1. Marine Chemistry Section, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark, Department of Biotechnology, Building 221, Technical University of Denmark, DK-2800 Lyngby, Denmark, Centre for Crystallographic Studies, Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark, and Novo Nordisk A/S, Microbiology, Novo Alle, DK-2880 Bagsværd, Denmark