75results about How to "Little loss of enzyme activity" patented technology

The invention relates to the method used to hydrolyze DL-fat acid mint ester and produce L-menthol by full cell biological method stereo-selectivity. It supplies the high stereo-selectivity strain, produces full cell, uses the DL-fat acid mint ester as substrate, hydrolyzes and produces L-menthol by full cell biological method stereo-selectivity. The by-product D-fat acid mint ester can be hydrolyzed to high purity D-menthol of which optical purity is 80%e.e-100%e.e; yield is 30%-60% while producing L-menthol of which optical purity is 90%e.e-100%e.e; conversion rate is 40%-50%. Compared with the international L-menthol preparation method, the adopted full cell catalysis can omit fussy enzyme purification, reduce enzyme activity damage, increase enzyme action substrate range and operation stability, and reduce L-menthol production cost.

The invention relates to a method for fossilizing pectinase by using nanometer silicon material. The method is characterized in that novel nanometer silicon material is prepared by using a layer-by-layer assembly technique, activation, modification and coating are performed on the material, and efficient immobilization to pectinase is achieved through glutaraldehyde crosslink. The carrier for immobilization, prepared in the invention has the advantage of high protein carrying capacity, and the obtained immobilized pectinase enzyme has the characteristics of small enzyme activity loss and low probability of enzyme dropping, and can be used repeatedly.

The invention provides a preparation method of an immobilized lipase with a purified cotton towel as a carrier. The method is an immobilization technique comprising the following steps of: adsorbing a polyethyleneimine aqueous solution with the purified cotton towel, adding a lipase solution after adsorption, vibrating with a constant-temperature shaking table, thus attaching the lipase to the purified cotton towel containing polyethyleneimine, removing the supernatant, and then cross-linking the purified cotton towel with the lipase and polyethyleneimine adsorbed by using a cross-linking agent. According to the invention, the towel carrier used by the preparation method has multiple gaps and long towel fibers, thus having a larger surface area, favoring the performing of immobilized-enzyme-catalyzed reaction, having very good mechanical strength, and the method can more easily separate the enzyme from the reaction system, compared with the granular carrier; the used cross-linking agent is tris(hydroxymethyl)phosphine which has a better cross-linking effect than glutaraldehyde; the used immobilization method has the advantages of mild conditions and multi-layer immobilization; and the obtained immobilized lipase has good temperature stability and high reaction activity, can shorten the reaction time and can be repeatedly used.

The invention discloses a method for preparing biodiesel by catalyzing vector-free immobilized lipase in an ionic liquid system. The method comprises the following two steps: (1) preparing vector-free immobilized lipase; and (2) preparing the biodiesel by catalyzing the prepared vector-free immobilized lipase in the ionic liquid system. The prepared vector-free immobilized lipase is high in activity and free of high-cost vectors; an ionic liquid medium is used as an immobilized enzyme for preparing the biodiesel; the stability and the stereoselectivity of substrates of the enzyme can be obviously improved; the problem of the enzyme poisoning caused by methyl alcohol and glycerol can also be avoided; the efficient catalysis of the enzyme is ensured; the yield of the biodiesel is greatly increased; the immobilized enzyme and the ionic liquid used in the method can be recycled and reused; the waste of resources is avoided; the production cost is reduced; the method has a good industrial application prospect.

The physical papain extracting process includes the following steps: forming papaya slurry, freezing, pre-treating, coarse filtering, fine filtering, twice ultrafiltering, and drying to obtain product. Compared with available chemical extraction process, the present invention has the advantages low cost, simple technological process, short drying time, low power consumption, high enzyme activity of the product, high heat stability of the product, etc.

The invention discloses a high-activity composite enzyme for feed, belonging to the technical field of preparation of an enzyme preparation for feed. An Aspergillus niger DM-18 strain for a high-yield composite enzyme for feed, which is used as an initial strain, is subjected to liquid submerged mixed fermentation in an optimized culture medium under specific fermentation conditions by an improve fermentation technique to obtain the composite enzyme for feed, which has the advantages of complete enzymatic system, high enzyme activity, high temperature resistance and wide pH value resistance range. The crude enzyme fermentation liquid of the high-activity composite enzyme for feed contains multiple enzymes, wherein the proteinase activity is 6500-6700 U/ml, the mannase activity is 1500-1700 U/ml, the alpha-galactase activity is 1200-1300 U/ml, and the pectinase activity is 1000-1200 U/ml. When the crude enzyme fermentation liquid is subjected to the heat stability test and pH stability test, the test result indicates that all the enzymes have higher enzyme activity (up to higher than 80%) at 30-75 DEG C under the pH value of 2-7.

