Preparation of glucose oxidase immobilized in different carriers using radiation polymerization

Abstract

Glucose oxidase (EC 1.1.3.4) was immobilized on different polymeric materials using different immobilization techniques (entrapping by γ -irradiation, and covalent binding using epichlorohydrin). Studies were carried out to increase the thermal stability of glucose oxidase (GOD) for different applications. The activity and stability of the resulting biopolymers have been compared with those of free GOD. The effect of different polyvinyl alcohol/polyacrylamide (PVA/PAAm) compositions of the copolymer carrier on the enzymatic activity of the immobilized GOD was studied. The maximum enzymatic activity was obtained with the composition ratio of PVA/PAAm of 60:40. The behaviour of the free and immobilized enzyme was analysed as a function of pH. A broadening in the pH profile (5.5-8) was observed for immobilized preparations. The activity and stability of the resulting biopolymers produced by immobilization of GOD onto different carriers have been compared, in both aqueous and organic media, with those of the free GOD. The enzyme's tolerance toward both heat and organic solvent was enhanced by immobilization onto polymers. The addition of different concentrations of organic solvents (10-50%, v/v) to the enzyme at higher temperature (60 • C) was found to stabilize the enzyme molecule. The strongest stabilizing effect on the enzymatic activity was achieved at a concentration of 10%.

Comparison of Kinetic Profile of Free and Immobilized Glucose Oxidase, Immobilized on Low‐Density Polyethylene Using UV Polymerization

“…The same type of trend was not observed at the other treatment temperatures, 25 and 10 °C (data not shown). Similar results were reported by other researchers wherein higher K m values were explained based on the lower local concentration of substrate around the immobilized enzyme compared to the bulk concentration (Atia and others 2003; Atia and El‐Batal 2005). …”

“…The values of K m and k cat / K m at 30, 25, and 10 °C indicate that the activity or the performance of the immobilized and free enzymes is not significantly different ( P > 0.05). And the values of K m for 30, 25, and 10 °C in the range of 0.026 to 6.41 mM are close to the values reported in the literature for GOx immobilized ( K m = 5.7 ± 0.19 at 25 °C, pH 6) by other immobilization techniques such as covalent immobilization (Atia and El‐Batal 2005). Specifically, at optimum conditions (35 °C and pH 5.1), the K m values obtained for UV immobilized GOx (data not shown) were less than the values obtained for immobilized GOx reported in literature.…”

“…The effects of immobilization on enzyme activity and the kinetic parameters of GOx have been studied previously (Bao and others 2001; Brahim and others 2002). Researchers found that immobilization such as entrapment and covalent attachment slightly affect the catalytic ability of the enzyme (based on the comparison of Michaelis constant [ K m ] and catalytic efficiency [ k cat / K m ]) but provides higher thermal stability and reusability to enzymes (Sungur and others 2004; Atia and El‐Batal 2005). …”

The growth of Scenedesmus sp. attachment on different materials surface

“…As shown in Figure 4, some of the active microalgae protein in the outer of the cell wall, for example alkylation of the amino group supplied free electrons to the supporting materials [11–13]. Therefore, the ability of accepting electrons directly determined the attachment of microalgae onto the supporting surface.…”

Simple and reliable biosensor for determination of glucose in alcoholic beverages

“…Campanella, Persi, Sammartino, and Tomasseti (1998b) prepared the OPEE glucose oxidase biosensor immobilized in kappaCarrageenan gel for measurements in aqueous media with chloroform (0.09%), ethyl acetate (1.5%) and acetonitrile (2.5%). Influence of different solvents (methanol, ethanol, isopropanol acetonitrile, n-butanol, dioxane, tetrahydrofuran) on GOx based OPEEs have been studied by Kröger, Setford, and Turner (1998), Adányi et al (2004) and Atia and El-Batal (2005).…”