CN104256086B - Technology for preparing docosahexaenoic acid (DHA)-rich feed additive by grain dreg raw material through fermentation - Google Patents

Abstract

The invention discloses a process method for producing animal feed additives rich in polyunsaturated fatty acid (DHA), protein and xylooligosaccharides by using dross raw materials as culture medium and microbial fermentation. Specifically, it includes: (1) mixing the dross raw material with water to make a material with a certain solid-to-liquid mass ratio; (2) pretreating the mixed dregs raw material by hydrothermal extraction; (3) enzymatically pretreating the dregs; (4) Cultivate DHA-producing microorganisms with enzymatic hydrolysis of dregs; (5) Concentrate or dry the fermented liquid of Schizochytrium to make liquid or solid feed. The method of the present invention can make full use of the rich hemicellulose and cellulose contained in the dregs to prepare xylooligosaccharides and cellooligosaccharides with prebiotic effects, and use soluble lignin to prepare polyphenolic antioxidants; and after degradation The cellulose and starch can be used as a carbon source for microbial growth, and protein can be used as a nitrogen source for cell growth, thereby reducing the cost of carbon and nitrogen sources for microbial fermentation.

Description

Process for producing DHA-enriched feed additive by fermenting dross raw materials

technical field

The invention relates to a production process of a feed additive, in particular to a process for producing a DHA-rich feed additive by using dross materials as raw materials.

Background technique

DHA (docosahexaenoic acid) is an extremely important highly unsaturated fatty acid, which is an important component of human cell membranes and nerve tissues. DHA plays an important role in preventing cardiovascular diseases, inhibiting and treating cancer, ensuring the normal development of the fetus and promoting the development and growth of infants and young children. However, the daily DHA intake of Chinese people from food is only 40mg, while the recommended minimum standard intake is 160mg), which is a serious deficiency. Invention patent 201210385417.5 discloses "a microalgae powder rich in DHA and its preparation method". In this patent, the fermented liquid rich in DHA is directly processed into microalgae powder, which is then used as a feed additive in animal husbandry, aquaculture and It is effectively enriched in animals, and then through the food delivery route of "DHA-rich microalgae powder→animal body→human", so that human beings can take in sufficient amounts of DHA from their daily diet. However, in the prior art, the production cost of DHA algae powder is very high, and it is difficult to increase the DHA intake of the public through this method. Therefore, in order to reduce the cost of raw materials for fermenting and producing DHA algae powder, it is necessary to find cheap microbial culture carbon and nitrogen sources, and waste residue resources provide a way to solve this problem. The dross is the residual watery residue after extracting the available carbohydrates in the raw material, which contains a lot of nutrients such as crude fiber, crude protein and crude fat. my country is rich in waste material resources. Only brewing, starch, and fruit processing can produce about 100 million tons of waste residue each year, which is a valuable renewable resource that can be used.

There are a variety of techniques for preparing livestock and poultry feed by using dross, mainly including drying dregs directly to make dry feed and biological fermentation to prepare bacterial protein feed. For example, preparing DDGS from corn distiller's grains, this method not only has high cost and high energy consumption, but also does not make full use of the nutrients in the distiller's grains. The preparation of bacterial protein feed by biological fermentation is another process route using dross materials. At present, most of them are simple and direct cultivation of Saccharomyces cerevisiae or other microorganisms. Invention patent 201210276611.X discloses "a method for bio-modification of brewer's grains to produce feed", invention patent 201010525743.2 discloses "method for producing biological feed using cassava distiller's grains", and invention patent 200510019848.X discloses "a method for producing distiller's grains Bacterial Feed Method". However, the bio-fermentation method can only utilize the residual starch and monosaccharides in the residue, while the cellulose and hemicellulose have not been further utilized. CN201210420826 discloses a method for reusing distiller's grains, specifically: drying the distiller's grains, crushing them, adding water medium to fully soak them, and performing steam explosion pretreatment to obtain a steam explosion pretreatment material; said steam explosion pretreatment material It is used as a solid medium, and probiotics are added for solid fermentation to obtain fermented feed. Although the method can partially utilize the cellulose and hemicellulose in distiller's grains, the technical problem it solves is the production of biological feed containing probiotics, and the raw materials need to be dried first, resulting in excessive energy consumption.

