Activity Of Immobilized Cellulase Research Articles

Preliminary Study of Immobilized of Cellulase in Silica from the Rice Husk Ash to Hydrolysis Sugarcane Bagasse

Cellulase in the production of bioethanol from sugarcane bagasse is used to hydrolyze cellulose into reducing sugars. Cellulase needs to be mobilized in a matrix to improve its efficiency because it can be used repeatedly. The purpose of this study was to conduct a preliminary study of potential cellulase immobilized on silica to hydrolyze sugarcane bagasse including the effect of contact time (15, 45, 60, and 75 minutes) and agitation speeds (50, 100, 150, and 200 rpm) on % immobilization and immobilized cellulase activity against sugarcane bagasse, and also decreased activity of immobilized cellulase after repeated use. Contact time and agitation speeds do not affect % immobilization. The optimum contact time and agitation speeds of immobilized cellulase formation based on its activity were at 15 minutes and 100 rpm. Immobilized cellulase activity in cycles II and III decreased to 75.2% and 58.8% compared to the first cycle. Therefore, immobilized cellulase in silica is good enough to hydrolyze sugarcane bagasse and has the potential to be applied as continue system in the production of bioethanol from sugarcane bagasse.

Investigation of nanoparticle immobilized cellulase: nanoparticle identity, linker length and polyphenol hydrolysis

Cellulase containing nanobiocatalysts have been useful as an extraction tool based on their ability to disrupt plant cell walls. In this work, we investigate the effect of nanoparticle composition and chemical linkage towards immobilized cellulase activity. Cellulase nanoconstructs have been prepared, characterized and compared for their loading efficiencies with standard assays and enzyme kinetics and correlate well with the cognate loading efficiencies. Application of the cellulase-immobilized nanoparticles on onion skins results in release of a distinctive composition of polyphenols. The aglycosidic form of quercetin is the dominant product of onion skin hydrolysis affected by cellulase nanobiocatalysts. Chitosan-coated iron oxide nanoparticles with APTES-conjugated cellulase are found to be most effective for polyphenol release and for transformation of glycosidic to aglycosidic form of quercetin. These results shed light on the activity of immobilized cellulase beyond their role in cell wall disruption and are important for the practical application of cellulase nanobiocatalysts.

Comparing Immobilized Cellulase Activity in a Magnetic Three-Phase Fluidized Bed Reactor under Three Types of Magnetic Field

A novel, magnetic three-phase fluidized bed reactor (MTFBR) was designed with magnetic immobilized cellulase (MIC) as the biocatalyst for preparing chitooligosaccharides from chitosan. The MIC showed higher enzyme activity in a pulse magnetic field (PMF) than that in a steady magnetic field (SMF) or alternating magnetic field (AMF) under certain operating parameters. The application of a magnetic field increased the maximum reaction rate (Vmax) and Michaelis constant (Km), and the reaction rates of the MIC-catalyzed reaction in PMF and SMF at high concentration of chitosan solution (Cs, 5 < Cs < 20 mg/mL) increased as the intensity of the magnetic field increased. The concentrations of chitosan pentamer and hexamer produced were higher in the PMF than in the SMF and AMF, and the application of a magnetic field greatly reduced (by as much as 37.5%) the biocatalytic reaction time required to reach the maximum concentration of the desired chitooligosaccharides. These results suggest that the customized MTFBR...

Adsorption, immobilization and activity of cellulase in soil: the impacts of maize straw and its humification

The present work aimed to study some aspects of sorption and immobilization of cellulase molecules on soil components by the analysis of the reactions of cellulase in a soil treated with different levels of maize residue and incubated for 90 days. The analysis of variance showed that the effects of the treatments of maize straw, incubation time and their interaction on cellulase adsorption, desorption and immobilization were statistically significant. The adsorption and immobilization capacities of soil by application of maize straw increased significantly. However they decreased with decreasing the soil organic matter (SOM) after 45 days of incubation. The desorption of adsorbed cellulase molecules from the soil by washing with distilled water depended on the SOM contents and its humification. The binding strength of cellulase molecule with fresh miaze straw was significantly stronger than that with humified maize straw. The immobilized cellulase activity, particularly its specific activity increased significantly by increasing the OC contents in the soil treated with maize straw.

Effects of low intensity ultrasound on cellulase pretreatment

This research was to explore the mechanism of ultrasonic impact on free cellulase activity and immobilize cellulase activities. The highest free cellulase activity was achieved when the sample was treated with low intensity ultrasound at 15W, 24kHz for 10min, under which the enzyme activity was increased by 18.17% over the control. Fluorescence and CD spectra revealed that the ultrasonic treatment had increased the number of tryptophan on cellulase surface slightly, with the deformation of certain number of α-helix structure and increase of random coil content in cellulase protein. The highest immobilized cellulase activity was achieved when the sample was treated with low intensity ultrasound at 60W, 24kHz for 10min, under which the enzyme activity was increased by 24.67% over the control. Scanning electron microscopy revealed that the ultrasonic treatment had increased the surface area of immobilized cellulase.

