Optimizing Microbial Screenings Using Controlled-Release Systems Von der Fakultät für Maschinenwesen der Rheinisch-Westfälischen Technischen Hochschule Aachen zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation vorgelegt von Marco Scheidle Berichter: Univ.-Prof. Dr.-Ing. Jochen Büchs Univ.-Prof. Dr.rer.nat. Ulrich Schwaneberg Tag der mündlichen Prüfung: 08.Oktober 2010 Diese Dissertation ist auf den Internetseiten der Hochschulbibliothek online verfügbar I dedicate this work to my father Norbert Scheidle (1952-2007)Preface III Preface This PhD thesis has been performed at the RWTH Aachen University, Aachener Verfahrenstechnik – Biochemical Engineering from March 2006 to December 2009 and was partially funded by the Deutsche Bundesstiftung Umwelt (AZ13144). I am deeply grateful to Prof. Dr.-Ing. Jochen Büchs for the opportunity to conduct my PhD thesis at his department and for his continuous support and excellent advice throughout the work. Furthermore, I would like to thank Prof. Dr. Ulrich Schwaneberg for being a member of my thesis committee. For the excellent cooperation during this project I would like to thank Dr. Barbara Dittrich and Prof. Dr. Doris Klee from the Institute for Textile Chemistry and Macromolecular Chemistry at the RWTH Aachen University and Dr.