35results about How to "Good stability for repeated use" patented technology

The invention relates to a method for immobilizing beta-glucosidase and hydrolyzing straw cellulose by cooperating the beta-glucosidase with cellulase, belonging to the technical field of biocatalysis. The method provided by the invention comprises the following steps of: (1) dissolving chitosan into a propionic acid solution to form a transparent and homogeneous colloid, mixing and stirring the colloid with Fe3O4 grains, dropwise adding a NaOH solution to obtain magnetic microspheres, and carrying out crosslinking on the magnetic microspheres in a glutaraldehyde solution to obtain an immobilized carrier; (2) adding the immobilized carrier into a beta-glucosidase solution for adsorption to obtain a magnetic immobilized beta-glucosidase, hydrolyzing a cellobiose substrate by using the magnetic immobilized beta-glucosidase, and measuring the enzyme activity of the magnetic immobilized beta-glucosidase; and (3) degrading maize straws by coordinating the magnetic immobilized beta-glucosidase with the cellulase. The immobilized beta-glucosidase prepared by the method has the characteristics of homogeneous shape, large specific surface area, high mechanical strength, high enzyme activity and easiness in recovery; and the immobilized beta-glucosidase can hydrolyze the straw cellulose by coordinating with the cellulase to increase the yield of hydrolyzed sugar, and the stability in repeated use is good, so that the cost for the enzymatic hydrolysis of the straw cellulose can be lowered.

The invention relates to environment-friendly novel choline ionic liquid and a method for preparing the choline ionic liquid. The novel choline ionic liquid contains levulinic acid choline, sorbic acid choline, glutaric acid choline, adipic acid choline, (p-, m- and o-)phthalic acid choline, trifluoromethanesulfonic acid choline, benzenesulfonic acid choline, (p-, m- and o-)toluenesulfonic acid choline, bis(trifluoromethane sulfonimide) choline and the like. The novel choline ionic liquid has the remarkable advantages that the preparation process is simple, the recovery is simple and convenient, the stability of reuse is good, and the like.

The invention relates to polyethylene imine-titanium oxide embedded with amine dehydrogenase and a preparation method of the polyethylene imine-titanium oxide, and belongs to the technical field of immobilized enzymes. A polyethylene imine (PEI)-titanium oxide immobilized particle embedded with the amine dehydrogenase has a grain size of 100-600 nm, wherein polyethylene imine has catalyzing and templating double effects in the immobilization process, namely the PEI promotes the formation of titanium oxide through an electrostatic and hydrogen bonding effect between an amino group in a molecule and a titanium precursor molecule; through a polyethylene imine structure, a template can also be induced, and the formation of a titanium oxide particle are regulated and controlled. The preparation method of the polyethylene imine-titanium oxide comprises the following steps: configuring the PEI (straight chain and branched chain) as well as mixed liquid containing the amine dehydrogenase; configuring a precursor II-dihydroxybis (2-hydroxypropanoato) titante diammonium (Ti-BALDH) solution of titanium; dropwise adding the precursor solution of the titanium into the PEI and the mixed liquid containing the amine dehydrogenase, stirring and generating the PEI-titanium oxide immobilized particle embedded with the amine dehydrogenase. The polyethylene imine-titanium oxide and the preparation method thereof have the advantages that the preparation conditions are mild, the process is simple and is easy to implement, the obtained immobilized particle embedded with the amine dehydrogenase has strong immobilization capacity and good reuse stability, and the temperature stability of the amine dehydrogenase can be obviously improved.

The invention discloses an organic heteropoly hybrid catalyst for an esterification reaction. The organic components comprise polyvinyl pyrrolidone, methyl-pyrrolidone and caprolactam. The heteropoly acid is 12-phosphotungstic acid, 12-phosphomolybdic acid and 12-silicotungstic acid. The preparation method comprises the step that the organic components and the heteropoly acids are subjected to protonation to obtain the organic heteropoly hybrid catalyst. The invention has the advantages that the preparation process of the catalyst is simple and practicable; and the obtained catalyst is suitable for the esterification reaction of many kinds of carboxylic acids and alcohol, and has the characteristics of high catalytic activity and selectivity, convenient recycling, and stable reutilization performance, thereby being an environment-friendly novel solid acid catalyst.

The invention discloses a multi-enzyme system with immobilized polyethylenimine and metal coordination and a method for preparing the multi-enzyme system, and belongs to the technical field of immobilized enzymes. The method includes immobilizing glycerol dehydrogenase, coenzyme oxidase and glycerol dehydrogenase-coenzyme oxidase fusion enzymes by the aid of coordination of polyethylenimine and metal ions; forming netted polyethylenimine frameworks by polyethylenimine molecules under coordination effects of imine and the metal ions in immobilizing procedures; forming coordination bonds by the metal ions coordinated on the polyethylenimine, C-end histidine tags of the glycerol dehydrogenase and the coenzyme oxidase and C-end histidine tags of the glycerol dehydrogenase-coenzyme oxidase fusion enzymes so as to acquire the immobilized multi-enzyme system. Coordination crosslinking effects can be realized by the metal ions in the immobilizing procedures, and the catalysis efficiency of the multi-enzyme system can be improved. The multi-enzyme system and the method have the advantages that the multi-enzyme system is high in multi-enzyme coupling efficiency, preparation conditions are mild, and processes are simple and feasible; the immobilized enzymes are high in immobilizing rate and activity recovery rate and good in reuse stability, the temperature stability can be obviously improved, and the like.

