55 results about "Oxaloacetic acid" patented technology

The invention provides a waterborne polyurethane enhancer, a cold-resistant and salt-resistant concrete composition as well as a preparation method and application of the cold-resistant and salt-resistant concrete composition, and belongs to the technical field of buildings and civil engineering. The waterborne polyurethane enhancer comprises diisocyanate, oligomer polyol, a small molecule chain extender, oxalic acid dihydrazide, oxaloacetic acid and a catalyst, and the cold-resistant and salt-resistant concrete composition comprises cement, aggregate, a water reducing agent, an anti-freezing agent, an air entraining agent, modified straw fibers, the waterborne polyurethane enhancer, calcium silicate and water. Through mutual cooperation of all the components, the obtained concrete has excellent cold resistance, salt resistance, impermeability and compressive strength, and can meet the engineering requirements for concrete durability and use safety under low-temperature and high-salt conditions.

An artificial synthesis method for malonyl-CoA and use thereof are provided. By means of heterologous expression of an aminotransferase and a malonyl-CoA reductase, an artificial synthesis pathway for synthesizing malonyl-CoA by using β-alanine (β-ala) as a precursor is constructed as follows: firstly, under catalysis of a transaminase, β-ala transfers amino groups to α-ketonic acid (such as pyruvic acid, oxaloacetic acid, or α-ketoglutaric acid, etc.), to form an intermediate product 3-oxopropanoate and a corresponding amino acid; the 3-oxopropanoate generates malonyl-CoA under the action of the malonyl-CoA reductase. This pathway addresses the defects of the natural malonyl-CoA synthesis pathway, such as low carbon utilization, consumption of energy substance ATP, release of greenhouse gas CO2, and strict regulation of pathway enzymes, a pyruvate dehydrogenase (PDH) and an acetyl-CoA carboxylase (ACC), thereby achieving high yielding of products using malonyl-CoA as a precursor, including flaviolin, octanoic acid, phloroglucinol, pentadecaheptaene, natamycin, and spinosad.

The present disclosure provides plants that express a variant phosphoenolpyruvate carboxylase (PEPC) enzyme. The plants have enhanced resistance to aluminum than comparable plants that lack the variant PEPC enzyme. In addition, the plants more effectively sequester carbon, extract phosphate, and produce oxaloacetate-derived amino acids and glucose than comparable plants that lack the variant PEPC enzyme. The disclosure also provides tools for production of plants that express the variant PEPC enzyme.

The invention belongs to the technical field of biology, and discloses a biosynthesis method of L-homoserine. According to the biosynthesis method, L-homoserine is synthesized by taking L-aspartic acid and formaldehyde as substrates, aldolase and transaminase are adopted, and oxaloacetic acid decarboxylase can be optionally added to improve the efficiency of a catalytic system. The method can be realized through an in-vitro multi-enzyme catalysis system, and can also be completed in a manner of introducing a way into microorganisms. According to the method, methanol, formaldehyde and other carbon resources can be introduced to synthesize the L-homoserine with high value, the raw materials are low in price, and the whole synthesis method has the advantages of high atom utilization rate and high conversion rate.

This invention relates to methods of measuring the activity of a FAMIN protein that comprise determining the aspartate transaminase activity of the FAMIN protein, for example by measuring the consumption of aspartate and / or α-ketoglutarate in the presence of the FAMIN protein and / or the production of oxaloacetate and / or glutamate. Methods of measuring and screening FAMIN activity are provided.

The invention discloses a recombinant genetically engineered bacterium for producing beta-alanine by dynamically regulating and controlling a competitive pathway and application of the recombinant genetically engineered bacterium, heterologous key genes pycCG and NCgl0580 are over-expressed on plasmids, accumulation of a beta-alanine precursor oxaloacetic acid pool is increased, and efflux of beta-alanine is enhanced; a heterologous gene gapN is introduced to adjust a glycolytic pathway, so that the efficiency of the glycolytic pathway is enhanced, and the carbon flow in a beta-alanine synthesis pathway is increased; the expression activity of the gene gltBD is up-regulated so as to enhance the supply of an amino donor when oxaloacetic acid is converted into aspartic acid; an EsaI / EsaR group sensing system is introduced to dynamically regulate and control an aspartic acid competition branch; after the thrA gene promoter is replaced by PesaS, the situation that excessive metabolic flow enters an aspartic acid competition branch is effectively weakened, the carbon flow is pulled to the synthesis direction of beta-alanine to the maximum extent, and the yield of beta-alanine is obviously increased.

The invention provides a preparation method of 3-fluoropyruvic acid, and belongs to the field of medicinal chemistry. The method comprises the following steps: by taking diethyl oxalate and ethyl fluoroacetate as raw materials, reacting under an alkaline condition to generate an intermediate fluoro-oxaloacetic acid ethyl ester sodium salt; then hydrolyzing under an acidic condition to generate a target product 3-fluoropyruvic acid; the method is simple to operate, mild in condition and suitable for large-scale industrial production.

The invention discloses a synthesis method of oxaloacetic acid, which comprises the following steps: S1, under the protection of inert gas, oxalyl chloride and alcohol react in an organic solvent, the reaction temperature is 0-70 DEG C, the reaction time is 1-12 hours, oxalic acid diester is obtained, and an alkaline substance is dispersed in the organic solvent; s2, under the protection of inert gas, oxalic acid diester and acetic ester are subjected to a Claisen ester condensation reaction in an organic solvent, the reaction temperature is 0-70 DEG C, the reaction time is 1-12 h, a condensation product is obtained, and an alkaline substance is dispersed in the organic solvent; and S3, adding an aqueous solution of an alkaline substance into the condensation product, reacting at 0-70 DEG C for 1-24 hours, adding acid to adjust the pH value to 1-6, and purifying to obtain oxaloacetic acid. According to the synthesis method of oxaloacetic acid, the total yield reaches up to 80.03%, the yield is stable, the reaction process is easy to control, and industrial production is easy.

The present invention relates to compositions and methods for treating aging-related diseases. The present invention provides a composition comprising at least three substances selected from the group consisting of alpha-ketoglutaric acid, malic acid, pterostilbene, micro-dose lithium, glycine, ginger, Rhodiola rosea, acetylglucosamine, vitamin C, glucosamine, fisetin, L-theanine, oxaloacetic acid, fumaric acid, succinic acid, hyaluronic acid, butyric acid, anthocyanins, piper longum amide, quercetin, curcumin, and a pharmaceutically acceptable salt thereof. And caffeine, trehalose and spermidine. The present invention also provides related pharmaceutical compositions, methods for improving senescence profiles, and articles of manufacture.

The invention provides a genetic engineering strain for efficiently producing beta-alanine, an escherichia coli strain is modified by adopting a genetic engineering means, and a multi-plasmid system is constructed, so that a metabolic pathway is optimized and the product synthesis efficiency is improved. The method comprises the following steps: firstly, by constructing a recombinant plasmid pET-PanD, introducing aspartic acid decarboxylase (L17F / G24R mutant) with mutation so as to promote efficient conversion of aspartic acid to beta-alanine; meanwhile, phosphoenolpyruvate carboxylase (PPC) is overexpressed through the recombinant plasmid pRSF-PPC, generation of oxaloacetic acid (OAA) is increased, and then the synthesis path of carbon flow to beta-alanine is improved. Besides, NADH dependent type aspartate dehydrogenase (AspDH) from pseudomonas aeruginosa is overexpressed by adopting a pBAD-AspDH plasmid, so that the dependence on NADPH is reduced, and the conversion efficiency is further improved.

The invention discloses an artificial synthesis method and application of malonyl coenzyme A. An artificial synthesis route for synthesizing malonyl-CoA by taking beta-alanine (beta-ala) as a precursor is constructed by heterologous expression of aminotransferase and malonyl-CoA reductase: firstly, under the catalysis of transaminase, amino of beta-ala is transferred to alpha-keto acid (such as pyruvic acid, oxaloacetic acid or alpha-ketoglutaric acid and the like), and then the malonyl-CoA is obtained; an intermediate product 3-oxopropionic acid and corresponding amino acid are formed; and the malonyl-CoA is generated from the 3-oxopropionic acid under the action of the malonyl-CoA reductase. According to the method, the defects existing in a natural malonyl-CoA synthesis route, such as low carbon utilization rate, energy substance ATP consumption, greenhouse gas CO2 release, pyruvate dehydrogenase (PDH) of route enzymes and acetyl-CoA carboxylase (ACC) which are strictly regulated and controlled, are overcome, and high yield of products taking malonyl-CoA as a precursor, including light flavomycin, octanoic acid, phloroglucinol, pentadecheptaene, natamycin, spinosad and the like, is realized.

The invention discloses a construction method and application of an ectoine-producing genetically engineered bacterium, and belongs to the field of biosynthesis. Escherichia coli BL21 is used as an original strain, lacI genes of the Escherichia coli BL21 are knocked out, an expression system regulated and controlled by tryptophan is constructed, and synthesis of a product ectoine can be regulated and controlled under the condition that an inducer is not added. According to the invention, a phosphotransferase system of Escherichia coli BL21 is modified, and a glucose readifier protein coding gene Zmglf is integrated at a ptsG gene locus, so that the inhibition effect of carbon catabolism is relieved, and the cost of a culture medium is reduced. Through overexpression of a phosphoenolpyruvate carboxylase coding gene ppc and an aspartate semialdehyde dehydrogenase coding gene asd, the accumulation of precursor substances oxaloacetic acid and L-aspartate-beta-semialdehyde in the growth and metabolism process is enhanced, and the synthesis level of the product ectoine is improved.

The invention belongs to the technical field of leaf surface resistance and control agents, and particularly relates to a leaf surface resistance and control agent for reducing the content of cadmium and lead in rice and a preparation method thereof. The invention relates to a leaf surface blocking and controlling agent, which is prepared by mixing the following components in percentage by mass: 3 to 15 percent of active component, 6 to 15 percent of dispersing agent and the balance of inorganic salt, the active component is formed by compounding ethylenediaminetetraacetic acid, oxaloacetic acid and silicon dioxide sol. The foliar blocking and controlling agent disclosed by the invention takes ethylenediaminetetraacetic acid, oxaloacetic acid and silicon dioxide as active ingredients, so that accumulation of heavy metals cadmium and lead in rice can be remarkably reduced, further the content of cadmium and lead in rice can be effectively reduced, and a support is provided for safe production of rice. Besides, positive ions in inorganic salts such as zinc sulfate, manganese sulfate and ferrous sulfate can antagonize transfer of cadmium and lead in rice plants to the rice, so that accumulation of heavy metal cadmium and lead in the rice is reduced, elements such as zinc, manganese and iron required by growth of the rice can be supplemented, and growth of the rice plants is promoted.

The present application relates to the field of polymerized rosin, more specifically, it relates to a zinc-free polymerized rosin and a preparation method thereof. A zinc-free polymerized rosin comprises the following raw materials: masson rosin, inorganic acid, zinc chloride, solvent, oxaloacetic acid, and phosphotungstic acid; the inorganic acid is 0.6-1% of the mass of masson rosin, the zinc chloride is 2.5-4.5% of the mass of masson rosin, the solvent is 75-85% of the mass of masson rosin, the oxaloacetic acid is 0.04-0.08% of the mass of masson rosin, and the phosphotungstic acid is 0.04-0.08% of the mass of masson rosin. The zinc-free polymerized rosin provided in this application can not only maintain a high yield of the product, but also thoroughly remove zinc residues, which helps to break the foreign technology monopoly, enhance the overall competitiveness of the domestic ink industry, and contribute to the healthy development of the national economy.

The present invention discloses a construction method and application of a genetically engineered bacterium producing ectoine, and belongs to the field of biosynthesis. The present invention uses Escherichia coli BL21 as a starting strain, knocks out the lacI Gene, construct tryptophan-regulated expression system, can regulate the synthesis of product ectoine without adding inducer. The present invention transforms the phosphotransferase system of Escherichia coli BL21. ptsG Glucose facilitator protein encoding gene Zmglf , relieving the inhibitory effect of carbon catabolism and reducing the cost of culture medium. ppc and aspartate semialdehyde dehydrogenase encoding genes asd , which enhanced the accumulation of precursor substances oxaloacetate and L-aspartate-β-semialdehyde during growth metabolism and increased the synthesis level of the product ectoine.

