微生物间歇发酵中酶催化非线性时滞动力系统的最优控制

发布时间：2019-03-11 15:23

【摘要】：本文以微生物(肺炎克雷伯氏菌)进行甘油歧化生产1,3-丙二醇(简记1,3-PD)的间歇发酵过程作为背景展开研究,考虑了一种酶催化非线性时滞动力系统及相应的最优控制模型,并得出了最优的控制参数解.这项研究结果,一方面有利于对最优控制的理论与优化算法和时滞微分方程的研究；另一方面为实现1,3-PD的大规模生产提供一些理论参考.本论文的主要内容概括如下：1.在微生物间歇发酵的动力学模型的基础上,本论文在甘油和1,3-PD的跨膜运输方式都是主被动运输相结合的假设下,在生物量的浓度中加入时滞,建立了相应的酶催化非线性时滞动力系统.并利用常微分方程和最优控制的有关理论讨论了该系统解的一些基本性质,包括解的存在唯一性、一致有界性以及解的连续性.2.针对所研究的非线性时滞系统,以1,3-PD的终点时刻的生产强度作为性能指标,以甘油、微生物的初始浓度以及终端时刻为控制参数,构建了描述该时滞系统的最优控制模型,并证明了最优控制的存在性.3.为了寻求最优控制模型的最优解,我们利用控制转录技术和连续状态处理技术,建构了一种改进的Nelder-Mead算法,并求出了最优解.最优的数值结果显示,最优控制下1,3-PD在终端时刻的产率能够被显著提高,这为1,3-PD的间歇发酵过程的最优控制提供了一定的理论指导.
[Abstract]:In this paper, the microbial (Klebsiella pneumoniae) was used to produce 1,3-propanediol (1,3-propanediol) by glycerin disproportion as the background of the batch fermentation of 1,3-propanediol. An enzyme-catalyzed nonlinear time-delay dynamical system and its corresponding optimal control model are considered, and the optimal control parameter solution is obtained. The results of this study are beneficial to the study of optimal control theory and optimization algorithm and delay differential equation on the one hand, and on the other hand, provide some theoretical reference for the realization of large-scale production of 1,3-PD. The main contents of this paper are summarized as follows: 1. On the basis of the kinetic model of microbial batch fermentation, under the assumption that glycerol and the transmembrane transport mode of 1,3-PD are the combination of active and passive transport, time delay is added to the concentration of biomass, and the transmembrane transport mode of glycerol and 1,3-PD is the combination of active and passive transport. The corresponding enzyme-catalyzed nonlinear time-delay dynamical system was established. Some basic properties of the solution of the system, including the existence and uniqueness of the solution, the uniformly boundedness and the continuity of the solution, are discussed by using the theory of ordinary differential equation and optimal control. For the studied nonlinear time-delay system, the optimal control model is constructed to describe the time-delay system, taking the production intensity at the end point of 1,3-PD as the performance index, the initial concentration of glycerol, microorganism and terminal time as the control parameters, and the optimal control model for the time-delay system is constructed. The existence of optimal control is proved. 3. In order to find the optimal solution of the optimal control model, an improved Nelder-Mead algorithm is constructed by using the control transcription technique and the continuous state processing technique, and the optimal solution is obtained. The optimal numerical results show that the yield of 3-PD at the terminal time can be significantly improved under the optimal control, which provides some theoretical guidance for the optimal control of the batch fermentation process of 1-3-PD.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O232

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