【摘要】 研究了不同硝酸盐浓度(50～250μmol/L)对南极塔玛亚历山大藻Alexandrium tamarensePolar(ATP)麻痹性毒素含量和组成的影响.结果表明,ATP所产毒素主要为N-磺酰氨甲酰基类毒素(C2毒素),占细胞毒素总量的90%,此外还含有少量的膝沟藻毒素(GTXs),如GTX5和GTX3,但未检出到其它麻痹性毒素.硝酸盐浓度的变化对ATP的细胞密度和生长率影响不大,但对GTXs和C毒素的单细胞毒素含量(fmol/cell)和毒素产量(μmol/L)均有显著影响.在培养期后期(第5天起),高硝氮浓度组(150μmol/L及以上)单细胞毒素含量比低硝氮浓度组(100μmol/L及以下)单细胞毒素含量增加了2～3倍,毒素产量提高20%～60%.但在整个生长过程中ATP的毒素组成保持相对稳定,均以C2为主要毒素组成.本研究结果表明,在海洋环境中硝酸盐浓度的增加可能会提高南极塔玛亚历山大藻细胞毒素的含量,从而提高了其潜在毒性.更多还原

【Abstract】 Alexandrium tamarense Polar(ATP) is a toxic dinoflagellate isolated from the South Polar.This study investigated toxin contents and toxin profiles of ATP grown in various nitrate concentrations.The result showed that ATP produced predominantly C2 toxin(90%of total cellular toxin),with a few of GTX5(10%of total cellular toxin) and trace GTX3 but no STX derivatives.Variation of nitrate concentrations had little effect on the cell density and growth rate of ATP,but affected both the toxin content and the toxin production significantly.At the later culture phase(day 5),the toxin contents(fmol/cell) of A.tamarense Polar grown in high nitrate concentration((150 μmol/L) was two to three times of that in low nitrate concentration((100 μmol/L),and toxin productions in the former group((mol/L) are 20%~60% higher than those in the latter’s.However,the toxin compositions of A.tamarense Polar maintained relatively constant with C2 as the dominant component.This study suggests that the increase of nitrate concentration in marine environment might enhance toxin production of ATP.This may results in high potential toxicity when ATP bloom occurs.更多还原