Hydrothermal extraction has been widely used in the pretreatment of lignocellulose to improve the efficiency of enzymatic hydrolysis of cellulose. The hydrothermal extraction method has the following advantages: (1) It does not require the participation of chemical substances such as acid, alkali or ammonia, and will not cause corrosion to the reaction equipment; water is an environmentally friendly resource, which not only reduces costs, but also does not cause serious environmental problems ; (2) High-pressure hot water can break the structure of lignin, without the need for material crushing process before pretreatment, which reduces production energy consumption; (3) Under optimized conditions, hemicellulose can be made into the form of oligosaccharides to the greatest extent Dissolve, and control the formation of monosaccharides to prevent their continued degradation to produce fermentation inhibitors such as furfural. The starch, hemicellulose and part of the cellulose in the dregs can be converted into monosaccharides (glucose, xylose and arabinose) and xylooligosaccharides and cellooligosaccharides with probiotic functions by applying hydrothermal treatment; The protein, fat and trace elements in the concentrated dross can be extracted, and the starch, cellooligosaccharide and protein in the extract after enzymatic hydrolysis can be used as high-quality and cheap carbon and nitrogen sources for microbial growth.

In summary, combined with the high value-added advantages of DHA-rich products and the low-cost characteristics of dregs raw materials, the dregs were treated by hydrothermal pretreatment combined with enzymatic hydrolysis, and then the dregs in the treated extract were used Nutrients are used as carbon and nitrogen sources for the growth of DHA-producing microorganisms to produce DHA-rich feed additives. On the one hand, it can maximize the utilization of nutrients in dross raw materials, and on the other hand, it reduces the cost of producing DHA by fermentation. Therefore, It is a feasible and efficient method for utilizing dregs of agricultural by-products.

Patent EP 2520608 A1 discloses a method of applying continuous hydrothermal method to pretreat lignocellulose to improve the efficiency of enzymatic hydrolysis of cellulose and the yield of ethanol. However, this method only solves the problem of degradation of lignocellulosic materials, and does not solve the problem of processing waste residue materials with high protein, high starch and high water content. Patent CN 103221518 A applies the hydrothermal carbonization method to the treatment of brewing slag, but under its process conditions, the biological material undergoes hydrothermal carbonization, and this method finally converts the brewing slag into high-carbon products (biological coal and humus).

Contents of the invention

Based on the problems in the prior art in the utilization of dregs and the production of DHA-rich feed, the present invention provides a process for producing feed additives rich in DHA, protein and xylooligosaccharides by using dregs as a medium and using microbial fermentation method.

Technical scheme of the present invention: the process of producing DHA-rich livestock and poultry feed additives by using dross materials, comprising the following steps:

①Material pretreatment: uniformly mix the dross material to be treated with water to obtain a mixed material, adjust the pH value of the mixed material to 3-8; the mass ratio of dry dregs and water in the dregs material is 1 :3-1:50; the slag-like material is any one or any combination of brewing slag, starch slag and pomace; the dry slag and water in the slag-like material in the step ① The mass ratio of is preferably 1:3-1:10, most preferably 1:3-1:8.

The brewing slag refers to the dross by-products produced in the production process of producing products containing ethanol and acetic acid by using starch-containing plant materials as fermentation raw materials and using plant stalks and seed shells as filling auxiliary materials, such as distiller's grains and distiller's grains. Vinegar bad. The starch-containing vegetable material includes tubers, roots, whole grains, and any combination thereof of starch-containing material. The starch-containing material includes corn, wheat, sorghum, barley, cassava, sweet potato, potato, rye, pea, soybean or any combination of the above materials. Plant stalks used for filling auxiliary materials are preferably barley stalks, wheat stalks and corn stalks; seed husks used for filling auxiliary materials are preferably rice husks. This kind of dross by-products contains: (a) fiber, husk, germ, oil, protein, and incompletely fermented starch and bacteria from starch raw materials; (b) lignin, Cellulose and hemicellulose.

The starch slag refers to the starch slag produced in the process of preparing starch from starch-containing materials. The starch-containing material includes corn, wheat, sorghum, barley, cassava, sweet potato, potato, rye, pea, soybean or any combination of the above materials. Preferred starch residues include corn starch residues, sweet potato starch residues, tapioca starch residues, potato starch residues. Starch residue contains fiber, husk, germ, oil and protein components from the starch raw material and residual starch.

