1. Department of Dairy and Food Science, Centre for Advanced Food Studies, LMC, The Royal Veterinary and Agricultural University, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark1
2. Department of Biochemistry, University of Stellenbosch, Private Bag X1, 7602 Matieland, South Africa2
3. German Research Centre for Biotechnology, Department of Cell Biology, Mascheroder Weg 1, Braunschweig D-38124, Germany3
4. Laboratoire de Microbiologie Fondamentale et Appliquée, CNRS FRE 2224, IBMIG, UFR Sciences, 40 Avenue du Recteur Pineau, 86022 Poitiers Cedex, France4