Agarose beads containing immobilized enzymes or affinity ligands have been made magnetically responsive by adsorbing freshly precipitated magnetite on their surface. These beads are used for affinity adsorption of proteins from complex mixtures containing suspended solids. The magnetically responsive beads and the unwanted (diamagnetic) solids are then separated by magnetic filtration. This mag...

In this paper, the stabilization of a lipase from Bacillus thermocatenulatus (BTL2) by a new strategy is described. First, the lipase is selectively adsorbed on hydrophobic supports. Second, the carboxylic residues of the enzyme are modified with ethylenediamine, generating a new enzyme having 4-fold more amino groups than the native enzyme. The chemical amination did not present a significant ...

Background Trypsin is an enzyme widely used for digestion of peptides in proteomic research. However, this enzyme is one of the least stable of the neutral proteases and presents rapid autolysis, which causes a decrease in catalytic efficiency and a consequential increase in costs of biotechnological process. Immobilization of the enzyme offers the advantages of enhanced stability, protection a...

The aim of this work was to assess the possibility of using native bacterial nanocellulose (BC) as a carrier for laccase immobilization. BC was synthesized by Gluconacetobacter xylinus, which was statically cultivated in a mannitol-based medium and was freeze-dried to form BC sponge after purification. For the first time, fungal laccase from Trametes versicolor was immobilized on the native nan...

We studied the immobilization of a recombinant thermostable lipase (Pf2001Δ60) from the hyperthermophilic archaeon Pyrococcus furiosus on supports with different degrees of hydrophobicity: butyl Sepabeads and octadecyl Sepabeads. The enzyme was strongly adsorbed in both supports. When it was adsorbed on these supports, the enzyme showed 140 and 237% hyperactivation, respectively. The assessment...

β-Galactosidase was immobilized on chitosan-coated magnetic Fe3O4 nanoparticles and was used to produce galactooligosaccharides (GOS) from lactose. Immobilized enzyme was prepared with or without the coupling agent, tris(hydroxymethyl)phosphine (THP). The two immobilized systems and the free enzyme achieved their maximum activity at pH 6.0 with an optimal temperature of 50 °C. The immobilized e...

Because the cholesterol oxidase from Brevibacterium sp. M201008 was not as stable as the free enzyme form, it had been covalently immobilized onto chemically modified Sepharose particles via N-ethyl-N'-3-dimethylaminopropyl carbodiimide. The optimum immobilization conditions were determined, and the immobilized enzyme activity obtained was 12.01 U/g Sepharose-ethylenediamine. The immobilization...

A thermostable β-glucosidase was effectively immobilized on alginate by the method of gel entrapment. After optimization of immobilized conditions, recovered enzyme activity was 60%. Optimum pH, temperature, kinetic parameters, thermal and pH stability, reusability, and storage stability were investigated. The K m and V max for immobilized β-glucosidase were estimated to be 5.0 mM and 0.64 U/ml...

Analysis of immobilized enzyme in situ is a crucial step to embed an enzyme onto the planar technology of standard integrated circuit (IC) and microelectromechanical systems (MEMS) for a bioreactor or enzyme-coupled biosensor. A surface reaction limited model, based on a systematized and standardized approach, mathematically derived from mass transfer dynamics and the Michaelis-Menten equation ...

The enzyme creatine amidinohydrolase is a clinically important enzyme used in the determination of creatinine in blood and urine. Continuous use biosensors are becoming more important in the clinical setting; however, long-use creatinine biosensors have not been commercialized due to the complexity of the three-enzyme creatinine biosensor and the lack of stability of its components. This paper,...