The pomace refers to by-products obtained after fruit juice is squeezed. Such fruits include apples, grapes and citrus. The pomace contains cellulose, hemicellulose, lignin, protein and fat from the peel, stone and stem.

②Hydrothermal treatment: transfer the mixed material prepared in step ① into a container, and slowly heat it up to T1 under agitation; keep it warm at T1 for 1-180 minutes, and then quickly cool it down to T2 to obtain a hydrothermal distiller Slag; the T1 is 120-230°C, and the T2 is 20-80°C. After hydrothermal treatment, the starch in the dross is degraded into dextrin, the hemicellulose is degraded into xylan, xylooligosaccharide and xylose with low degree of polymerization, and part of the cellulose is dissolved and degraded into cellooligosaccharides, The indigestible protein - gliadin can be converted into a protein that is easily digested by the enzyme. The physical and chemical properties of the dross have changed dramatically, making it easier to be hydrolyzed by enzymes.

③Enzymatic hydrolysis treatment: (a) Batch enzymatic hydrolysis: adjust the temperature of hydrothermal dregs to 20-90°C, and adjust the pH value to 3-8; then add glucoamylase and xylan to hydrothermal dregs Enzyme, cellulase, after reacting for 48-72 hours, then add protease to react for 2-24 hours to obtain enzymolysis material; or (b) feeding batches: adding hydrothermal residues to the enzyme solution in batches, the The enzyme solution is a mixed enzyme solution of glucoamylase, xylanase and cellulase. After reacting for 48-72 hours, protease is added to react for 2-24 hours to obtain the enzymolysis material. After enzymatic hydrolysis, starch and some cellooligosaccharides are degraded into glucose, xylan is degraded into xylooligosaccharides, and proteins are degraded into short peptides and amino acids.

The glucoamylase (α-1,4-glucohydrolase, EC.3.2.1.3) can use one or more glucoamylases, and the amount of the enzyme added is 0.02-200 AGU per gram of dry dregs solid. The xylanase is an endo-1,4-beta xylanase (3.2.1.8), preferably an endo-1,4-beta xylanase of GH10 or GH11; the xylanase The dosage is to add 1g of xylanase per 1×10 ² -1×10 ⁵ g of dried grain residue or 1×10 ⁶ IU of xylanase with total enzyme activity. The cellulase is an enzyme with cellobiohydrolase activity (EC3.2.1.91) and endoglucanase (EC3.2.1.91) activity and beta-glucosidase (EC3.2.1. 21) Active enzymes, the enzymes with cellobiohydrolase activity (EC3.2.1.91) include cellobiohydrolase I and cellobiohydrolase II; the added amount of the cellulase is per gram Add 0.1-100FPU enzyme to the dry residue solid. The protease is an acid protease, and its added amount is 1×10 ^-4 -1×10 ² LAPU enzyme per gram of dry distiller's grain solid.

④ liquid-solid separation: the solid in the enzymolysis material is separated from the liquid, and the separation method is centrifugation, pressing or filtration; preferred embodiments include plate and frame filter presses, belt filter presses, screw presses and Butterfly centrifuge. The solid phase components are mainly cellulose, lignin and minerals; the liquid phase components include glucose, cellooligosaccharides, xylooligosaccharides, proteins, polypeptides, amino acids and phenolic substances, and a small amount of acetic acid.

⑤ Microbial fermentation: adjust the concentration and ratio of carbon source and nitrogen source in the liquid phase after liquid-solid separation, add essential nutrients (yeast extract, vitamins, metal ions, phosphate, etc.), and then inoculate DHA-producing microorganisms, Microbial fermentation is carried out to obtain a microbial fermentation liquid. The DHA-producing microorganisms are Schizochytrium/Aurantiochytrium sp, Thraustochytrium, Crypthecodinium, Ulkenia and Mortierella Any one of the genera (Mortierella) or any mixed group of multiples.

⑥Drying and pulverizing: (a) drying and pulverizing the mixture of various microbial fermentation culture fluids to obtain solid feed additives; or (b) drying and pulverizing single microbial fermentation fluids and mixing them to obtain solid feed additives. The drying method is freeze drying, vacuum drying, hot air drying or spray drying. Freeze-drying is preferred, because drying under low temperature and vacuum conditions effectively protects the easily oxidized and heat-sensitive DHA. At the same time, the polyphenolic antioxidants produced by hydrothermal extraction of dross lignin can also play a protective role on DHA.

