Abstract: The denitrification potential of a Danish forest soil is studied by the combination of acetylene and chloramphenicol inhibition techniques, and the effect of temperature on its related reduction enzyme activities is investigated.The activities and synthesis of reduction enzymes are inhibited by oxygen. It takes some time to consume the O₂ left in an anaerobic incubation to release this inhibition.When protein synthesis is not inhibited by antibiotic, nitrate reductase is synthesized slightly, while N₂Oreductase is significantly induced, which is of significance to study the N₂O absorbing capacity of soil. Nitrite is not considerably accumulated in all treatments, indicating that the activity of nitrite reductase is higher than nitrate reductase. Denitrification is stimulated by adding glucose, while the synthesis of enzymes and the releasing of electron competitions in the reduction processes are probably promoted as well. There shows a strong anaerobic respiration in the sampled soil, which is stimulated by Csource addition. The activation energy for denitrification is lower than that for anaerobic respiration, therefore, the Q₁₀ value for denitrification is lower, and the ratio between CO₂ and N₂Oevolution is higher with temperature.

Key words: Denitrification, N₂O reduction, Dynamics, Activation energy