Enzymes as industrial biocatalysts offer numerous advantages over traditional chemical processes with respect to sustainability and process efficiency. Enzyme catalysis has been scaled up for commercial processes in the pharmaceutical, food and beverage industries, although further enhancements in stability and biocatalyst functionality are required for optimal biocatalytic processes in the energy sector for biofuel production and in natural gas conversion. The technical barriers associated with the implementation of immobilized enzymes suggest that a multidisciplinary approach is necessary for the development of immobilized biocatalysts applicable in such industrial-scale processes. Specifically, the overlap of technical expertise in enzyme immobilization, protein and process engineering will define the next generation of immobilized biocatalysts and the successful scale-up of their induced processes. This review discusses how biocatalysis has been successfully deployed, how enzyme immobilization can improve industrial processes, as well as focuses on the analysis tools critical for the multi-scale implementation of enzyme immobilization for increased product yield at maximum market profitability and minimum logistical burden on the environment and user.

Carbonic anhydrase (CA) was previously proposed as a green alternative for biomineralization of carbon dioxide (CO2). However, enzyme’s fragile nature when in synthetic environment significantly limits such industrial application. Herein, we hypothesized that CA immobilization onto flexible and hydrated “bridges” that ensure proton-transfer at their interfaces leads to improved activity and kinetic behavior and potentially increases enzyme’s feasibility for industrial implementation. Our hypothesis was formulated considering that water plays a key role in the CO2 hydration process and acts as both the reactant as well as the rate-limiting step of the CO2 capture and transformation process. To demonstrate our hypothesis, two types of user-synthesized organic metallic frameworks [metal–organic frameworks (MOFs), one hydrophilic and one hydrophobic] were considered as model supports and their surface characteristics (i.e., charge, shape, curvature, size, etc.) and influence on the immobilized enzyme’s behavior were evaluated. Morphology, crystallinity and particle size, and surface area of the model supports were determined by scanning electron microscopy, dynamic light scattering, and nitrogen adsorption/desorption measurements, respectively. Enzyme activity, kinetics, and stability at the supports interfaces were determined using spectroscopical analyses. Analysis showed that enzyme functionality is dependent on the support used in the immobilization process, with the enzyme immobilized onto the hydrophilic support retaining 72% activity of the free CA, when compared with that immobilized onto the hydrophobic one that only retained about 28% activity. Both CA–MOF conjugates showed good storage stability relative to the free enzyme in solution, with CA immobilized at the hydrophilic support also revealing increased thermal stability and retention of almost all original enzyme activity even after heating treatment at 70 °C. In contrast, free CA lost almost half of its original activity when subject to the same conditions. This present work suggests that MOFs tunable hydration conditions allow high enzyme activity and stability retention. Such results are expected to impact CO2 storage and transformation strategies based on CA and potentially increase user-integration of enzyme-based green technologies in mitigating global warming.

The continued integration of technology capable of achieving higher degrees of sustainability while meeting global material and energy demands is of singular importance in halting human-caused climate change. Unit operations...

Enzymes are proteins that control the efficiency and effectiveness of biological reactions and systems, as well as of engineered biomimetic processes. This review highlights current applications of a diverse range of enzymes for biofuel production, plastics, and chemical waste management, as well as for detergent, textile, and food production and preservation industries respectively. Challenges regarding the transposition of enzymes from their natural purpose and environment into synthetic practice are discussed. For example, temperature and pH-induced enzyme fragilities, short shelf life, low-cost efficiency, poor user-controllability, and subsequently insufficient catalytic activity were shown to decrease pertinence and profitability in large-scale production considerations. Enzyme immobilization was shown to improve and expand upon enzyme usage within a profit and impact-oriented commercial world and through enzyme-material and interfaces integration. With particular focus on the growing biomedical market, examples of enzyme immobilization within or onto hyaluronic acid (HA)-based complexes are discussed as a definable way to improve upon and/or make possible the next generation of medical undertakings. As a polysaccharide formed in every living organism, HA has proven beneficial in biomedicine for its high biocompatibility and controllable biodegradability, viscoelasticity, and hydrophilicity. Complexes developed with this molecule have been utilized to selectively deliver drugs to a desired location and at a desired rate, improve the efficiency of tissue regeneration, and serve as a viable platform for biologically accepted sensors. In similar realms of enzyme immobilization, HA’s ease in crosslinking allows the molecule to user-controllably enhance the design of a given platform in terms of both chemical and physical characteristics to thus best support successful and sustained enzyme usage. Such examples do not only demonstrate the potential of enzyme-based applications but further, emphasize future market trends and accountability.

The catalytic efficiency and unrivaled selectivity with which enzymes convert substrates to products have been tapped for widespread chemical transformations within biomedical technology, biofuel production, gas sensing, and the upgrading of commodity chemicals, just to name a few. However, the feasibility of enzymes implementation is challenged by the lack of reusability and loss of native catalytic activity due to the irreversible biocatalyst denaturation at high temperatures and in the presence of industrial solvents. Enzyme immobilization, a prerequisite for enzyme reusability, offers controllable strategies for increased functional viability of the biocatalyst in a synthetic environment. Herein we used molecular dynamics (MD) simulations and probed the noncovalent interactions between model enzymes of technological interest, i.e., carbonic anhydrase (CA) and myeloperoxidase (MPO), with selected metal–organic frameworks (MOFs; MIL-160 and ZIF-8) of proven industrial implementation. We found that the CA and MPO can bind to MIL-160 at optimal binding energies of 201 and 501 kJ mol–1, respectively, that are strongly influenced by the increased incidence of hydrogen bonding between enzymes and the frameworks. The free energy of binding of enzymes to ZIF-8, on the other hand, was found to be less strongly influenced by hydrogen bonding networks relative to the occurrence of hydrophobic–hydrophobic interactions that yielded 106 kJ mol–1 for CA and 201 kJ mol–1 for MPO.