REACTION ENGINEERING STUDY ON THE CATALYST ACTIVITY OF immobilized biocatalysts

研究了固定化微生物和固定化植物细胞包埋在海藻酸钙凝胶颗粒中对颗粒内传质的影响。Baker‘s酵母和发酵单胞菌。以罂粟为研究对象，以罂粟为植物细胞模型。研究了固定化静止酵母和固定化生长酵母对传质的影响。在后一种情况下。观察到载体内细胞分布不均匀。考虑到凝胶保持池的有效扩散面积的减小，采用随机孔模型对凝胶保持池的有效扩散系数进行了测量和关联。利用游离细胞测定了乙醇生产的反应速率。结合有效扩散系数和反应速率，计算了固定化酵母的总体反应活性。计算值与实验值吻合较好。当载体中的细胞浓度增加时，由于扩散阻力较大，总反应速率降低。一种类似的方法也被用来研究固定化静息发酵运动的行为。有效因子是从总反应速率得到的。细胞的固有反应率约为游离细胞的80%。对于固定化植物细胞的情况再次进行了分析。利用固定化罂粟花对可待酮生物转化为可待因进行了研究。生物催化剂的反复使用导致酶活性下降。尽管固定化细胞的初始反应活性与游离细胞的反应活性几乎相同。根据对衬底扩散行为的分析。氧转移对固定化植物细胞的稳定性有显著影响。

Investigation of the influence of intraparticle mass transfer was carried out using immobilized microorganisms and immobilized plant cells entrapped in Ca-alginate gel particles. Baker's yeast and Zymomonas sp. were used as microorganisms and Papaver somniferum was used as a model of plant cells.1. The influence of mass transfer was studied using immobilized resting yeast and immobilized growing yeast. In the latter case. the inhomogeneous cell distribution in the carrier was observed. Effective diffusivity in the gel holding cells was measured and correlated by the random pore model taking account of the decrease of effective diffusion area caused by the cells. The reaction rate of ethanol production was obtained using free cells. Combining the effective diffusivity and the reaction rate, the overall reactivity of the immobilized yeast was calculated. The calculated value coincided with the experimental data. The overall reaction rate decreased due to the large diffusion resistance when the cell concentration in the carrier increased.2. A similar approach was applied to study the behavior of immobilized resting Zymomonal mobilis. The effectiveness factor was obtained from the overall reaction rate. The inherent reaction rate of the cells was found to be about 80% of that of the free cells.3. The analysis was again carried out for the case of immobilized plant cells. The biotransformation of codeinone to codeine was investigated using immobilized Papaver somniferum. The repeated use of the biocatalyst resulted in the decrease of the activity. although the initial reactivity of the immobilized cell was almost identical with that of the free cells. According to the analysis of the diffusion behavior of substrates. the oxygen transfer was found salient to the stability of the immobilized plant cells.