range (4-50 ℃), and the optimal measuring conditions were 37 ℃ of reaction temperature, pH 8, and 50 min of reaction time. There are significant differences in the hemolytic activity of P. parvum in different growth phases. Hemolytic activity of P.parvum in the exponential phase (5.67×10-7 HU·cell-1) was significantly higher than that of the stationary (2.32×10-7 HU·cell-1) and decline phases (3.40×10-7 HU·cell-1). Potent hemolytic activity was also observed from other two harmful al-gae isolated from Pearl River Estuary, K.veneficum and A.sanguinea. More specifically, the hemolytic activity of A.sanguinea(976.20×10-7 HU·cell-1) was much higher than those of P.parvum (5.67×10-7 HU·cell-1) and K. veneficum (2.58 × 10-7 HU·cell-1 ). It is noteworthy that the hemolytic activity of Chinese strain of A. sanguinea JX14 was significantly higher than that of the American strain AS2, which was more than twice as high. Our re-sults confirmed as the first time that the three important harmful species P.parvum, K.veneficum and A.sanguinea exhibited the strong hemolytic activity and, when these algae form blooms, it may cause serious damage to estuar-ine ecosystems and aquaculture via producing hemolytic toxins.