环境因子对微小亚历山大藻Amtk-9生长与产毒的综合影响

微小亚历山大藻是产生麻痹性贝毒的主要生物之一。产毒藻株在不同培养条件下所产生的毒素总量有差异,因此研究环境因子对微小亚历山大藻生长与产毒的综合影响,找到微小亚历山大藻生长和产毒的适宜条件,对麻痹性贝毒在赤潮中是否造成贝类蓄毒有十分重要意义。本文设计了一个四因素三水平的正交实验,研究温度、盐度、营养盐、光照强度等环境因子对微小亚历山大藻Amtk-9生长与产毒的综合影响。结果表明:在实验范围内,微小亚历山大藻Amtk-9生长最佳条件为温度25℃,盐度30,培养基中氮含量为基础f/2培养液配方中氮磷含量的2倍,光照强度10000 lx。最佳产毒条件除了氮磷含量为基础f/2培养液配方中氮磷含量的3倍外,其它条件与生长的最佳条件相同。盐度、营养盐、光照这三个因素的不同水平对微小亚历山大藻Amtk-9指数生长期细胞比增长率、指数生长末期单位细胞含毒量均有极显著影响(F>F0.01)。温度对微小亚历山大藻Amtk-9的生长和产毒则无显著影响(F

Effects of some ecological factors on the growth and toxin production of dinoflagellate Alexandrium minutum Amtk-9

Alexandrium minutum is one of the dinoflagellates which can produce paralytic shellfish toxins (PSTs).The toxin content of Alexandrium mimutum varied under different culturing conditions but the repetitive content and the composition remained the same.Study on the combined effects of environmental factors on the growth and toxin production of A.minutum iS very important for the shellfish bioaccumulation of paralytic shellfish toxins during red tide.An orthogonal test L_9(3~4)was designed to study the combined effects of temperature,salinity,nutrient concentration and light intensity on the growth of A.minutum(Amtk-9).The results showed that the optimal culturing conditions of A.minutum(Amtk-9)is under 25 ℃,30 salinity,10 000 lux light intensity,and two times of nitrate/phosphate concentrations of f/2 culture medium.The optimal condition for toxin production was found almost the same as the culturing conditions,expect for the nitrate/phosphate concentrations which was three times.Different levels of salinity,nutrient concentration and light intensity significantly influenced the specific growth rate and toxin production of A.minutum(Amtk-9)(F>F_(0.01)),while different temperature showed minor or no effects(F