固定化静止酵母细胞的扩散─反应特性的模拟

Abstract

测定了聚丙烯酰胺包埋酵母的固定化细胞中葡萄糖和乙醇的有效扩散系数，研究了葡萄糖和乙醇对于悬浮静止酵母细胞反应动力学的影响.计算了固定化静止细胞中酵母细胞的存活分数，考察了具有不同细胞包埋量及不同厚度的固定化细胞的反应特性。用组分的有效扩散系数、悬浮细胞的反应动力学及固定化细胞的细胞存活分数很好地模拟了具有内扩散影响的固定化细胞的反应结果。

Reaction rate using native yeast cell was investigated with respect to dependence on glucose concentration and ethanol inhibition.No substrate inhibition was observed.but product inhibition took linear regression Form at T=30℃, s<200 kg/m￣3 and P<100 kg/m￣3.The reaction kineticsequation was arrived.The Fractional residual cell activity.x_a,of the immobilized yeast cellentrapped in the polyacrylamide gel was determined and x_a=0.519.The eFFective diFFusivities ofglucose and ethanol in the ICMes( Immobilized cell matrix )with diFFerent cell loadings was rneasured without reaction.Using the results stated above the eFFect of inter-mass-transFer resistance on,reaction by using immobilized yeast cell entrapped by polyacrylamide gel was modelled.Th approximately analytical solution agrees well with the experimental resuIts.It shows that the diFFusion-reaction problem of ICMes can be modelled by the eFFective diFFusivity measured without reaction,the Fractional residual cell activity,x_a and the reaction kinetics of the Free cells.