Intracellular and extracellular urease and dehydrogenase activities of soil

The aim of this work was to identify intra- and extracellular contributions to dehydrogenase and urease activities of three soils in two different conditions: air-dried and fresh samples. Microbial activity and growth were stimulated by additing glucose and potassium nitrate to soil samples. Dehydrogenase activity was always higher (3-5 times) in the air-dried than in fresh samples while urease activity was higher in fresh than in air-dried samples. It is furthermore confirmed that the approach of determining the extracellular activity by relating enzyme activity versus ATP content is not always correct.