Sensitivity analysis and parameter identification for a nonlinear time-delay system in microbial fed-batch process

Abstract

a b s t r a c tDeveloping suitable dynamic models of bioprocess is a difficult issue in bioscience. In this paper, considering the microbial metabolism mechanism, i.e., the production of new biomass is delayed by the amount of time it takes to metabolize the nutrients, in glycerol bioconversion to 1,3-propanediol, we propose a nonlinear time-delay system to formulate the fed-batch fermentation process. Some important properties are also discussed. Then, in view of the effect of time-delay and the high number of kinetic parameters in the system, the parametric sensitivity analysis is used to determine the key parameters. Finally, a parameter identification model is presented and a global optimization method is developed to seek the optimal key parameters. Numerical results show that the nonlinear time-delay system can describe the fed-batch fermentation process reasonably.

Robust Optimal Control of a Microbial Batch Culture Process

“…Methods for estimating the values of these uncertain parameters using experimental data are given in [18,19,[29][30][31][32]. The following estimates are used in [6]: …”

“…An experimental investigation into the multiple inhibitions of the fermentation process is given in [8], and studies based on metabolic flux and metabolic pathway analysis are given in [9][10][11][12][13]. Mathematical models of the microbial conversion process, together with various process control strategies, have been considered in [14][15][16][17][18][19][20]. However, these references do not take parameter uncertainty into account.…”

The model equivalence based parameter estimation methods for Box–Jenkins systems

“…Parameter estimation plays an important part in the filtering [5,6,7], state estimation [8,9], system control [10,11] and others [12]. Because of the use of the system identification in many fields [13,14], many identification methods were proposed, such as the least squares (LS) methods [15,16] and the hierarchical identification methods [17].…”

Nonlinear state-dependent impulsive system and its parameter identification in microbial fed-batch culture

“…A nonlinear multistage dynamical system [8] and a switched system with variable switching instants [9] were also proposed to formulate the fed-batch culture, in which the feeding of glycerol and alkali were taken as a time-continuous process. Liu etc [10,11,12] discussed modelling, optimal control, sensitivity analysis and parameter identification for time-delayed switched system and nonlinear time-delay system in fed-batch fermentation. However, A C C E P T E D M A N U S C R I P T glycerol fermentation by K. pneumoniae is a complex bio-process since the microbial growth is subjected to multiple inhibitions of substrate and products [13].…”