1. Department of Genetics, Microbiology and Statistics, University of Barcelona, Av. Diagonal, 643, 08028 Barcelona, Spain
2. Department of Nutrition, Food Science and Gastronomy, University of Barcelona, Avda. Prat de la Riba, 171, 08921 Sta. Coloma de Gramanet, Barcelona, Spain
3. Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands