Hunik J H, Bos C G, van den Hoogen M P, De Gooijer C D, Tramper J
Department of Food Science, Food and Bioprocess Engineering Group, Wageningen Agricultural University, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
Biotechnol Bioeng. 1994 May;43(11):1153-63. doi: 10.1002/bit.260431121.
A dynamic model for two microbial species immobilized in a gel matrix is presented and validated with experiments. The model characterizes the nitrification of ammonia with Nitrosomonas europaea and Nitrobacter agilis co-immobilized in K-carrageenan gel beads. The model consists of kinetic equations for the microorganisms and mass transfer equations for the substrates and products inside and outside the gel beads. The model predicts reactor bulk concentrations together with the substrate consumption rate, product formation, and biomass growth inside the gel beads as a function of time. A 50-day experiment with immobilized cells in a 3.3-dm(3) air-lift loop reactor was carried out to validate the model. The parameter values for the model were obtained from literature and separate experiments. The experimentally determined reactor bulk concentrations and the biomass distribution of the two microorganisms in the gel beads were well predicted by the model. A sensitivity analysis of the model for the given initial values indicated the most relevant parameters to be the maximum specific growth rate of the microorganisms, the diffusion coefficient of oxygen, and the radius of the beads. The dynamic model provides a useful tool for further study and possible control of the nitrification process. (c) 1994 John Wiley & Sons, Inc.
提出了一个用于描述固定在凝胶基质中的两种微生物的动态模型，并通过实验进行了验证。该模型描述了欧洲亚硝化单胞菌和敏捷硝化杆菌共同固定在κ-卡拉胶凝胶珠中时对氨的硝化作用。该模型由微生物的动力学方程以及凝胶珠内外底物和产物的传质方程组成。该模型可预测反应器内的总体浓度，以及凝胶珠内底物消耗速率、产物生成和生物量增长随时间的变化情况。在一个3.3立方分米的气升式环流反应器中对固定化细胞进行了为期50天的实验，以验证该模型。模型的参数值取自文献和单独的实验。模型对实验测定的反应器总体浓度以及凝胶珠中两种微生物的生物量分布进行了很好的预测。对给定初始值的模型进行敏感性分析表明，最相关的参数是微生物的最大比生长速率、氧气扩散系数和珠子半径。该动态模型为进一步研究和可能控制硝化过程提供了一个有用的工具。(c) 1994约翰威立父子公司。
