1. Laboratory of Microbial Gene Technology, Department of Chemistry, Biotechnology, and Food Science, Norwegian University of Life Sciences (UMB), P.O. Box 5003, N-1432 Ås, Norway
2. Institute of Food Science and Nutrition, Laboratory of Food Biotechnology, ETH Zuerich, Schmelzbergstrasse 7, CH-8092 Zuerich, Switzerland
3. TINE BA, Oslo, Norway