1. Technological Laboratory, Ministry of Fisheries, Building 221, The Technical University of Denmark, DK-2800 Lyngby, Denmark; Carlsberg Research Laboratory, Department of Brewing Chemistry, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark; and Carlsberg Research Laboratory, Department of Biotechnology, Gamle Carlsberg Vej 10, DK-2500 Valby, Denmark