185 results about "Enzyme action" patented technology

The invention herein disclosed provides for devices and methods that can detect and control an individual polymer in a mixture is acted upon by another compound, for example, an enzyme, in a nanopore. Of particular note is the stability of the system in a saline medium and to detect individual nucleotide bases in a polynucleotide in real time and which may be used to sequence DNA for many hours without change of reagents. The invention is of particular use in the fields of forensic biology, molecular biology, structural biology, cell biology, molecular switches, molecular circuits, and molecular computational devices, and the manufacture thereof.

The invention relates to binding agents which can be induced to aggregate in response to a specific stimulus. In preferred embodiments the binding agents comprise at least a binding member for a binding partner and the binding partner. At least one of the binding member and binding partner are reversibly masked such that a plurality of binding agents are not able to aggregate with one another until the masked moiety is unmasked. Preferred mechanisms to induce aggregation include irradiation and enzyme action. Applications of the invention include signal amplification in biochemical assays and provision of high local concentrations of therapeutic agents in vivo.

The invention discloses pullulanase with high secretion capacity and application thereof, and belongs to the technical field of enzyme engineering and microbial engineering. The pullulanase has high extracellular secretion capacity, and escherichia coli carrying the pullulanase is fermented in a shake flask for 48 hours, the total enzyme activity in the fermentation liquor can reach 212.0 U mL<-1>, wherein the extracellular enzyme activity reaches 200.5 U mL<-1>, which accounts for 94.5% of the total enzyme activity; therefore, the pullulanase is easy to prepare through fermentation, and the control difficulty and cost of the fermentation process can be obviously reduced; the pullulanase has mild action condition, and can hydrolyze alpha-1, 6-glucosidic linkage at a condition with a temperature of 40-60 DEG C and a pH value of 6.0-7.5, therefore, the pullulanase can reduce the cost in industrial transformation, and has potential utilization value in industries such as food, starch sugar and the like.

The invention relates to the field of anti-browning agents, and particularly relates to a potato anti-browning agent, and a preparation method and application thereof. The potato anti-browning agent is prepared by mixing ascorbic acid, cysteine, edible acidic pH regulator, chlorine additive, calcium additive, antioxidant and water according to a certain order. According to the invention, the potato anti-browning agent contains multiple components capable of inhibiting enzyme activity and changing enzyme action environment, such as citric acid, ascorbic acid, cysteine and malic acid; oxidation of a substrate can be prevented; sulfite is not contained, thereby avoiding injury of sulfate to a human body; the potato anti-browning agent is simple to operate and long in fresh-keeping time; and the browning degree can be kept basically unchanged in a preservation period of 30 days.

The invention provides a fragrant black tea red-enriching technique. Combined with the traditional tea technology and black tea process, the technique provided by the invention has no added foreign substances in the producing process and promotes aromatic precursor, amino and sugars in the fresh leaves to be subjected to enzyme action to change and then form various aromatic substances by the processes such as sun withering, green making, rolling, red-enriching, and drying, so that the black tea has thicker fragrance; meanwhile, complex catechins such as ester type catechins which have strongbitter taste are subjected to oxidative condensation to generate theaflavin and thearubigins with thickened taste. With the adoption of the technique, the natural novel black tea products with various fragrance and mellow taste are produced without adding any flower and additive, so the production safety of tea is ensured and the industrial benefit is enhanced; the safe and healthy tea consumption concept is satisfied; the problems of single black product and way of summer and autumn are solved; and the economic benefit is improved by times than the traditional methods.

The invention relates to a refrigeration pretreatment production line for shrimps. The production line is characterized in that: the production mainly comprises a conveying mesh belt, the conveying mesh belt is divided into a water spraying segment conveying mesh belt, a water draining segment conveying mesh belt and a freezing segment conveying mesh belt from the front to the rear according to technological requirements; the water spraying segment conveying mesh belt and the water draining segment conveying mesh belt are provided with a salt brine spraying, cooling and water draining device; the freezing segment conveying mesh belt is provided with a fast freezing device; the discharging end of the freezing segment conveying mesh belt is provided with a vibration ice coating device; and thus the refrigeration pretreatment production line for the shrimps is formed, and the whole refrigeration pretreatment on the shrimps in the production line is realized, the treatment efficiency on the shrimps is substantially improved, and the health status of the shrimps is improved. Also, the salt brine sprayed on the surface of the shrimps helps to inhibit corrosion caused by biological action and enzyme action, weaken the generation conditions of large ice crystal in the freezing segment, reduce possibility of damages to shrimp tissues and guarantee the quality of the shrimps; and the shrimps do not need secondary freezing because of vibration ice coating, and thus energy consumption is reduced.

