ABSTRACT
Ninety years have passed since the first report was presented by Woods on oxidizing enzymes, especially peroxidase, in soils at the annual meeting of the American Association for the Advancement of Science in Columbus, Ohio. The enzyme activity of soils results from the activity of accumulated enzymes and from those in proliferating microorgansms. Sources of enzymes in soils are primarily the microbial biomass, although they can also originate from plant and animal residues. Enzyme activities in soils are derived from free enzymes, such as exoenzymes released from living cells, endoenzymes released from disintegrating cells, and enzymes bound to cell constituents. Numerous studies have demonstrated that free enzymes are readily decomposed or are inactivated very rapidly when added to soils.