The invention relates to a method for using alginic acid-calcium carbonate hybrid gel to immobilize beta-glucuronidase, wherein, calcium carbonate powdered precipitation is generated by mixing and stirring sodium carbonate solution and calcium chloride solution at room temperature, and then kept, washed by water and acetones and dried, and micron mesoporous calcium carbonate particles are obtained which are added into trihydroxymethyl aminomethane-hydrochloric acid (Tirs-HCl) buffer of beta-glucuronidase or aqueous solution thereof for absorption, and calcium carbonate particles absorbing glucuronidase are obtained after centrifugal separation, then uniformly mixed with sodium alginate solution and added into calcium chloride solution by dropping for aging. The invention has the advantages of mild preparation conditions, simple and easy preparation technologies, good immobilization ability of obtained hybrid vectors on enzymes, low leakage rate of immobilized beta-glucuronidase, low swelling capacity and good reusage stability.

The invention discloses a method for flexibly immobilizing papain by using modified polyacrylonitrile resin, which comprises the following steps: 1) preparation of a flexible carrier: modifying polyacrylonitrile resin microspheres by use of tetraethylenepentamine to obtain a modified polyacrylonitrile flexible carrier; 2) activation of the carrier: soaking the modified polyacrylonitrile flexible carrier in a phosphate buffer solution, and performing crosslinking reaction by using glutaraldehyde to obtain a glutaraldehyde modified polyacrylonitrile flexible carrier; 3) preparation of immobilized papain: performing immobilization reaction between the glutaraldehyde modified polyacrylonitrile flexible carrier and papain to obtain immobilized papain. The method disclosed by the invention overcomes the enzyme activity loss caused by rigid collision in the enzyme immobilization process of the carrier synthesized by the prior art, and can maintain the homogeneous catalysis activity of free enzymes to the greatest degree so as to solve the problem of low recovery rate of the immobilized enzyme activity of a covalent binding method.

The invention relates to a preparation method and application of a resin carbon sphere supported palladium catalyst. The method comprises the following steps: polymerizing resorcinol and formaldehydeto form resin pellets, calcining and carbonizing to generate catalyst carrier carbon spheres, and finally loading metal palladium on the carbon sphere carrier by a hydrothermal method to obtain the resin carbon sphere supported palladium catalyst. The catalyst provided by the invention realizes mild and efficient conversion under vanillin hydrosilylation conditions, avoids the use of high-pressurehydrogen and acidic additives, and enables the bio-oil upgrading process to be more environment-friendly and safer.

The invention discloses an alcohol dehydrogenase embedded gelatin-silica hybrid gel and a preparation method thereof. According to invention, the grain diameter of the alcohol dehydrogenase embedded gelatin-silica hybrid gel is 3-4mm, and a silica coating is coated on a gelatin core. The preparation method comprises the following steps of: preparing a mixed solution of gelatin and alcohol dehydrogenase; preparing a mixed solution of sodium silicate and a glutaraldehyde solution precursor; adding the mixed solution of gelatin and alcohol dehydrogenase into deionized water at a temperature of 0-4 DEG C droplet by droplet to generate alcohol dehydrogenase embedded gelatin gel particles; stirring and incubating to obtain the alcohol dehydrogenase embedded gelatin-silica hybrid gel. The preparation method has the advantages that the preparation condition is mild, the preparation process is simple and feasible, and the alcohol dehydrogenase embedded gelatin-silica hybrid gel has a strong fixing capability; compared with gelatin gel, the hybrid gel has a lower leakage rate of immobilized alcohol dehydrogenase, and lower swelling degree and better recycling stability.

The invention provides a method for preparing a magnetic attapulgite molecularly imprinted material, which comprises the following steps: dissolving ferric chloride and sodium acetate in ethylene glycol, adding carboxylated carbon nanotubes and attapulgite, ultrasonically dispersing, and using high pressure React in the reactor to obtain magnetic particles; disperse the magnetic particles in ethanol aqueous solution, add ammonia water and tetraethyl orthosilicate dropwise in turn, stir at room temperature, wash, separate and dry, then disperse in purified toluene, under nitrogen protection, add alkenyl silane modifier and triethylamine, reflux reaction, washing and drying to obtain silane-modified magnetic silica particles; 4,4-methylene-two-(2-chloroaniline) and vinylpyridine were added to toluene, mixed and pre- Assemble, add silane-modified magnetic silica gel particles and ethylene glycol dimethacrylate, then add azobisisobutyronitrile, heat the reaction, separate under the action of an external magnetic field, wash repeatedly, and dry in vacuum to obtain a magnetic attapulgite Soil Molecularly Imprinted Materials.