The use of the livestock and poultry feed additive prepared by the above method is used as a feed additive for livestock and poultry, aquaculture animals and companion animals; the livestock and poultry include cattle, pigs, chickens, ducks and geese, and the aquaculture animals include shrimp and fish; the companion animals are cats and dogs.

Beneficial effects of the present invention:

(1) The method of the present invention can make full use of the rich hemicellulose and cellulose contained in the dregs to prepare xylooligosaccharides and cellooligosaccharides with prebiotic effects, and use soluble lignin to prepare polyphenolic antioxidants; The degraded cellulose and starch can be used as a carbon source for microbial growth, and protein can be used as a nitrogen source for cell growth, thereby reducing the cost of carbon and nitrogen sources for microbial fermentation.

(2) The present invention uses the dregs after the hydrothermal treatment for the microbial fermentation of DHA, fully utilizes the characteristics of high water content of the material, can directly process directly without adding water or adding less water, and reduces the water content. consumption; the weakly acidic substances contained in the dross material itself can be used as self-catalysts in hydrothermal treatment, without adding external acidic catalysts;

(3) The high temperature conditions of the hydrothermal method can liquefy starch, which not only makes starchy substances easier to separate from other solid substances, but also reduces the amount of amylase in the enzymolysis step; cellulose and dextrin after hydrothermal treatment are more easily digested by enzymes. Decompose into glucose, reduce the dosage of cellulase and glucoamylase;

(4) After hydrothermal treatment, most of the hemicellulose in the dregs is converted into xylooligosaccharides and xylans and dissolved in water; the polyphenolic antioxidants contained in lignocellulose are extracted, which is beneficial to the algae powder containing DHA Stability; the enzymatic hydrolysis rate of non-digestible protein (mainly gliadin) can be significantly improved.

detailed description

Below in conjunction with embodiment the present invention will be further described.

Example 1:

Liquor distiller's grains are by-products of the winemaking industry. According to statistics, my country's annual production of liquor in 2013 was 10 million tons, and liquor lees reached more than 30 million tons. If it is not dealt with in time, it will become corrupt and deteriorate, which will not only waste precious resources, but also seriously pollute the surrounding environment.

Take 100g of fresh liquor distiller's grains with a water content of 70%, add 20ml of water, stir and mix well, and make a mixed material with a solid-liquid mass ratio of 1:3 and a pH value of 3. The mixed material was placed in a hydrothermal reactor with a stirring speed of 200 rpm, heated at 180° C., and maintained at this temperature for 10 minutes. After the treatment was completed, the heating was stopped and the temperature was rapidly lowered to 55°C. Adjust the pH value to 3, add glucoamylase with a total activity of 3000AGU, xylanase with 20000IU, and cellulase with 2000FPU to react for 72 hours. After 72 hours, add 2000 LAPU of acid protease and act for 9 hours. After filtering with 200-mesh gauze, take the filtrate to measure the glucose concentration and ammonia ion concentration. The filtrate glucose concentration was adjusted with glucose and water. The main components of the fermentation medium are glucose 60g/L, yeast extract 10g/L, potassium dihydrogen phosphate 5g/L, magnesium sulfate 3g/L, sodium citrate 3g/L, vitamin B 150mg/L, vitamin B6 310mg/L, Vitamin B12 20mg/L, biotin 20mg/L. The pH of the medium is 6.8, and the culture temperature is 25°C. The DHA-producing microorganism was Schizochytrium Aurantiochy trium sp. SD116 (preserved in the General Microorganism Center of China Committee for the Collection of Microorganisms, and its preservation number is CGMCC No: 6208). The initial inoculum size is 0.5g (0.1-0.6g) dry weight per liter, cultured on a shaking table for 72 hours, and the rotation speed is 200rpm. After the cultivation is finished, the fermentation culture liquid is vacuum freeze-dried and the dried solid is crushed to obtain the DHA-rich livestock and poultry feed additive.