The invention discloses a construction method and application of engineering bacteria for improving carbon flow supply in L-malic acid production, and belongs to the technical field of biological engineering. A construction method of the engineering bacteria comprises the following steps: amplifying malate dehydrogenase genes mdh1, mdh2 and mdh3 from a genome of saccharomyces cerevisiae, constructing double-gene combined expression recombinant plasmids, and respectively introducing the recombinant plasmids into host bacteria to obtain the engineering bacteria mdh1, 2, mdh1, 3 and mdh2, 3. The yield of accumulated L-malic acid is increased by 13-16 times compared with the yield of the L-malic acid accumulated by the engineering bacteria containing double-gene combined expression, which is constructed by the method disclosed by the invention, compared with the yield of the L-malic acid accumulated by an original strain. According to the engineering bacterium construction method for improving carbon flow supply in L-malic acid production, the capacity of converting oxaloacetic acid into malic acid is improved, carbon flow supply is increased, then the yield of L-malic acid is increased, and good industrial application value and prospects are achieved.

The invention belongs to the technical field of leaf surface resistance and control agents, and particularly relates to a leaf surface resistance and control agent for reducing the cadmium content of rice and a preparation method thereof. The leaf surface blocking and controlling agent for reducing the cadmium content of the rice is formed by compounding active ingredients of oligosaccharide and oxaloacetic acid, and the mass ratio of the oligosaccharide to the oxaloacetic acid is (1-100): (100-1). Chitosan oligosaccharide and oxaloacetic acid are mixed to serve as an active component of the leaf surface blocking and controlling agent, and rice tests find that when the active component is sprayed on leaf surfaces of rice in the booting stage and the filling stage respectively, transportation and accumulation of heavy metal cadmium in soil in the rice can be effectively prevented and controlled, and then the content of the heavy metal cadmium in the rice can be reduced; and support can be provided for green and safe production of rice. In addition, positive ions in inorganic salts such as zinc sulfate, manganese sulfate and ferrous sulfate can antagonize transfer of cadmium and lead in rice plants to the rice, so that accumulation of heavy metal cadmium and lead in the rice is reduced, elements such as zinc, manganese and iron required by growth of the rice can be supplemented, and growth of the rice plants is promoted.

This invention discloses a culture medium and process for alleviating ammonium accumulation in cells. The concentrations of the substances added to the culture medium are as follows: 2 g / L glutamate, 0 g / L glutamine, 2 g / L aspartic acid, 2 g / L asparagine, 1 g / L serine, 1 g / L pyruvate, 0.5 g / L α-ketoglutarate, 0.5 g / L oxaloacetic acid, 0.5 g / L proline, 0 g / L glucose, 8 g / L galactose, and 0.1% glycerol. Compared with the prior art, the advantages of this application are: this method mainly achieves the purpose of maintaining cell viability and reducing the cell metabolic byproduct ammonium ions by adjusting the proportion of substances related to cell metabolic pathways and adding additional cell protectants; using the optimized culture medium of this invention, the cell viability can be increased from 42.38% to 95.21% and the ammonium ion concentration can be reduced from 6.308 mM to 0.914 mM by day 7.

The invention belongs to the field of synthetic biology, and particularly relates to a genetically engineered bacterium for high-yield non-protein amino acid as well as a construction method and application of the genetically engineered bacterium. The genetically engineered bacterium is obtained by taking Escherichia coli HSCC4 as an original strain and carrying out the following various series of metabolic engineering modifications on the original strain, including a way of reducing the consumption of malic acid to generate pyruvic acid; the carbon flow is limited to enter a complete TCA cycle for oxygenolysis, and carbon metabolism is forced to more depend on a supplementation pathway to generate oxaloacetic acid; and the competitive pathway of carbon and nitrogen flowing to branched chain amino acid synthesis is reduced. The original strain is subjected to specific metabolic engineering modification, so that the original strain can better utilize carbon source substances such as glucose and the like to produce the L-homoserine, nutritional defects are remarkably reduced, and the strain without plasmids has better production performance. Compared with a starting strain HSCC4, the genetically engineered strain disclosed by the invention has the advantages that the shake flask level of a plasmid-free strain is improved from 18.83 g / L to 20.25 g / L, and the genetically engineered strain has important industrial application value.

