title: Size characterization of inclusion bodies by sedimentation field-flow fractionation.
abstract: Sedimentation field-flow fractionation (sedFFF) was evaluated to characterize the size of Delta(4-23)TEM-beta-lactamase inclusion bodies (IBs) overexpressed in fed-batch cultivations of Escherichia coli. Heterologous Delta(4-23)TEM-beta-lactamase protein formed different sizes of IBs, depending upon the induction conditions. In the early phases of recombinant protein expression, induced with low concentrations of IPTG (isopropyl-beta-d-thiogalactoside), IB masses were larger than expected and showed heterogeneous size distributions. During cultivation, IB sizes showed a Gaussian distribution and reached a broad range by the end of the fed-batch cultivations. The obtained result proved the aptitude of sedFFF to rapidly assess the size distribution of IBs in a culture.
authors.affiliation: University of Natural Resources and Applied Life Sciences (BOKU), Vienna, Department of Biotechnology, Muthgasse 18, A-1190 Vienna, Austria.
authors.forename: Gerd
authors.initials: G
authors.lastname: Margreiter
authors.forename: Paul
authors.initials: P
authors.lastname: Messner
authors.forename: Karin D
authors.initials: KD
authors.lastname: Caldwell
authors.forename: Karl
authors.initials: K
authors.lastname: Bayer