1. BIOMERIT Research Centre, Department of Microbiology, National University of Ireland, Cork, Ireland1
2. UMR CNRS Ecologie Microbienne du Sol, Université Claude Bernard (Lyon 1), 69622 Villeurbanne cedex, France2
3. MSU-DOE Plant Research Laboratory and Department of Microbiology, Michigan State University, East Lansing, MI 48824, USA3