Enzymes in soil: Properties, behavior and potential applications

Publisher Summary This chapter presents an outline of investigations performed on various aspects of enzymes in soil—namely, (1) enzymes in soil, as an example of “naturally immobilized enzymes,” (2) enzymes in soil, as affected by natural and anthropogenic factors, and (3) enzymes as potential detoxifying agents of polluted systems, including soils, with specific reference to phenolic pollutants. Three enzymes—invertase, phosphatase, and urease—and pure clays (montmorillonite), dirty clays (montmorillonite covered by different amounts of OH–Al species), and tannic acid, were used as representative of inorganic and organic soil components. The influence of metal (Al, Fe, and Mn) species on the interactions between enzymes and tannic acid was examined in the study discussed in the chapter. Synthetic enzyme complexes showed catalytic and stability properties that depended on the matrix and the bonding mechanism involved in their formation. Usually, a reduced activity and a kinetic behavior conforming to Michaelis–Menten kinetics were observed. Various responses in terms of thermal and proteolytic stability were observed. Finally, the potentiality of a laccase, an oxidoreductive enzyme, to detoxify a phenol-polluted system was addressed. The enzyme showed a satisfying efficiency toward different phenolic molecules when acting in the presence of complex system (phenol-soil colloids suspensions).