Journal Article•
Enhancement of glucose isomerase activity by immobilizing on silica/chitosan hybrid microspheres B Enzymatic
TL;DR: In this article, the enzyme activity was found to be above 90% with a wide pH range of 5.8-8.0, temperature range of 40-80°C, storage range of 3 months and an increase in operation range of >15 times.
About: This article is published in Journal of Molecular Catalysis.The article was published on 2016-01-01 and is currently open access. It has received 23 citations till now. The article focuses on the topics: Glucose-6-phosphate isomerase & Chitosan.
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TL;DR: A general overview of the characteristics and properties of the materials applied for enzyme immobilization can be found in this article, where support materials are divided into two main groups, called Classic and New materials.
Abstract: In recent years, enzyme immobilization has been presented as a powerful tool for the improvement of enzyme properties such as stability and reusability. However, the type of support material used plays a crucial role in the immobilization process due to the strong effect of these materials on the properties of the produced catalytic system. A large variety of inorganic and organic as well as hybrid and composite materials may be used as stable and efficient supports for biocatalysts. This review provides a general overview of the characteristics and properties of the materials applied for enzyme immobilization. For the purposes of this literature study, support materials are divided into two main groups, called Classic and New materials. The review will be useful in selection of appropriate support materials with tailored properties for the production of highly effective biocatalytic systems for use in various processes.
580 citations
Cites background from "Enhancement of glucose isomerase ac..."
...The relative activity of the enzyme was found to be above 90% over a wide pH range of 6–8, a temperature range of 40–80 ◦C, a storage time of 3 months and after 15 repeated catalytic cycles [185]....
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TL;DR: In this paper, aldose-ketose interconversion reactions have been studied in terms of yields, catalysts, solvents, catalytic systems, etc., by both enzymatic and chemo-catalytic approaches.
Abstract: The well-known interconversion of aldoses to their corresponding ketoses was discovered more than a century ago, but has recently attracted renewed attention due to alternative application areas. Since the pioneering discovery, much work has been directed toward improving the process of isomerization of aldoses in terms of yields, catalysts, solvents, catalytic systems, etc., by both enzymatic and chemo-catalytic approaches. Among aldose–ketose interconversion reactions, fructose production by glucose isomerization to make high-fructose corn syrup (HFCS) is an industrially important and large biocatalytic process today, and a large number of studies have been reported on the process development. In parallel, also alternative chemo-catalytic systems have emerged, as enzymatic conversion has drawbacks, though they are typically more selective and produce fructose under mild reaction conditions. Isomerization of glucose is also a central reaction for making renewable platform chemicals, such as lactic acid, ...
136 citations
TL;DR: In this article, the effects of enzyme immobilization on reusability, physical, kinetic and thermodynamic parameters were considered, and the effect of enzymes on organic and organic-inorganic hybrid nano-supports were compared.
99 citations
TL;DR: This review provides an overview of various carriers for enzyme immobilization, with the primary focus on food industry.
Abstract: 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.
96 citations
01 Jan 2017
TL;DR: In this paper, the environmental and geopolitical legacy of the petroleum era as well as its impact on human society are thoroughly discussed in order to highlight seriousness of those issues and the necessity for an alternative sustainable economic model for the future.
Abstract: During the industrial revolution of the nineteenth century, the use of coal as fuel set the “train” of progress in motion, which definitely induced a significant improvement in the living standards. After several discoveries, inventions, and innovations, the use of crude oil, the so-called black gold, enabled humanity to reach a higher level of prosperity, especially so between the end of the second World War and the oil embargo crisis. Currently, crude oil is the most traded commodity in the world market and is the main feedstock to produce a wide range of fuels and products such as plastics, textile fibers, dyes, etc. The heavy reliance on petroleum and other fossil fuels for decades caused many environmental disasters around the world and major geopolitical tensions especially in oil-producing countries. In this chapter, the environmental (water, soil, and air) and geopolitical legacy of the petroleum era as well as its impact of human society are thoroughly discussed in order to highlight seriousness of those issues and the necessity for an alternative sustainable economic model for the future.
54 citations
References
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TL;DR: Results show that the cellulase chemically linked to MSN exhibiting carboxyl groups and a large pore size could achieve an effective cellulose-to-glucose conversion exceeding 80% yield and excellent stability.
