title: Perturbation Experiments: Approaches for Metabolic Pathway Analysis in Bioreactors.
abstract: In the last decades, targeted metabolic engineering of microbial cells has become one of the major tools in bioprocess design and optimization. For successful application, a detailed knowledge is necessary about the relevant metabolic pathways and their regulation inside the cells. Since in vitro experiments cannot display process conditions and behavior properly, process data about the cells' metabolic state have to be collected in vivo. For this purpose, special techniques and methods are necessary. Therefore, most techniques enabling in vivo characterization of metabolic pathways rely on perturbation experiments, which can be divided into dynamic and steady-state approaches. To avoid any process disturbance, approaches which enable perturbation of cell metabolism in parallel to the continuing production process are reasonable. Furthermore, the fast dynamics of microbial production processes amplifies the need of parallelized data generation. These points motivate the development of a parallelized approach for multiple metabolic perturbation experiments outside the operating production reactor. An appropriate approach for in vivo characterization of metabolic pathways is presented and applied exemplarily to a microbial L-phenylalanine production process on a 15 L-scale.
authors.affiliation: Lehrstuhl für Bioverfahrenstechnik, Technische Universität München, Garching, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Weiner
authors.affiliation: Lehrstuhl für Bioverfahrenstechnik, Technische Universität München, Garching, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Tröndle
authors.affiliation: Institut für Mikrobiologie, Universität Stuttgart, Stuttgart, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Albermann
authors.affiliation: Institut für Mikrobiologie, Universität Stuttgart, Stuttgart, Germany.
authors.forename: Georg A
authors.initials: GA
authors.lastname: Sprenger
authors.affiliation: Lehrstuhl für Bioverfahrenstechnik, Technische Universität München, Garching, Germany. d.weuster-botz@lrz.tum.de.
authors.forename: Dirk
authors.initials: D
authors.lastname: Weuster-Botz
mesh_terms: D019149:Bioreactors; D004926:Escherichia coli / Q000254:growth & development*; D055442:Metabolome; D008954:Models, Biological; D010649:Phenylalanine / Q000096:biosynthesis*
chemical_list: D010649:Phenylalanine
keywords: Constraint-based approaches; Escherichia coli; Glycerol; L-phenylalanine; Metabolic flux analysis; Metabolome quantification; Perturbation experiments; Steady-state experiments