1. Department of Applied Chemistry and Microbiology, PO Box 56, Viikki Biocentre, FIN-00014 University of Helsinki, Finland
2. Laboratorium voor Microbiologic, Universiteit Gent, K. L. Ledeganckstraat, 35, B-9000 Gent, Belgium
3. Laboratoire de Microbiologic des Sols, ORSTOM BP 1386, Dakar, Senegal
4. Pennsylvania State University, Berks Campus, POB 7009, Reading, PA 19610-6009, USA
5. Institute of Biotechnology, POB 56, Biocentre 1, FIN-00014 University of Helsinki, Finland
6. Department of Applied Microbiology, Sichuan Agricultural University, Yaan 625014, People’s Republic of China