新月菱形藻的光生物反应器半连续培养

Semi-continuous Culture of Alga Nitzschia closterium in a Flat Plate Photobioreactor

利用平板式光生物反应器对新月菱形藻进行半连续培养,探讨更新率、更新周期对新月菱形藻生长、细胞采收量、生化成分及细胞生物量产率的影响。结果显示,随更新率的增大,新月菱形藻的生长速率增大,藻液中氮磷的平均含量上升,而平均细胞密度及产率呈下降趋势;总采收量与更新率呈抛物线关系,细胞生物量、胞内多糖和蛋白的最大采收量分别收获于33%、25.2%和34.7%的更新率下,其最大值分别为2.11×1012cell、3623 mg和2347 mg。更新周期的延长导致新月菱形藻平均生长速率减小,藻液中氮磷的平均含量下降,而采收的平均细胞密度与产率增大,胞内代谢物蛋白质和多糖的含量增加;总细胞采收量随着更新周期的延长减小,当更新周期为1 d时采收量最大,为3.12×1012cell。综合考虑,更新率为33%、更新周期为1 d,是收获生物量的最佳条件。

The marine microalga Nitzschia closterium was cultured semi-continuously in a flat plate photobioreactor to study the effect of renewal rate and renewal cycle on cell growth, cell recovery yield, biochemical components and output rate of biomass. The average growth rate of cells and the concentrations of nitrate and phosphate in the culture medium were found to show a progressive rise with the increase in renewal rate while the average cell density and biomass output rate declined. The total recovery yield showed a parabolic distribution with the renewal rates and the maximal recovery yield of the cell biomass, and levels of polysaccharide and protein were 2.11 × 10^12cell, 3623 mg and 2347 mg at the renewal rate of 33%, 25.2% and 34.7% ,respectively. The extension of renewal period led to the decrease in the growth and concentrations of nitrate and phosphate, but promoted the cell density,output rate and the production of polysaccharide and protein. The total cell recovery yield reduced with the increase in the renewal period, and the maximal recovery yield was achieved at 3.12 × 10^12 cell at renewal period of 1 d. In general, the optimum renewal condition for biomass recovery yield was renewal rate of 33 % and renewal period of 1 d,indicating that the renewal rate and the renewal period are valuable tools in controlling output rate and total recovery yields of cell biomass and secondary metabolites in semi-continuous culture of marine microalga.