1. 1Department of Food and Nutrition, University of Helsinki, 00014 Helsinki, Finland
2. 2Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
3. 3New England Biolabs, Ipswich, MA 01938-2723, USA
4. 4Senson Oy, 15141, Lahti, Finland
5. 5VTT Technical Research Centre of Finland, 02044 VTT, Finland