title: Carbon 13-Metabolic Flux Analysis derived constraint-based metabolic modelling of Clostridium acetobutylicum in stressed chemostat conditions.
abstract: The metabolism of butanol producing bacteria Clostridium acetobutylicum was studied in chemostat with glucose limited conditions, butanol stimulus, and as a reference cultivation. COnstraint-Based Reconstruction and Analysis (COBRA) was applied using additional constraints from (13)C Metabolic Flux Analysis ((13)C-MFA) and experimental measurement results. A model consisting of 451 metabolites and 604 reactions was utilized in flux balance analysis (FBA). The stringency of the flux spaces considering different optimization objectives, i.e. growth rate maximization, ATP maintenance, and NADH/NADPH formation, for flux variance analysis (FVA) was studied in the different modelled conditions. Also a previously uncharacterized exopolysaccharide (EPS) produced by C. acetobutylicum was characterized on monosaccharide level. The major monosaccharide components of the EPS were 40n-% rhamnose, 34n-% glucose, 13n-% mannose, 10n-% galactose, and 2n-% arabinose. The EPS was studied to have butanol adsorbing property, 70(butanol)mg(EPS)g(-1) at 37°C.
authors: Aalto University, School of Chemical Technology, Department of Biotechnology and Chemical Technology, P.O. Box 6100, FIN-02015, Finland. Electronic address: janne.wallenius@aalto.fi.
authors: Janne
authors: J
authors: Wallenius
authors: VTT, Technical Research Centre of Finland Ltd, P.O. Box 1000, FI-02044 VTT Espoo, Finland.
authors: Hannu
authors: H
authors: Maaheimo
authors: Aalto University, School of Chemical Technology, Department of Biotechnology and Chemical Technology, P.O. Box 6100, FIN-02015, Finland.
authors: Tero
authors: T
authors: Eerikäinen
mesh_terms: D020001:1-Butanol / Q000378:metabolism; D001089:Arabinose / Q000378:metabolism; D000440:Butanols / Q000378:metabolism; D002247:Carbon Isotopes / Q000032:analysis / Q000378:metabolism; D046969:Clostridium acetobutylicum / Q000378:metabolism / Q000502:physiology; D064688:Metabolic Flux Analysis / Q000379:methods*; D008954:Models, Biological; D013312:Stress, Physiological / Q000502:physiology*
chemical_list: D000440:Butanols; D002247:Carbon Isotopes; D020001:1-Butanol; D001089:Arabinose
keywords: (13)C Metabolic Flux Analysis; Butanol stress; C. acetobutylicum; COBRA; Exopolysaccharide