营养胁迫对雨生红球藻虾青素累积的影响

THE EFFECT OF NUTRITIONAL STRESSES ON ACCUMULATION OF ASTAXANTHIN IN HAEMATOCOCCUS PLUVIALIS

通过改变营养条件可诱导雨生红球藻积累虾青素。氮限制实验表明，色素的累积速率与原初氮浓度成反比，也与细胞分裂速率负相关，当BBM培养基中的NaNO3浓度减半时（0．13g·L－1），对细胞增殖及色素累积相对都有利。在高光强下，进一步进行氮、磷饥饿，红球藻细胞分裂明显受抑，但色素的累积作用增强，培养9d，细胞内次生类胡萝卜素的含量分别比对照组提高141．0％和60．5％，色素的累积高峰也比对照组提前2－4d。提高NaCl浓度至0．8％时的盐胁迫，不能诱导虾育素的形成。实验结果还表明，色素的累积与厚壁孢子的形成并不完全相关，游动细胞也能大量积累红色色素。

Haematococcus pluvialis was induced to accumulate astaxanthin by altering nutritional conditions. The experiment of N-limited condition showed that the rate of astaxanthin accumulation was inversely proportional to the initial nitrogen concentration and to the rate of cell division. When the concentration of nitrogen in BBM mediun was reduced from 0.25g. L-1 to 0.13g·L-1, a higher rate of cell division and astaxanthin accumulation was relatively favourable. Under starvation of nitrogen or phosphate, the cell division of H. pluvialis was inhibited, but astaxanthin accumulation was enhanced with 141.0% and 60.5% higher content than the controls respectively. The maximum astaxanthin accumulation occurred 2-4 days earier than the control. This induction did not occur under salt stress condition where NaCl concentration increased to 0.8%. The experiments also showed that the astaxanthin accumulation was not totally associated with the formation of akinete. Under nitrogen starvation condition, the motile cells were found to accumulate large amount of red pigment.