68 results about "Alkaline xylanase" patented technology

A method of using compound enzyme preparation to execute same bath boiling-off and bleaching to cotton fabric, relates to a plurality of alkaline enzyme preparation in the application technique field of the cotton fabric boiling-off and bleaching technique. The enzyme preparation for boiling-off and bleaching is compounded and mixed by horniness enzyme , alkaline pectic enzyme, alkaline xylanase, alkali cellulose enzyme and sugar oxidizing enzyme. The invention adds in the compound enzyme preparation, amylaceum, oxygen bleaching stabiliser RB-3, osmotic agent and JFC triton X-100 under the condition of 55-70 EDG C and ph 8-10 to execute boiling-off to the cotton fabric. After the boiling-off, four acetyl ethylene diamine (TAED) is added in the boiling-off bath to activate hydrogen peroxide to bleach the fabrics for 30min. After the inventive process to cotton fabric, the invention has a high cotton fabric impurity clearance, good fabrics wetting property and high whiteness. The invention is adopted to substitute the traditionary concentrated alkali high temperature chemical processing method, thereby having saved energy, reduced consumption, short process flow and friendly surroundings.

The invention relates to the field of genetic engineering, specifically to alkaline xylanase with improved heat stability and a coding gene and application thereof. According to the invention, the crystal structure of Bacillus subtillis B230 xylanase xyn-B230 is used as a starting structure, and selected mutation sites are S23H and I129Y. Compared with the xylanase xyn-B230, mutated xylanase has substantially improved heat stability and can retain 90% of enzymatic activity when maintained at a temperature of 70 DEG C for 120 min and more than 65% of enzymatic activity when treated at a temperature of 75 DEG C for 30 min. The xylanase xyn-B230-m has good properties and is applicable to the industry of papermaking.

The invention relates to an alkalic xylanase gene and an engineering bacterium containing the same. The alkalic xylanase gene has the overall length of 687 bp, is called XynG1-3, encodes 228 amino acids and predicts that the molecular weight of the amino acids is 25444Da, wherein the first 27 amino acids are signal peptides of the alkalic xylanase gene, and 38th-221st amino acids are conserved sequences of a glycoside hydrolase GH11 family. Compared with a reported xylanase gene sequence, individual nucleotides of the obtained and expressed alkalic xylanase gene are different; the optimal operative temperature and the optimal pH of the recombinase are respectively 55 DEG C and 8.0, relative enzyme activity is more than 50 percent after preserving heat at the pH of 9.0 and 60 DEG C for 1 hour, and the relative enzyme activity is more than 70 percent after preserving the heat under the conditions of the pH of 6-9 and the temperature of 55 DEG C for 1 hour.

The invention discloses an alkaline xylanase-containing dedicated enzyme for piglets and a preparation method of the alkaline xylanase-containing dedicated enzyme, and belongs to the technical field of enzyme preparation. Thermophilic bacillus culture, acidic xylanase, beta-glucanase, acid protease, cellulose, amylase, beta-mannase, phytase, Chinese herb extracts, a protective agent and an activating agent are scientifically compounded to prepare the dedicated enzyme, wherein thermophilic bacillus cells in the thermophilic bacillus culture can improve animal body immunity, promote the development of immune organs, promote the maturity of animal intestinal structures and functions, and increase piglet daily gains and feed conversion rates. According to the invention, a safe digestive enzyme, namely the dedicated enzyme, is provided for piglets; the digestion burden is effectively reduced; the utilization rates of the raw materials and the growth rates of the piglets are increased; the environment is effectively protected; the effectiveness of the enzyme preparation can be brought into full play due to the addition of a proper amount of the activating agent; due to the scientific compound of the Chinese herb extracts, not only is the expiration date of the complex enzyme preparation prolonged, but also the immunity of the piglets is improved.

