Dino Dinelli

[18] Fiber-entrapped enzymes

Publisher Summary This chapter discusses the analytical determination, properties, and application of fiber-entrapped enzymes. Entrapment of invertase is reported in the chapter. It is stressed that any other enzyme can be entrapped using the same procedure. The activity of a fiber-entrapped enzyme is determined by incubating the enzyme fibers and the substrate solution while stirring. The physical properties of enzyme fibers depend on the chemical nature of the polymer and are generally different from those of fibers normally obtained in the textile industry. These differences arise chiefly from the fact that, while in the normal wet-spinning procedure a homogeneous solution of the polymer is spun, in the technology of enzyme entrapment an emulsion is extruded. The catalytic properties of fiber-entrapped enzymes are generally different from those of the corresponding free enzymes. The principal differences are ascribed to, the restricted diffusion of substrates and products inside the porous enzyme support. Because of their excellent activity and stability, fiber-entrapped enzymes have potential technological application in industry, medicine, and analytical chemistry. The easy and inexpensive preparation procedures for enzyme fibers show a clear economic advantage in a large number of applications, which include both replacement of currently used free enzymes and the use of sophisticated enzymes considered too expensive in the soluble form.

Fiber-entrapped enzymes.

Fixed enzymes, regarded as very selective heterogeneous catalysts working at room temperature in aqueous solution, appear very attractive for any industrial activity connected with chemical transformations. However, their development is determined by the economy realized in their applications. We shall not consider here the problems related to enzyme production and purification, but only problems related to enzyme fixation. In particular we shall describe the desirable characteristics of an enzyme fixation technique developed in our laboratories and based on entrapment of enzymes in fibers (1,2).