115 results about "D fructose" patented technology

The invention discloses a strain for producing D-piscose by using microorganism to transform D-fructose and a preparation method thereof, pertaining to food biotechnology field. The invention relates to a strain of spherical Rhodobacter sphaeroides SK011 screened from bottom mud of a fish-pond with the preservation number, CCTCC NO: M 207185, and the preparation method that the spherical Rhodobacter sphaeroides SK011 is used for transforming the D-fructose and producing the D-piscose through culture and fermentation. The invention adopts the SK011 as the strain and a fermentation culture medium which consists of carbon and nitrogen sources, inducer and inorganic salt; the obtained strain is further treated, so as to obtain cell biocatalyst; then by using the D-fructose as a substrate to do bio-transformation, the D-piscose is prepared. Under optimum conditions during the fermentation culture, fermenting solution or free cells or permeability cells or frozen dry powder or solidified cells thereof are used for transforming the D-fructose for 0.5 to 4.8 hours, and the content of the D-piscose in the transformation solution is 2 to 50g/L.

The invention provides a preparation method of carbon quantum dots based on a chemical reaction of fructose and sodium hydroxide, and belongs to the technical field of nanomaterials. The method comprises a first step of preparing a D-fructose solution; a second step of preparing a sodium hydroxide solution; a third step of mixing the D-fructose solution with sodium hydroxide solution; and a fourth step of standing the mixed solution to obtain a carbon quantum dot solution. The preparation method is simple and economic, is easy to operate, and has extremely low energy consumption. The prepared carbon quantum dots have high fluorescent intensity, can transform ultraviolet light to green visible light, have no biological toxicity and no pollutions to the environment, and have great application potentiality in in improving conversion efficiency of solar cells and in the fields of biological labels, biological medicine and the like.

The invention provides a preparation method of carbon quantum dots based on atmospheric pressure micro-plasma technology. The method comprises a first step of preparing a D-fructose solution; a second step of preparing a solution of sodium hydroxide, or sodium bicarbonate potassium or dihydrogen phosphate; a third step of mixing the D-fructose solution with the solution of sodium hydroxide, or sodium bicarbonate potassium or dihydrogen phosphate; and a fourth step of performing atmospheric pressure micro-plasma electro discharge treatment on the mixed solution to obtain a carbon quantum dot solution. The preparation method is simple and economic, is easy to operate, and has extremely low energy consumption. The prepared carbon quantum dots have high fluorescent intensity, can transform ultraviolet light to blue visible light, have no biological toxicity and no pollutions to the environment, and have great application potentiality in improving conversion efficiency of solar cells and in the fields of biological labels, biological medicine and the like.

The invention discloses a method for efficiently preparing D-psicose 3-epimerase and a use of the D-psicose 3-epimerase and provides a method for efficiently preparing an enzyme catalyst for catalyzing the same reaction through isozyme combined expression. The method utilizes corynebacterium glutamicum as a host cell to construct a recombinant strain expressed by plasmid dissociation and chromosomal integration, measures D-fructose catalytic efficiency, improves enzyme catalytic efficiency by 2-4 times than that of single expression of D-psicose 3-epimerase through combined expression and hasa conversion ratio of 29% when 70% of fructose is a substrate. The method improves D-psicose production efficiency and is suitable for industrial production of D-psicose. The invention also disclosesa novel use of the D-psicose 3-epimerase in psicose synthesis. The enzyme is derived from Paenibacillus senegalensis, has catalytic activity of about 25 U/mg and can be used to convert D-fructose intoD-psicose.

Disclosed herein is a method of producing D-psicose. The method of producing D-psicose includes subjecting D-fructose to D-psicose epimerization to produce a D-psicose-containing solution, subjecting the D-psicose-containing solution to first cooling and ion purification, subjecting the purified D-psicose-containing solution to first concentration and second cooling, subjecting the D-psicose-containing solution, which has been subjected to first concentration and second cooling, to chromatography to obtain a D-fructose-containing mother liquor and a D-psicose-containing separated solution, and subjecting the D-psicose-containing separated solution to second concentration and third cooling to obtain D-psicose crystals, wherein the D-fructose-containing mother liquor produced by chromatography is reused in the D-psicose epimerization.

