|Evaluation of nitrifying activity in sediments by dark 14C-bicarbonate incorporation|In: Water Research. Elsevier: Oxford; New York. ISSN 0043-1354, more
A method has been developed for measuring the activity of nitrifying bacteria in sediment samples within very short incubation times (a few hours). Biological dark 14C-bicarbonate incorporation is measured with and without addition of 5 mg 1-1 N-serve, a substance which was proved to be a specific inhibitor of autotrophic CO2-fixation by nitrifying bacteria. The value of N-serve sensitive bicarbonate incorporation can be quantitatively related to the rate of nitrogen oxidation by autotrophic nitrifiers. First application of this method on marine sediments gives results in good agreement with information provided by other methods. Nitrification rates in the range 0–20 µmole nitrogen oxidized per dm3 sediment and per hour are found in the upper cm of the sediments of the coastal regions of the Southern Bight of the North Sea.