铁、钙离子补料对杜氏盐藻生长的影响

通过原子吸收光谱测定了杜氏盐藻对钙、镁、钾、铁四种离子的消耗速率，构建金属离子含量限制型培养基，研究了补加金属离子对杜氏盐藻生长光合速率、色素含量的影响。结果表明，对数期杜氏盐藻细胞对铁离子与钙离子的消耗呈线性降低，每增殖106个细胞分别消耗0.042μg的铁离子与0.708μg的钙离子，而在稳定期后，钙、铁离子浓度继续下降。生长时期中钾离子与镁离子的含量变化不显著。铁、钙离子补料能恢复杜氏盐藻的生长，但光合活性与色素含量变化较补料前的对数期光合速率与色素含量要低，但总类胡萝卜素含量要高于补料前对数期的。培养到稳定期的培养基经过回收补加有限的铁、钙离子后，细胞生长延滞期消失，但稳定期细胞浓度降低。回流培养基对数期细胞的光合速率与叶绿素含量降低，但是总类胡萝卜素含量升高。

Effects of the fed-batch cultivation of mineral nutrients on Dunaliella salina growth

The consum ption rate of D unaliella salina on iron,potassium ,calcium and m agnesium w ere determ ined by atom ic absorption spectrum . The m etalion contentlim ittype m edium w asestablished and the effectofadding m etalion on D .salina grow th,photosynthetic rate and pigm entcon-tentw ere studied.The results show ed thatthe consum ption of iron and calcium decreased linearly during the log grow th phase.The consum ption rates ofiron and calcium in the m edium w ere 0.042 μg and 0.708 μg for 106 cellproliferation,and after stable phase,calcium ,iron concentration continued to fall.H ow ever,the difference ofpotassium and m agnesium concentration in the m edium w as notsignificantin the grow th period.The feeding ofiron and calcium ionscould prom ote the grow th ofD .salina cellsto revive butw ith a low erphotosynthetic ratesand chlorophyllcontents, the totalcarotenoid contentw as higherthan logarithm ic phase before feeding.A fterrecycling adding lim ited iron and calcium to the m edium in the stable phase,the celllag phase disappeared butthe cellconcentration decreased in the stable phase.The photosynthetic rate and chlorophyllcontent ofcellin log phase in backflow m edium decreased,butthe totalcarotenoid contentincreased inversely.