4种海洋单胞藻生化组成的环境因子效应研究

Study of the effects of environmental factors on the biochemical compositions of four species of marine single-celled algae

在实验室模拟条件下，应用14C示踪法测定4种海洋单胞藻的光合作用速率，研究光、温度和营养盐等环境因子对藻类细胞生化组成的影响．结果表明，三角褐指藻、盐藻、中肋骨条藻和等鞭金藻适宜生长的光强范围为5．8×103～15×103lX．4种单胞藻光合作用速率随光强增加而增大，其中盐藻和等鞭金藻的光响应比较明显．随光强增加，4种单胞藻细胞的碳水化合物含量及其变化量呈增加趋势，而蛋白质含量及其变化量则减少，脂类含量变化很小．三角褐指藻、盐藻、中肋骨条藻和等鞭金藻最适生长温度分别为：14、26、21、26℃左右．在上述4个实验温度时，4种单胞藻光合作用速率最高，细胞内的碳水化合物、蛋白质、脂类含量及其变化量也达到最大值．三角褐指藻、盐藻、中肋骨条藻和等鞭金藻光合作用过程的表观活化能（E）分别为：23．2、38．5、22．4和61．7KJ／mol，温度系数（Q10）分别为：1．74、1．74。1．38和1．69．三角褐指藻和中肋骨条藻在氮磷比（N／P）为16时，盐藻和等鞭金藻在氮磷比为28时，光合作用速率最大．在N／P为16时，4种单胞藻细胞内的碳水化合物、蛋白质、脂类含量和变化量均达到最大值．

Photosynthetic rates (PR ) of four species of marlne single - celled algae were determined by means of 14 C- tracer methodunder the experimental modeling conditions. The effects of environmental factors, such as light, temperature and nutrients, on thebiochemical compositions of the algae were studied. The results indicate that the suitable light intensities for the growth of Phacodactylum tricornutum, Dunaliella spp., Skeletonema costatum and Isochrysis galbana are in the range 5. 8 × 103 to 15 × 103lx,showing an increasing trend of PR with the heightened light intensities. The irradiance response of Dunaliella spp. and Isocrysisgalbana is significant. The contents of carbohydrate increase, but those of protein decrease, otherwise, the contents of lipidschanged little. The optimum temperatures for the growth of the four species of algae are 14, 26, 21 and 26℃ respectively, characterized by the maxima of PR and the contents of carbohydrate, protein and lipids as well as their variations. The apparent activationenergies in the photosynthesis process of Phaedotylum tricornutum, Dunaliella spp., Skeletonema costatum and Iswtrysis galhana are 23. 2, 38. 5, 22. 4 and 61. 7 KJ/mol respectively, and the temperature coefficients for the four algae are 1. 74, 1. 74,1. 38 and 1 .69 respectively. The peaks of PR appeared in some culture media (N/P = 16) of Peaeodactylum tricornutum andSkeletonema costatum, while in other media (N/P = 28) of Dunaliella spp. and lsochrysis galbana. The contents and their variations of carbohydrate, protein and lipids of the four species of algae are all maximum when N/P is equal to 16 in culture media.