1. Teagasc Environmental Research Centre; Johnstown Castle Wexford Ireland
2. UCD Bioresources Research Centre/Biosystems Engineering; University College Dublin; Belfield Dublin 2 Ireland
3. Microbial Ecology Laboratory, Department of Microbiology; National University of Ireland; Galway Ireland
4. Teagasc Ashtown Research Centre; Rural Economy and Development Programme; Dublin Dublin 15 Ireland