[1] Univ Cattolica Sacro Cuore, Ist Microbiol, I-29122 Piacenza, Italy
[2] Univ Cattolica Sacro Cuore, Ist Chim Agrariaed Ambientale, I-29122 Piacenza, Italy
[3] Wageningen Univ, Sub Dept Environm Technol, NL-6700 AA Wageningen, Netherlands
[4] UFZ Helmholtz Ctr Environm Res, Dept Isotope Biogeochem, D-04318 Leipzig, Germany