脱落酸对紫球藻（Porphyridiu sp.）生长代谢的影响

Effects of abscisic acid on growth and metabolism of Porphyridiu sp.

为优化培养条件和提高紫球藻（Porphyridiu sp.）生物量及代谢产物产量，研究了7种浓度的脱落酸（ABA）在三种氮素营养水平下对紫球藻生长的影响，结果表明，ABA浓度在0.01～1.0mg·L^-1范围内，外源ABA浓度的升高有利于紫球藻增殖，对紫球藻的干重、叶绿素a含量、蛋白质含量、胞外多糖含量、藻红素含量都有一定的促进作用；但在ABA浓度在10mg·L^-1时，则呈递抑制趋势。其中中氮水平下外源ABA浓度1.0mg·L^-1是紫球藻生长的最佳浓度，最有利于紫球藻生物量及代谢产物的积累，此时紫球藻的生物量为3.463mg·mL^-1，胞外多糖含量最高，占藻体干重的34.31%。在高氮营养水平下还能体现ABA对紫球藻生长所起的作用，而低氮下生长的紫球藻对ABA的作用不敏感。

To optimize the culture conditions ofporphyridiu sp. and to improve the biomass and production of metabolites of porphyridiu sp., the effect of abscisic acid （ABA） on the growth ofporphyridiu sp. was investigated under three nitrogen levels in ASW medium. The results showed that ABA could improve the growth of Porphyridiu sp. within the concentration of 0.01-1.0 mg·L^-1 by increasing the biomass and contents of chlorophyll-a, protein, extracellular polysaccharide and rhodophyll. But the growth of Porphyridiu sp. was decreased if ABA concentration was higher than 1.0 mg·L^-1.. Under middle level of nitrogen, 1.0 mg·L^-1 was the best concentration for the growth and accumulation of metabolites of Porphyridiu sp., in which the biomass was 3.463 mg·L^-1, with the extracelluar polysaecharide content accounting for 34.31% of the dry weight. The promotion of ABA on the growth of Porphyridiu sp. was also be found in high nitrogen condition, but in low nitrogen level, Porphyridiu sp. was insensitive to ABA.