123 results about "Lactulose" patented technology

The invention provides a method for preparing lactulose from immobilized beta-galactosidase, and belongs to the technical field of functional sugar preparation.The method comprises the following steps that an immobilized enzyme column is prepared, specifically, macroporous alkalescent styrene anion exchange resin is soaked and washed with an ethanol solution, a NaCl solution, an HCl solution and a NaOH solution in sequence; the pretreated resin and beta-galactosidase liquid are mixed, a buffer solution is added, shaking table adsorption is performed, and standing is performed after adsorption; adding a glutaraldehyde solution for cross-linking, and discarding the supernatant to obtain an immobilized enzyme column; adding a magnesium ion solution into a mixed solution of lactose and fructose, and then performing conversion through an immobilized enzyme column to obtain a lactulose conversion solution; the lactulose conversion liquid is sequentially subjected to decoloration, ion exchange, vacuum concentration and continuous simulated moving bed chromatographic separation to obtain a lactulose solution, by means of the method, the lactulose conversion rate is larger than or equal to 60%, the lactulose yield is larger than or equal to 92%, the preparation process is simple, and the cost is low.

The invention relates to the technical field of biology, and particularly discloses a method for removing lactulose-based isomers in an oligosaccharide separation and purification process. The method comprises the following steps: taking oligosaccharide fermentation liquor for producing oligosaccharide through fermentation by using lactose as a substrate, sequentially carrying out thallus removal, decoloration, electrodialysis desalination, ion exchange resin desalination, concentration, sequential simulated moving bed chromatographic purification, ultrafiltration, re-concentration and spray drying, and detecting the oligosaccharide and the lactulose-based isomer in the oligosaccharide. According to the method disclosed by the invention, the content of lactulose-based isomers in the separation and purification process is greatly reduced, so that the product purity is effectively improved; the method can be applied to the synthesis process of other milk oligosaccharides such as fucose lactose (FL), lactose-N-tetraose (LNT), lactose-N-neotetraose (LNnT), lactose-N-fucopentasaccharide (LNPFI) and the like or other carbohydrates containing a lactosyl group, has a very high application value, and accords with laws and regulations.

The invention provides a cellobiose epimerase mutant E250Q, an engineering bacterium and application of the cellobiose epimerase mutant E250Q, and belongs to the technical field of genetic engineering. According to the invention, glutamic acid at the 250th site of an amino acid sequence of wild cellobiose epimerase is mutated into glutamine, so that the cellobiose epimerase mutant E250Q is obtained. The amino acid sequence of the cellobiose epimerase mutant disclosed by the invention is shown as any one of SEQ ID NO.1-6. The invention further discloses a preparation method of the cellobiose epimerase mutant. According to the method, recombinant bacteria or cellobiose epimerase mutant E250Q is used as a catalyst, lactose is used as a substrate, the conversion rate of converting lactose to lactulose reaches 67.1%, the yield of brepinose is only 4.0-5.7% and is lower than the by-product proportion permitted by Chinese Pharmacopoeia, and the method has extremely high application value in industrial production of lactulose.

The invention discloses a lactobacillus rhamnosus composition for relieving gastrointestinal diarrhea and application of the lactobacillus rhamnosus composition, the composition is composed of a probiotic mixture, a prebiotic mixture and a carrier, the probiotic mixture is composed of lactobacillus plantarum JY055 bacterial powder, lactobacillus rhamnosus JM039 bacterial powder and lactobacillus rhamnosus JY027 bacterial powder, and the prebiotic mixture is composed of lactobacillus plantarum JY055 bacterial powder, lactobacillus rhamnosus JM039 bacterial powder and lactobacillus rhamnosus JY027 bacterial powder. The prebiotic mixture comprises inulin, xylitol, lactulose, resistant dextrin, a hawthorn extract and a dandelion extract, and the carrier is modified montmorillonite. The composition for relieving gastrointestinal diarrhea provided by the invention is composed of a mixture of three probiotics and prebiotics, and the probiotics are adhered to small intestinal mucosa epithelial cells to form a mycoderm and form an intestinal barrier, so that colonization and growth of harmful bacteria are prevented, self-protection of intestinal epithelial cells is enhanced, and the damaged intestinal barrier is repaired; the prebiotic mixture provides a breeding place and nutrient elements for growth and breeding of the probiotics, and the efficacy can be improved through mutual cooperation of the prebiotic mixture and the probiotics.

