Abstract: | The effects of two metabolic inhibitors on an enriched nitrifying biomass during incubation for short periods of time were investigated by determining respirometric measurements. Allylthiourea (86 μM) and azide (24 μM) were shown to be strong, selective inhibitors of ammonia and nitrite oxidation, respectively. Consequently, a differential respirometry method for estimating nitrifying and heterotrophic bacterial activities within a mixed biomass is proposed. |