19 results about "NADH oxidase" patented technology

The invention belongs to the technical field of biology, and particularly relates to a method for producing xylitol through two-step enzyme catalysis of hemicellulose hydrolysate, and the method comprises the following steps: taking hemicellulose hydrolysate as a raw material, adding arabinose dehydrogenase, NADH oxidase and coenzyme NADH, and carrying out first-step fermentation until no L-arabinose residue exists in fermentation liquor to obtain fermentation reaction liquor I; and adding xylose reductase and glucose dehydrogenase into the fermentation reaction liquid I, and carrying out second-step fermentation to obtain a fermentation product containing xylitol. According to the two-step enzyme catalysis method provided by the invention, xylitol is prepared, and high-purity xylose does not need to be used as a raw material; according to the present invention, the cheap hemicellulose hydrolysate can be directly adopted as the raw material, the xylose conversion rate and the xylitol yield can exceed 99%, the impurity arabitol content in the product is low, the other impurity saccharic acid is easy to separate, and the problems of complex process, large separation difficulty and high cost in the xylitol refining process are successfully solved.

The invention belongs to the technical field of catalyst materials, and particularly relates to a catalyst material integrated with Au-Ir cascade catalytic sites as well as a preparation method and application of the catalyst material. The catalyst material comprises micron-sized urchin-like carbonaceous particles loaded with cascaded Au clusters and Ir monatomic materials, and the micron-sized urchin-like carbonaceous particles have glucose oxidase-like activity, oxidases-like activity, peroxidase-like activity and NADH oxidase-like activity, so that metabolic inhibition can be combined with reactive oxygen attack to eliminate stubborn dental caries related biological membranes.

The present invention discloses a mutant of reduced coenzyme NADH oxidase and its application. In the mutant, at least one amino acid at positions 156, 158, and 294 in the amino acid sequence shown in SEQ ID No. 1 is replaced; glycine Gly at position 156 is mutated to alanine Ala, isoleucine Ile at position 158 is mutated to histidine His, and isoleucine Ile at position 294 is mutated to phenylalanine Phe. By mutating the active site of NADH oxidase, the mutant finally obtained by the present invention improves the regeneration efficiency of reducing coenzyme NADH to oxidized coenzyme NAD+.

This invention discloses an enzyme preparation for catalytic synthesis of epiinositol and a method for synthesizing epiinositol, belonging to the field of genetic engineering technology. The enzyme preparation includes squalinositol dehydrogenase, NADH oxidase, formate dehydrogenase, and muscle inositol dehydrogenase; the amino acid sequence of squalinositol dehydrogenase is shown in SEQ ID NO. 6, and the amino acid sequence of muscle inositol dehydrogenase is shown in SEQ ID NO. 8. The enzyme activities of the squalinositol dehydrogenase mutant and the muscle inositol dehydrogenase mutant obtained by mutation in this invention are significantly increased, thus further improving the yield and conversion rate of epiinositol during catalytic synthesis. Furthermore, the enzyme preparation of this invention also contains NADH oxidase and formate dehydrogenase, achieving in-situ regeneration of NADH, thereby effectively reducing the amount of cofactors and NADH used in the catalytic synthesis of epiinositol, and thus reducing production costs.

The invention discloses recombinant escherichia coli for producing D-tagatose by using redox enzyme driven by cofactor regeneration as well as a construction method and application of the recombinant escherichia coli, and belongs to the technical field of biological engineering. The method comprises the following steps: introducing xylose reductase xyrB, glucose dehydrogenase Gox2015, galactitol dehydrogenase RlGDH mutant T193G / G98C and water-producing NADH oxidase SpNox into escherichia coli, so as to construct recombinant escherichia coli; according to the method disclosed by the invention, a way for synthesizing the D-tagatose by regenerating and driving oxidoreductase through cofactors is designed and constructed, and lactose in whey can be completely converted into the D-tagatose and sodium gluconate by combining the way with beta-galactosidase, so that high-valued utilization of a dairy product processing by-product whey is realized.

The invention relates to the technical field of biology, in particular to an engineering strain of zymomonas mobilis for high-yield acetoin and application of the engineering strain. The engineering strain is characterized in that Zymomonas mobilis ZM4 delta pdc-BDO is taken as an original strain, a ZMO0038 gene is replaced by an NADH oxidase gene noxE, a 2, 3-butanediol dehydrogenase gene bdh is knocked out, and potential reductase genes outside two conventional knowledge systems, namely ZMO0318 and ZMO1576, are further knocked out, so that the engineering strain capable of producing acetoin at high yield is obtained. When the strain is fermented in typical non-grain biomass raw materials with complex components, about 80% of production capacity can still be maintained, and the strain shows good potential for industrial production by utilizing renewable lignocellulose biomass.

The invention provides an NADH oxidase mutant with improved enzyme activity. Compared with the amino acid sequence as shown in SEQ ID NO: 1, the NADH oxidase has the advantages that the amino acid sequence is more stable; the amino acid sequence has substitution mutation at any one position, any two positions, any three positions, any four positions, any five positions, any more than six positions, any more than seven positions or all eight positions of the 120th position, the 152nd position, the 157th position, the 158th position, the 176th position, the 181th position, the 183th position and the 239th position.

The application belongs to the technical field of catalyst materials, and particularly relates to a catalyst material integrated with Au-Ir cascade catalytic sites and a preparation method and application thereof. The catalyst material comprises micron-scale urchin-like carbonaceous particles loaded with cascade Au clusters and Ir monatomic material, has glucose oxidase-like activity, oxidase-like activity, peroxidase-like activity and NADH oxidase-like activity, and can combine metabolic inhibition and active oxygen attack to eliminate stubborn caries-related biofilms.

The invention relates to the technical field of gene engineering, and discloses a method for biosynthesizing butanone alcohol, which is characterized in that 1, 3-butanediol is used as a substrate to produce recombinant escherichia coli of butanone alcohol, and the escherichia coli expresses acetoin reductase, NADH oxidase and hemoglobin through plasmids. According to the method for biologically synthesizing the butanone alcohol, the butanone alcohol is generated by carrying out whole-cell catalysis on the modified escherichia coli from 1, 3-butanediol, so that the green and efficient industrial production of the butanone alcohol is achieved. According to the engineering strain for producing the butanone alcohol by taking 1, 3-butanediol as a substrate, acetoin reductase, NADH oxidase and hemoglobin are subjected to free expression through plasmids, a combination with high butanone alcohol yield and high butanone alcohol conversion rate is screened, the acetoin reductase, the NADH oxidase and the hemoglobin are integrated through a genome, so that protein is stably expressed, and the high yield and stability of the butanone alcohol are achieved.

One embodiment of the present disclosure addresses the problem of providing a novel NADH oxidase.　Embodiments of the present disclosure relate to: an NADH oxidase having amino acid sequence identity of not less than 70% with any amino acid sequence from among SEQ ID NOs: 1, 3, 5, 7, 9, 11, 13, 15, 17, 74, 76, and 78; an N-terminal domain deleted variant of the same; an amino acid substituted variant of the same; and a freeze dried sample, a kit, and an electrode which include the same; a sensor comprising the electrode; and an NADH measurement method using the NADH oxidase.

The invention provides a metal monatomic nano enzyme and application thereof. The metal monatomic nano-enzyme comprises graphene, a nitrogen atom and a metal monatomic, the metal monatomic is anchored on the graphene through the nitrogen atom, and a metal-nitrogen active site is formed. The nano-enzyme disclosed by the invention has relatively high NADH oxidase-like activity, so that the nano-enzyme plays a role in improving dermatitis and promoting skin regeneration or healing.

This invention belongs to the field of catalytic materials technology, specifically relating to a porous carbon biocatalytic material loaded with rhodium-iron bimetallic active sites, its preparation method, and its applications. The porous carbon biocatalytic material comprises a spiky porous carbon substrate, and rhodium clusters and iron single atoms uniformly loaded on its surface, forming Rh-Fe bimetallic active sites with charge transfer effects. The porous carbon biocatalytic material of this invention exhibits peroxidase-like and NADH oxidase-like activities under acidic conditions, and glucose oxidase-like, catalase-like, and superoxide dismutase-like activities under neutral conditions. It can efficiently kill bacteria and adsorb bacterial antigens, preventing macrophages from excessively polarizing to a pro-inflammatory state, ultimately promoting tissue regeneration and achieving ultra-rapid healing of inflammatory diabetic ulcers, with good biocompatibility.

The invention discloses a biocatalysis method for synthesizing a material precursor alpha-hydroxy ketone, and belongs to the technical field of biocatalysis synthesis. According to the invention, a coenzyme circulating enzyme lactic dehydrogenase LcLDH1 in an alpha-hydroxy ketone synthesis system is replaced by NADH oxidase EfNox from enterococcus faecalis, so that the yield of 2-hydroxy-4-chloroacetophenone reaches 84.7 or above, and the highest yield reaches 90%. According to the method, the coenzyme regeneration cost is effectively reduced, the overall economical efficiency of a reaction system is improved, and a more favorable technical support is provided for large-scale synthesis and industrial application of the alpha-hydroxy ketone compound.

The invention discloses an NADH oxidase mutant with significantly improved stability and / or enzymatic activity. The NADH oxidase mutants E51K, K187E, R246T, H396Y, Q426N, Q426H and P427C provided by the invention have improved stability and / or enzymatic activity, and show improved catalytic efficiency and operation stability in biological catalytic application.

This invention provides a nanozyme, its preparation method, and its application, belonging to the field of analytical chemistry detection technology. The nanozyme is vanadium oxide doped with a metal, in the form of nanoribbons. The metal is titanium, which is atomically loaded onto the vanadium oxide, with an atomic percentage of 1%-2%. The nanozyme of this invention possesses dual-enzyme activity similar to NADH oxidase and peroxidase. Utilizing its dual-enzyme activity in combination with natural enzymes, the amount of hydrogen peroxide is converted into a final measurement standard. Through the color change of a 3,3',5,5'-tetramethylbenzidine solution system, rapid qualitative and quantitative analysis of biomarkers for rare genetic metabolic diseases is achieved, providing a rapid, sensitive, and reliable colorimetric detection method.

The invention provides an engineering bacterium for producing 2-deoxy-D-ribose as well as preparation and application thereof, plasmids for expressing deoC and yfbT genes and plasmids for expressing nox and PDC genes are respectively constructed and transferred into escherichia coli, and genetic engineering bacteria capable of simultaneously expressing deoC, yfbT, nox and PDC are constructed and obtained. According to the present invention, with the application of the recombinant plasmid, the 2-deoxy-d-ribose 5-phosphate aldolase (DERA), the sugar phosphatase, the NADH oxidase (H2O-forming NADH oxidase) and the pyruvate decarboxylase (PDC) can be subjected to the overexpression by using the recombinant plasmid, such that the recombinant plasmid can be subjected to the overexpression so as to obtain the 2-deoxy-d-ribose 5-phosphate aldolase (DERA); by adopting the engineering bacterium, the 2-deoxy-D-ribose can be stably produced at high yield through fermentation, acetaldehyde or Gap-3P does not need to be added as a substrate, the preparation process is simpler, more convenient and more efficient, the cost is low, the application prospect is wide, and a foundation is laid for green production of the 2-deoxy-D-ribose.

The application provides a method for improving 2,5-dimethylpyrazine yield by expressing polyhydroxybutyrate (PHB) biosynthesis key genes, comprising the following steps: introducing an expression vector containing polyhydroxybutyric acid synthesis module encoding genes and an expression vector containing threonine dehydrogenase genes and NADH oxidase genes into host cells to obtain engineering bacteria; the engineering bacteria are subjected to fermentation culture, and then lactose is added for induction, and the method is completed. The method for high-yield 2,5-dimethylpyrazine provided by the application introduces a PHB biosynthesis pathway into E. coli, and cooperatively expresses threonine dehydrogenase and NADH oxidase to construct an engineering strain for biosynthesis of 2,5-dimethylpyrazine; the fermentation result shows that after introducing the PHB biosynthesis pathway, the fermentation yield of 2,5-dimethylpyrazine of the engineering strain is significantly improved, and the yield of 2,5-dimethylpyrazine of the engineering strain EC-3 reaches 2097.68 mg / L after 60 h of shake flask fermentation.

The invention relates to a process for the preparation of an aqueous solution containing glycolic acid, in which ethylene glycol, which is present in an aqueous solution, is oxidised by treatment with a first NAD-dependent oxidoreductase and NAD+ in vitro to form glycol aldehyde and this is oxidised in vitro with a further NAD-dependent oxidoreductase and NAD+ to form glycolic acid, and the reduced NADH created by these oxidations is oxidised again by means of an NADH oxidase or an alcohol dehydrogenase and is thus regenerated.