Example 2:

Take 100g of fresh vinegar grains with a water content of 90%, add 410ml of water, stir and mix well, and make a mixed material with a solid-liquid mass ratio of 1:50 and a pH value of 8. The mixed material was placed in a hydrothermal reactor with a stirring speed of 300 rpm, heated to 230° C., and maintained at this temperature for 1 minute. After the treatment was completed, the heating was stopped and the temperature was rapidly lowered to 80°C. Adjust the temperature to 90° C. and pH to 8, add glucoamylase with a total activity of 1 AGU, 1000 IU of xylanase, and 1000 FPU of cellulase to react for 48 hours. After 48 hours, add 1000 LAPU of acid protease and act for 2 hours. After filtering with 200-mesh gauze, take the filtrate to measure the glucose concentration and ammonia ion concentration. The filtrate glucose concentration was adjusted with glucose and water. The main components of the fermentation medium are glucose 60g/L, yeast extract 10g/L, potassium dihydrogen phosphate 5g/L, magnesium sulfate 3g/L, sodium citrate 3g/L, vitamin B 150mg/L, vitamin B6 310mg/L , vitamin B12 20mg/L, biotin 20mg/L. The pH of the medium is 6.8, and the culture temperature is 25°C. The DHA-producing microorganism was Thraustochytrium (purchased from American Type Culture Collection, number ATCC 28210). The initial inoculum size is 0.5g (0.1-0.6g) dry weight per liter, cultured on a shaking table for 72 hours, and the rotation speed is 200rpm. After the cultivation is finished, the fermentation culture liquid is vacuum freeze-dried and the dried solid is crushed to obtain the DHA-rich livestock and poultry feed additive.

Example 3:

Take 100g of cornstarch residue with a water content of 80%, add 420ml of water, stir and mix thoroughly, and make a mixed material with a solid-liquid mass ratio of 1:25 and a pH value of 5. The mixed material was placed in a hydrothermal reactor with a stirring speed of 150 rpm, heated to 120° C., and maintained at this temperature for 180 minutes. After the treatment was completed, the heating was stopped and the temperature was rapidly lowered to 20°C. Adjust the pH value to 5, add glucoamylase with a total activity of 1000AGU, xylanase with 2500IU, and cellulase with 2FPU to react for 68 hours. After 68 hours, add 0.002 LAPU of acid protease and act for 24 hours. After filtering with 200-mesh gauze, take the filtrate to measure the glucose concentration and ammonia ion concentration. The filtrate glucose concentration was adjusted with glucose and water. The main components of the fermentation medium are glucose 60g/L, yeast extract 10g/L, potassium dihydrogen phosphate 5g/L, magnesium sulfate 3g/L, sodium citrate 3g/L, vitamin B150mg/L, vitamin B6 310mg/L, Vitamin B12 20mg/L, biotin 20mg/L. The pH of the medium is 6.8, and the culture temperature is 25°C. The DHA-producing microorganism used was Crypthecodinium (purchased from American Type Culture Collection, number ATCC30556). The initial inoculum size is 0.5g (0.1-0.6g) dry weight per liter, cultured on a shaking table for 72 hours, and the rotation speed is 200rpm. After the cultivation is finished, the fermentation culture liquid is vacuum freeze-dried and the dried solid is crushed to obtain the DHA-rich livestock and poultry feed additive.

Example 4:

Take 100g of citrus pomace with a water content of 70%, add 230ml of water, stir and mix thoroughly, and make a mixed material with a solid-liquid mass ratio of 1:10 and a pH value of 4. The mixed material was placed in a hydrothermal reactor with a stirring speed of 150 rpm, heated to 140° C., and maintained at this temperature for 120 minutes. After the treatment was completed, the heating was stopped and the temperature was rapidly lowered to 30°C. Adjust the pH value to 4, add glucoamylase with a total activity of 30AGU, xylanase with 1000IU, and cellulase with 900FPU to react for 54 hours. After 54 hours, add 300 LAPU of acid protease and act for 8 hours. After filtering with 200-mesh gauze, take the filtrate to measure the glucose concentration and ammonia ion concentration. The filtrate glucose concentration was adjusted with glucose and water. The main components of the fermentation medium are glucose 60g/L, yeast extract 10g/L, potassium dihydrogen phosphate 5g/L, magnesium sulfate 3g/L, sodium citrate 3g/L, vitamin B 150mg/L, vitamin B6 310mg/L, Vitamin B12 20mg/L, biotin 20mg/L. The pH of the medium is 6.8, and the culture temperature is 25°C. The DHA-producing microorganism was Ulkenia sp (purchased from American Type Culture Collection, number ATCC28207). The initial inoculum size is 0.5g (0.1-0.6g) dry weight per liter, cultured on a shaking table for 72 hours, and the rotation speed is 200rpm. After the cultivation is finished, the fermentation culture liquid is vacuum freeze-dried and the dried solid is crushed to obtain the DHA-rich livestock and poultry feed additive.

