title: Control of endotoxin release in Escherichia coli fed-batch cultures.
abstract: High amounts of outer membrane (OM) components were released in glucose-limited fed-batch (GLFB) cultures at 37 degrees C at specific growth rates approaching 0.05 h(-1). Endotoxin analyses from a 20 degrees C GLFB culture gave similar results. An alternative fermentation technique, the temperature-limited fed-batch (TLFB) technique, reduced the endotoxin concentration in a culture with a biomass concentration of 30 g l(-1) from the 850 mg l(-1) in traditional GLFB cultures to about 20 mg l(-1). The TLFB technique uses the temperature to regulate the dissolved oxygen tension, while all substrate components are unregulated. It appears to be severe glucose limitation that triggers the extensive release of endotoxins rather than a low growth rate. Furthermore, it is not the low temperature that stabilizes the OM when using the TLFB technique. Simulations and experimental data show that this technique results in the same biomass productivity as the GLFB technique.
authors.affiliation: Department of Biotechnology, Royal Institute of Technology (KTH), Roslagstullsbacken 21, 10691 Stockholm, Sweden.
authors.forename: Marie
authors.initials: M
authors.lastname: Svensson
authors.forename: Ling
authors.initials: L
authors.lastname: Han
authors.forename: Gustav
authors.initials: G
authors.lastname: Silfversparre
authors.forename: Lena
authors.initials: L
authors.lastname: Häggström
authors.forename: Sven-Olof
authors.initials: SO
authors.lastname: Enfors
mesh_terms: D019149:Bioreactors / Q000382:microbiology*; D018929:Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation; D003198:Computer Simulation; D004731:Endotoxins / Q000096:biosynthesis*; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000096:biosynthesis*; D008954:Models, Biological; D010100:Oxygen / Q000378:metabolism*; D013696:Temperature
chemical_list: D004731:Endotoxins; C114999:K-12 lipopolysaccharide; D008070:Lipopolysaccharides; C044101:endotoxin, Escherichia coli; D010100:Oxygen