假微型海链藻的培养条件研究

The study of the culture conditions of Thalassiosira pseudonana

假微型海链藻（Thalassiosirapseudonana）被广泛应用于基础研究、水产养殖以及生物质能开发。本文对浙江沿岸海区分离的一株富含中性脂的假微型海链藻人工培养条件进行了研究，分别就光温盐、氮磷以及摇瓶强度对细胞增殖的影响进行了分析，以期为该藻的大量培养提供参考。结果显示：（1）该藻盐度适应范围广，培养在盐度为10～45海水中，细胞增殖率没有显著差异，易于培养。温度是改变该藻细胞增殖速率的主要因子，22～25℃之间的温差即显著改变增殖速率，光照与温度的协同作用也发生改变：25℃下，增殖速率随光照增加而增加，22℃下，光强差异的作用则消失。两个温度下，较低光照（2000lx）利于该微藻的稳定增殖。（2）一次培养过程中，该藻对氮的吸收比对磷的吸收迅速，指数生长期对氮吸收显著增加；缺氮强烈抑制细胞分裂和光合潜能（Fv/Fm）。当氮源充足磷限制胁迫时，该藻仍有细胞分裂，并在增殖期能维持与对照组一样的光合潜能。（3）适度摇瓶强度比完全静置能促进对该藻的培养效率，但过度摇瓶不利于该藻细胞分裂。

Thalassiosira pseudonana is an important microalgal species in the basic research as model organism, and widely applied in the development as aquaculture feed and biofuel. In the present study, the culture conditions for one strain of oil-rich T. pseudonana isolated from Zhejiang coastal area was analyzed. The cultivation factors included temperature, light intensity, salinity, nitrogen, phosphate, and shaking. The results indicated that： （1） there was no significant difference in growth rate when the strain of T. pseudonana was cultured in medium with different salinity ranging from 10‰ to 45‰. However, the species is sensitive to temperature. Even with minor temperature changes between 22℃ and 25 ℃, the growth rate varied significantly. High light intensity （100001x） together with higher temperature （25℃） could stimulate rapid population growth. At 22℃, growth rate was not affected by the light intensity; （2） this species could absorb nitrogen more rapidly than phosphate, especially in the exponential growth phase. Lack of nitrogen inhibited the cell division and photosynthesis capacity （Fv/Fm）. However, such phenomena did not exhibit very obviously for the lack of phosphate; （3） the perturbation, at moderate extent, was better than suspending culture.