The invention provides a quality control method for synthesizing 3 '-sialic acid lactose by an enzymatic process, which comprises the following steps: A) dissolving and extracting a test sample by using a solvent to obtain a to-be-detected solution; the test sample is a reaction solution or a finished product of 3 '-sialic acid lactose synthesized by enzyme catalysis; b) determining the liquid to be detected by adopting a high performance liquid chromatography to obtain an HPLC (High Performance Liquid Chromatography) spectrum of the 3 '-sialic acid lactose; according to the method, an HPLC-UV-RI combined detection method is adopted, the specificity is high, the sensitivity is high, the linear correlation is good, and the pretreatment process of the sample is simple and rapid; according to the method, the content of 3 '-lactulose sialylate, 6'-lactose sialylate sodium salt, D-lactose, CMP, CMP-SA and SA in the 3 '-SL process development process can be accurately detected, control over the conversion rate and impurities in the process is facilitated, effective detection of a product 3'-SL related substance-isomer can be achieved, and control over the product quality is facilitated.

The invention is applied to agricultural production, and particularly relates to a biostimulant formula and application of the biostimulant formula in promoting or regulating crop growth and inducing disease resistance in agricultural production. The biostimulant active component contains lactulose and nicotinamide mononucleotide; wherein the weight ratio of lactulose to nicotinamide mononucleotide is (1-10): (1-10). The formula of the biostimulant has the functions of promoting crop growth, improving crop quality and inducing disease resistance at the same time. The raw materials required by the formula are low in price and easy to obtain, the preparation process is simple, the equipment requirement is low, and the formula can be applied to the field of agricultural production.

The invention discloses a high-temperature-resistant cellobiose epimerase mutant and application thereof. The mutant is obtained by performing single mutation on the 242nd site of an amino acid sequence as shown in SEQ ID No.1. The invention also discloses a preparation method of the high-temperature-resistant cellobiose epimerase mutant. According to the invention, molecular modification is carried out on cellobiose epimerase (DiCE) from Dictyoglomus thermophilum, a mutant with improved thermal stability is screened out, the lactulose conversion efficiency of the obtained mutant is obviously improved, the mutant A242L can tolerate the temperature of 80 DEG C, the lactulose conversion rate is 64.41%, and the industrial application prospect is good.

The invention provides a method for preparing lactulose and co-producing lactitol, and belongs to the field of functional sugar. The method comprises the following steps: sequentially carrying out first high-temperature isomerization, concentration and second high-temperature isomerization on a decolored lactose solution to obtain a mixed solution; sequentially carrying out refining and chromatographic separation extraction on the mixed solution to obtain a lactulose solution and raffinate; refining, crystallizing and drying the lactulose solution to obtain crystalline lactulose; refining the raffinate, adjusting the pH value, and carrying out hydrogenation reaction to obtain a lactitol crude liquid; the lactitol crude liquid is subjected to refining and nanofiltration membrane filtration in sequence, and a lactitol solution is obtained; and refining, crystallizing and drying the lactitol solution in sequence to obtain crystallized lactitol. According to the method, the lactose is subjected to two times of high-temperature conversion under the alkaline condition, the conversion rate of the lactulose can reach 55% or above and is far higher than that of an existing lactulose preparation method, the content of the lactose in the converted feed liquid is reduced, and the problem that unreacted lactose is easy to separate out and crystallize in the lactulose preparation process is solved.

The present application relates to the field of biotechnology, and in particular to a cellobiose epimerase mutant and its application. The cellobiose epimerase mutant and its application provided in the embodiment of the present application is produced in at least one key site in the amino acid sequence shown in SEQ ID NO: 51, which produces a mutation that is beneficial to improving the catalytic activity of lactose epimerization to form lactulose; through the above-mentioned method, the cellobiose epimerase mutant exhibits excellent catalytic activity of lactose epimerization to form lactulose, can efficiently convert lactose into lactulose, and is beneficial to improving the efficiency of lactulose synthesis.

Prebiotic formulations can modulate the growth and / or activity of microorganisms in the urogenital area. Such prebiotic formulations can comprise isomaltulose along with at least one other prebiotic, such as 1-kestose or lactulose. These microorganisms which are modulated can be directly related to urogenital health, and their modulation can be used for the prevention, control, or treatment of dysbiosis of the urogenital area.

