营养环境对微小亚历山大藻C4生长和产毒的影响

Influences of nutrient environment on growth and toxin productivity of Alexandrium minutum C4

为考察营养成分以及培养基础液再利用对一株微小亚历山大藻的生长和产毒的影响,采用单因素实验分别研究了氮(NaNO_3)、磷(NaH_2PO_4)、微量元素(FeCl_3、Na2EDTA、CuSO_4、Na_2MoO_4、ZnSO_4、CoCl_2、MnCl_2)、维生素(Vitamin B12、Vitamin H、Vitamin B1)、碳(NaHCO_3)的不同含量以及海水(培养基础液)利用方式(不循环与循环利用)对微小亚历山大藻C4生长、毒素含量(μmol/L)与毒素组成的影响。结果显示,氮、磷浓度对C4藻的毒素总含量(μmol/L)有显著影响,其他因素影响均不显著;氮、磷、碳及微量元素的浓度对GTX1/4(GTX1+GTX4)在总毒素(GTX1+GTX2+GTX3+GTX4)中所占比例均影响显著,而维生素浓度和海水循环利用对GTX1/4所占比例影响均不明显。氮浓度在0~883μmol/L范围内,毒素含量与氮浓度呈正相关关系,氮浓度进一步增加,毒素含量没有明显变化;磷浓度在0~145.2μmol/L范围内增加,毒素含量先增后降,最终保持稳定的趋势。最佳的产毒条件为氮883μmol/L,磷18.15μmol/L,微量元素为f/2海水培养基中微量元素的0.5倍,碳不添加。

In order to grasp the influences of nutrients and sea water reuse on growth and toxin productivty of the Alexandrium minutum, single factor experiments were used to observe the influences of the concentrition of nitrogen（NaNO_3）, phosphorus（NaH_2 PO_4）, trace element（FeCl_3, Na_2EDTA, Cu SO_4, Na_2Mo O_4, ZnSO_4, CoCl_2,MnCl_2）, vitamin（Vitamin B12, Vitamin H, Vitamin B1）, carbon（NaHCO_3） and the style of sea water（new or reuse） on the growth, toxin content（μmol/L） and toxin constitution of Alexandrium minutum C4. The results showed that nitrogen and phosphorus had a significant effect on the total toxin content（μmol/L）, while others had non-significant effect（μmol/L）; nitrogen, phosphorus, trace element and carbon had a significant effect on the ratio of GTX1/4（GTX1＋GTX4） to total toxin content（GTX1＋GTX2＋GTX3＋GTX4）, while vitamin and sea water reuse had non-significant effect on that ratio. There was a positive correlation between the concentration of toxin and nitrogen when the nitrogen concentrition was between 0 and 883 μmol/L, and then toxin content stayed invariant with the increase of nitrogen. However, with the increase of phosphorus concentrition from 0 to 145.2 μmol/L, the toxin content increased at first, then reduced,and stayed invariant in the end.The optimal conditions for the toxin production were nitrogen 883 μmol/L, phosphorus 18.15 μmol/L, trace element one half of that in the f/2 medium and carbon free.