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133 Computation of stoichiometric models for bioprocess
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Abstracts
125 On-Line Analysis of Volatiles tn Fermenter Exhaust Gas using Mass Spectrometry A. Oeggerll, E. Helnzle, pp 295-298 In addition to the well-established analysis of oxygen and carbon dioxide in the exhaust gas of fermentations, online gas analysis of ethanol, acetoin and butanediol was studied using a high-precision gas analysis mass spectrometer (PGM 407, Balzers, FL) in a baker's yeast cultivation and in a Bacillus subtilis fermentation. These substances are produced by many organisms and cover a wide range of volatility.
126 A New Method of Continuous Cultivation with Computer-Controlled Change of Dilution Rate T. Paalme, R. Vilu, pp 299-302 A new method of continuous cultivation of cells with computer controlled (smooth) change of dilution rate (Astat) was developed and introduced into laboratory practice. The A-stat was used for determination of growth parameters of Escherichia coil K12,
microscopy images during the first hours of culture. The method, taking into account the spherical shape of the microcarriers, provides data on the number of cell clusters and the extent of coverage of the mierocarriers by the cells in function of the culture age.
130 Industrial Application of Adaptive Nonlinear Control for Bakers' Yeast Production Y. Pomerleau, G. Viel, pp 315-318 An adaptive nonlinear control law was used for the regulation of the ethanol concentration in industrial bakers' yeast production. Based on the closed-loop linearizing approach, the control law was originally designed for a 20 L fermentor. The control law required ethanol measurement and oxygen transfer rate evaluation. Except for volume value, the scale-up to a 60 000 L fermentor was done without any change in model parameters or tuning parameter values. The results at the industrial scale can be considered as good as those obtained at the laboratory scale.
Saccharomyces cerevisiae and Pseudomonas putida. The maximum values of specific respiration rates on different substrates investigated vary in E.coli and Ps.putida only slightly. The results obtained suggest that the maximum values of growth rates are limited by the capacity of the respiratory chain. The idea of two "life strategies", one for growth in conditions of limitation by a substrate and another for conditions of abundance of substrates is proposed.
127 Measurement of Cellular Differentiation of Filamentous Fungi using Image Analysis G.C. Paul, C.A. Kent, C.R. Thomas, pp 303-306 An image analysis method has been developed to measure cellular differentiation of filamentous fungi growing in dispersed form in submerged culture. The proportions of vacuoles and empty cells, and growing (mainly apical) and non-growing regions in the mycelia have been quantified. The shape and size distributions of vacuoles and empty cells in the hyphae were also obtained. It has been demonstrated with Penicillium chrysogenum that these differentiation states might be manipulated by the nutrient conditions in the fermentation. The method permits rapid and accurate quantitative studies of fungal physiology and might be used to improve process models and process control strategies for antibiotic fermentations.
128 Growth Monitoring of Filamentous Microorganisms by Image Analysis D. Pichon, H. Vivier, M.N. Pons, pp 307-310 The growth of filamentous microorganisms is monitored via analysis of light microscopy images. The method provides data on the size of the microorganisms and classifies their morphological types into three categories : single filaments, entangled filaments and pellets. The kinetics of the distribution in number and in area of the morphological types during the fermentation are obtained.
129 Growth Monitoring of Mammalian Cells on Microcarriers by Image Analysis D. Pichon, H. Vivier, M.N. Pons,
pp 311-314 The growth of anchorage-dependent mammalian cells on microcarriers is monitored via analysis of light
131 Application of Linear Balance Equations in an On-Line Observation System for Fermentation Processes R. Schneider, C. Posten, A. Munack, pp 319-322 A model-based observation system is described which enables the user to apply mathematical models on-line to fermentation processes. The aim of this approach is
predictivesimulation and supervision. Differentmodels are being used in the system. The classification for the selection of a suitable model is based on the evaluation of the Fisher information matrix. If the parameters of the supplied models are detected not to be identifiable an online supervision of the process should still be possible. For this task an improved on-line estimator based on linear balance equations has been added to the observer system. Simulations and experimental results are presented.
132 Fault Detection and Identification in Fermenters F.W. Roche, N.F. Thornhill, K.M. Stone, S.W. Carleysmith, pp 323-326 This paper outlines a method for detection and analysis of abnormal fermenter operation for small-scale fermenters, such as those typically used for strain development work. The work was based on the desire to further improve the operability of fermenters used in the strain improvement effort of the project's sponsors. The work was based on fed-batch penicillin fermentations, performed by the method described by Mou and Cooney. The method is illustrated by a case study from a specific fed-batch penicillin fermentation.
133 Computation of Stoichiometric Models for Bioprocess U. Saner, E. Heinzle, D. Bonvin pp 327-330 In most complex chemical or biotechnological processes, singular value decomposition provides an efficient methodology to derive an abstract, empirical stoichiometry from experimental data. This paper presents an algebraic approach to transform this abstract stoichiometry into a more useful one with an underlying physical meaning.
