Improved Stabilization of Genetically Modified Penicillin G Acylase in the Presence of Organic Cosolvents by Co‐ Immobilization of the Enzyme with Polyethyleneimine

Abstract

Penicillin G acylase (PGA) is an enzyme that hardly interacts with polycationic polymers (e.g., polyethyleneimine, PEI) and thus the enzyme cannot be stabilized against the action of organic solvents by its co-immobilization with the polymer in the same support, neither covalently attached to the support nor adsorbed on the already immobilized enzyme. However, a new mutant PGA bearing eight additional Glu residues homogenously distributed throughout the enzyme surface may interact with the polymer. The co-immobilization of the enzyme and PEI on glyoxyl-agarose allows one to fully take advantage of the stabilization produced by the multipoint covalent attachment and by the protective hydrophilic micro-environment generated by the polycationic polymer, enabling a significant stabilization of the immobilized PGA in the presence of organic solvents.

Phenol degradation by Aureobasidium pullulans FE13 isolated from industrial effluents

“…Desimone et al [12] reported that the tolerance of sol-gel-immobilized Saccharomyces cerevisiae is correlated with the log K ow value of the solvent, and it increases with the increase in the value. It has been shown that this hydrophilic microenvironments performed by immobilization improved stabilization of enzymes in the presence of organic co-solvents [15,41,59]. The authors suggested that these micro-environments seems to be very useful not only to reduce the concentration of cosolvent existing microenvironment of the enzyme molecule, but also to prevent the direct interaction between the enzyme surface and a potentially harmful reaction medium as organic solvents and supercritical fluids.…”

Improvement of the catalytic performance of immobilized penicillin acylase through assembly of macromolecular reagents in nanopore to create a crowding environment

“…The development of biocatalysts is necessary to make the production of 6-APA economically feasible. Nowadays, technologies have been focused on modification of carriers [4] and immobilization techniques [5,6].…”

Penicillin acylase-catalyzed synthesis of N-bromoacetyl-7-aminocephalosporanic acid, the key intermediate for the production of cefathiamidine

“…Therefore, the enzymatic method exhibited promising application potential for the chemoenzymatic production of cefathiamidine. However, many problems associated with this enzymatic process such as relatively low substrate concentrations and unsatisfactory operational stability for its large-scale application may be addressed by the corresponding measures (e.g., using the supersaturated substrate solutions and fed-batch feeding strategy, and improving enzyme immobilization methods) (Volpato et al 2010; Ferreira et al 2007; Youshko et al 2004; Illanes et al 2007; Montes et al 2007). …”