Display omitted
•Immobilization of GOx on Ti3C2 MXene for cascade glucose oxidation reaction.•PLL modification provides the Ti3C2 with a bio biocompactible surface for GOx loading.•Superior enzymatic ...activity and stability are obtained in the Ti3C2-PLL-GOx .•The Ti3C2-PLL-GOx nanosheet can be used to build a high-performance glucose sensor.
Two-dimensional (2D) nanoreactors with cascade catalytic activity for glucose oxidation and hydrogen peroxide decomposition are prepared via immobilizing glucose oxidase (GOx) on Ti3C2 MXene nanosheets. Amino-rich polypeptide, poly-l-lysine (PLL), is applied to modify the ultra-thin Ti3C2 MXene nanosheets with a compatible surface for GOx immobilization. The PLL-modified Ti3C2 nanosheets possess a positively charged surface and show an excellent GOx loading capacity as high as 50 wt% of the Ti3C2 nanosheets. The physically adsorbed enzymes are then cross-linked with the amine groups in the PLL chains to form a robust GOx-PLL network covered on the MXene nanosheets. The GOx-conjugated Ti3C2-PLL (Ti3C2-PLL-GOx) nanosheets showed superior enzymatic activities than the activities of GOx immobilized on an inert porous silica substrate, largely because that the Ti3C2 nanosheets can catalyze the decomposition of the toxic intermediate H2O2 generated from the glucose oxidation. Given the excellent electrical conductivity of Ti3C2 MXene, the Ti3C2-PLL-GOx nanosheets are further deposited on glassy carbon electrode to construct a high-performance biosensor with a glucose detection limit of 2.6 μM.
Application of Immobilized Enzymes in Food Industry Yushkova, Ekaterina D; Nazarova, Elena A; Matyuhina, Anna V ...
Journal of agricultural and food chemistry,
10/2019, Letnik:
67, Številka:
42
Journal Article
Recenzirano
Enzymes are macromolecular biocatalysts, widely used in food industry. In applications, enzymes are often immobilized on inert and insoluble carriers, which increase their efficiency due to multiple ...reusability. The properties of immobilized enzymes depend on the immobilization method and the carrier type. The choice of the carrier usually concerns the biocompatibility, chemical and thermal stability, insolubility under reaction conditions, capability of easy regeneration and reusability, as well as cost efficiency. In this review, we provide an overview of various carriers for enzyme immobilization, with the primary focus on food industry.
Display omitted
•Dye and phenol removal via enzyme immobilization technology are reviewed.•Factors affecting the performance of immobilized enzymes are discussed.•Recent developments on enzyme ...immobilization technologies are elucidated.•Potential and challenges of nanotechnology in enzyme immobilization are discussed.•Future perspectives in this direction have been proposed.
Global water pollution caused by dye and phenol contaminants has been reported to have reached an alarming level. These hazardous contaminants pose significant threats to humans and ecosystem, due to their toxicity, carcinogenicity, and mutagenicity. Various technologies have emerged for dyes and phenols removal from wastewater, such as physical adsorption, chemical oxidation, ozonation, extraction, and electrochemical treatments. However, these conventional methods are constrained by low efficiency and stability, high cost, and formation of harmful by-products. In recent years, there has been growing interest towards the development of immobilized enzyme technologies because they are more economical, effective and eco-friendly. Among various enzymes, peroxidases have generated extraordinary interest attributed to their ability to catalyze reactions of a variety of undesirable pollutants, such as dyes and phenol effluents. Immobilization of enzyme can enhance its catalytic efficiency, improve storage and operational stabilities, as well as allow enzyme recovery and reusability. Although numerous existing immobilized enzymatic systems have been established, their practical applications are limited due to mass transfer restriction, lack of feasibility for scaling-up and continuous operations, and difficulty for separation of immobilized enzymes from reaction mixtures. Therefore, much attention has been devoted to the immobilization of enzymes on nano-structured materials. In the current review, effects of process parameters on immobilized enzymes for applications in both dye and phenol treatment are discussed and summarized. Recent advanced technologies as well as challenges and future perspectives for research and development in this field are also highlighted.
The commercial application of biocatalysts depends on the development of effective methods of immobilization. The immobilization of enzymes greatly increases the stability of enzymes and eases the ...burden of enzyme cost and thus, is widely pursued for efficient, selective, and environmentally friendly catalysis. This brief perspective focuses on recent development in the area of enzyme immobilization in porous materials. Recent work regarding the immobilization of enzymes in inorganic mesoporous materials as well as the modifications to those materials is summarized in this paper. The configuration of supported enzyme as membranes and fibers may facilitate their application in areas that require a biocatalytic process. Enzymes immobilized in or on fibrous membranes provide high surface area for high throughput biocatalysis. These membrane bioreactors also allow for biotransformations to be carried out within a continuous flow process while maintaining enzyme stability under operating conditions as a result from the enzyme immobilization. A summary of efforts to prepare immobilized enzymes in fibers and electrospun fibers will also be discussed.
