[1] Characterization of immobilized biocatalysts

Immobilized biocatalysts comprise both enzymes and whole cells immobilized by attachment to soluble polymers or insoluble carriers or by entrapment in membrane systems. This chapter discusses the characterization of biocatalysts with emphasis on aspects relevant to reaction engineering. A considerable number of parameters exist for characterizing immobilized biocatalysts with respect to reaction engineering and for the purpose of practical application. This includes the physical and mechanical parameters and the transport phenomena and kinetics that are intimately linked to biochemical systems. . These parameters are discussed in the chapter. These were recently emphasized by the Working Party on Immobilized Biocatalysts within the European Federation of Biotechnology. A better insight into the basic aspects of immobilized biocatalysts is essential for improved characterization, optimization in catalyst synthesis, and reactor design, and some examples of such efforts are given in the chapter. The most important aspects include the interaction of the catalyst with interfaces––namely, solid surfaces, mass-transfer phenomena, involved in immobilization and catalytic reaction, mechanisms of catalysis, influence of the bonding of catalysts to carriers, influence of microenvironments, and inactivation and stabilization mechanisms.