Biocatalysts and Enzymatic Conversion of Substrates to Valuable Products of Chemical Organic Synthesis: A Review of Domestic Developments

Abstract

Biocatalysis in both the homogeneous and heterogeneous versions is an independent interdisciplinary direction in scientific and practical research of single-stage conversions of feed reagents (substrates) to valuable marketable products involving, in most cases, a single enzyme as a catalyst. Single-enzyme biocatalytic processes exhibiting all specific features of enzymatic catalysis are a fairly competitive alternative to conventional chemical production. This review provides information on the results achieved by domestic research teams/laboratories that have been involved in extensive and efficient studies in the field of biocatalysis over the past decades and have practical developments protected by RF patents, which, under favorable circumstances, can be offered to commercial enterprises/companies for testing and use on a laboratory and/or pilot-scale with the prospects of industrial scale-up. In the review, special attention is given to targeted systematic studies of lipolytic enzymes (lipases), which have a unique ability to catalyze reactions in a medium of organic solvents, primarily esterification and transesterification reactions, which lead to the formation of valuable products of organic synthesis, such as esters. Lipases are active components of heterogeneous biocatalysts (BCs) synthesized by fixing (immobilizing) these enzymes on the surface of solid adsorbing supports. The review briefly describes the results of studies of domestic research teams and gives complete lists of their reports providing information on the methods of immobilization of target enzymes, the catalytic properties of the developed BCs (enzyme activity, substrate specificity, operational stability) and describing the conditions for biocatalytic processes involving heterogeneous BCs, such as the synthesis of acrylamide and various esters. Taking into account the average activity (А), which is similar to the activity measured at the half-inactivation time (t_1/2), and the operational stability of BCs characterized by the t_1/2 value, a fairly rough assessment of the productivity of BCs is conducted by calculating the amount of valuable product produced (in tons) per kilogram of BC.