The invention discloses a cellobiose 2-epimerase mutant as well as a gene, an expression vector, recombinant bacteria, a preparation method and application thereof. The mutant is obtained by performing the following point mutation on an amino acid sequence as shown in SEQ ID No.1: S12A, S24A, G131A, G176A, G224A, K46R, K69R, K72R, K91R, K103R, K201R, K219R, K223R, K241R, K263R, K266R, K273R, K284R, K325R, K335R, K349R and K387R. The invention further discloses a preparation method of the mutant. The invention further discloses a gene segment, a plasmid and a recombinant bacterium for recombinant expression of the mutant, and the gene segment, the plasmid and the recombinant bacterium are used for recombinant expression preparation of the mutant. The mutant can be used for continuously and stably catalyzing and preparing lactulose at high temperature, is relatively good in thermal stability and has a relatively good industrial application prospect.

The invention discloses an N-acetyl glucosamine 2-epimerase mutant as well as preparation and application of the N-acetyl glucosamine 2-epimerase mutant. The mutant enzyme comprises an amino acid sequence as shown in SEQ ID No.3. The preparation method comprises the following steps: by taking a recombinant vector containing a Sumo enhancing element and a wild type N-acetyl glucosamine 2-epimerase gene as a template, carrying out PCR (Polymerase Chain Reaction) by adopting a mutation primer to obtain a mutant gene segment; transforming the mutant gene segment into an engineering bacterium to obtain a recombinant bacterium for expressing the N-acetyl glucosamine 2-epimerase mutant protein; culturing recombinant bacteria, collecting and crushing thalli, centrifuging thallus crushing liquid, and taking supernatant, so as to obtain crude enzyme liquid containing the enzyme mutant; the thermal stability of the wild-type enzyme is improved through point mutation of specific amino acid sites, and the substrate affinity and the catalytic efficiency of the mutant are superior to those of the wild-type enzyme. The mutant can be used for efficient catalytic preparation of lactulose, and has the advantages of few byproducts, high product yield and the like.

The present invention provides a neomycin-lactulose cocrystal and a preparation method thereof. The cocrystal is prepared from neomycin and lactulose. The powder X-ray diffraction pattern of the neomycin-lactulose cocrystal has diffraction angles 2θ=12.3°±0.2°, 13.9°±0.2°, 14.9°±0.2°, 16.2°±0.2°, 17.3°±0.2°, 18.1°±0.2°, 18.8° The neomycin-lactulose cocrystal of the present invention has characteristic peaks at 14.5°±0.2°, 19.5°±0.2°, 22.1°±0.2°, 23.2°±0.2°, 24.7°±0.2°, 25.4°±0.2°, 27.4°±0.2°, 28.0°±0.2°, 29.2°±0.2°, 29.8°±0.2°, 31.7°±0.2°, and 33.3°±0.2°. Compared with existing neomycin, the neomycin-lactulose cocrystal of the present invention has more stable physical properties and significantly improved bioavailability under the same conditions.

1. Name of the designed product: packing box (milk fruit sugar oral solution). 2. Use of the designed product: for product packing. 3. Design points of the designed product: combination of shape and pattern. 4. Picture or photo showing the design points: perspective view 1.

This invention discloses a pet food with coat-enhancing, shine-promoting, and coat-protecting effects, its preparation method, and applications. The food comprises the following components: chicken meal, fresh chicken meat, duck meal, sardine meal, chicken liver, sweet potato meal, corn meal, chicken heart, beef bone meal, duck meat pear, chicken oil, and egg yolk granules; coriander root powder, inulin, seaweed powder, beet pulp, flaxseed, fish oil, cranberry powder, carrot, krill, honeysuckle, turmeric, chrysanthemum, mannan oligosaccharide, lactulose, etc. The raw materials and auxiliary ingredients of this pet food are widely available, palatable, inexpensive, and readily available. The coriander root powder, other auxiliary ingredients, and nutritional supplements / additives work synergistically to improve the shine of the pet's coat, promote growth, and maintain coat health, while also improving the microstructure of the hair cuticle, fundamentally preventing pet coat health problems. The pet food preparation method disclosed in this invention is simple to operate, safe, and environmentally friendly, and is particularly suitable for feed products with high humidity and high heat sensitivity.

