1. Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence , P.le delle Cascine 18, 50144 Firenze, Italy
2. Magnetic Resonance Center (CERM) and Department of Chemistry “Ugo Schiff”, University of Florence , via Sacconi 6 , Sesto Fiorentino 50019, Italy
3. Consorzio Interuniversitario Risonanze Magnetiche MetalloProteine (CIRMMP) , via Sacconi 6 , Sesto Fiorentino 50019, Italy
4. Department of Biology (DBIO), University of Florence , via Madonna del Piano 10 , Sesto Fiorentino 50019, Italy
5. Centro Interdipartimentale per lo Studio delle Dinamiche Complesse (CSDC), University of Florence , c/o Department of Physics and Astronomy, via G. Sansone 1, Sesto Fiorentino 50019, Italy
6. Department of Microbiology, University of Tennessee , 1311 Cumberland Avenue , Knoxville, TN 37996-1937, United States