1. Laboratory of Microbial Ecology and Technology (LabMET), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, B-9000 Gent, Belgium.
2. Laboratory of Chemical Analysis, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium
3. Department of Materials Science and Engineering, Faculty of Engineering, Ghent University, Technologiepark 903, B-9052 Gent, Belgium.