Model based design of a biochemical cultivation process

Abstract

In this paper a simple design procedure is used to enhance the performance of a biotechnical cultivation process. A model supported approach is proposed. It starts with a simple classical process model obtained from literature data, which is used to design the ®rst experiment. Then, the main procedure is an iteration of (i) improving the model making use of the deviations between the experimental data and the data predicted by the model, (ii) of designing the next experiment by determining the optimal control pro®les from the current model, and (iii) of executing that designed experiment. Important for the success of the procedure is that the model development is oriented at the process performance. The procedure is demonstrated at the simple practical example of a laboratoryscale fed-batch cultivation of Escherichia coli.

Model Predictive Feeding Rate Control in Conventional and Single-use Lab-scale Bioreactors: A Study on Practical Application

“…Therefore, to obtain a more suitable process run for safer control, a slightly lowered predefined substrate consumption rate may be applied, which does not reduce process yield significantly 11 . Model-based process optimization is desirable for such cases 12 . In this paper, the authors demonstrate a developed tool for model-based fed-batch control and feeding profile selection, implemented in a laboratory bioreactor system that is commercially available for a wide range of users.…”

“…Investigation of model parameter sensitivity with respect to the optimization objective function (for biomass amount control problem) has shown 12 that the most sensitive parameters for this type of model are the conversion yields and maximal specific reaction rates of the main components involved. Therefore, the biomass/glucose conversion yield Y xs and the maximal specific glucose consumption rate σ max were selected as the main model parameters to be re-identified on-line every time the new sample for biomass and glucose measurement is evaluated.…”

“…The theoretical estimation of the maximal productivity in particular cultivation process may be performed by means of a model-based design procedure similar to that described in the research of Galvanauskas et al 12,16 , i.e. by applying a realistic process model, taking into account the main limiting factors (constraints) of the real process (e.g., maximal oxygen transfer rate, maximal allowed culture volume, etc.…”

“…For typical processes, these flows consist of sampling, evaporation, and carbon loss in off-gas rates, as well as alkali, acid, antifoam agent, and feeding addition rates. A more detailed expla nation on the equations for mass flow modeling for prediction and their parameters can be found in 12 .…”

Interval and Possibilistic Methods for Constraint-Based Metabolic Models

“…Simulations can be used to choose a preliminary list of promising profiles, which can then be tested experimentally. See, for example, the model-based design of cultivation processes proposed in (Galvanauskas, 1998). …”