1. BiOMaDe Technology Foundation, Nijenborgh 4, 9747 AG Groningen, The Netherlands, Department of Microbiology, Kerklaan 30, 9751 NN Haren, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands, and Department of Molecular Genetics, Kerklaan 30, 9751 NN Haren, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands