100 results about "Alanine dehydrogenase" patented technology

The invention discloses construction of a trigenic coexpression vector for synthesizing DL-alanine and application. The construction is characterized in that encoding alanine dehydrogenase (ald), alanine racemase (alr) and glucose dehydrogenase (gdh) genes in pseud bacillus firmus are connected in series and then are inserted into reconstructed plasmid pET-22bNS, so as to construct the trigenic coexpression vector pET-22bNS-G / A / A. After constructed trigenic coexpression vector is transformed into escherichia coli BL21(DE3) and is subjected to whole-cell catalytic reaction for 3h through recombination strain, the output of L-alanine and the output of D-alanine are the highest and are correspondingly 7.0mg / mL and 6.5mg / mL, and the maximum synthesizing efficiency of L-alanine and the maximumsynthesizing efficiency of D-alanine are correspondingly 56.4mg / mL / d and 51.9mg / mL / d. The constructed trigenic coexpression vector has a capacity of efficiently synthesizing DL-alanine and is high inapplication value.

The invention relates to a homocysteine diagnostic kit utilizing technologies of an indirect enzymatic recycling method, an enzymatic-colorimetric method and an enzyme-link method, also relates to a method and a principle of measuring homocysteine concentration and compositions and components of reagents, and belongs to the technical field of testing and measuring of medical science. The kit mainly comprises the following compositions: buffer solution, pyruvic acid, reduced coenzyme, homocysteine-alpha, gamma-lyase, alanine dehydrogenase, glycine oxidase, peroxidase, reduced form chromogen composition, and stabilizer; the colorless reduced form chromogen composition is oxidized into colored dye through a series of enzymatic reactions; moreover, dye content can be measured at the position where wave length is between 400 and 700nm through a visible analyzer so as to directly reflect the homocysteine concentration.

The invention relates to an inorganic phosphorus (phosphate radical) diagnosis / determination kit using the technology of an enzyme colorimetric method and an ELISA method, a method for determining inorganic phosphorus (phosphate radical) concentration and composition and components of a reagent, and belongs to the technical field of test and determination of medical science, food, and environment. The kit comprises the following main components: buffer solution, reduced coenzyme, adenosine diphosphate, oxaloacetic acid, ammonium chloride, potassium chloride, phosphoenolpyruvate carboxykinase, pyruvate kinase, pyruvate dehydrogenase and a stabilizer. The method comprises the following steps: mixing a sample and the reagent according to a certain volume ratio to perform a series of enzymic reaction, and then placing reactants under a UV / visible light analyzer to test the descending speed of absorbance at the position where the dominant wave length is 340nm to determine the inorganic phosphorus (phosphate radical) concentration.

The invention discloses a genetically engineered bacterium for producing L-theanine by utilizing glucose de novo fermentation, and the genetically engineered bacterium contains gamma-glutamyl methylamine synthetase for synthesizing theanine and a gene for coding a path enzyme for de novo synthesis of theanine. The theanine de novo synthetic pathway enzymes comprise phosphoketolyase, transaminase, acetaldehyde dehydrogenase and alanine dehydrogenase. A complete anabolism pathway from glucose to theanine is constructed, a genetic engineering strain which does not carry plasmids, does not need to add ethylamine and can stably produce theanine by using glucose is obtained, after the strain is fermented for 33 hours, the yield of theanine can reach 46 g / L, the conversion rate can reach 0.16 g theanine / g glucose, the production intensity can reach 1.4 g theanine / L / h, and the production cost can be greatly reduced. The highest yield, the conversion rate and the production intensity of the theanine produced by directly utilizing the glucose for de novo fermentation without adding ethylamine are reported at present, and the method has a good industrial application prospect.

The invention relates to an adenosine deaminase diagnostic kit utilizing technologies of an enzymatic-colorimetric method and an enzyme-link method, also relates to a method and a principle of measuring activity concentration of adenosine deaminase and compositions and components of reagents, and belongs to the technical field of testing and measuring of medical science. The kit mainly comprises the following compositions: buffer solution, coenzyme, adenosine, pyruvic acid, hydrogen peroxide, glycine oxidase, alanine dehydrogenase, and stabilizer; samples are mixed with the reagents in certain volume ratio to perform a series of enzymatic reactions; then reactants are placed under a UV / visible analyzer; and the descending speed of absorbance is tested at the position where dominant wave length is 340nm so as to measure and calculate the activity concentration of the adenosine deaminase.