Biocatalysts (enzymes and whole cells) catalyze reactions with the advantage of superior chemo-, regio-, and stereo-specificity in mild conditions, thereby avoiding the production of larger amounts ...of waste. The currently great practical importance of immobilized biocatalysts is expressed by the high number of scientific publications together with an ever increasing number of different applications in this area of enzyme technology. This mainly relies on new research results with respect to immobilization techniques and the development of advanced carrier materials designed for this purpose.
The employment of immobilized biocatalysts is one of the most effective and powerful tools used in the modern chemical industry as a prerequisite for an economical and environmentally friendly production process. The book presented here reflects the currently great practical importance of immobilized biocatalysts by means of a variety of actual examples. They comprise the immobilization of enzymes from different enzyme classes and a variety of whole cells with particular importance for the production of compounds for application in the chemical, pharmaceutical and food industry (in part from renewable resources), biohydrogen production, the fabrication of biosensors, and the treatment of waste water. Several articles introduce new research results with respect to immobilization techniques and the development of carrier materials designed for this purpose.
In addition, review articles provide among others an overview of the industrial application of immobilized biocatalysts in various areas including the energy sector, or discuss the many advantages of metal–organic frameworks (MOFs) as platforms for enzyme immobilization. They deal with the pros and cons of many inorganic, organic, hybrid and composite materials, including nano-supports, used for the immobilization of biocatalysts, and with the development of engineered strains applied to the conversion of lignocellulosic biomass to platform chemicals by consolidated bioprocessing.
In summary, the articles meet the state of the art of both scientific and technical standards and the book is indispensable for all those involved in the various aspects of this topic.
Multienzymatic cascade reactions are a most important technology to succeed in industrial process development, such as synthesis of pharmaceutical, cosmetic, and nutritional compounds. Different ...strategies to construct multienzyme structures have been widely reported. Enzymes complexes are designed by three types of routes: (i) fusion proteins, (ii) enzyme scaffolds, or (iii) immobilization. As a result, enzyme complexes can enhance cascade enzymatic activity through substrate channeling. In particular, recent advances in materials science have led to syntheses of various materials applicable for enzyme immobilization. This review discusses different cases for assembling multienzyme complexes via random co-immobilization, compartmentalization, and positional co-immobilization. The advantages of using immobilized multienzymes include not only improved cascade enzymatic activity via substrate channeling but also enhanced enzyme stability and ease of recovery for reuse. In this review, we also consider the latest studies of different model enzyme reactions immobilized on various support materials, as multienzyme systems allow for economical product synthesis through bioprocesses.
Immobilization of proteins on a solid support is critical with respect to the fabrication and performance of biosensors and biochips. Protein attachment with a preferable orientation can effectively ...avoid its denaturation and keeps its active sites fully exposed to solution, thus maximally preserving the bioaffinity or bioactivity. This review (with 140 refs.) summarises the recent advances in oriented immobilization of proteins with a particular focus on antibodies and enzymes. Following an introduction that describes reasons for oriented immobilization on (nano)surfaces, we summarize (a) methods for (bio)chemical affinity-mediated oriented immobilization (with sections on immunoglobulin G (IgG)-binding protein as the capture ligand, DNA-directed immobilization, aptamer- and peptide-mediated immobilization, affinity ligand and fusion tag-mediated immobilization, material-binding peptide-assisted immobilization); (b) methods for covalent oriented immobilization (with sections on immobilization via cysteine residues or cysteine tags, via carbohydrate moieties; via enzyme fusion or enzymatic catalysis, and via nucleotide binding sites of antibodies); (c) methods based on molecular imprinting techniques; (d) methods for characterization of oriented immobilized proteins; and then make conclusions and give perspectives.
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This review summarises recent advances in oriented immobilization of proteins based on strategies via bio−/chemical affinity, covalent bonding, and molecular imprinting techniques. Advantages and disadvantages of each approach are discussed.
•Overview of nanomaterial immobilized enzyme.•Binding force for enzyme immobilization.•Performance of nanomaterial immobilized enzyme.•Application of immobilized enzyme.•Outlook of nanomaterial in ...enzyme immobilization.
Enzymes have been widely used because of their catalytic properties, and immobilization is a promising technique to improve their catalytic activity and stability. Due to their large specific surface areas, exceptional chemical, mechanical, thermal and cost effective characteristics, nanomaterials should be ideal carriers for the immobilization of enzymes. Enzymes immobilized on nano-carriers are more robust and stable, and can be recycled and reused. This review focuses on the nanomaterial immobilized enzymes and their applications. The introduction addresses the advantages of immobilized enzymes and the features of enzyme immobilization nanocarriers. The next section covers carbonaceous nanomaterials used in enzymes immobilization, with subsections on carbon nanotube, graphene, graphene oxide and reduced graphene oxide. The third section treats metallic nanomaterials for enzymes immobilization, with subsections on metal (gold), metal oxide (titanium dioxide, zinc oxide) and metal hydroxide (layered double hydroxide) nanomaterials. Then, the next section summarizes the applications of nanomaterial immobilized enzymes. A concluding section discusses the challenges and prospects of nanomaterial immobilized enzymes.
The fate of heavy metals is crucial to the reuse of municipal waste incineration ash (MWIA) as construction materials. It is, however, not completely clear how they interact with cementitious phases ...at the molecular scale. This study investigated the uptake and speciation of Cu(II) and Zn(II) during the generation of Al-hydrocalumite-type high-pH phases through co-precipitation and adsorption experiments. Hydrocalumite (Hc) and minor phases, such as calcite and hydrogarnet, were identified as primary phases using X-ray diffraction (XRD). The characterization of Hc+Cu(II), Hc+Zn(II), and Hc+Cu(II)+Zn(II) via XRD, SEM, and bulk Cu(II)/Zn(II) EXAFS showed that both Cu(II) and Zn(II) exists as the surface/interlayer adsorption on the Hc+Cu(II)/Hc+Zn(II) and Hc+Cu(II)+Zn(II). Thermodynamic calculations support the experimental observations for the bulk phase. This study help understand the interacting mechanism between Cu(II)/Zn(II) and Hc phase, and pave the way of safe utilization of heavy-metal-containing waste as supplementary cementitious materials.
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•Hydrocalumite (Hc), a member of AFm phases, is synthesized to immobilize Cu(II) and Zn(II).•Hc proved highly effective in immobilizing Cu(II) and Zn(II) at high concentrations.•EXAFS data indicate Cu(II) and Zn(II) in an edge-sharing configuration within Hc interlayer.•Thermodynamic calculations establish the predominance diagram of phases for Cu(II) and Zn(II).
Compared with free enzymes, immobilized enzymes are more robust and resistant to environmental changes. In addition, with enhanced stability, immobilized enzymes can be separated from the reaction ...mixture and used for repeated cycles. These advantages prompt their applications in various fields. This review outlines the existing methods and easy separated support materials for enzymes immobilization. After a brief introduction on the immobilized enzyme, the immobilization methods of adsorption, entrapment, covalent attachment and cross-linking are discussed. The emphasis is given on the easy separated support materials of magnetic nanoparticles (MNPs), membranes and capillary columns. An outlook on the immobilized enzyme is given at last.
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•Detailed methods for enzymes immobilization are discussed.•MNPs, membranes and capillary columns are presented to solve the separation problems of immobilized enzymes.•Applications of easy separated support matrices in enzymes immobilization are summarized.•Future perspectives of immobilized enzymes are presented.
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