The invention discloses a bleaching compound enzyme for papermaking and a preparation method of the bleaching compound enzyme. The bleaching compound enzyme for papermaking, which has the advantages of complete enzyme system, good bleaching effect, easiness in preservation and good storage stability, is prepared by taking high temperature-resistant alkaline xylanase as main raw material, scientifically compounding a thermophilic bacillus culture, laccase and a medium thereof, dextranase, EDTA (ethylenediaminetetraacetic acid), a protecting agent, an activator, mannose, lipase, tannase, pectase, a whiteness stabilizer, a nonionic surfactant, an antioxidant and the like, completely retaining paper pulp cellulose and simultaneously dissolving out and degrading lignin to the greatest extent. The bleaching compound enzyme disclosed by the invention can significantly improve yield and quality of paper pulp against broad-leaf wood, coniferous wood and reed yellow slurry, and the whiteness is improved by 10.94%, 11.97% and 11.10% respectively; the yellow index is reduced by 39.84%, 37.31% and 24.32% respectively; the amount of conventional chemical products can be saved by 50-60%; and the purposes of reducing cost and protecting an environment are finally achieved.

The invention discloses a composite enzyme preparation for degumming of a linen fiber raw material, a preparation method of the composite enzyme preparation and a degumming method of the linen fiber raw material. The composite enzyme preparation comprises components in percentage by mass as follows: 70% of alkaline pectate lyase, 2% of alkaline cellulase, 18% of alkaline xylanase and 10% of laccase. With the adoption of the technical scheme, more than 20% of bleaching liquor is reduced in the linen fiber bleaching process, more than 40% of caustic soda is reduced in the linen fiber bleaching process, the breaking strength of the linen fiber is increased by more than 5%, the fineness of the linen fiber is increased by more than 20%, the elongation at break is increased by more than 30%, the fiber strength is uniform, the spinnability of the fiber is remarkably improved, accordingly, economic benefits are increased, and the production cost is reduced; the COD (chemical oxygen demand) is reduced by more than 30%.

The invention relates to the genetic engineering field, and concretely relates to high temperature alkaline xylanase XYN10A, a gene thereof and an application thereof. The new high temperature alkaline xylanase XYN10A provided by the invention has an amino acid sequence represented by SEQ ID NO.1 or 2. The gene which codes the high temperature alkaline xylanase XYN10A and has a nucleotide sequence represented by SEQ ID NO.4 or 5, a recombinant vector containing the gene, a recombinant strain containing the gene, and the application of the xylanase XYN10A are also provided. The xylanase provided by the invention, which has an optimum pH value of 7.0, has an enzymatic activity of more than 75% in the pH value range of 5.0-10.0, and has an enzymatic activity of more than 50% and a good pH stability when the pH value is 12.0, has an optimum temperature of 70DEG C. The xylanase XYN10A of the invention can effectively degrade various types of xylans, cannot degrade celluloses, and performs large potentials in the papermaking industry and the textile industry.

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 an alkaline biological enzyme deinking agent and an application technology thereof in waste paper deinking, and belongs to the industrial field of a novel biocatalyst and an application thereof. According to the technical scheme, the application technology comprises the following steps: making waste paper into paper pulp liquid with the pulp concentration of 10%-15%, adding 0.5*10<6>-15*10<6>U of alkaline lipase (ARL) and 0.2*10<6>-1*10<6>U of alkaline xylanase to per ton of oven dry stock, then adding a surface active agent-tween-80 to 0.06% oven dry stock (w / w), uniformly blending, and pulping for 20 minutes to 30 minutes at the optimum temperature of enzyme; and then carrying out flotation for 7 minutes to 10 minutes in a flotation tank under the conditions of the pulp concentration of 1% and the temperature of 60-65 DEG C, and washing for 2 minutes to 3 minutes with water by a punching sieve, thus obtaining delinked pulp. By adopting the deinking technology, the yield of the paper pulp is relatively high, and the COD (Chemical Oxygen Demand) value of waste water is low. The deinking technology is suitable for large-scale industrial application in production.

The invention discloses a method for preparing high-temperature-resistant alkaline xylanase, belonging to the technical field of preparation of enzyme preparations. Bacillus thermophilus 701 capable of producing high-temperature alkaline xylanase is taken as a starting strain, and high-temperature-resistant alkaline xylanase, which has strong high-temperature resistance and alkali resistance, wide acting conditions, no cellulase activity and is suitable for the fields such as papermaking, food and feed, is prepared by optimizing the culture medium composition and fermentation process in a way of liquid submerged fermentation. The specific activity of the enzyme is 350-420IU / ml; the optimal reaction temperature is 65 DEG C, the application temperature range is 40-75 DEG C; the optimal reaction pH value is 10.0 and the pH range applicable to reaction is 5.0 to 11.0.