The present invention relates to a prebiotic composition comprising a microbially produced oligosaccharide, wherein the oligosaccharide is characterised by being selective for a pre-determined probiotic bacterial strain and also capable of being produced by the pre-determined probiotic bacteria by reverse enzyme action. The present invention also relates to methods of screening a composition suitable for use as a prebiotic and methods for screening of prebiotics for incorporation into synbiotic formulations.

The invention relates to a method for producing stock solution from sea cucumber by using ultrasonic glycolysis. Using fresh sea cucumbers as raw materials, the stock solution is prepared by the following processing steps: cutting intestines, cleaning, mincing, refining, conducting ultrasonic glycolysis, and decoloring and deodorizing and the like. The product can be further processed into food or drug with all kinds of characters and dosage forms, such as capsules, tablets, and granules and the like. Besides, with the aid of enzyme action of fresh sea cucumbers and auxiliary addition of accompanying batches of sea cucumber intestines, the sea cucumbers are colloid-refined and then beer yeast is added. Then the ultrasonic glycolysis is conducted without adding acid, alkali or enzyme, thus leading to a high yield of hydrolysate, good product taste, easy absorption by human body, simple production process, low production cost and shortened manufacturing time.

The invention discloses a hesperetin dihydrochalcone-7-O-glucoside, wherein the compound is obtained by generating a rhamnose deglycosylation reaction of new hesperidin dihydrochalcone in water or a water and organic solvent system under an enzyme action. The sweetness multiple of the hesperetin dihydrochalcone-7-O-glucoside prepared by the invention is about 1800 times of sucrose, and the hesperetin dihydrochalcone-7-O-glucoside can be widely used for industries of foods, medicines, feed, daily use chemicals and the like and used as a sweetening agent, a flavoring agent, a flavor enhancer and the like.

The invention discloses high-temperature-resistant alkaline xylanase and belongs to the technical field of preparation of enzymic preparations. The high-temperature-resistant alkaline xylanase is prepared by taking bacillus thermophilus 701 for producing the high-temperature-resistant alkaline xylanase as an original strain and performing liquid submerged fermentation. The specific activity of the high-temperature-resistant alkaline xylanase is 350-420IU/ml, the applicable temperature range is 40-75 DEG C, the optimal reaction temperature is 65 DEG C, the enzyme activity at the temperature of 75 DEG C is completely stable, the applicable reaction pH value ranges from 5.0 to 11.0, the enzyme activity at the pH value of 11.0 is completely stable, and the optimal reaction pH value is 10.0. Compared with the conventional high-temperature-resistant alkaline xylanase, the high-temperature-resistant alkaline xylanase in the invention is high in enzyme activity, high in temperature resistance, high in alkali resistance and wide in enzyme action optimal pH value range and is particularly suitable for industrial requirements in the fields of papermaking, foods and feed.

The invention discloses a composition which is extracted from moraceae lupulus and takes xanthohumol, isoxanthohumol, 8-isopentenyl naringenin, 6-isopentenyl naringenin, alpha-acid and beta-acid as main ingredients. An in-vivo experiment initially proves that the composition disclosed by the invention has activity of inhibiting lipase, so that the composition disclosed by the invention has new application in preparation of a medicine with a lipase inhibiting effect.

The invention belongs to the food processing field and relates to a method for preparing pea protein polypeptide powder. The method comprises extruding and crushing a pea protein, adding a papain promoter and a papain into the pea protein powder, and carrying out enzymolysis and enzyme deactivation on the pea protein powder to obtain the pea protein polypeptide powder. The space structure of the pea protein powder becomes a chain structure conducive to enzyme action after extrusion so that the use amount of papain is reduced. The papain promoter improves the activity of papain, shortens enzymolysis time and improves the efficiency of enzymolysis. After the pea protein powder enzymolysis, the pea protein polypeptide powder is obtained by freeze drying so that free radical removal efficiency is high. Compared with pea protein polypeptide powder without the papain promoter, the pea protein polypeptide powder provided by the invention improves a hydroxyl radical removal rate by 22.3%-51.1%. The pea protein polypeptide powder can be used in the development of functional foods for resisting aging and oxidation.