The effects of carbonates removal on adsorption, immobilization and activity of cellulase in a calcareous soil

Enzymes are able to be sorbed and immobilized by clay minerals and humic colloids in soil environments. The present study was done to elucidate the effects of soil innate carbonates on the sorption, immobilization and activity of cellulase in a calcareous soil by treating it with different levels of acetic acid. The study of adsorption isotherm revealed that soil carbonates removal with acetic acid increased the intensity of cellulase adsorption (1/n) estimated by the Freundlich model. Based on the Freundlich isotherm model it is predicted that cellulase molecules will be increasingly adsorbed on acetic acid treated soil with increasing cellulase concentration. However, practically the amounts of cellulase protein adsorbed and immobilized on untreated soil with high levels of ECC were significantly higher than those on acetic acid treated soils. The immobilized cellulase activity and particularly its specific activity decreased considerably with increasing carbonate contents in soil.

The effects of CaCO3 on adsorption, immobilization and activity of cellulase in a decarbonated soil

The interaction of organic molecules with mineral surfaces is a subject of interest in a variety of disciplines. The present study was done to elucidate some aspects of sorption and immobilization of cellulase on soil components by analysis of the sorption, desorption, immobilization and activity of cellulase on a decarbonated soil treated with different levels of CaCO3 (0, 2.5, 10 and 20 %). Applied concentrations of cellulase protein on Ca-homoionized soil suspensions were 0, 0.014, 0.028, 0.070, 0.140, 0.280, 0.701, 0.981 and 1.402 mg mL-1. After shaking for 1 h in sterile conditions, they were centrifuged and the amount of the cellulase protein remaining in solution was determined. The adsorbed cellulase protein was calculated. The immobilized and desorbed cellulase proteins were calculated after washing soil suspensions thrice with distilled water. Analysis of variance showed that the effects of the enzyme concentration, CaCO3 level and their interaction on cellulase protein adsorption and activity were statistically significant. The adsorption and immobilization capacities of the decarbonated soil increased by application of CaCO3. However, these effects of CaCO3 were only significant when high concentrations of cellulase protein were added to the soil. The desorption of cellulase protein from the decarbonated soil did not depend on the amount of cellulase adsorbed on the soil and the CaCO3 level in the soil. The immobilized cellulase activity, and particularly its specific activity, decreased considerably by increasing CaCO3 levels in the soil. This negative effect of CaCO3 on the cellulase specific activity in the decarbonated soil was significant even for low levels.

흡착법에 의한 Fomitopsis pinicola 유래 cellulase의 고정화와 그에 따른 효소특성 변화

Formiptosis pinicola KMJ812에 의해 생산된 조효소액은 섬유소 분해효소 복합체로서 매우 활성이 높으며 특히 <TEX>${\beta}$</TEX>-glucosidase의 활성이 높아 포도당 전환수율이 높다. 본 연구에서는 F. pinicola KMJ812 생산 cellulase를 고정화에 따른 효소특성의 변화와 고정화 효소의 재사용에 따른 효소의 불활성 정도를 관찰하였다. 담체는 고정화 수율이 cellulase활성 61.7%와 <TEX>${\beta}$</TEX>-glucosidase활성 64.4%로 우수한 Duolite A568로 선정하였다. 고정화 효소의 최적반응온도는 cellulase와 <TEX>${\beta}$</TEX>-glucosidase 활성의 경우 모두<TEX>$55^{\circ}C$</TEX>로서 수용성효소보다 높았으며, 최적 pH는 cellulase활성은 4.0이었고, <TEX>${\beta}$</TEX>-glucosidase활성은 4.5로 cellulase활성의 경우에서만 수용성효소와 비교하여 약간 염기성으로 변화하였다. 본 고정화 효소는 <TEX>$50^{\circ}C$</TEX>에서 72시간 후에 98%의 활성을 유지하고 있었으며, <TEX>$50^{\circ}C$</TEX>에서 8회 사용 후에 50%정도의 잔존활성을 나타내었다. Cellulase from Formiptosis pinicola KMJ812 is an efficient cellulose degradation enzyme complex, especially with a high <TEX>${\beta}$</TEX>-glucosidase activity. In this study, the change in enzymatic characteristics by immobilization and the reduction of immobilized enzyme activity by repeated usages were evaluated using cellulases from F. pinicola KMJ812. Among tested four resins, Duolite A568 resin had the best enzyme activity yield with 61.7% cellulase activity and 64.4% <TEX>${\beta}$</TEX>- glucosidase activity during the cellulase immobilization. The best reaction temperature was <TEX>$55^{\circ}C$</TEX> for both cellulase and <TEX>${\beta}$</TEX>-glucosidase activities which were higher than the unimmobilized soluble cellulases. The best reaction pH was 4.0 for cellulase activity which was a little more basic than a soluble form and 4.5 for <TEX>${\beta}$</TEX>-glucosidase activity. The immobilized cellulase activity was remained 98% of the beginning activity after 72 h incubation at <TEX>$50^{\circ}C$</TEX> and 50% of the beginning activity after eight times usage at <TEX>$50^{\circ}C$</TEX>.