Jump to Main Content
Enzymatic Nitrate Assay by a Kinetic Method Employing Escherichia coli Nitrate Reductase
- Schild, Johannes, Klemme, Jobst-Heinrich
- Zeitschrift für Naturforschung 2014 v.40 no.1-2 pp. 134-137
- Escherichia coli, nitrate reductase, nitrates
- An enzymatic assay system for nitrate employing the membrane-bound nitrate reductase (EC 22.214.171.124) of E. coli is described. Contrary to previous enzymatic assay systems, the present method is a kinetic one, i.e. the substrate, nitrate, is assayed by measuring the reaction rate of the nitrate reductase-catalyzed reaction. Based on the observation that the nitrate reductase-catalyzed reaction obeys pseudo-first order kinetics, a test system is described allowing the assay of nitrate at a concentration as low as 1 ppm. The relatively high M ichaelis-M enten constant for nitrate (0.3 mᴍ) of the E. coli nitrate reductase favours nitrate assay by the kinetic method.