The invention relates to the field of polymerized rosin, in particular to zinc-free polymerized rosin and a preparation method thereof. Zinc-free polymerized rosin comprises the following raw materials: masson pine, inorganic acid, zinc chloride, a solvent, oxaloacetic acid and phosphotungstic acid. The inorganic acid accounts for 0.6-1% of the mass of the masson pine, the zinc chloride accounts for 2.5-4.5% of the mass of the masson pine, the solvent accounts for 75-85% of the mass of the masson pine, the oxaloacetic acid accounts for 0.04-0.08% of the mass of the masson pine, and the phosphotungstic acid accounts for 0.04-0.08% of the mass of the masson pine. According to the zinc-free polymerized rosin provided by the invention, the high yield of a product can be kept, zinc residues can be thoroughly removed, the overseas technical monopoly can be broken, the overall competitiveness of the domestic ink industry is improved, and a strength is contributed to the healthy development of national economy.

The invention belongs to the technical field of biology, and discloses a biosynthesis method of 2, 4-dihydroxybutyric acid. According to the biosynthesis method, L-malic acid and formaldehyde serve as substrates to synthesize 2, 4-dihydroxybutyric acid, L-malic acid is converted into oxaloacetic acid through L-malic dehydrogenase, oxaloacetic acid is decarboxylated to generate pyruvic acid, pyruvic acid and formaldehyde are condensed under the action of aldolase to generate 2-ketone-4-hydroxybutyric acid, and 2, 4-dihydroxybutyric acid is converted into 2, 4-dihydroxybutyric acid through dehydrogenase. The invention relates to 2, 4-dihydroxybutyric acid. The method can be realized through an in-vitro multi-enzyme catalysis system, and can also be completed by introducing a way into microorganisms. Furthermore, the formaldehyde can be generated from methanol, formic acid or sarcosine under the action of enzyme. Therefore, the monocarbon resources such as methanol and formaldehyde can be introduced to synthesize the 2, 4-dihydroxybutyric acid with high value, the raw materials are low in price, and the whole synthesis method has the advantages of high atom utilization rate and high conversion rate.

The present invention relates to an oil and gas field acid solution system and an injection method, and relates to the technical field of oil and gas field development engineering. In terms of weight percentage, the oil and gas field acid solution system comprises the following components: 8-15% of hydrochloric acid, 3-7% of hydrofluoric acid, 1-5% of oxaloacetic acid, and 3-12% of additives; the remainder is water; the additive is obtained by compounding 1-heptyl-3-methylimidazolium bromide and a Schiff base compound shown in formula (I) in a weight ratio of 100:(21-37). The present invention adds oxaloacetic acid to the existing soil acid system, and simultaneously cooperates with an additive compounded with 1-heptyl-3-methylimidazolium bromide and a specific Schiff base compound, significantly improving the initial acidification speed of the system, and having excellent precipitation inhibition ability, avoiding the generation of secondary precipitation, and meeting the operating requirements of acidification of deep formations, and having good application prospects in exploitation such as sandstone reservoirs.

The invention discloses a construction method and application of an engineering bacterium for increasing the yield of alpha-ketoglutaric acid. Wild E.coli.W3110 serves as a chassis strain, lactic dehydrogenase ldhA, pyruvate dehydrogenase poxB and formic acid C-acetyltransferase pflB are knocked out firstly, and the flow direction of pyruvic acid to lactic acid, acetic acid and formic acid is blocked; meanwhile, the promoter PBBaJ23109 is used for replacing a natural promoter of the sucA gene, so that alpha-ketoglutaric acid dehydrogenase is weakened, and the decomposition way of alpha-ketoglutaric acid is weakened; the phosphoenolpyruvate carboxylase ppc is overexpressed, and the flow direction of phosphoenolpyruvate to oxaloacetic acid is enhanced; isocitrate dehydrogenase icd from escherichia coli is overexpressed, so that synthesis of a product is promoted; besides, pyruvate dehydrogenase derived from saccharomyces cerevisiae is introduced and coded by genes PDB1, PDA1 and LAT1, so that an important precursor, namely pyruvic acid, is promoted to flow to acetyl coenzyme A; the engineering strain with high yield of alpha-ketoglutaric acid is finally obtained, the yield of 75.1 g / L can be achieved in a 5L fermentation tank through a fed-batch fermentation method for 40 hours, and the conversion rate is 39.6%.

