New frontiers in enzyme immobilisation: robust biocatalysts for a circular bio-based economy

Abstract

This tutorial review focuses on recent advances in technologies for enzyme immobilisation, enabling their cost-effective use in the bio-based economy and continuous processing in general.

Enzyme entrapment, biocatalyst immobilization without covalent attachment

“…Sheldon et al have highlighted the usefulness of CLEA for enzyme immobilization over the years and have recently updated the progress in their reviews. 86,87 A representative example is given. The enzyme nitrile hydratase was precipitated with ammonium sulfate and crosslinked with glutaraldehyde to make CLEAs for the hydration of hexanenitrile.…”

“…This review is concerned with the development and possible future applications of entrapment methods that do not involve covalent linking to the protein. For more details on the research and industrial application of covalent bonding and crosslinking to enzyme immobilization an up to date review was recently published by Sheldon et al 87…”

Engineering proteinaceous colloidosomes as enzyme carriers for efficient and recyclable Pickering interfacial biocatalysis

“…Enzymes have shown extraordinarily high catalytic activity and selectivity in chemical processes under mild and sustainable conditions. [1][2][3][4][5] Because the substrates in many situations are soluble in organic solvents and the enzyme as the biocatalyst is often active in water, enzymatic reactions typically occur at the organic-aqueous biphasic interface, in which the interfacial area is the critical factor to the catalytic efficacy. 6,7 One common and efficient method for increasing the oil-water contacting area is to create emulsions, which are usually stabilized by surfactants.…”

Surface Modulation of Graphene Oxide for Amidase Immobilization with High Loadings for Efficient Biocatalysis

“…Amidases or amide hydrolases (EC 3.5.1.X) are a type of important versatile biocatalyst, which have been employed in the production of various chiral amino acids, carboxylic acids and amides via the cleavage of C-N bonds [1]. With the increasing demand of green chemistry, amidases have received broad attention in pharmaceutical and chemical industries for the production of D-or L-amino acids and β-lactam antibiotics due to their high activity and specificity under mild conditions [1,2]. However, the intrinsically fragile nature of enzymes under incompatible conditions (e.g., high temperature, unfavorable pH and organic solvents) greatly limits the industrialization of amidases [3].…”

“…To improve their stability and recyclability, various methods have been developed, such as enzyme immobilization, protein engineering and so on [4]. In the past decades, immobilization of amidases on solid materials has received broad attention with the relatively easy procedure and available reusability [2], in which the selection of solid support is critically important as the materials have strong influence on the resultant properties. In search of an ideal support for amidase immobilization, various materials with different compositions, structures and morphologies have been explored [5], including inorganic carries (e.g., mesoporous silica) [6], organic carries (e.g., chitosan and nanocrystalline cellulose) [7,8], composite carriers (e.g., silica nanoflower and metal-organic framework hybrids) [9], etc.…”