Nitrification in the Schelde estuary: methodological aspects and factors influencing its activity

M.J.M. De Bie, Mathieu Starink, H.T.S. Boschker, J. Peene, H.J. Laanbroek

Research output: Contribution to journal/periodicalArticleScientificpeer-review


We present a 15-month dataset on nitrification measurements in the Schelde estuary (Belgium and The Netherlands). Nitrification was estimated using the N-serve sensitive dark 14C-bicarbonate incorporation technique. A peak of nitrification activity was observed in the freshwater part of the estuary. Downstream from this peak, nitrification declined, probably because of ammonium limitation. A range of nitrification inhibitors was tested on both a Nitrosomonas europaea culture and estuarine samples. It was found that methyl fluoride and acetylene stimulated dark 14C-bicarbonate incorporation and those inhibitors were therefore considered inappropriate nitrification inhibitors in combination with this technique. The effect of the inhibitor N-serve was studied on the dark incorporation of 13C-bicarbonate into polar lipid derived fatty acids to further identify the dominant chemoautotrophic processes. Inhibition of polar lipid derived fatty acid labelling in the presence of N-serve was complete, suggesting that nitrifying bacteria dominated the chemoautotrophic community. [KEYWORDS: Nitrification; Estuary; Polar lipid derived fatty acid; Nitrification inhibitor; Ammonium concentration]
Original languageEnglish
Pages (from-to)99-107
JournalFEMS Microbiology Ecology
Issue number1
Publication statusPublished - 2002


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