Denitrifying bacteria Denitrifying bacteria were determined
by plating on nitrate-sucrose-agar (NSA) medium with the following
composition (per liter of distilled water): NaNO 3 2.0 g,
K2HPO 4 1.0 g, MgSO4.7H20 0.5 g, KC1 0.5 g, FeSO4.7H20 0.01
g, yeast extract 1.0 g, sucrose 30.0 g and agar 20.0 g, at pH 7.2.
The inoculated agar plates (three replicates) were incubated anaerobically
(Anaerogen system; Oxoid) at 30-1°C for 2 weeks
before the colonies were counted. Approximately 5 randomly selected
bacterial colonies were subcultured from each NSA plate.
Single colonies were restreaked on NSA for purification.