The invention provides novel injection type glycerine enema which comprises an injection assembly, and the injection assembly comprises an injection tube, a piston, a push rod, a push block, a nipple, a fixing ring, a sealing ring, a gradually-hardened tube, a cavity, an L-shaped plate, a clamping block, a flexible steel rope, a pull ring, a mounting block and a clamping groove. And a piston is connected to the inner wall of the injection tube in a sliding manner. The gradually-hard tube is inserted into a place where the injection tube is inserted, the push block is pushed to drive the push rod to move, the push rod drives the piston to slide on the injection tube, and liquid medicine is pushed in through the gradually-hard tube, outflow and injection caused by two-time extrusion of common glycerine enema are avoided through one-time injection of 20 ml, two-time mucosa damage is avoided, pollution caused by excrement back-pumping after extrusion is finished is avoided, and the injection efficiency is improved. The pull ring is pulled leftwards, the pull ring drives the clamping block to be separated from the clamping groove through the flexible steel rope, the sealing ring is moved to take down the gradually-hard tube, and the gradually-hard tube is disinfected and cleaned respectively, so that the comfort degree is improved, the rectal mucosa is not prone to being damaged, all liquid medicine can be pushed in in a pushing injection mode, and the liquid medicine is not left and wasted.

The present invention relates to the field of pharmaceutical preparations, and in particular, to a sevelamer carbonate dry suspension and a preparation method thereof. In the sevelamer carbonate dry suspension, the dosage of the suspending agent is 0.13 - 0.33% of the total mass, the dosage of the flocculant is 0.05 - 0.39% of the total mass, the dosage of lactulose is 72.53 - 86.90% of the total mass, the dosage of the flavoring agent is 0.34 - 0.72% of the total mass, and the dosage of the sevelamer carbonate crude drug is 12.51 - 26.20% of the total mass. This sevelamer carbonate dry suspension not only has excellent dispersibility, but also can improve its gastrointestinal side effects.

The invention relates to the technical field of calcium fortifying methods of foods, and particularly discloses a preparation method and application of a calcium fortified food for preventing constipation. The preparation method of the calcium-fortified food comprises the following steps: preparing a wall material: adding the wall material into deionized water, and stirring to obtain a wall material solution; the wall material is prepared from the following raw materials: modified starch, xanthan gum, carboxymethyl cellulose sodium, magnesium stearate, modified inulin, sodium alginate and fucoidin; the composition for improving constipation, Arabic gum, carrageenan, lactulose and perilla seed oil are mixed, stirred to be uniform, ground and sieved, and the core material is obtained; and mixing the core material solution and the wall material solution, homogenizing by a colloid mill, and spray-drying to obtain the calcium-fortified food. According to the calcium-fortified food for preventing constipation, all the components are matched with one another to jointly improve the mechanical property of the wall material, so that the wall material is not prone to being broken, the storage life of the food is further prolonged, and meanwhile the occurrence rate of constipation caused by calcium supplement products can be obviously reduced.

The embodiment of the invention discloses a preparation method of a concentrated lactulose solution. The method comprises the following steps: by taking a lactose solution as a raw material and sodium sulfite as a catalyst, carrying out an isomerization reaction in the presence of alkali, and then sequentially carrying out primary crystallization, primary centrifugal separation, deionization treatment, concentration, secondary crystallization, secondary centrifugal separation, filtration and concentration adjustment to prepare the concentrated lactulose solution. According to the method, a raw material recycling mode of'reaction-separation-circulation 'is adopted, lactose which does not participate in an isomerization reaction is recycled by adopting two-time crystallization centrifugal separation operation, and the lactose is put into the isomerization reaction again, so that the recycling of the raw materials is realized. The method effectively avoids the problem of environmental pollution caused by boric acid or borate as a catalyst, simplifies the process, reduces the cost, has high product purity, and is suitable for industrial large-scale production.

The problem addressed by this invention is to provide a method for producing a solid molded body excellent in transportation aptitude and solubility, and use thereof. Said problem is solved by a method for producing a solid molded body, the method comprising: a granulation step for granulating a composition containing a protein-containing food (a) and a carbohydrate (b); and a molding step for molding a granulated product obtained in the granulation step, wherein the amount of the carbohydrate (b) is 1-50 mass% with respect to the total amount of the composition, and the carbohydrate (b) contains one or more selected from the group consisting of maltose, erythritol, trehalose, glucose, lactose, lactulose, and dextrin.

