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.

• January 2014 – ongoing
  ACIB projects 4.5-6 and 24.011 - Engineering hydratases
  

  We are engineering hydratases for industrial fitness. This project is carried out with company partners at DSM Chemical Technology R&D B.V., Innovative Synthesis (Geleen, The Netherlands).

  ---

• February 2015 – ongoing
  Industrial collaboration project - Terpenoid screening
  

  We are developing a medium for a high throughput terpenoid screening procedure in collaboration with Isobionics (Geleen, The Netherlands).

• September 2005 – June 2009
  Applied Biocatalysis projects 2.11 and P09 - Recombinant esterase for alpha-substituted aliphatic esters – improving the yield
  

  We have identified a novel isoform of the pig liver esterase protein family, markedly improved expression of pig liver esterases in P. pastoris and E. coli, and have evolutionarily engineered pig liver esterases for biocatalytic applications. This project has been carried out in close collaboration with Prof. Helmut Schwab, Prof. Karl Gruber and company partners at DSM Chemical Technology R&D B.V., Innovative Synthesis (Geleen, The Netherlands) and DPx Fine Chemicals (Linz, Austria).

  ---

• July 2009 – December 2013
  ACIB projects PÜ4.1 and 4.2-1 - Enzyme engineering for complex reactions
  

  We have generated a promising yeast whole-cell biocatalyst that makes (+)-nootkatone from simple carbon sources. To foster plant terpenoid biosynthesis in yeasts, and to improve the industrial applicability of membrane-attached cytochrome P450 enzymes we have identified several endogenous helper factors in P. pastoris and S. cerevisiae. This project has been carried out in close collaboration with company partners at DSM Chemical Technology R&D B.V., Innovative Synthesis (Geleen, The Netherlands) and DPx Fine Chemicals (Linz, Austria).

  ---

• October 2009 – April 2014
  DK Molecular Enzymology (FWF) PhD project Dr. Christine Winkler - Probing the secretory pathway of the yeast Pichia pastoris
  

  We have devised a novel, medium-throughput, random mutagenesis/screening protocol for improved protein secretion in P. pastoris. A couple of highly interesting target genes have been identified, partially characterized and filed for patenting. This project has been carried out in close collaboration with Prof. Helmut Schwab.

  ---

• January 2010 – December 2015
  ACIB project 3.2-1 - Pichia pastoris cell factory for protein production
  

  We have applied multiple approaches to identify key genes that determine protein secretion rates in P. pastoris. Upregulation of several target genes has improved recombinant protein titers and yields. This project has been carried out in close collaboration with Prof. Diethard Mattanovich (Vienna), Prof. Guenther Daum and company partners at Biocrates (Innsbruck, Austria), Biomin (Tulln, Austria), Boehringer Ingelheim-RCV (Vienna, Austria), LONZA (Visp, Switzerland), Sandoz (Kundl, Austria) and VTU (Grambach, Austria).

  ---

• January 2010 – June 2015
  ACIB projects 4.2-2 and 54.041 - Enzyme engineering and substrate channeling for vitamin production
  

  We have developed and employed screenings for improved production of vitamin precursors. Remarkably, we have managed to engineer a very complex enzyme that has evaded structural elucidation to date. This project was carried out in close collaboration with company partners at DSM Nutritional Products (Kaiseraugst, Switzerland).

---

• January 2015 – February 2017
  ACIB project 23.021 - Engineering of protein secretion in Pichia pastoris
  

  We were following up on several approaches to enhance recombinant protein titers and yields. This project was carried out in close collaboration with Prof. Diethard Mattanovich (Vienna), Prof. Guenther Daum and company partners at Biomin (Tulln, Austria), Boehringer Ingelheim-RCV (Vienna, Austria), LONZA (Visp, Switzerland), Sandoz (Kundl, Austria) and VTU (Grambach, Austria).

• PhD Theses

  • Sandra Moser
    Triterpenoid synthesis in yeast

• Master Theses

  • Uchralbayar Tugel
  • Anna Katharina Lämmerer
  • Antonia Volpini de Maestri
  • Andreas Proksch
  • Astrid Radkohl
  • Simon Kobalter

<hints id="hah_hints"></hints>

• PhD Theses

  • Dr. Martin Trinker (né Kietzmann)
    January 2009
    Pig liver esterase: Molecular development of a biocatalyst for the industrial production of high-value pharmaceuticals
  • Dr. Veeresh Juturu
    June 2010
    Enhancing the expression of recombinant proteins in the methylotrophic yeast Pichia pastoris
  • Dr. Anita Emmerstorfer
    April 2014
    Improving heterologous cytochrome P450 function in S. cerevisiae
  • Dr. Christine Winkler
    April 2014
    Probing the secretory pathway of the yeast Pichia pastoris
  • Dr. Melanie Hirz
    May 2017
    Tuning of Pichia pastoris for the expression of membrane proteins and small peptides
  • Dr. Matthias Engleder
    July 2018
    Selective hydration of carbon-carbon double bonds: From structure function studies to enzyme engineering

• Master Theses

  • 2005
    Dr. Veeresh Juturu
  • 2007
    Anja Egger Dr. Michael Tscherner Dr. Eva Hoffmann
  • 2008
    Dr. Andreas Braun Dr. Julia Feichtinger
  • 2009
    Dr. Amin El-Heliebi Dr. Christine Winkler 
  • 2010
    Dr. Andreas Küberl Michael Felber Dr. Anita Emmerstorfer Dr. Birgit Ploier
  • 2011
    Dr. Thomas Vogl Dr. Corinna Odar Dr. Peter Augustin Gerald Richter
  • 2012
    Dr. Melanie Hirz
  • 2013
    Dr. Ariane Fankl Peter Neugebauer
  • 2014
    Katharina Littringer Sandra Moser Miriam Wimmer-Teubenbacher
  • 2015
    Dr. Matthias Engleder Florian Ungerböck Johannes Fuchs
    Sabine Schrempf Bernd Albrecht Mia Potocnjak
  • 2016
    Simon Arhar Stefanie Gabriel Manfred Briendl Elisabeth Hirschböck
  • 2017
    Birgit Grill Christoph Schilling Melissa Horvat Valentin Steinwender Edmund Dittmann Alena Voit Kerstin Stadler Klara Lanz Zan Caf-Feldin Sanja Tunjic
  • 2018
    Johanna Zwick Claudia Gafko Philippe Oberhemm Carolin Kunz Martin Senekowitsch Daniela Brunner Katharina Nagl Johannes Blamauer Chiam Hashem

<hints id="hah_hints"></hints>

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)