An amino-functionalized magnetic metal organic framework (MOF), Fe3O4-NH2@MIL-101(Cr), was employed for laccase immobilization for the first time. The immobilized laccase was synthesized by the ...adsorption and covalent binding method, thus exhibited high activity recovery, large immobilization capacity and good tolerance to low pH and high temperature conditions. The excellent stability enabled the immobilized laccase to retain 89% of its initial activity after storage for 28 days. When the ambient temperature reached 85 °C, the immobilized laccase showed 49.1% residual activity even after 6 h preservation. The stability of laccase in organic solvents such as methanol was also greatly improved. Application of the immobilized laccase for 2,4-dichlorophenol removal was also investigated. The adsorption by Fe3O4-NH2@MIL-101(Cr) contributed to a quick removal in the first hour, and the removal efficiency reached 87% eventually. When the reaction was completed, the immobilized laccase could be separated from the solution by a magnet. The results introduced a novel support for laccase immobilization, and the immobilized laccase had great potential in wastewater treatment.
Display omitted
•A novel amino-functionalized magnetic MOF was applied for laccase immobilization.•The immobilized laccase was synthesized by the adsorption and covalent binding.•A high laccase loading and activity recovery was obtained.•The immobilized laccase showed improved thermal and storage stability.•The removal of 2,4-dichlorophenol was efficient by the immobilized laccase.
There are growing demands by the biodiesel companies to get cheap lipase formulation, preferably in liquid forms, which can give an answer to their needs. Thus, many commercial or home-produced ...enzymes are being used in this process in free form. Among these enzymes, Eversa is a liquid lipase formulation derived from the lipase from Thermomyces lanuginosus designed for the enzymatic biodiesel production. The potential of this promising enzyme is hereby reported. However, the specificity of lipases is a problem in biodiesel production. That way the concept of an optimal lipase for biodiesel production is not appropriate, being preferable the use of concept of combi-lipases, using Eversa as a component of the lipase mixture. The application of Eversa for the production of biodiesel through the transesterification, esterification and hydroesterification of oils and fats with different free fatty acids content is thoroughly discussed. Finally, even though Eversa was launched to be used as liquid biocatalyst in the production of biodiesel, this work will discuss how the immobilization of this enzyme through different strategies enhances its performance. That is, a properly designed immobilized Eversa biocatalyst may be more expensive, but it may have some advantages that overcome this drawback.
Display omitted
•Enzymatic biodiesel production is a demand of the combustible companies.•Eversa has been launched to fulfill the requirements of biodiesel industry.•The use of its liquid formulations in biodiesel production is habitual.•Eversa immobilization may further improve the potential of this enzyme formulation.
Display omitted
Metal–organic frameworks (MOFs), with large specific surface area and tunable porosity, have gained lots of attention for immobilizing enzymes. However, the intrinsic open channels of ...most reported MOFs are generally smaller than 2 nm, which significantly prevents the passage of enzymes, and the diffusion efficiency of substrates and products. Here we report a new hierarchical micro-mesoporous zeolitic imidazolate framework-8 (ZIF-8) with core–shell superstructure (HZIF-8) using colloidal hydrated zinc sulfate (ZnSO4·7H2O) as a soft template for enzyme immobilization. The ZnSO4·7H2O forms an aggregation of colloids due to the self-conglobation effect in methanol, which affords a soft template for the formation of HZIF-8. Cytochrome C (Cyt C) was immobilized in interior of HZIF-8 through entrapment during the formation of HZIF-8. The resultant immobilized Cyt C (Cyt C@HZIF-8) exhibited 4-fold and 3-fold higher activity than free Cyt C and Cyt C encapsulated in conventional microporous ZIF-8 (Cyt C@ZIF-8), respectively. Meanwhile, the Km value of Cyt C@HZIF-8 significantly decreased due to the presence of mesopores compared with Cyt C@ZIF-8, indicating enhanced substrate affinity. After 7 cycles, Cyt C@HZIF-8 still maintained 70% of its initial activity whereas Cyt C@ZIF-8 only retained 10% of its initial activity. Moreover, the obtained HZIF-8 showed outstanding performance in co-immobilization of multi-enzyme for the detection of glucose.
Inevitable use of pesticides due to modern agricultural practices and the associated worldwide environmental pollution has called the special attention of the researchers to overcome the persistence, ...recalcitrance, and multi-faceted toxicity of pesticides-based emerging contaminants. Some restricted use pesticides (RUPs) are highly toxic and carcinogenic chemicals that can be easily accumulated into non-target organisms, including humans, aquatic invertebrates, algae, and microbes. With regard to physicochemical strategies, enzymes-mediated bioremediation is a compelling and meaningful strategy for biodegradation and biotransformation of pesticides into harmless chemical species. Oxidoreductases hydrolases and transferases are among the most representative classes of enzymes pursued and engineered for this purpose. Ligninolytic enzymes, particularly laccases, are of exceptional interest due to high efficiency, specificity, eco-sustainability, and wide-ranging substrates. However, the use of native enzymes is often hindered in industrial processes for the effective removal of refractory compounds by their high cost and susceptibility. Many of these drawbacks can be addressed by enzyme immobilization on some suitable support materials. Increase in stability, reusability, reduction of product inhibition, enhanced activity, specificity, and easier product separation are amid the desirable characteristics of immobilization to construct biocatalysts for continuous systems. This review summarizes recent and up-to-date literature on the use of enzymes, explicitly, free as well as immobilized laccases in the degradation of different pesticides. In the first part, source and occurrence of pesticides in the environment, their types, and associated detrimental effects on the ecosystem/human health are comprehensively described. Afterward, we highlighted the use of different enzymes with a particular emphasis on laccase for the degradation and detoxification of an array of pesticides. Finally, the review is closed with concluding remarks, and possible future direction is proposed in this very important research arena. In conclusion, it is envisioned that effective deployment of laccase-assisted biocatalytic systems for the degradation or removal of diverse pesticides and related contaminants will help to better understand the persistence and removal fate of these hazardous pollutants. Moreover, the current research thrust presented in this review will additionally evoke researcher to engineer robust and sustainable processes to remediate pesticides-contaminated environmental matrices effectively.
