中国近岸海域优势藻种吸收利用磷的过程

通过现场采样和室内培养实验分析了藻类植物的生长状况和细胞结合态磷对磷酸盐浓度的响应.现场调查结果发现，在水华区域藻类植物的细胞磷库分布特点与非水华区域明显不同.室内培养结果发现，中肋骨条藻和东海原甲藻的最大磷酸盐吸收速率为7.71，2.39μmol/（L·d），最大比生长率分别为0.517，0.262d^-1，磷酸盐吸收同化率为5.9×10^-8，4.7×10^-7μmol/cell，前者具有更快的磷酸盐吸收能力，更高的比生长率和较低的磷酸盐吸收同化率.2种藻细胞内结合态磷通常占细胞总磷库的50%以上，是细胞磷库主要存在形式.中肋骨条藻种群可以通过藻细胞数量增长来吸收环境中的磷源，而东海原甲藻则会优先满足细胞自身的磷储存后进行细胞增殖.在高浓度磷环境中，东海原甲藻种群的细胞不同结合态磷的质量浓度会达到饱和.磷匮乏时，中肋骨条藻和东海原甲藻的细胞内结合态磷的质量浓度与零时刻相比分别降低了45%和66%，前者明显低于后者.培养过程中，中肋骨条藻单个细胞的细胞表面吸附态磷库（95%）比细胞内磷库（50%）的降低幅度更大，东海原甲藻则与之相反.

Phosphorus assimilation process by dominant algaespecies in Chinesecoastal sea

The growth of algaes and the response of cell-bound phosphorus to phosphate were studied by the field sampling and indoor culture experiments. The cell-bound phosphorus pool of phytoplankton from the bloom station and non-bloom station were different. The maximum P-Uptake rates of Skeletonema costatum and Prorocentrum donghaiensis were 7.71 and 2.39μmol/(L·d),the maximum specific growth rates of themwere 0.517 and 0.262d^-1, the P-assimilation rates of them were 5.9×10^-8 and 4.7×10^-7μmol/cell, respectively. S. costatum showed higher P-Uptake capacity,faster specific growth rate and lower P-assimilation rate compared with P. donghaiensis during the incubation period. The intracellular phosphorus, which is the main form of cell phosphorus pool, usually accounts for more than 50% of total cellular phosphorus pool. The S.costatum could utilize phosphorus from the environment by cell multiplication. While P.donghaiensis preferentially satisfied the phosphorus storage in cells. The contents of cell associated phosphorus in the cell of P.donghaiensis could reach saturation in phosphorus rich waters. When phosphorus was deficient, the mass concentration of intracellular phosphorus in S.costatum and P.donghaiensis decreased by 45% and 66%, respectively, compared with the start of the experiment. During the culturing, the cell surface-adsorbed phorsphous(95%) of the single cell of S.costatum decreased more than intracellular phosphorus(50%), while P.donghaiensiswas different from it.