The invention belongs to the genetic engineering technology field, and specifically relates to a new alkaline xylanase and a code gene thereof. The invention discloses a sequence of the gene and a coding area thereof. Escherichia coli DH5alpha / Mn22 / 6p / Kxyn which contains the gene plasmid is collected in China Center for Type Culture Collection (CCTCC) with the collection No. of M208201. The xylanase Kxyn is proved to have strong alkali resistance and thermal stability through the biological verification, thereby being capable of specially degrading xylan. The xylanase Kxyn can be used for paper making and other related fields.

The invention relates to the field of dyeing, in particular to a composite boiling-dyeing one-bath enzyme and a dyeing method. The enzyme comprises the following components by mass percentage: 5-30 percent of acidic cellulase, 2-30 percent of alkaline pectinase, 0.1-20 percent of alkaline xylanase, 0.1-10 percent of mannose and balance of water. The method for formula treatment is a boiling-dyeing one-bath short-flow process, a refining process is omitted, and pretreatment and one-bath dying are enabled to be synchronously performed. The boiling-dyeing one-bath enzyme is sued for boiling-dyeing one-bath short-flow treatment, treated fabrics are dyed more deeply, the chromatic aberration of dyed cotton fiber and modal fabrics is small, horizontal marks which occur on the surfaces of the fabrics are remarkably reduced and the grade of chromatic aberration reaches grade 5 through national standard grey card chromatic aberration rating.

The invention discloses a basophilic micrococcus and alkaline xylanase produced by the basophilic micrococcus and an application. The basophilic micrococcus is a bacterial strain for producing alkaline xylanase, which is obtained by screening from mangrove soil in Shenzhen. The invention further discloses the alkaline xylanase produced from the basophilic micrococcus. The enzyme has excellent enzymatic characteristics of wide pH application range, heat resistance and alkaline resistance; metal ions, a surfactant and the like are suitable for industries such as papermaking. The basophilic micrococcus disclosed by the invention belongs to alkali-resistant extremophiles, can be cultivated under a high-alkali condition, and has the characteristics that living contaminants can be effectively inhibited, and large-scale fermenting production is facilitated.

The invention discloses a method for preparing alkali-resistant xylanase by screening Suaeda salsa, and belongs to the technical field of alkali-resistant xylanase preparation. The present invention mixes glucose, cellulose, etc., prepares bacterial culture medium through high-temperature sterilization, inoculates Bacillus pumilus M-26, and cultivates Bacillus pumilus colonies for use. Blank Suaeda pumilus culture medium was prepared by mixed magnesium sterilization, inoculated with Bacillus pumilus colonies, repeatedly cultivated and screened to obtain alkali-resistant Bacillus pumilus colonies, filtered to obtain a filtrate, centrifuged to obtain a supernatant, mixed with ammonium sulfate, and treated in an ice-water bath, isolated The bottom layer of the experience was precipitated and freeze-dried to obtain alkali-resistant xylanase. The beneficial effects of the present invention are: the preparation steps of the present invention are simple, the production cycle is shortened by 11.2%, and the yield is increased by more than 25.6%; The effect is good.

The invention discloses alkaline xylanase as well as a coding gene and an application thereof and belongs to the technical field of biology. The gene sequence of WMN-3 is a complete ORF (open readingframe), wherein the ORF starts with start codon ATG, stops with stop codon TAA and totally contains 1476 nucleotides, and the nucleotide sequence is shown as SEQ ID NO:1. An amino acid sequence of a protein coded by a gene of alkaline xylanase WMN-3 is shown as SEQ ID NO:2. The invention further discloses the application of the alkaline xylanase WMN-3 to industries such as papermaking and the like.

A method for scouring and bleaching cotton fabric with composite enzyme preparation in one bath is provided. The method relates to the application of composite alkaline enzyme preparation in scouring and bleaching processes of cotton fabric. The enzyme preparation for scouring and bleaching cotton fabric is compounded from cutinase, alkaline pectase, alkaline xylanase, alkaline cellulose, and carbohydrate oxidase. The method includes: scouring the cotton fabric by adding the composite enzyme preparation, glucose, oxidation bleaching stabilizer RB-3, penetrant JFC, and Triton X-100 in a treating bath at 55-70° C. and pH 8-10, and then bleaching the cotton fabric for 30 min by directly adding tetraacetyl ethylenediamine (TAED) in the scouring bath to activate hydrogen peroxide. After being treated by the method of the present invention, the cotton fabric has high impurity removal ratio, favorable wettability, and high whiteness. The present invention has the advantages of low power consumption, short process flow, and being environment friendly, and may be used to replace conventional chemical treatment process under the condition of concentrated alkali and high temperature.