The application discloses a construction method and application of recombinant bacteria for efficiently converting glucose to produce tetrahydropyrimidine, and the recombinant bacteria are constructed according to a biosynthesis pathway of tetrahydropyrimidine and a carbon metabolic flow distribution of balanced phosphoenolpyruvic acid to oxaloacetic acid and pyruvic acid, and the recombinant bacteria strain directly produces tetrahydropyrimidine by fermentation with glucose as a substrate; 36-53 g / L of tetrahydropyrimidine can be accumulated in a 56-hour fermentation liquor, the yield per cell reaches 1.21-1.91 g / g DCW, and the glucose molar conversion rate reaches 0.31-0.38 mol / mol, and the yield, the yield and the conversion rate are all higher than those of an existing process; compared with an existing fermentation method and a whole-cell catalysis method for producing tetrahydropyrimidine salt, the recombinant bacteria provided by the application have the advantages of low raw material cost, simple culture condition, small equipment loss, short fermentation period, simple operation, no need to collect bacterial bodies to extract enzyme liquor and high tetrahydropyrimidine production efficiency.

To provide a working electrode useful as a working electrode to be used for an enzyme reaction for generating malic acid.SOLUTION: A working electrode to be used for an enzyme reaction for generating malic acid from oxaloacetic acid is disclosed. The working electrode includes nano-carbon and malate dehydrogenase, and a cofactor of malate dehydrogenase is present while being attached or in proximity to the working electrode.SELECTED DRAWING: None

The invention relates to methods for treating symptoms of PMS and PMDD including muscle ache, bloating, cramping, acne, tender breasts, bloating, fatigue, difficulty concentrating, diminished impulse control, irritability, anxiety, tension, anger, depression, insomnia and / or rapid fluctuations in mood (mood swings). The method comprises administration of a pharmaceutical composition comprising oxaloacetate, oxaloacetate salts, oxaloacetic acid and / or anhydrous enol-oxaloacetate.

Method and compositions for producing malonyl-CoA and / or triacetic acid lactone within peroxisomes using genetically modified yeast cells to metabolize a substrate containing fatty acids, vegetable oil, or alkanes, and genetically modified organisms are provided. Also provided are methods to generate acetyl-CoA, which is retained in the peroxisomes due to genetic modifications that prevent its export therefrom. A modified enzyme with a peroxisomal targeting sequence catalyzes a reaction between acetyl-CoA and oxaloacetate, producing pyruvate and malonyl-CoA. The methods can include deleting carnitine acetyltransferase (CAT2) alleles to prevent acetyl-CoA export from peroxisomes, and using genes encoding methylmalonyl-CoA carboxyltransferase subunits with peroxisomal targeting sequences. Additionally, the method incorporates 2-pyrone synthase genes to further facilitate production processes.

Disclosed is a novel genetically modified microorganism showing improved yields of 3-hydroxyadipic acid and / or α-hydromuconic acid. The genetically modified microorganism is a microorganism having an ability to produce 3-hydroxyadipic acid and / or α-hydromuconic acid, in which the reaction to generate malic acid from oxaloacetic acid is enhanced, and the reaction to generate acetyl-CoA from pyruvic acid is enhanced. In addition, the reaction to generate carbon dioxide from formic acid is enhanced.

The present invention relates to a fig grafting and cultivation method, and relates to the technical field of fig planting. The fig grafting and cultivation method includes selecting and treating a rootstock, selecting and treating a scion, a first grafting and cultivation, and a second grafting and cultivation. The rootstock selection and treatment step includes soaking the root of the rootstock in a first treatment agent for a first soaking treatment. The first treatment agent comprises 200-350 g of oxaloacetic acid, 1-5 g of gibberellin, and 50-60 g of carbendazim per 1000 L of water. The scion collection and treatment step includes soaking the scion in a second treatment agent for a second soaking treatment. The second treatment agent comprises 2-5 g of oxaloacetic acid per 500 mL of water. The present invention significantly improves the grafting survival rate and fig yield by introducing oxaloacetic acid to soak the rootstock and scion during fig grafting and cultivation, thus overcoming the shortcomings of the prior art.