微生物批式流加发酵动力系统及参数辨识

Dynamic system of microbial fed-batch fermentation and its parameters identification

微生物批式流加发酵生产1,3-丙二醇是一种重要的生产方式,但是目前研究只考虑了细胞外5种物质浓度的变化,没有考虑代谢机理、细胞内物质浓度的变化及重要的中间产物。本文将细胞内甘油、3-羟基丙醛和1,3-丙二醇三种物质的浓度变化考虑在内,假设甘油跨膜运输情形为主动运输和被动扩散,1,3-丙二醇的跨膜运输情形为主动运输和被动扩散,建立了微生物批式流加发酵动力系统。以实验值与计算值的误差平方和作为性能指标建立参数辨识模型,并用改进的粒子群算法求解模型中参数。结果表明,改进后模型平均相对误差比现有文献略有降低,说明了模型的有效性。

The method of microbial fermentation is an important mode of production in producing 1,3-Propanediol（1,3-PD）. Although the microbial fed-batch culture of glycerol to 1,3-PD is a vital production mode, the present research results of microbial fed-batch culture system which only think about the concentration of five kinds extracellular materials changed instead of metabolic mechanism, concentration of intracellular materials changed and important intermediate products. We take the concentration of intracellular glycerol, 3-HPA and 1,3-PD into consideration in this paper. A dynamic system of microbial fed-batch fermentation is built under the active transport and passive diffusion of glycerol and active transport and passive diffusion of 1,3-PD. Taking the sum of square error between experimental data and computational values as the performance index, the parameter identification model is presented and an improved particle swarm optimization algorithm is developed to seek the unknown parameters in the model. Numerical simulations show that the average relative errors of biomass and glycerol have reduced slightly and illustrate the availability in the improved model.