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Immobilized enzyme
About: Immobilized enzyme is a research topic. Over the lifetime, 15282 publications have been published within this topic receiving 401860 citations.
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TL;DR: A potentiometric enzyme electrode for the direct measurement of organophosphate (OP) nerve agents was developed and the best sensitivity and response time were obtained using a sensor constructed with 500 IU of OPH and operating in pH 8.5, 1 mM HEPES buffer.
183 citations
TL;DR: The immobilized lipase proved to be stable and lost little activity when was subjected to repeated uses and the optimum pH for free and immobilized enzyme were 6, resulting in 80% immobilization yield.
Abstract: In the present work, a novel method for immobilization of lipase within hydrophilic polyurethane foams using polyglutaraldehyde was developed for the immobilization of Thermomyces lanuginosus lipase to produce biodiesel with canola oil and methanol. The enzyme optimum conditions were not affected by immobilization and the optimum pH for free and immobilized enzyme were 6, resulting in 80% immobilization yield. Using the immobilized lipase T. lanuginosus, the effects of enzyme loading, oil/alcohol molar ratio, water concentration, and temperature in the transesterification reaction were investigated. The optimal conditions for processing 20 g of refined canola oil were: 430 μg lipase, 1:6 oil/methanol molar ratio, 0.1 g water and 40 °C for the reactions with methanol. Maximum methyl esters yield was 90% of which enzymatic activity remained after 10 batches, when tert-butanol was adopted to remove by-product glycerol during repeated use of the lipase. The immobilized lipase proved to be stable and lost little activity when was subjected to repeated uses.
183 citations
TL;DR: In this article, a fungal lipase on a unique macroporous support was demonstrated to catalyze ester synthesis in quantitative yields, employing attractive commercial conditions, and the capability of the catalyst to operate efficiently in reverse under a variety of unnatural, hostile, solvent-containing environments was discussed.
Abstract: The lipase-catalyzed synthesis of ester bonds has been well-documented lately and is of much current commercial interest. Immobilization of a fungal lipase on a unique macroporous support allows not only the ability to operate in non-aqueous media but to catalyze ester synthesis in quantitative yields, employing attractive commercial conditions. Catalyst dose and process configurations will be illustrated. The capability of the catalyst to operate efficiently in reverse under a variety of unnatural, hostile, solvent-containing environments will be discussed. The range of substrates for this immobilized lipase, Lipzome, has been investigated. The enzyme will catalyze ester synthesis with saturated, unsaturated and a variety of branched carboxylic acids. The alcohol specificity for this enzyme also is equally broad. A wide variety of straight-chain, branched and polar alcohols can be substrates. In addition, some examples of alcohol specificity for kinetic isomer resolution will be cited.
183 citations
TL;DR: The biomimetic mineralization process can be potentially used as an effective technique for realizing the entrapment of biomacromolecules and constructing efficient catalysts for industrial biocatalysis.
Abstract: Enhancing the activity and stability of enzymes and improving their reusability are critical challenges in the field of enzyme immobilization. Here we report a facile and efficient biomimetic mineralization to embed thermophilic lipase QLM in zeolite imidazolate framework-8 (ZIF-8). Systematic characterization indicated that the entrapment of lipase molecules was successfully achieved during the crystal growth of ZIF-8 with an enzyme loading of ∼72.2 ± 1.88 mg/g lipase@ZIF-8, and the enzymes could facilitate the construction of framework building blocks. Then the composite lipase@ZIF-8 was observed to possess favorable catalytic activity and stability in the ester hydrolysis, using the hydrolysis of p-nitrophenyl caprylate as a model. Finally, the composite was successfully applied in the kinetic resolution of (R,S)-2-octanol, with favorable catalytic activity and enantioselectivity during 10 cycle reactions. Thus, the biomimetic mineralization process can be potentially used as an effective technique for...
182 citations