The invention provides a method for preparing catalase by using bovine livers, wherein fresh bovine livers are used as raw materials and subjected to chopping and homogenization, and a catalase product with high enzyme activity is obtained by means of processes such as ultrasonic extraction, ion exchange chromatography, gel filtration chromatography and freeze drying. The method of the invention solves the problems of complex production process, heavy pollution, high production cost and low product yield of the prior art in preparing the product. The catalase prepared by the method of the invention has an enzyme activity of 6000 U/mg and a colony count of less than or equal to 1000 cells/ml, and is suitable to be widely used in the fields of food, paper making and textile industry.

This invention discloses a method for preparing radish peroxydase. The method comprises: (1) pulverizing fresh radish at 0-15 deg.C, and separating the juice; (2) adding ammonium sulfate 30-50% into the juice, standing for 10-18 h, removing the precipitate, collecting the supernatant, adding ammonium sulfate 75-90%, standing for 10-18 h, decanting the supernatant, collecting the precipitate, diluting with water, and filtering; (3) filtering with an ultrafiltration membrane, recovering the filtrate, and collecting the concentrated liquid; (4) freeze-drying the concentrated liquid to obtain crude radish peroxydase, and performing column chromatography to obtain purified radish peroxydase. The method has such advantages as low peroxydase activity loss, low energy consumption, and easy operation. The radish peroxydase is safe and effective when used in animals and plants.

The invention discloses a method for extracting and obtaining a bromelain from pineapple peel residues, which comprises the following steps of: cleaning pineapple peel residues, putting the pineapplepeel residues into a crushing and filtering device for multi-stage crushing, adding 0.05-0.1 % of ascorbic acid and 0.5-1 Kg of distilled water, and finally obtaining filtrate through extrusion and filtration; adding 0.03-0.05 % of calcium propionate into the filtrate for corrosion prevention, stirring and centrifuging the filtrate at a high speed for 10-15 minutes at a stirring speed of 4000-5000r/min, taking supernatant, adding pre-dissolved tannin solution into the supernatant, stirring while leading the final concentration of the tannin to be 0.1-0.2 %, and allowing the solution to standafter adding the tannin. The enzyme activity of the bromelain prepared from the pineapple peel residues is good, the purity is high, and the utilization rate of pineapple peel residues is improved.

The invention provides a method for extracting purified Tth DNA polymerases. The method comprises the following steps: taking engineering bacteria of Tth DNA polymerases for activation, and adding IPTG for inducible expression; adding DTT and tween-20 after the engineering bacteria are treated with lysozyme at room temperature, treating for a period of time on ice and then centrifuging to obtain crude protein; slowing adding silicon dioxide particles in the crude protein, stirring in a magnetic stirring apparatus, centrifuging to remove precipitates; allowing supernatant to flow through an Ni<2+>-chelated Ni-NTA column after the supernatant is supplemented with NaCl, then washing sequentially with washing buffer solutions which have 5 times of bed volume, and at last, eluting the target protein with an eluent, and receiving the eluent containing the target protein; desalting to obtain the purified Tth DNA polymerases; adding glycerol in the obtained purified Tth DNA polymerases, so that the volume fraction is 50%, and saving at -20 DEG C. The method is simple, small in enzyme activity loss, and high in purity and recovery capacity of the recovered protein.

The invention discloses a nattokinase drying protective agent. The nattokinase drying protective agent comprises trehalose and maltodextrin, wherein the mass ratio of the trehalose to the maltodextrinis 2:(1-4). A preparation method comprises the steps: respectively weighing the trehalose and the maltodextrin according to the mass ratio being 2:(1-4) of the trehalose to the maltodextrin, adding the trehalose and the maltodextrin to distilled water, and stirring to obtain the nattokinase drying protective agent. A nattokinase drying method comprises the following steps: mixing a nattokinase crude enzyme with the nattokinase drying protective agent according to the volume ratio of 1: (2-5), homogenizing, carrying out spray drying, and collecting nattokinase enzyme powder, wherein the average value of the enzyme activity of produced nattokinase is (210200+/-19126)FU/g. The nattokinase drying method has the advantages that (1) bean dregs are used as a matrix to produce the nattokinase, the added value of the bean dregs is increased, and the enzyme activity of the nattokinase is comparable to the enzyme activity of the nattokinase produced by using soybeans as the matrix; and (2) the loss of the enzyme activity in the drying process is reduced, and the stability of the nattokinase is improved.