The invention discloses a uracil-DNA glycosylase activity measurement method. The method comprises the following steps: firstly, carrying out PCR amplified reaction; with a double-chain DNA as a template, carrying out polymerization reaction by using polymerase in the presence of a dU/A/G/CTP mixture and a primer, and carrying out amplification to generate amplification product UDNA double chains containing dU; secondly, carrying out uracil-DNA glycosylase reaction, and forming a lot of DNA chains in base deletion from the amplification product through the uracil-DNA glycosylase action; and finally, measuring the relative quantity of a single-chain DNA product or UDNA double chains in the reaction system, and deriving the uracil-DNA glycosylase activity degree according to the measurement result, wherein the uracil-DNA glycosylase activity degree is inversely proportional to the quantity of the DUNA double chains in the reaction system, and is directly proportional to the quantity of the single-chain DNA product. The method disclosed by the invention is free of radioactive pollution, simple and rapid in operation, high in sensitivity, and stable, and quantitative determination can be carried out.

The invention discloses a wood raw material pre-treatment method, belonging to the technical field of wood processing. The wood raw material pre-treatment method comprises the following concrete treatment processes: soaking wood raw material into a soak solution, regulating pH of the soak solution, controlling temperature of the soak solution, adding laccase, and taking out the wood raw material and drying the wood raw material after the wood raw material is under enzyme action for a while. The wood raw material pre-treatment method disclosed by the invention has the advantages that performances of the pretreated wood raw material are changed, namely a surface shell-shaped covering layer of the wood raw material is obviously loose, and partial surface shell-shaped covering layer is removed to form a hole structure; and surface wetting property is obviously improved. During wood processing, the changes of the performances can reduce water consumption and energy consumption in a softening stage, and spreading and penetration of glue solution on the surface of the wood raw material are improved and condensation adhesive and penetration adhesive properties of the glue solution are enhanced, thus the internal bonding strength of a wood product is improved.

The invention belongs to the technical field of biological medicines, and particularly relates to a preparation method of a mediated-heparin intracellular delivery crosslinking nanometer carrier. PEG-modified PEI is adopted; and heparin is entrapped by using cation performance of PET, so that the cell endocytosis ability is increased; the water solubility, the stability and the blood metabolic capability of a carrier and nano composites are improved by PEG molecules; removal of combination of composites and protein is avoided; meanwhile, degradation of the heparin caused by heparin enzyme action is avoided; in addition, effective release of the heparin in cells is achieved; and a disulfide bond is introduced through a crosslinking agent on the basis, so that nanoparticles are degraded to release the heparin, thus the heparin plays a biological effect in the cells.

The invention discloses an alpha-L-fucosidase detection kit consists of an independent reagent 1 and an independent reagent 2, wherein the reagent 1 consists of components of a buffer agent, a preservative, a metal ion chelating agent, a stabilizing agent and water; and the reagent 2 consists of components of a buffer agent, a preservative, an enzyme action substrate, a surfactant, a stabilizing agent and water. The preparation method comprises the following steps: (1) preparing the reagent 1: dissolving the various components in distilled water or double distilled water, uniformly mixing, regulating pH to 6.5-8.5, and setting a constant volume; (2) preparing the reagent 2: dissolving various components in distilled water or double distilled water, uniformly mixing, regulating pH to 6.5-8.5, and setting a constant volume; and (3) independently sub-packaging the reagent 1 and the reagent 2, and sealing. The detection kit disclosed by the invention has the advantages of good stability, high precision, broad linear test range, good repeatability, strong anti-interference performance and the like.

The invention relates to an Aspergillus aculeatus ZJ bacterial strain and an application thereof. The collection number of the Aspergillus aculeatus ZJ is CCTCC NO.M2011264. The bacterial strain is mainly used for converting effective components of the pod of Chinese scholartree to produce 5,7,8,4'-tetrahydroxyisoflavone. The specific method provided by the invention comprises the following steps of: acting the Aspergillus aculeatus ZJ with strong specificity or the produced enzyme on the pod of Chinese scholartree or extracting solution thereof; converting glucosides compounds including sophoricoside and the like, genistein and the like to produce the 5,7,8,4'-tetrahydroxyisoflavone. The invention provides the method for producing the 5,7,8,4'-tetrahydroxyisoflavone through utilizing the Aspergillus aculeatus with high specificity and high conversion efficiency to convert the sophoricoside; and the method provided by the invention has moderate conditions, green process and simple requirements on the process and the device, and has a very good application value.