氮和磷对东海原甲藻吸收Cd（Ⅱ）及其分布的影响

研究了不同氮和磷浓度下,东海原甲藻（Prorocen trum dongha ineseLu）对微量Cd（Ⅱ）的吸收及其在细胞亚结构和大分子物质中的分布.结果表明,硝酸盐的添加促进了藻细胞对Cd（Ⅱ）的吸收,而磷酸盐的添加在低浓度Cd（Ⅱ）时对藻细胞吸收Cd（Ⅱ）没有影响,但在高浓度Cd（Ⅱ）时则抑制藻细胞对Cd（Ⅱ）的吸收;尿素为氮源时,细胞中Cd（Ⅱ）的含量较硝酸盐为氮源时高.细胞内的Cd（Ⅱ）主要分布在可溶性物质中.硝酸盐的添加主要影响Cd（Ⅱ）在细胞亚结构中的分布,细胞壁中Cd（Ⅱ）的含量随培养液中硝酸盐浓度的增加而降低,而细胞器中的含量却随培养液中硝酸盐浓度的增加而增加;培养液中磷浓度的添加增加了细胞壁内Cd（Ⅱ）的含量.Cd（Ⅱ）在各生化组成中的分布以蛋白质中含量最高,可达总Cd（Ⅱ）含量的55.0%~79.6%,脂类中含量最低,仅为总Cd（Ⅱ）含量的5.9%~7.1%,蛋白质内Cd（Ⅱ）的含量随培养液中硝态氮浓度的增加而增加.蛋白质内Cd（Ⅱ）的含量与藻细胞内的蛋白质含量密切相关.

Effects of Nitrogen and Phosphorus on Cd（Ⅱ）Uptake and Distribution in Prorocentrum donghaiense Lu

The influences of major nutrient（N、P） on Cd（Ⅱ） distribution in structural and biochemical composition of Prorocentrum donghaiense Lu were examined.The result showed that accumulation and distribution of Cd（Ⅱ） in structural and biochemical composition were influenced by nutrient concentration in culture media.Nitrate increased the uptake of algae.Phosphate had not influenced the uptake of Cd（Ⅱ） in the low Cd（Ⅱ） concentration,but it could restrain the uptake of algae while in the high Cd（Ⅱ） concentration.The content of Cd（Ⅱ） in algae was less in the nitrate culture than in the urea culture.The metal distribution in the cell wall decreased,and that in the organelle increased.On the other side,an ambient P enhanced Cd（Ⅱ） distribution in the cell wall.The largest amount of Cd（Ⅱ） distribution in biochemical composition was in the protein,up to 55.8 %~79.2 %.There was least Cd（Ⅱ） in the fat,only 5.9 %~7.1 %.Under most circumstances,the amount of metal distribution in the protein increased exponentially with increasing amount of protein in the algae.