| 摘要: |
| 通过实验室培养, 在不同氮磷浓度及氮磷比率的营养条件下, 对中肋骨条藻(Skeletonema costatum)的生长及藻细胞硝酸还原酶的活性进行研究。实验结果表明, 中肋骨条藻属于营养型藻类, 氮磷营养盐的添加, 极大地促进了藻细胞的增殖。在接种后的第4～5天, 各培养组藻密度达到最大值并与对照组形成极显著性差异(P< 0. 01)。实验进一步发现, 环境中的氮、磷浓度及氮磷比率都会影响中肋骨条藻的生长及藻细胞硝酸还原酶活性(NRA)。此外, 在各培养组中, 中肋骨条藻硝酸还原酶活性的最大值(NRAmax)均出现在指数生长期(接藻后第1, 2 天),早于最大藻密度的出现时间(第4, 5 天), 这表明藻对营养盐的同化速率与生长速率并不一致, 后者存在一定的滞后效应。在本实验条件下, 中肋骨条藻的硝酸还原酶活性存在一定的阈值。 |
| 关键词: 硝酸盐 磷酸盐 中肋骨条藻(Skeletonema costatum) 硝酸还原酶 硝酸还原酶活性 比生长率 |
| DOI： |
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| 基金项目:国家自然科学基金项目( 40376033) ; 国家重点基础研究发展计划项目( 2005CB422305) |
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| The effects of nitrate and phosphate on the growth and nitrate reductase activity of Skeletonema costatum |
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| Abstract: |
| The growth and nitrate reductase activity (NRA) of Skeletonema costatum were studied under different concentrations and structures of nitrate and phosphate in laboratory cultures. The results indicated that S. costatum is a nutrients-dependent species and the algae multiplied exponentially after adding nitrate or phosphate into the culture. The cell density in each group not only reached its maximum value in the fourth to fifth day after inoculation, but also showed a significant differ ence (P< 0. 01) to the control group. The results also revealed that the growth and NRA of S. costatum were affected by both concentrations and ratio of nutrients. Furthermore, the appearing time of NRAmax ( 1～2 d) was during the period of exponential growth which was earlier than that of the maximum cell density ( 4～5 d) .It was suggested that the growth of S. costatum had a lagging effect, which was not consistent with the assimilation of the nutrients. In addition, the NRA of S. costatum has a certain threshold. |
| Key words: Nitrate Phosphate Skeletonema costatum nitrate reductase nitrate reductase activity specific growth rate |