The application provides a method of immobilizing beta-fructofuranosidase and glucose oxidase by a sol-gel process. The method comprises the steps of (1) producing beta-fructofuranosidase; (2) isolating and purifying beta-fructofuranosidase; (3) immobilizing the purified beta-fructofuranosidase and glucose oxidase solution to gel in the presence of a silane coupling agent. Compared with traditional production of lactosucrose via immobilization of beta-fructofuranosidase, the method has the advantages that the sol-gel process is used herein for the first time to immobilize beta-fructofuranosidase and glucose oxidase so as to improve enzymic stability, high enzyme activity recovery rate is attained, lactosucrose yield is increased, and the method is simpler to operate than the traditional art, has mild conditions and is an environment-friendly method.

The invention relates to a method for preparing magnetic cellulose immobilized lysozyme. The method comprises the following steps: preparing magnetic cellulose nanoparticles, preparing an immobilizedcarrier, and preparing the magnetic cellulose immobilized lysozyme. The immobilized operation is simple, the prepared magnetic cellulose immobilized lysozyme has the advantages of uniform shape, largespecific surface area, high enzyme activity recovery rate, and easy storage, can be used for lysis sludge reduction, also has the advantages of easy recovery, repeated usage and good stability, can reduce the lysis sludge reduction cost by a biological method, and overcomes the disadvantages of difficult enzyme recovery and high cost in a traditional biological method lysis technology.

The invention discloses a bimetallic composite oxide catalyst and preparation and application methods thereof. The bimetallic composite oxide catalyst mainly solves the problems such low yield of methyl phenyl carbonic ester and separating and recovery difficulty of catalysts. The bimetallic composite oxide catalyst is prepared by taking MgO as the carrier and 5-30% of PbO by weight percentage asthe active constituent to perform hydro-thermal synthesis at a calcination temperature of 400-600 DEG C; the bimetallic composite oxide catalyst is high in catalytic activity and selectivity when applied to synthesizing methyl phenyl carbonic ester through ester exchange reaction, has the advantages of being easy to separate and recycle from a reaction system, good in reusability and stability, free from environmental pollution and the like and accordingly achieves potential industrial application values.

The invention discloses a Bi2O3-PbO-SBA-15 catalyst for synthesis of methylphenyl carbonate. The molar ratio of Pb<2+> to Bi<3+> in the catalyst is (5-6):1, and the mass ratio of the mass sum of Bi2O3and PbO to SBA-15 is 1:(4-24). The invention also provides a preparation method for the Bi2O3-PbO-SBA-15 catalyst for synthesis of methylphenyl carbonate. The synthesized Bi2O3-PbO-SBA-15 catalyst has the characteristics of a convenient and controllable synthesis route, a stable structure and the like, and has good catalytic activity for a transesterification reaction, so that MPC has high yieldand selectivity. The prepared catalyst is environmentally friendly, has the advantages of easy separation and recycling and good recycled use stability, and is a novel green catalyst.

The invention discloses a wollastonite-loaded strontium and lanthanum solid base catalyst and a preparation method and application thereof, and the solid base catalyst comprises a wollastonite carrierand strontium oxide and lanthanum oxide loaded on wollastonite. In the process of loading strontium oxide and lanthanum oxide on wollastonite, strontium oxide and lanthanum oxide are loaded, active sites can be uniformly distributed on the surface of the carrier, the agglomeration phenomenon of active sites is effectively avoided, effective contact between reactant molecules and active sites is enhanced, high catalytic activity of the catalyst is ensured, and the mechanical strength of the catalyst is enhanced in the presence of the wollastonite carrier. According to the present invention, the active site loss caused by the mechanical stress of the collision between the catalyst particles and other particles or the container wall is reduced, and the strontium oxide (SrO) and the wollastonite react to generate the new phase CaSrSiO4 so as to improve the immobilization rate of the active site, such that the catalyst has good reuse stability.

A mesoporous supported composite catalyst is a (Ni0.13Mn0.87)(Ni0.87Mn1.13)O/SBA-15 composite material, bimetallic oxide (Ni0.13Mn0.87)(Ni0.87Mn1.13)O4 particles are uniformly attached to the surfaceof the SBA-15 and the interior of a mesoporous channel, and are orderly arranged, and the total loading capacity of the (Ni0.13Mn0. 87)(Ni0.87Mn1.13)O4 on the SBA-15 is 20%. In the prepared (Ni0.13Mn0.87)(Ni0.87Mn1.13)O4/SBA-15, the size of (Ni0.13Mn0.87)(Ni0.87Mn1.13)O4 is small, the loading uniformity on the SBA-15 is good, agglomeration is avoided, the catalytic activity is high and can reach 99.47%, the time required for degrading sulfadiazine is short, and the composite catalyst has excellent catalytic performance in a large-range pH change environment, has a good stability in the catalytic performance, and can be repeatedly used; and after the composite catalyst is used for 10 times, the catalytic activity still can reach 94.6%, stability is kept, and the repeated use stability is excellent.