The invention provides a method for preparing D-fructose through isomerization of D-glucose .The method includes the following processing steps that firstly, adding D-glucose, solvent and a catalyst into a high-pressure reaction kettle to form a reaction system, wherein the mass concentration of D-glucose is 0.1-99%, and the mass ratio of the catalyst to D-glucose is 0.01-10; secondly, conducting reaction for 0.01-100 hours under the protection of inert gas at a temperature of 20-400 DEG C, and conducting separation and purification after reaction ends to prepare D-fructose .The method has the advantages that the applied catalyst is low in price, easy to obtain, free of toxin, environmentally friendly and high in product yield .

The invention discloses an inulin soya-bean milk beverage and a preparation method thereof, belonging to the technical field of food processing. The inulin soya-bean milk beverage disclosed by the invention mainly consists of the following components in parts by weight: 80-120 parts of soya-bean milk, 2-20 parts of inulin, 1-5 parts of honey and 0.1-0.4 parts of a stabilizer, wherein the inulin, which is also called as synanthrin, is linear straight-chain polysaccharide formed by D-fructose through key jointing of beta (1 to 2), the tail end of the inulin is provided with a glucose residue, and the degree of polymerization is 2-60. The inulin, as a soluble dietary fiber different from a starch structure, can selectively promote the growth of colon probiotics and improve the health condition of a host. The inulin soya-bean milk beverage disclosed by the invention is white, is exquisite and smooth in mouth feel, has a low caloric value and can promote the growth of human colon probiotics, inhibit toxic fermentation products, promote the absorption of mineral materials such as calcium, magnesium and iron and improve the physiological functions such as immunity of the organism.

The invention discloses a D-psicose 3-epimerase mutant with improved catalytic efficiency and belongs to the technical field of enzyme engineering. The Dorea sp. DPEase mutant enzyme A38E/G105A keepsthe optimal catalytic conditions. Under the optimal catalytic conditions, the relative enzyme activity of the enzyme for catalytic conversion of D-fructose as a substrate into D-psicose is improved by38.6%. The discovery has an important research value for the industrial production of D-psicose.

The invention belongs to the technical field of genetic engineering and in particular relates to novel D-allulose 3-epimerase, DNA (Deoxyribonucleic Acid) for encoding the novel D-allulose 3-epimerase, an expression vector and a transformant containing the DNA and application of the enzyme to production of D-allulose. The D-allulose 3-epimerase is derived from thermoacidophile mesoaciditoga lauensis of a deep-sea spring and has relatively high conversion rate and thermal stability when being used for converting D-fructose into the D-allulose.

The invention discloses an immobilization method for cells containing glucose isomerase. The immobilization method comprises the following steps of adding wet bacteria obtained by performing fermented culture on a recombinant genetic engineering strain containing glucose isomerase genes in buffer liquor so as to obtain bacterial suspension; adding a carrier in the bacterial suspension; uniformly stirring the bacterial suspension; adding polyethyleneimine and glutaraldehyde to perform crosslinking; filtering the bacterial suspension after performing stirring crosslinking on the bacterial suspension for 1-2 hours at the temperature of 0-30 DEG C; washing filter cakes by using distilled water; extruding the filter cakes into long strips by using an axial extruder; airing the long strips at room temperature; and smashing the long strips into granules so as to obtain immobilized glucose isomerase cells containing the glucose isomerase. The immobilization method has the advantages that the cost of an immobilization material is low, the method is easy to operate and high in mechanical strength, the immobilization material is stable at high temperature, prepared recombinant escherichia coli whole cells for producing the glucose isomerase in an immobilization manner can be used for catalyzing D-glucose to produce D-fructose at high temperature, the conversion rate is 54% at the temperature of 85 DEG C, after being repeatedly used ten times, the cells still have enzyme activity which is higher than 90%, and the industrial application prospect is high.