Display omitted
•Adverse consequences of pesticides used in agricultural settings are reviewed.•The occurrence of pesticides in the environment and their associated detrimental effects are described.•Immobilization offers tunable laccases with exceptional biocatalytic interests.•Implementation of enzyme-based systems can degrade an array of pesticides.
Bisphenol A (BPA) is a known endocrine disruptor that poses concerning environmental and human-health related issues and ecological risks. It has been largely used as an intermediate in the ...manufacture of epoxy resins and polycarbonate plastics. Traces of BPA can reach into the environment through inadequate or inefficient removal during wastewater treatment, uncontrolled landfill leachates, and leaching out from the discarded BPA-based materials. Several physicochemical treatment methods including adsorption, Fenton, ozonation, electrochemical and photochemical degradation, and membrane filtration, have been applied for BPA elimination. However, these methods are not adequate for large-scale treatment due to some inherent limitations. Benefiting from high catalytic efficiency and specificity, enzyme-based bio-catalytic degradation strategies are considered quite meaningful alternative for efficient and effective BPA removal from different routes. Among various oxidoreductases, i.e., laccases exhibited a superior potential for the remediation of BPA-containing wastewater. Enzymatic oxidation of BPA can be boosted by using various natural or synthetic redox mediators. Immobilized enzymes can expand their applicability to continuous bioprocessing and facilitates process intensification. Therefore, optimized formulations of insolubilized biocatalysts are of strategic interest in the environmental biotechnology. In this review, recent research studies dealing with BPA removal by the laccase-catalyzed system are presented. At first, the presence of BPA in the ecosystem, sources, exposure, and its impact on the living organisms and human beings is summarized. Then, we highlighted the use of crude as well as immobilized laccases for the degradation of BPA. In addition to toxicity and estrogenicity removal studies, the unresolved challenges, concluding remarks, and possible future direction is proposed in this important research area. It is palpable from the literature reviewed that free as well as immobilized forms of laccases have displayed noteworthy potential for BPA removal from wastewater.
Display omitted
•Mitigation of bisphenol A (BPA) using laccase-based bio-catalytic cues is reviewed.•Source and occurrence of BPA in the environment are described.•Environmental and human-health related risks of BPA are discussed.•Laccase-immobilized micro- and nano-4catalytic cues are robust bioremediation tools.
Manures may contain considerable amounts of organophosphates (org-P) that must be enzymatically converted to inorganic phosphate (i.e., PO4-P) to be plant available. Although adding enzymes into ...manures can facilitate mineralization of org-P to PO4-P, enzymes that are not immobilized are easily lost through leaching, degradation, or denaturation. In this study, the immobilization of enzymes onto nine different biochar surfaces was explored. Phytase, which mineralizes a main class of org-P, was used as the model enzyme. Immobilization methods included covalent grafting accomplished by the carbodiimide crosslinker method and physical sorption. The results showed that physisorption was as effective as grafting for loading phytase to the biochars. Phytase loading after mixing 0.1 g biochar and 2 mg phytase correlated positively with biochar C:H ratio (an indicator of aromatic content) suggesting the importance of the hydrophobic effect. An increase in pH led to a decrease in phytase loading consistent with repulsion between negatively charged sites on phytase and the increasing negative charge on biochar. Less than 4% of the immobilized phytase leached after sequential extractions over seven days using manure dissolve organic matter solutions. However, the activity of immobilized phytase decreased markedly compared to the free state phytase. The specific activity of immobilized phytase was two orders of magnitude lower than that of free phytase at pH 5 and 7. Nevertheless, results showed that deactivation of phytase by biochars were reversible once the phytase was detached from the surfaces. Compared to the biochars, clay minerals (montmorillonite, kaolinite and hematite) tended to have greater loading rates and higher phytase activity. Composting manures with coamendments of biochar and minerals may enhance both short- and long-term P mineralization potential.
Display omitted
•Phytase is effectively bound by physisorption with no need for covalent grafting.•Phytase loading rate is largely influenced by pH and biochar aromatic content.•Phytase binding was irreversible even in high concentrations of manure extract.•Binding to biochars reduces phytase activity more so than clay mineral tested.
PDF