All the transformations of nutrients occurring in soil are stimulated by the enzymes that condition their conversion into forms available to plants and microorganisms. Enzymes are frequently referred to as markers of soil environment purity (Aon and Colaneri, 2001). Microbial activity measurements appear as good indicators of the degree of pollution of contaminated soils (Nordgren et al., 1988; Aoyama and Nagumo, 1995; Insam et al., 1996; Kuperman and Margret, 1997).