In this study we report the use of functionalized carbon-based nanomaterials, such as amine-functionalized graphene oxide (GO) and multi-walled carbon nanotubes (CNTs), as effective immobilization supports for various lipases and esterases of industrial interest. Structural and biochemical characterization have revealed that the curvature of the nanomaterial affect the immobilization yield, the...

A partially purified phophotriesterase was successfully immobilized onto nylon 6 and 66 membranes, nylon 11 powder, and nylon tubing. Up to 9000 U of enzyme activity was immobilized onto 2000 cm2 of a nylon 6 membrane where 1 U is the amount of enzyme necessary to catalyze the hydrolysis of 1.0 mumol of paraoxon/min at 25 degrees C. The nylon 66 membrane-bound phosphotriesterase was characteriz...

A torus reactor was used to perform hydrolysis of casein with a protease immobilized on beads. Chitosan beads with two different sizes were tested as immobilization matrices. The mechanical resistance of beads in the torus reactor was tested for different times and rotation speeds. Chitosan beads were considered to be suitable as an immobilizing support. The more stable hydrolysis rates in succ...

We describe a novel fluorometric technique for simple, rapid, and economical assay of glucose by use of immobilized glucose oxidase and peroxidase. A cylindrical magnetic stirrer was specially designed to hold the immobilized enzymes firmly and to allow the reaction minzymic transformation quickly. Blood plasma can be assayed directly with no pretreatment. Ascrobic acid, uric acid, and creatini...

We present a rate-determination method for analyzing glucose. A glucose enzyme electrode serves as the sensor and is made by placing a gel-immobilized layer of glucose oxidase over the tip of a Clark-type O2 electrode. The electrode membrane is made of Teflon and is derivatized by etching with a suspension of colloidal sodium metal in organic solvent. The enzyme is coupled to the membrane surfa...

Enzyme-based biofuel cells are attracting attention rapidly partially due to the promising advances reported recently. However, there are issues to be addressed before biofuel cells become competitive in practical applications. Two critical issues are short lifetime and poor power density, both of which are related to enzyme stability, electron transfer rate, and enzyme loading. Recent progress...

This paper reports the covalent immobilization of penicillin G acylase from E. coli on sepabeads EC-EP, an epoxy-activated polymethacrylic carrier, and describes kinetic properties of the immobilized enzyme. The selected enzyme belongs to a class of biocatalysts whose industrial interest is due to their versatility to mediate hydrolysis of penicillins and semi-synthetic β−lactam antibiotics syn...

Chitosan is an attractive natural biopolymer from renewable resources with the presence of reactive amino and hydroxyl functional groups in its structure. Due to the good biocompatibility of chitosan, it can be used in magnetic-field assisted drug delivery, enzyme or cell immobilization and many other industrial applications. In the past decade, nanotechnology has been a considerable research i...

The thermal and solvent tolerance of enzymes is highly important for their industrial use. We show here that the enzyme lipase from Rhizopus oryzae exhibits exceptionally high thermal stability and high solvent tolerance and even increased activity in acetone when immobilized onto a graphene oxide (GO) nanosupport prepared by Staudenmaier and Brodie methods. We studied various forms of immobili...

The effect of glutaraldehyde on the conformational properties of Kluyveromyces lactis β-galactosidase was determined. The optimum substrate of the enzyme interchanged from lactose to sucrose when it reacted with a certain concentration of glutaraldehyde. Its mechanism was studied by detecting the changes in fluorescence absorption. This is the first discovery that β-galactosidase can be convert...