FIG. 2.
Denitrification of nitrate and nitrite by P. denitrificans and strain TR2. P. denitrificans (A and C) (34 mg cells [dry weight]) and strain TR2 (B and D) (16 mg cells) were incubated with 20 mM Na15NO3 (A and B) or 20 mM Na15NO2 (C and D) in the presence of 60 mM sodium acetate under initially microaerobic (3% O2) (open symbols) or anaerobic (argon-purged; closed symbols) conditions. Symbols: circles, 15N2; triangles, 15N2O; gray diamonds (for only initially microaerobic conditions), O2.