The invention discloses a method for producing laccase through solid-state fermentation of pseudo-ginseng residues. The method comprises the following steps: (1) drying, crushing and screening the pseudo-ginseng residues; (2) uniformly mixing the pretreated pseudo-ginseng residues, a proper amount of nitrogen source, water, copper sulfate, magnesium sulfate, monopotassium phosphate, tween-80 and veratryl alcohol according to a certain proportion; (3) performing steam sterilization treatment on the uniformly mixed materials; (4) inoculating at least one ganoderma lucidum on the sterilized material for solid state fermentation; and (5) drying the fermentation culture to obtain the ganoderma lucidum laccase. By adopting the method disclosed by the invention, the pseudo-ginseng residues can be converted into laccase. According to the method, the pseudo-ginseng residues are subjected to resource utilization, waste is turned into wealth, pollution caused by the pseudo-ginseng residues to the environment is reduced, and low-cost laccase can be provided for the environmental protection industry.

The invention discloses a method for extracting endoenzyme generated by fungal mycelium liquid submerged fermentation. The method comprises the following steps: separating a fermentation liquor to obtain mycelia, diluting the mycelia with water, and performing beating processing and ultrasonication processing on the diluted mycelia to obtain a crude enzyme. Through combination of the beating processing and the ultrasonication processing, the crude enzyme of endoenzyme generated by fungal mycelium liquid submerged fermentation is obtained, so that the loss of enzyme activity is less. The method provided by the invention is simple in operation, convenient, feasible and suitable for the extraction of enzymes generated by liquid submerged fermentation of various fungal mycelia such as ganoderma, champignon and Grifola frondosa.

The invention discloses a resin-enzyme composite catalyst and a preparation method thereof, belonging to the field of composite materials. The method comprises the following steps: dissolving a target enzyme in a phosphate buffer with pH value being neutral so as to obtain a solution A with concentration of 0.2mg/mL-10mg/mL; selecting a suitable large-hole type ion exchange resin as a carrier according to isoelectric points of an enzyme molecule; mixing and stirring the solution A and the resin carrier at room temperature; and taking out the resin, washing the surface of the resin by utilizing the phosphate buffer and drying the resin to obtain the resin-enzyme composite catalyst. The preparation method provided by the invention has the advantages of simplicity in operation, easiness in control and less loss of enzymatic activity; the fixed-load enzyme composite catalyst prepared by the method provided by the invention ensures that the stability of ordinary enzyme is greatly improved on the basis of maintaining the original catalytic activity of the enzyme molecules, can be applied to a water phase system and has the characteristic of good leaching-resisting property within a wide pH range and under high ionic strength.

The invention discloses a method for producing laccase through mixed bacteria solid-state fermentation of pseudo-ginseng residues. The method comprises the following steps: (1) drying, crushing and screening the pseudo-ginseng residues; (2) uniformly mixing the pretreated pseudo-ginseng residues, a proper amount of nitrogen source, water, copper sulfate, magnesium sulfate, monopotassium phosphate, tween-80 and veratryl alcohol according to a certain proportion; (3) performing steam sterilization treatment on the uniformly mixed materials; (4) inoculating at least one kind of ganoderma lucidum and at least one kind of saccharomycetes on the sterilized material for mixed bacteria solid-state fermentation; and (5) drying the fermentation culture to obtain the ganoderma lucidum laccase. By adopting the method disclosed by the invention, the pseudo-ginseng residues can be converted into laccase. According to the method, the pseudo-ginseng residues are subjected to resource utilization, waste is turned into wealth, pollution caused by the pseudo-ginseng residues to the environment is reduced, and low-cost laccase can be provided for the environmental protection industry.

The invention is applicable to the technical field of biochemistry, in particular to a calibrator for a biochemical calibrator and the biochemical calibrator. Each liter of the matrix for the biochemical calibrator comprises the following components of 10 to 100 mmol of a pH regulator, 2-50 g of a saccharide protective agent, 2-100 g of a polymer protective agent, 5-50 g of a protein protective agent, 0.5 to 5 grams of surfactant, 5 to 20 millimoles of amino acid, 0.02 to 50 millimoles of antioxidant, 0.05 to 2 millimoles of protease inhibitor, 5 to 30 grams of alcohol organic solvent, 0.2 to0.5 gram of preservative, 8.5 to 9.5 grams of sodium chloride and 0.1 to 5 millimoles of magnesium salt and/or zinc salt. According to the calibrator for the biochemical calibrator, when the analysiscomponents are added into the matrix for the biochemical calibrator, the components in the matrix for the biochemical calibrator can play a better role in protecting the analysis components, particularly, the structural variation caused by water loss of the analysis components in the freeze-drying process can be avoided, and the effect of the analysis components is effectively reserved.