We are interested in processes that involve biological membranes. We engineer the membranes of microbes, i.e. bacteria and yeasts, regarding lipid and membrane protein composition, either to understand the complex interactions of these hydrophobic compounds or to apply the modified microorganisms for interesting goals of industrial biotechnology. Our particular focus in the yeast lipid field are sterols, their biosynthesis and homeostasis, and their interactions with membrane proteins. Pichia pastoris, a methylotrophic yeast, is our favourite host, which we employ for expression and secretion of recombinant soluble proteins as well as for the biosynthesis of valuable metabolites, e.g. plant terpenoids, through heterologous expression of membrane proteins. We have uncovered several endogenous yeast proteins and mechanisms that render protein secretion or membrane protein expression more efficient and sustainable. Based on our expertise in medium to high-throughput screening approaches involving microbes and a background in yeast cell biology, we expand the knowledge on membrane-related processes and extend the molecular toolboxes for applications on industrial scale. Rational and evolutionary enzyme engineering approaches allow us to make novel enzymes or enzyme families fit for biocatalytic applications, as isolated enzymes or in whole-cell applications. Therefore, we study enzyme characteristics by classical protein analytics and devise novel enzyme assays. We usually team up with structural biologists, biochemists as well as analytical and organic chemists.

Scientific partners

• Prof. Erich Leitner - Institute of Analytical and Food Chemistry, Graz University of Technology, Austria
• Dr. Gernot Strohmeier - Institute of Organic Chemistry, Graz University of Technology, Austria
• Prof. Guenther Zellnig - Institute of Plant Physiology, University of Graz, Austria
• Prof. Harro Bouwmeester - Laboratory of Plant Physiology, University of Wageningen, The Netherlands
• Prof. Howard Riezman - Department of Biochemistry, University of Geneva, Switzerland
• Prof. Karl Gruber - Institute of Molecular Biosciences, University of Graz, Austria
• Prof. Koichi Funato - Department of Biofunctional Science and Technology, Graduate School of Biosphere Science Hiroshima University, Japan
• Prof. Maria A Vanoni - Department of Biomolecular Sciences and Biotechnology, University of Milano, Italy
• Dr. Michael Haertlein - Institut Laue-Langevin, Grenoble, France
• Prof. Steven JD Karlish - Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel

Industrial collaborations

• ACIB, Austrian Centre of Industrial Biotechnology (Graz, Vienna, Innsbruck, Austria)
• DSM Chemical Technology R&D B.V., Innovative Synthesis (Geleen, The Netherlands)
• DPx Fine Chemicals (Linz, Austria)
• Biomin (Tulln, Austria)
• Boehringer Ingelheim RCV (Vienna, Austria) 
• LONZA (Visp, Switzerland)
• Sandoz (Kundl, Austria)
• VTU (Grambach, Austria)