机械搅拌生物反应器的CFD模拟及剪切力对红花细胞悬浮培养的影响

CFD Simulation of a Mechanically Stirred Bioreactor and Effect of Shear Stress on Suspension Cultures of Carthamus tinctorius

采用计算流体力学(CFD)技术模拟5L机械搅拌生物反应器中不同搅拌转速对流场的影响,分别考察不同搅拌速度下,红花悬浮细胞培养过程中生物量、细胞活力、pH、糖耗、DO(溶解氧)、电容、电导、CER(单位体积发酵液在单位时间释放CO2的物质的量)的变化。结果表明:红花细胞对剪切环境有个适应过程,在搅拌生物反应器中悬浮培养,能够耐受剪切力值εave,CFD≤0.8 W/kg,细胞可以适应剪切环境,细胞活力能够恢复,结束延滞期快速积累生物量;当剪切力εave,CFD>0.8 W/kg时,细胞不能耐受剪切环境,受到较大损伤,导致细胞活力很低,裂解死亡。

The effect of agitation speed on agitation current field was studied in 5Lmechanically stirred bioreactor by computational fluid dynamics（CFD）method.Safflower（Carthamus tinctorius）cells were cultivated in stirred tank reactor under different agitation speeds.The resultant changes in the cells were evaluated on the basis of biomass,cell viability and change of fermentation liquor about pH,sugar concentration,DO,capacitance,conductivity and CER.Results showed that there was an adaptive process of cell cultured in the shear flow field.To a certain extent,cells were able to tolerate the shear force in mechanically stirred bioreactor withεave,CFD ≤0.8 W/kg.Under this shear flow field,the lag phase was shorter,and the speed of biomass accumulation and recovery of cell activity was faster.Ifεave,CFD 〉0.8 W/kg,cells couldn’t tolerate the shear force,because it was not easy for cells to recover cell activity,and even cells were lysised after suffering from damnification.