title: Production of recombinant antibody fragments in Bacillus megaterium.
abstract: BACKGROUND
  Recombinant antibodies are essential reagents for research, diagnostics and therapy. The well established production host Escherichia coli relies on the secretion into the periplasmic space for antibody synthesis. Due to the outer membrane of gram-negative bacteria, only a fraction of this material reaches the medium. Recently, the gram-positive bacterium Bacillus megaterium was shown to efficiently secrete recombinant proteins into the growth medium. Here we evaluated B. megaterium for the recombinant production of antibody fragments.
  
  
  RESULTS
  The lysozyme specific single chain Fv (scFv) fragment D1.3 was successfully produced using B. megaterium. The impact of culture medium composition, gene expression time and culture temperatures on the production of functional scFv protein was systematically analyzed. A production and secretion at 41 degrees C for 24 h using TB medium was optimal for this individual scFv. Interestingly, these parameters were very different to the optimal conditions for the expression of other proteins in B. megaterium. Per L culture supernatant, more than 400 microg of recombinant His6-tagged antibody fragment were purified by one step affinity chromatography. The material produced by B. megaterium showed an increased specific activity compared to material produced in E. coli.
  
  
  CONCLUSIONS
  High yields of functional scFv antibody fragments can be produced and secreted into the culture medium by B. megaterium, making this production system a reasonable alternative to E. coli.
authors.affiliation: Technische Universität Braunschweig, Institut für Biochemie und Biotechnologie, Abteilung Biotechnologie, Spielmannstr, 7, 38106 Braunschweig, Germany. e.jordan@tu-bs.de
authors.forename: Eva
authors.initials: E
authors.lastname: Jordan
authors.forename: Michael
authors.initials: M
authors.lastname: Hust
authors.forename: Andreas
authors.initials: A
authors.lastname: Roth
authors.forename: Rebekka
authors.initials: R
authors.lastname: Biedendieck
authors.forename: Thomas
authors.initials: T
authors.lastname: Schirrmann
authors.forename: Dieter
authors.initials: D
authors.lastname: Jahn
authors.forename: Stefan
authors.initials: S
authors.lastname: Dübel