The invention provides a gene expression cassette for improving CsCE expression quantity and application. The gene expression cassette provided by the invention comprises a regulatory element and a target gene, the regulatory element comprises at least one of a coding sequence of dtRNA, a coding sequence of a signal peptide and a coding sequence of a fusion tag, and the target gene comprises a coding sequence of CsCE enzyme. Wherein the dtRNA contributes to keeping the structural stability when the CsCE enzyme is transcribed into mRNA, the signal peptide can promote the secretion of the CsCE enzyme, and the fusion tag can assist the correct folding of the CsCE enzyme, so that the expression of the CsCE enzyme can be synergistically regulated under the three-tube alignment of a DNA transcriptional mRNA layer, a protein secretion layer and a protein folding layer, the expression quantity of the CsCE enzyme can be effectively up-regulated, and the expression quantity of the CsCE enzyme can be effectively up-regulated. Therefore, the volume enzyme activity of the CsCE enzyme is improved, and the CsCE enzyme with higher volume enzyme activity can catalyze lactose to be converted into lactulose in the preparation of lactulose, so that the preparation yield of lactulose is improved.

The prebiotic formulation is capable of modulating the growth and / or activity of microorganisms in a region of the urogenital system. Such prebiotic formulations can comprise isomaltulose and at least one other prebiotic, such as 1-kestose or lactulose. These modulated microorganisms can be directly related to the health of the urogenital system, and their modulation can be used to prevent, control or treat dysbacteriosis in the region of the urogenital system.

The invention discloses a functional composition and complete food for kidneys of dogs and cats and a preparation method of the functional composition and the complete food, and relates to the technical field of animal feed. The functional composition comprises a plant extract, prebiotics and probiotics. The plant extract consists of an astragalus extract, a rhodiola rosea extract, a centella asiatica extract, a gynostemma pentaphylla extract and a poria cocos extract. The prebiotics are composed of fucoidan, synanthrin and lactulose. The probiotics are prepared from streptococcus thermophilus, lactobacillus acidophilus and bifidobacterium longum. According to the functional composition and the complete food for the kidney of the dog and the cat and the preparation method of the functional composition and the complete food, plant extracts, prebiotics and probiotics are selected to be matched, and the functional composition and the complete food have the anti-oxidation, anti-inflammatory and anti-fibrosis effects on the kidney of the dog and the cat. The complete food containing the functional composition for the kidneys of the dogs and the cats is applied to pet food, so that the kidney injury of the dogs and the cats can be prevented or the disease progress of chronic kidney diseases of the dogs and the cats can be delayed.

The invention provides an intelligent preparation process and probiotics suitable for intestinal flora. The probiotics provided by the invention are prepared by adopting an intelligent production process, and have the advantages of high production efficiency and uniform proportioning of the probiotics, and the satisfaction degree and credibility of a user on products and services are enhanced. The probiotics at least comprise prebiotics, probiotic strains, a sweetening agent, a filling agent and / or a stabilizing agent; the prebiotics comprise at least one of isomaltooligosacharide, fructo-oligosaccharide, resistant dextrin and inulin; the probiotic strains comprise at least one of lactic acid bacteria, bifidobacterium lactis, lactobacillus casei and lactobacillus rhamnosus; the sweetening agent comprises at least one of sweet sorbitol and erythritol; the filling agent and / or the stabilizing agent comprise at least one of lactitol, lactulose and resistant dextrin. According to the intelligent preparation method, high-quality probiotics suitable for intestinal flora can be prepared in an intelligent preparation mode, and the intelligent preparation method has great benefits on intestinal peristalsis and digestive system of a human body.

The present invention relates to a preparation process of high-purity lactulose. The boric acid group contained in the boric acid ionic liquid of the present invention is selectively combined with lactulose generated by isomerization reaction, and lactulose is further extracted into the ionic liquid, thereby eliminating the product inhibition, so that the isomerization reaction proceeds in the direction of generating lactulose, thereby greatly improving the lactulose yield. The lactulose extracted into the ionic liquid exists in the form of [lactulose-boric acid complex]. By adding an acidic aqueous solution, the [lactulose-boric acid complex] is decomposed into lactulose and a boric acid ionic liquid, and the dissociated lactulose enters the acidic aqueous solution to obtain a high-purity lactulose solution, and the dissociated boric acid ionic liquid can be repeatedly recycled for a new batch of isomerization reactions. The preparation process of the present invention has mild reaction conditions, recyclable reaction catalysts, energy saving and environmental protection, and is more suitable for industrial production.

