NITRITE REDUCTION BY BACTERIUM DENITRIFICANS IN RELATION TO OXIDATION-REDUCTION POTENTIAL AND OXYGEN TENSION

Abstract

Both growing and resting cells of Bacterium denitrificans rapidly reduced nitrite-N to gaseous forms of N. Oxidation-reduction potential was not a controlling factor in the process although the bacterial cells excreted materials into the medium that lowered the potential. The organism simultaneously uses both molecular oxygen and nitrite but the former is used preferentially. Marked denitrification occurred when cultures were vigorously aerated with a mixture of 6% O2 in N gas.