1. Department of Microbial Ecology; Netherlands Institute of Ecology (NIOO-KNAW); PO BOX 50 6700 AB Wageningen The Netherlands
2. MicroLife Solutions B.V.; Science Park 406 1098 XH Amsterdam The Netherlands
3. Mass Spectrometry Research Group; Max Planck Institute for Chemical Ecology; Hans-Knoell-Str. 8 D-07745 Jena Germany
4. BioDetection Systems B.V.; Science Park 406 1098 XH Amsterdam The Netherlands
5. Department of Soil Quality; Wageningen University and Research Centre (WUR); PO BOX 47 6700 AA Wageningen The Netherlands