Evaluation of D-amino acid oxidase from Rhodotorula gracilis for the production of alpha-keto acids: a reactor system.

The study reports on the development of a bioreactor for the production of alpha-keto acids from D,L- or D-amino acids using Rhodotorula gracilis D-amino acid oxidase. D-amino acid oxidase was co-immobilized with catalase on Affi-Gel 10 matrix, and the reactor was operated as a continuous-stirred tank reactor (CSTR) or stirred tank with medium recycling conditions. The optimum substrate concentration and quantity of biocatalyst were determined (5 mM and 1.

Structure and properties of enzyme graft copolymers: effects of using dissolved agarose on horseradish peroxidase immobilization.

The immobilization of horseradish peroxidase (HRP) onto dissolved agarose by a photochemically initiated graft copolymerization reaction, carried out at room temperature, was studied. Enzyme immobilization parameters such as the catalyst (FeCl3) and the enzyme concentration were considered. Using hexhydro-1,3,5-triacryloyl-s-triazine (HTsT) as vinyl monomer, the agarose/HTsT ratio was the main reaction parameter controlling the copolymer characteristics.

Structure and properties of enzyme graft copolymers: Temperature effects on HRP immobilization mechanism.

The possibility of obtaining immobilized horseradish peroxidase (HRP) materials with K'(m) values close to that of the native enzyme, but with good thermal stability, was investigated. The photochemical reaction was used as the immobilization methodology. Temperature and catalyst concentration were found to be the main parameters able to control the immobilization reaction mechanism more than type of functional monomer, polymer-matrix, and enzyme-polymer ratios.

Kinetic and thermal characteristics of enzyme-graft copolymers.

The characteristics of horseradish peroxidase (HRP) immobilized onto Sepharose by a photochemical-initiated graft copolymerization are presented. Active copolymers were synthesized using different amounts of glycidylmethacrylate (GMA), bisacryloylpiperazine (BAP), or 1,3,5-hexhydrotriacryloyl-(s)-triazine (HTsT) as functional monomer. The activities, the K'(m) values (pGMA) copolymers: 0.

Immobilization of glucose oxidase on sepharose by UV-initiated graft copolymerization.

The performance of a new method of enzyme immobilization based on photochemically initiated direct graft copolymerization was recently investigated. The immobilization reaction can be carried out in a simple way and by carefully selecting the reaction conditions, the enzyme-graft copolymer can be obtained as the main reaction product. Coupling efficiency of glucose oxidase has been found to depend only on the amount of photocatalyst (FeCl(3)) fixed on Sepharose used as polysaccharide support.