1. All‐Russia Research Institute for Agricultural Microbiology, Podbelsky chaussee 3, Saint‐Petersburg, Pushkin 8, 196608, Russia;
2. Departamento de Microbiologia, Estacion Experimental del Zaidin‐CSIC, Profesor Albareda 1, E‐18008 Granada, Spain;
3. Ökologie des Bodens, RWTH Aachen, Worringer Weg 1, 52056 Aachen, Germany