The invention provides a method for separating lactulose and lactose by using a sequential simulated moving bed chromatography system, and relates to the technical field of saccharide separation and purification. According to the invention, the sequential simulated moving bed chromatography system is used for separating and purifying lactulose, and the analysis area, the refining area, the adsorption area and the isolation area can be operated at the same time under the set temperature condition, so that the separation and purification efficiency of lactulose is remarkably improved, continuous large-scale separation and purification of lactulose can be realized, the separation and purification effect is good, the yield is high, and the product quality is good. According to the method, pure water is used as an eluent, so that analyzed and purified compounds are free of damage and toxicity, rich in source and low in cost.

The invention belongs to the technical field of food processing, and provides horse milk powder for improving intestinal health and a preparation technology thereof. The horse milk powder capable of improving intestinal health is prepared from the following components in parts by weight: 60 to 70 parts of whole horse milk powder, 3.0 to 4.0 parts of galactooligosaccharide, 4.0 to 5.0 parts of lactulose, 3.5 to 4.5 parts of beta-glucan, 1.5 to 2.5 parts of inulin, 5.0 to 6.0 parts of complex probiotics, 2.5 to 3.5 parts of pachymaran, 6.5 to 7.5 parts of astragalus polysaccharide and 5.0 to 6.0 parts of calcium carbonate. According to the horse milk powder capable of improving intestinal health disclosed by the invention, medicinal and edible components are added, and probiotics and various prebiotics are compounded, so that the activities of DAO, D-LAC and MPO in intestinal tissues can be remarkably reduced, the contents of acetic acid, propionic acid and butyric acid are increased, and the barrier function of the intestinal tract is improved.

This invention discloses a cellobiose epimerase mutant, engineered bacteria, and its applications. The mutant is obtained by mutating leucine at position 227 of the cellobiose epimerase to valine. The nucleotide sequence of the cellobiose epimerase is shown in SEQ ID NO.1. This invention involves site-directed mutagenesis of existing cellobiose epimerases, maximizing the catalytic performance of the natural enzyme. The resulting mutant exhibits a high lactulose conversion rate. Under optimized conditions, using crude enzyme solution from recombinant bacteria as a catalyst and lactose as a substrate, the conversion rate from lactose to lactulose reaches 70%–73.3%, while the yield of ipilactose is only 7–10%, lower than the byproduct ratio allowed by the Chinese Pharmacopoeia. This demonstrates the potential for large-scale application and has extremely high application value in the industrial production of lactulose.

The invention discloses a method for preparing lactulose by electrolysis, comprising the following steps: S1, electrolyzing water; applying a direct current power supply until the pH value of the solution is 14.0 to 14.8; stopping the electrolysis; S2, adding lactose and a montmorillonite / chitosan / Al(OH)3 complex to one side of a hydroxyl aggregation unit; S3, stirring, converting lactose into lactulose, reducing the pH value of the solution of the hydroxyl aggregation unit to 7.5 or below, and at the same time, adding a montmorillonite / chitosan / Al(OH)4 ‑ Converted into montmorillonite / chitosan / Al(OH)3 complex; S4, filter the material, separate the solution and the solid from each other, and obtain a mixture of lactose and lactulose; S5, separate the obtained mixture of lactose and lactulose through a membrane, crystallize, and dry to obtain lactulose; the present invention utilizes electrolysis in conjunction with an electric field to separate and enrich hydrogen ions and hydroxide ions, enriches and catalyzes the conversion of lactose into lactulose through adsorption, and the catalyst has a stable structure and is easy to separate.

The application discloses a cellobiose epimerase mutant with high lactulose yield and application thereof, and belongs to the technical field of enzyme engineering. Dictyoglomus The cellobiose epimerase (referred to as Disp-WT enzyme) derived from microorganism Bifidobacterium longum sp. is used as a parent, a gene mutation technology is used, a histidine His at the 245th position is replaced by glutamic acid Glu, and a mutant H245E is obtained.The optimal catalytic condition of the mutant enzyme H245E does not change, but the isomerase activity of the enzyme at 85 DEG C is increased to 254 % of the original, and the generation amount of epi-lactose is greatly reduced.This finding has important research value for researching more cellobiose epimerases with low isomerase activity.