Abstracts
125 On-Line Analysis of Volatiles tn Fermenter Exhaust Gas using Mass Spectrometry A. Oeggerll, E. Helnzle, pp 295-298 In addition to the well-established analysis of oxygen and carbon dioxide in the exhaust gas of fermentations, online gas analysis of ethanol, acetoin and butanediol was studied using a high-precision gas analysis mass spectrometer (PGM 407, Balzers, FL) in a baker's yeast cultivation and in a Bacillus subtilis fermentation. These substances are produced by many organisms and cover a wide range of volatility.
126 A New Method of Continuous Cultivation with Computer-Controlled Change of Dilution Rate T. Paalme, R. Vilu, pp 299-302 A new method of continuous cultivation of cells with computer controlled (smooth) change of dilution rate (Astat) was developed and introduced into laboratory practice. The A-stat was used for determination of growth parameters of Escherichia coil K12,
microscopy images during the first hours of culture. The method, taking into account the spherical shape of the microcarriers, provides data on the number of cell clusters and the extent of coverage of the mierocarriers by the cells in function of the culture age.
130 Industrial Application of Adaptive Nonlinear Control for Bakers' Yeast Production Y. Pomerleau, G. Viel, pp 315-318 An adaptive nonlinear control law was used for the regulation of the ethanol concentration in industrial bakers' yeast production. Based on the closed-loop linearizing approach, the control law was originally designed for a 20 L fermentor. The control law required ethanol measurement and oxygen transfer rate evaluation. Except for volume value, the scale-up to a 60 000 L fermentor was done without any change in model parameters or tuning parameter values. The results at the industrial scale can be considered as good as those obtained at the laboratory scale.
Saccharomyces cerevisiae and Pseudomonas putida. The maximum values of specific respiration rates on different substrates investigated vary in E.coli and Ps.putida only slightly. The results obtained suggest that the maximum values of growth rates are limited by the capacity of the respiratory chain. The idea of two "life strategies", one for growth in conditions of limitation by a substrate and another for conditions of abundance of substrates is proposed.
127 Measurement of Cellular Differentiation of Filamentous Fungi using Image Analysis G.C. Paul, C.A. Kent, C.R. Thomas, pp 303-306 An image analysis method has been developed to measure cellular differentiation of filamentous fungi growing in dispersed form in submerged culture. The proportions of vacuoles and empty cells, and growing (mainly apical) and non-growing regions in the mycelia have been quantified. The shape and size distributions of vacuoles and empty cells in the hyphae were also obtained. It has been demonstrated with Penicillium chrysogenum that these differentiation states might be manipulated by the nutrient conditions in the fermentation. The method permits rapid and accurate quantitative studies of fungal physiology and might be used to improve process models and process control strategies for antibiotic fermentations.
128 Growth Monitoring of Filamentous Microorganisms by Image Analysis D. Pichon, H. Vivier, M.N. Pons, pp 307-310 The growth of filamentous microorganisms is monitored via analysis of light microscopy images. The method provides data on the size of the microorganisms and classifies their morphological types into three categories : single filaments, entangled filaments and pellets. The kinetics of the distribution in number and in area of the morphological types during the fermentation are obtained.
129 Growth Monitoring of Mammalian Cells on Microcarriers by Image Analysis D. Pichon, H. Vivier, M.N. Pons,
pp 311-314 The growth of anchorage-dependent mammalian cells on microcarriers is monitored via analysis of light
131 Application of Linear Balance Equations in an On-Line Observation System for Fermentation Processes R. Schneider, C. Posten, A. Munack, pp 319-322 A model-based observation system is described which enables the user to apply mathematical models on-line to fermentation processes. The aim of this approach is
predictivesimulation and supervision. Differentmodels are being used in the system. The classification for the selection of a suitable model is based on the evaluation of the Fisher information matrix. If the parameters of the supplied models are detected not to be identifiable an online supervision of the process should still be possible. For this task an improved on-line estimator based on linear balance equations has been added to the observer system. Simulations and experimental results are presented.
132 Fault Detection and Identification in Fermenters F.W. Roche, N.F. Thornhill, K.M. Stone, S.W. Carleysmith, pp 323-326 This paper outlines a method for detection and analysis of abnormal fermenter operation for small-scale fermenters, such as those typically used for strain development work. The work was based on the desire to further improve the operability of fermenters used in the strain improvement effort of the project's sponsors. The work was based on fed-batch penicillin fermentations, performed by the method described by Mou and Cooney. The method is illustrated by a case study from a specific fed-batch penicillin fermentation.
133 Computation of Stoichiometric Models for Bioprocess U. Saner, E. Heinzle, D. Bonvin pp 327-330 In most complex chemical or biotechnological processes, singular value decomposition provides an efficient methodology to derive an abstract, empirical stoichiometry from experimental data. This paper presents an algebraic approach to transform this abstract stoichiometry into a more useful one with an underlying physical meaning.