The invention discloses alkaline xylanase as well as an encoding gene and application thereof. The S1 gene sequence is a complete open reading frame (ORF), the open reading frame starts with an initiation codon ATG and ends up with a termination codon TAA and comprises 609 nucleotides in all, and the nucleotide sequence of the open reading frame is as shown in SEQ ID No:1. The nucleotide sequence of the protein of the gene code of alkaline xylanase S1 is as shown in SEQ ID No:2. The invention further discloses application of the alkaline xylanase S1 in industries such as paper making.

The invention relates to the field of gene engineering, and particularly relates to high-temperature alkaline xylanase XYN11A as well as a gene and an application thereof. An amino acid sequence of the xylanase XYN11A is as shown in SEQ ID NO.1 or 2. The invention also provides the gene for coding the high-temperature alkaline xylanase XYN11A, a recombinant vector containing the gene, a recombinant strain containing the gene and an application of the gene, wherein a nucleotide sequence of the gene is as shown in SEQ ID NO.4 or 5. The optimum pH of the xylanase provided by the invention is 7.0, and the xylanase has enzyme activity of above 75% in the pH range from 5.5-8.5 and very good pH stability in the pH range from 4.0-12.0; and the optimum temperature of the xylanase is 60 DEG C. The xylanase XYN11A provided by the invention can be used for effectively degrading various types of xylan, has no degradation effect on celluloses, is a novel enzymic preparation and has enormous potential and commercial value when being applied in papermaking and textile industries.

The invention discloses a cotton fabric bio-enzyme and a method for performing co-bath scouring and bleaching on a cotton fabric. The cotton fabric bio-enzyme comprises the following components in parts by weight: 5-10 parts of cutinase, 5-10 parts of protease, 5-10 parts of alkaline pectinase, 20-30 parts of alkaline xylanase, 5-10 parts of B-1, 4-glucan glucano-hydrolase, 10-20 parts of glucose oxidase and 15-25 parts of laccase. The cotton fabric bio-enzyme disclosed by the invention is adopted for performing co-bath scouring and bleaching on the cotton fabric, the treatment conditions are mild, the damages to the fabric are small, an environment is friendly, the process flow is short, and the energy consumption is saved.

The invention discloses a compound enzyme preparation for promoting fiber modification through pulping novel household paper and a preparation method and application thereof. The compound enzyme preparation comprises, by mass, 70% of an alkaline pectic acid disintegrating compound enzyme, 2% of alkaline cellulase, 18% of alkaline xylanase and 10% of laccase. By adopting the technical scheme, in the process of degumming, consumption of bleaching liquid in the process of bleaching flax fibers is reduced by higher than 20%, consumption of caustic soda in the process of bleaching the flax fibers is reduced by higher than 40%, breaking strength of the flax fibers is increased by higher than 5%, fineness is increased by higher than 20%, elongation at break is increased by higher than 30%, the fibers are uniform in strength, and spinnability of the fibers is improved remarkably, so that economic benefit is increased, production cost is lowered, and COD is lowered by higher than 30%.

The invention discloses a xylanase (Xyn A) gene derived from streptomyces chartreusis. The gene comprises nucleic acid and protein / polypeptide sequence. The xylanase encoded by the gene has 1393 base pairs; the content of G and C is 68%, the gene encodes 460 amino acids, the molecular weight is about 48.2 kDa, the isoelectric point (pI) is 9.04, and the gene contains a section of signal peptide sequence. The xylanase has a typical structure of F / 10 glucoside hydrolase, can translate a section of cellulose binding domain (CBD) with a molecular weight of 10 kDa. The enzyme activity, which is measured by a DNS method, of xylanase is 19.7 + / - 1.2 U / mL. The alkaline xylanase and products thereof can be applied to papermaking industry, textile industry, food processing, biological energy, feed industry, cosmetics, medicine, health products, wine industry, crop production, and various biological reactors.

