Nitrite inhibition of aerobic growth of Acinetobacter sp.

Nitrite inhibition of Acinetobacter sp. growing under aerobic conditions was studied. Specific growth rates under non-limiting concentrations of acetate and dissolved oxygen averaged 0.62 h−1. Growth and phosphate uptake by Acinetobacter sp. were both inhibited by increasing nitrite concentrations. The median inhibitory concentration (IC50) of free nitrous acid (FNA) was 0.10 mg/L and the IC10 of FNA was 0.05 mg/L. Removing nitrite from cultures reversed the inhibitory effect. Comparison of the IC10 of FNA for Acinetobacter sp. to inhibitory concentrations for other wastewater heterotrophic bacteria suggests that Acinetobacter sp. are relatively sensitive to this compound.