39 results about "Oxalate oxidase" patented technology

The invention discloses a genetically engineered bacterium for recombinantly expressing oxalate oxidase, its construction method and application, and relates to the field of genetic engineering. The method for constructing the genetically engineered bacteria comprises the following steps: optimizing the oxalate oxidase gene derived from Cerexinus worms according to the codon preference of Trichoderma reesei to obtain the optimized gene of oxalate oxidase; knocking out Trichoderma reesei The pyr4 gene and mus53 gene in the genome were used to construct a mutant strain of Trichoderma reesei with simultaneous deletion of the pyr4 gene and mus53 gene; the optimized gene of oxalate oxidase was used to construct a recombinant expression vector; the vector for recombinant expression of oxalate oxidase was used to transform T. reesei A mutant strain of the mold pyr4 gene and mus53 gene deletion at the same time is obtained to obtain a genetically engineered bacterium expressing oxalate oxidase recombinantly. The genetically engineered bacterium of the invention can efficiently express the oxalate oxidase with natural activity, and is suitable for the research and development of recombinant oxalate oxidase medicines and the production of low-oxalate foods and beverages.

The invention relates to an electrochemical biosensor for detecting oxalic acid concentration, and preparation and application thereof. Oxalic acid oxidase is fixed on the surface of part of reduction-oxidation grapheme, a dispensing method is adopted to enable immobilized oxalic acid oxidase to be decorated on the surface of a glassy carbon electrode, and the electrochemical biosensor based on decoration of oxalic acid oxidase and part of reduction-oxidation grapheme is formed. The glassy carbon electrode serves as a working electrode, and a difference volt-ampere pulse method is adopted to detect the oxalic acid concentration. The biosensor has good electro-catalysis activity on oxalic acid. Along with increase of the immobilization amount, the electro-catalysis activity is reinforced. The detection range of the electrode is wide, and the electrode has low detection lower limit and responds rapidly.

The invention discloses an Escherichia coli expression system for producing oxalate oxidase, a production method of oxalate oxidase and application thereof. The recombinant expression plasmid in the Escherichia coli expression system comprises: an oxalate oxidase gene, a molecular chaperone gene and a gene for promoting manganese ion pumping into Escherichia coli cell-related proteins. The present invention obtains the optimal expression of oxalate oxidase by screening and testing the genes and copy numbers of different manganese ion-related proteins, the type of promoters controlling the expression of molecular chaperones, and the type of medium used in the production process of oxalate oxidase Combined, the expression activity of oxalate oxidase in Escherichia coli exceeds 80U / mL. The specific activity of the oxalate oxidase preliminarily purified from the supernatant of the cell disruption liquid is greater than 20 U / mg, and the molecular weight of the monomer is about 25 kDa. The technical scheme of the invention has the advantages of simple production and purification process, high expression amount and specific activity, easy industrial scale-up, low cost, and favorable industrial production and application of this type of enzyme.

The invention relates to a simple method for determining oxalic acid concentration. The method comprises the following steps: (1) reacting synthetic 3NO ligand with manganese perchlorate to prepare a manganese complex; (2) reacting the prepared metal manganese complex with standard hydrogen peroxide sample with concentration being 1-400 mum, determining absorbance of the reaction product at the wavelength being 450 nm, and making a standard curve of absorbance of the standard hydrogen peroxide sample at the wavelength being 450 nm; (3) reacting oxalic acid sample having unknown concentration with excessive oxalate oxidase, and decomposing the oxalic acid into equal amount of hydrogen peroxide; and (4) reacting the product of the step (3) with the metal complex prepared in the step (1), determining the absorbance of the product at the wavelength being 450 nm, and comparing with the standard curve of the absorbance of the standard hydrogen peroxide sample at the wavelength being 450 nm to obtain the concentration of the oxalic acid in the sample. The method has the advantages of simple step, high flexibility, low cost and short time.