5 COORDINATED NITROSYLHEMOPROTEIN IN THE WHOLE CELLS OF DENITRIFYING BACTERIUM, ACHROMOBACTER-XYLOSOXIDANS NCIB-11015

The denitrifying bacterium, Achromobacter xylosoxidans NCIB 11015, was cultivated in meat extract-peptone medium and in Mn-free synthetic me dium under denitrifying or non-denitrifying conditions. Electron param agnetic resonance (EPR) spectra for the whole cells of the bacteria th us obtained were measured at 77 K. The characteristic three-line signa l was observed in the whole cells of the bacteria under denitrifying c onditions, but not under non-denitrifying conditions. The three-line s ignal was more distinctly observed in the cells cultured in Mn-free me dium. This signal could be assigned to nitrosylcytochrome c' containin g a five-coordinated nitrosylheme. The elemental composition in these cells is also discussed.