1. VTT Biotechnology, FI-02044 VTT, Finland, Biomade Technology, Nijenborgh 4, 9747 AG Groningen, The Netherlands, Groningen Biotechnology and Biomolecular Sciences Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands, and Microbiology Department, Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands