Nitrate reduction activity in a continuous flow-through system in marine sediments.

Nitrate reduction in a non-polluted, coastal marine sediment was measured with an open flow-through system. The recorded rates depended upon nitrate concentration but were largely independent of the weight of sediment (14-35 g) and the dilution rate (0.7-5 h(-1)). Rate of nitrate uptake followed classical Michaelis-Menten kinetics, and km and Vmax values were equal to 78μM and 0.168μm mol g(-1) hour(-1), respectively. These values are in good agreement with those found by the other authors for the same biotope but by different methods. This technique of the open flow-through system is fast, simple, and inexpensive and involves small quantities of sediment (∼10 g).