The invention discloses a bleached compound enzyme and a preparation method thereof. The preparation method comprises the following steps: by taking high-temperature-resistant alkaline xylanase as a main raw material, scientifically compounding a bacillus thermophilus culture, laccase and media thereof, dextranase, EDTA, a protective agent, an activating agent, mannose, lipase, tannase, pectinase, a whiteness stabilizer, a nonionic surfactant and an antioxidant, dissolving the lignin to the greatest degree when the pulp cellulose is completely remained, degrading the lignin, thereby obtaining the bleached compound enzyme with the advantages of complete enzyme system, good bleaching effect, simplicity in preservation and good storage stability. According to the broadleaf wood, needlebush and reed yellow pulp, the pulp yield and quality can be obviously improved, and the whiteness is respectively improved by 10.94 percent, 11.97 percent and 11.10 percent; the yellowing value is respectively reduced by 39.84 percent, 37.31 percent and 24.32 percent; the amount of conventional chemicals can be saved by 50-60 percent; and finally, the aims of reducing the cost and protecting the environment are achieved.

The invention discloses an alkaline xylanase activity determination method and belongs to the field of xylanase activity determination. The method comprises the following steps: preparing a sodium biphosphate-sodium hydrogen phosphate buffer solution with the pH value of 7.8, and on the basis, preparing a xylose standard solution, a xylan standard solution and an alkaline xylanase sample; creating a xylose absorbency-xylose concentration standard curve; in the alkaline environment with the pH value of 7.8, using alkaline xylanase to be detected to hydrolyze xylan, and detecting the absorbency AE of the xylose obtained through hydrolysis; meanwhile, providing a blank control group not added with alkaline xylanase and determining the absorbency AB; correspondingly acquire the content of hydrolysis product xylose according to the measured absorbency of xylose obtained through hydrolysis by use of a standard curve; calculating the alkaline xylanase activity according to a formula. The alkaline xylanase activity determination method is improved to solve the problem that a conventional detection method cannot be used for objectively reflecting the activity of alkaline xylanase.

This invention is a manufacturing method of bacterial xylanase. Its characteristics are: adopt heat-fast subtilin as creating bacterial seed and manufacture bacterial xylanase through liquid deep-seated fermentation. The bacterial xylan ase of this method has high hydrolysis and can effectively hydrolyze the substance to produce the alkali ase with low or high molecular weights, it has wide range of pH value and has better function in different animal livers. This invention adopts deep-seated liquid fermentation to produce bacterial xylanase with good enzyme performance, and the producing glow is easily controlled, the manufacturing cycle is short, the quality of products is stable, and it is suitable for industrial manufacture and the roboticized degree is high.

The invention discloses recombinant basic xylanase resistant to chelating agent ethylenediamine tetraacetic acid and a construction method thereof. A basic xylanase encoding gene xynA is mutated by adopting a site-directed mutation technology to obtain mutant genes xynA-M-W19Y, xynA-M-W19F and xynA-M-W19H, induction, expression and purification are performed in E.coli BL21(DE3), enzyme activity determination is performed to purified enzyme, and the obtained xylanase mutants XynA-M-W19Y, XynA-M-W19F and XynA-M-W19H have a better capacity of resisting EDTA, wherein under conditions of pH 9.2, 60DEG C and 5mM EDTA, the enzyme activity of a mutant W20Y is approximate 20 percent higher than the enzyme activity of wild type XynA. Thereby, a good foundation is laid for the wide application of basic xylanase.

The invention provides an alkaline xylanase mutant and application thereof. Protein engineering modification is performed on the xylanase derived from bacillus to obtain a mutant protein; the heat resistance and the optimum reaction pH of the mutant protein are remarkably increased, and therefore, the mutant protein can be widely applied to the field of papermaking. The amino acid sequence of the xylanase mutant is SEQ ID NO: 3. The optimum pH of the xylanase mutant XynT6 is 9.0; more than 75% of enzyme activity can be kept within the pH range of 7.0-10.0, and the enzyme activity level of the mutant under the alkaline condition is obviously higher than that of a wild type; the optimum operation temperature of the xylanase mutant XynT6 is 60 DEG C, and about 80% of enzyme activity of the xylanase mutant XynT6 still can be kept under the condition of 65 DEG C, and therefore, the xylanase mutant XynT6 has better heat resistance than the wild type. The xylanase mutant XynT6 is capable of effectively improving the whiteness of the paper pulp, advantageous for a papermaking enterprise to improve the paper pulp bleaching process, reduce the use of a chemical bleaching agent and reduce the environmental pollution, and wide in prospect.