139 citations
TL;DR: Two new electron-rich molecules, 2,3,4,5-tetra[4,4'-bis(methoxyphenyl)aminophen-4"-yl]-thiophene (H111) and 4,4',5,5'-tetRA[4,'"yl]-2,2,'"bithiophene" (H112), which contain thiophene cores with arylamine side groups, are reported.
Abstract: Two new electron-rich molecules, 2,3,4,5-tetra[4,4'-bis(methoxyphenyl)aminophen-4 ''-yl]-thiophene (H111) and 4,4',5,5'-tetra[4,4'-bis(methoxyphenyl) aminophen-4 ''-yl]-2,2'-bithiophene (H112), which contain thiophene cores with arylamine side groups, are reported. When used as the hole-transporting material (HTM) in perovskite-based solar cell devices, power conversion efficiencies of up to 15.4% under AM 1.5G solar simulation were obtained. This is the highest efficiency achieved with HTMs not composed of 2,2',7,7'-tetrakis(N,N'-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) and its isomers. Both HTMs, especially H111, have great potential to replace expensive spiro-OMeTAD given their much simpler and less expensive syntheses.
133 citations
TL;DR: Candida antarctica lipase B immobilization by covalent attachment on chitosan and on ch itosan–alginate complex previously activated by different strategies was studied.
130 citations
TL;DR: An adaptation of the state-of-the-art AI-based robust optimization technique, non-dominated sorting genetic algorithm with jumping genes (NSGA-II-JG) is used in finding the Pareto solutions for both the existing as well as SMBR system at the design stage.
91 citations
TL;DR: The synthesis and application of different enzyme-immobilized MSNs for multistep cellulose-to-fructose conversion in an aqueous solution is demonstrated and showed great potential as a green biocatalyst with high working efficacy and enhanced stability.
Abstract: Fructose, an isomer of glucose, is widely used as a sweetener or as high-fructose corn syrup (HFCS) in the food industry, because fructose is the sweetest sugar in nature and its sweetening capacity is twice that of sucrose. Recently, other than as a sweetener, fructose has been considered as a renewable energy resource derived from lignocellulosic biomass. Fructose can be converted easily into 5-hydroxyfurfural (HMF), which is a versatile platform for biofuels such as 2,5-dimethylfuran (DMF). Three major approaches have been widely used in cellulosic conversion, and they are physical (e.g. , high temperature and pressure), chemical (e.g. , strong acid treatment), and biological procedures. Although the physical and chemical processes have shown their efficacy to a certain extent, these processes are energy consuming and produce many byproducts. 5] On the contrary, enzyme-based biological processes are performed under mild conditions with high specificity for one product. Therefore, enzyme-assisted cellulosic conversion is an alternative green approach that reduces experimental costs, inhibits unwanted byproducts, and elevates reaction efficiency and specificity. The maintenance of enzyme activity upon reaction and the recyclability of the enzyme after the reaction are two big issues in enzymatic reactions. To overcome these problems while keeping the advantages of enzymes, immobilization of enzymes on a suitable host material has been considered as a good solution, because immobilization can offer several advantages, including repeated use, ease of separation from the product, alteration of the properties of the enzyme, improved stability of the enzyme, and easy storage. For example, several solid materials, such as amorphous silica or agarose gel, have been used as host materials for the immobilization of enzymes. In addition, mesoporous silica materials have also been used as potential host materials for the immobilization of enzymes owing to their large surface areas, adjustable pore sizes, and diverse surface functionalities. 9] We previously synthesized mesoporous silica nanoparticles (MSNs) and used them to immobilize cellulase through physical adsorption and chemical binding for cellulose-to-glucose conversion. The cellulase-immobilized MSNs showed great potential as a green biocatalyst with high working efficacy and enhanced stability. However, as with our previous report, most of the enzyme-related papers report single-step reactions with the use of a single enzyme-immobilized catalyst. For multistep reactions such as cellulose-to-fructose conversion, it is necessary to use more than one enzyme. In this study, we demonstrate the synthesis and application of different enzyme-immobilized MSNs for multistep cellulose-to-fructose conversion in an aqueous solution, as shown in Scheme 1. Because each enzyme has its own optimal reaction conditions, we separately immobilized cellulase and isomerase into MSNs instead of their
82 citations