title: Hollow fiber supported gas membrane for in situ removal of ammonium during an antibiotic fermentation.
abstract: To study the influence of ammonium on an antibiotic cultivation, mass transfer measurements of ammonium through microporous hydrophobic membranes using different stripping methods were carried out and compared. The higher overall mass transfer coefficients for ammonium were obtained with an acid stripping solution compared to water, vacuum, or sweeping air. A hollow fiber module for in situ removal of ammonium during cultivation was designed and operated in an external bypass to a 10-L fermentor. Compared to a control fermentation, the cell dry mass could be increased 2.6 times and the antibiotic concentration 8 times, if the in situ ammonium removal was in operation.
authors.affiliation: Departments of Bioengineering and Microbiology, Gesellschaft für Biotechnologische Forschung m. b. H., Mascheroder Weg 1, D-3300 Braunschweig-Stöckheim, Federal Republic of Germany.
authors.forename: V
authors.initials: V
authors.lastname: Hecht
authors.forename: L
authors.initials: L
authors.lastname: Bischoff
authors.forename: K
authors.initials: K
authors.lastname: Gerth