The invention discloses basophilic streptomyces as well as alkaline xylanase produced by the basophilic streptomyce and application. The basophilic streptomyces is an alkaline xylanase producing strain screened from soil of a mangrove forest. The invention further discloses the alkaline xylanase produced by the basophilic streptomyce; the alkaline xylanase has a wide pH (Potential of Hydrogen) applicable range, resists heat, alkali, metal ions, a surfactant and the like and has good enzymatic characteristics that the alkaline xylanase is applicable to industries including papermaking and the like; the alkaline xylanase can be applied to the industries including the papermaking and the like. The basophilic streptomyces disclosed by the invention belongs to an alkali-resisting extreme microorganism and can be cultured under a high-alkaline condition; the basophilic streptomyces has the characteristics that bacterium pollution can be effectively inhibited and large-scale fermentation production is easy to realize.

The invention discloses a special growing pig enzyme containing alkaline xylanase and a preparation method thereof, belonging to the technical field of preparation of enzyme preparations. The special growing pig enzyme is made by scientifically compounding a bacillus thermophilus culture, acid protease, acidic xylanase, beta-glucanase, pectinase, cellulase, amylase, phytase, Chinese herb extracts, a protective agent and an activating agent. Bacillus thermophilus thalli in the bacillus thermophilus culture can enhance the body immunity of animals, promote the growth of immune organs and maturity of the intestinal structures and functions of animals, and increase the daily gain of animals and the feed conversion ratio. By adopting the special growing pig enzyme, safe digestive enzymes are supplied to growing pigs, so that the digestion load is relieved effectively, the raw material utilization ratio and the growing rate are increased, and the environment is protected. Meanwhile, by adding a proper amount of the activating agent, the potency of an enzyme preparation can be brought into full play. The Chinese herb extracts are compounded scientifically, so that the shelf life of a compound enzyme preparation is prolonged, and the immunity of fed livestock can be enhanced.

The invention discloses a feed complex enzyme containing alkaline xylanase and a preparation method thereof and belongs to the technical field of enzyme preparations. The feed complex enzyme is prepared by scientifically compounding concentrated maltase, acid proteinase, alkaline xylanase, acidic xylanase, cellulose, beta-glucanase, pectinase, amylase, mannose, phytase, Chinese herb extracts, a protective agent and an activating agent. Alkaline xylanase has broad action conditions and strong thermal stability and is more suitable for animal growth. The feed complex enzyme provides a safe digestive enzyme for livestock and poultry, can be used for effectively reducing digestion burden, improving the utilization rate and growth rate of raw materials, effectively protecting the environment, bringing natural malt fragrance for the feed and increasing the appetite of livestock and poultry; a proper amount of activating agent can be used for fully exerting the effectiveness of an enzyme preparation under the equal condition and making the best of the raw materials; the addition amount of the enzyme preparation is saved; by virtue of the scientific compounding of the Chinese herb extracts, not only can the guarantee period of the complex enzyme preparation be prolonged, but also the immunity of the fed livestock and poultry can be improved.

The invention relates to the technical field of microbial fermentation and enzymic preparation and specifically relates to a method for preparing an alkali xylanase preparation by combining bran fermentation with spray drying. Bran fermentation is adopted; the alkali xylanase is generated by fermenting bran with bacillus pumilus; enzyme-generating activity of fermentation liquor is 2700IU / ml and is greatly improved; the fermentation liquor is prepared into the alkali xylanase preparation through spray drying, so that the salting out of ammonium sulfate is avoided and the emission of effluent is greatly reduced; the enzyme-generating activity during the preparation process of alkali xylanase preparation is increased by more than four times, the production efficiency is greatly increased andthe technical industrialization is benefited. The method provided by the invention comprises the processing steps of 1) fermenting and 2) preparing the enzyme preparation.