The invention relates to a high-purity SiC ceramic prepared through normal-pressure solid-phase sintering and a preparing method thereof. The preparing method of the high-purity SiC ceramic comprisesthe steps of 1, adding alpha-SiC powder and an aqueous solution containing a sintering aid into a solvent, and mixing the materials to obtain SiC slurry, wherein the sintering aid comprises a source Band a source C, the source B is boric acid, and the source C is selected from at least one of D-fructose and glucose; 2, drying and forming the obtained SiC slurry to obtain an SiC blank; 3, conducting vacuum debinding on the obtained SiC blank, putting the SiC blank in an inert atmosphere, and conducting sintering for 30-120 minutes at 2,050-2,250 DEG C to obtain the high-purity SiC ceramic, wherein the addition amount of the element B in the source B accounts for 0.1-1 wt% of the mass of the alpha-SiC powder, and the addition amount of the element C in the source C does not exceed 5 wt% ofthe mass of the alpha-SiC powder.

The invention relates to the technical field of microelectrode biological sensing, and particularly discloses a microelectrode biosensor for in-situ real-time monitoring of the fructose content of a plant. According to the microelectrode biosensor, mercaptoacetic acid is assembled onto a work electrode through a drip coating method, then an ionic liquid [Bmim]PF6 is adsorbed to further modify a mixture of fructose dehydrogenase and a potassium ferricyanide medium micromolecule, then the process is repeated to achieve a multilayer modified work electrode of the ionic liquid and the fructose dehydrogenase, the fructose dehydrogenase can catalyze 5-keto-D-fructose generation from D-fructose, and real-time dynamic responses of the enzyme to fructose changes are recorded through chronoamperometry. Through application of the microelectrode biosensor, in-situ real-time monitoring of the fructose content of the plant can be achieved, a tested sample is free of substantial damage, an obtained data result can reflect content changes of fructose in the plant in real time and dynamically, and practical application and operation are simple and convenient and easy to master.

The invention discloses a glucose isomerase, a gene, a vector, an engineering bacteria and the application thereof in preparing D-fructose through catalyzing the D-glucose isomerization. The amino acid sequence of the glucose isomerase is shown in SEQ ID NO. 1. The invention provides a novel high-temperature-resistant glucose isomerase. The glucose isomerase is higher in enzyme activity (2.42 U/mg) and excellent in thermal stability. At the temperature of 85 DEG C, 20 mM of a manganese salt additive is added and 80% of the initial enzyme activity is still retained even after the temperature is maintained for 48 hours. Therefore, the glucose isomerase has an industrial application potential in the biocatalytic production of high fructose syrup at a high temperature.

The object is to provide a novel enzyme which enables to determine the glucose level more accurately, a bacterium capable of producing the enzyme, and use of the enzyme. Disclosed is a flavin adenine dinucleotide-binding glucose dehydrogenase having the following properties (1) to (3):(1) the enzyme has an activity of catalyzing a reaction for oxidizing a hydroxyl group in glucose in the presence of an electron acceptor to produce glucono-delta-lactone; (2) the enzyme has a molecular weight of about 100 kDa as measured by SDS-polyacrylamide gel electrophoresis or about 400 kDa as measured by gel filtration chromatography; and (3) the enzyme is less reactive to maltose, D-fructose, D-mannose and D-galactose. Also disclosed is a microorganism Aspergillus oryzae which can produce the enzyme. Further disclosed are a glucose determination method, a reagent for the determination of glucose, and a kit for the determination of glucose, each utilizing the enzyme.

The invention discloses a glucose isomerase, an encoding gene, a recombinant vector, a genetically engineered bacteria and a mutant thereof and an application of the glucose isomerase and the mutant thereof in preparation of D-fructose for catalyzing D-glucose isomerization. A recombinant escherichia coli capable of efficiently expressing high-temperature resistant glucose isomerase, provided by the invention, solves the problem of low optimal reaction temperature of a common glucose isomerase, is applied to production of the glucose isomerase and has the advantages of high yield, simple process and convenient industrial application; the strain can be directly used for the high fructose syrup production without cell disruption; after finishing fermentation, the total enzyme activity for D-fructose at the temperature of 90 DEG C is 414.3U/g, the conversion rate of D-fructose is 55.4%, the remnant enzyme activity at the temperature of 90 DEG C after storage for 24h is 68% and the equilibrium of reaction is shortened to 1.5h; a good technical support for the large-scale production of the high fructose syrup and for the use of high fructose syrup as an important food additive can be provided.