Example 5:

Take 100g of distiller's grains with a water content of 80%, add 80ml of water, stir and mix thoroughly, and make a mixed material with a solid-liquid mass ratio of 1:8 and a pH value of 6. The mixed material was placed in a hydrothermal reactor with a stirring speed of 150 rpm, heated to 180° C., and maintained at this temperature for 90 minutes. After the treatment was completed, the heating was stopped and the temperature was rapidly lowered to 50°C. Adjust the pH value to 6, add glucoamylase with a total activity of 500AGU, xylanase with 5000IU, and cellulase with 20FPU to react for 58 hours. After 58 hours, add 20 LAPU of acid protease and act for 16 hours. After filtering with 200-mesh gauze, take the filtrate to measure the glucose concentration and ammonia ion concentration. The filtrate glucose concentration was adjusted with glucose and water. The main components of the fermentation medium are glucose 60g/L, yeast extract 10g/L, potassium dihydrogen phosphate 5g/L, magnesium sulfate 3g/L, sodium citrate 3g/L, vitamin B 150mg/L, vitamin B6 310mg/L, Vitamin B12 20mg/L, biotin 20mg/L. The pH of the medium is 6.8, and the culture temperature is 25°C. The DHA-producing microorganism was Schizochytrium Aurantiochy trium sp. SD116 (preserved in the General Microorganism Center of China Committee for the Collection of Microorganisms, and its preservation number is CGMCC No: 6208). The initial inoculum size is 0.5g (0.1-0.6g) dry weight per liter, cultured on a shaking table for 72 hours, and the rotation speed is 200rpm. After the cultivation is finished, the fermentation culture liquid is vacuum freeze-dried and the dried solid is crushed to obtain the DHA-rich livestock and poultry feed additive.

Embodiment 6:

Take 100g of apple pomace with a water content of 60%, add 140ml of water, stir and mix thoroughly, and make a mixed material with a solid-liquid mass ratio of 1:5 and a pH value of 8. The mixed material was placed in a hydrothermal reactor with a stirring speed of 150 rpm, heated to 200° C., and maintained at this temperature for 60 minutes. After the treatment was completed, the heating was stopped and the temperature was rapidly lowered to 65°C. Adjust the pH value to 8, add glucoamylase with a total activity of 8000AGU, xylanase with 5000IU, and cellulase with 200FPU to react for 60 hours. After 60 hours, add 4LAPU acid protease and act for 20 hours. After filtering with 200-mesh gauze, take the filtrate to measure the glucose concentration and ammonia ion concentration. The filtrate glucose concentration was adjusted with glucose and water. The main components of the fermentation medium are glucose 60g/L, yeast extract 10g/L, potassium dihydrogen phosphate 5g/L, magnesium sulfate 3g/L, sodium citrate 3g/L, vitamin B 150mg/L, vitamin B6 310mg/L, Vitamin B12 20mg/L, biotin 20mg/L. The pH of the medium is 6.8, and the culture temperature is 25°C. Mortierella sp (purchased from American Type Culture Collection, number ATCC32222) was used as the DHA-producing microorganism. The initial inoculum size is 0.5g (0.1-0.6g) dry weight per liter, cultured on a shaking table for 72 hours, and the rotation speed is 200rpm. After the cultivation is finished, the fermentation culture liquid is vacuum freeze-dried and the dried solid is crushed to obtain the DHA-rich livestock and poultry feed additive.

Embodiment 7:

Take 100g of potato starch slag with a water content of 50%, add 300ml of water, stir and mix thoroughly, and make a mixed material with a solid-liquid mass ratio of 1:7 and a pH value of 5. The mixed material was placed in a hydrothermal reactor with a stirring speed of 150 rpm, heated to 220° C., and maintained at this temperature for 10 minutes. After the treatment was completed, the heating was stopped and the temperature was rapidly lowered to 75°C. Adjust the pH value to 5, add glucoamylase with a total activity of 500AGU, xylanase with 1000IU, and cellulase with 500FPU to react for 62 hours. After 62 hours, add 0.5 LAPU of acid protease and act for 5 hours. After filtering with 200-mesh gauze, take the filtrate to measure the glucose concentration and ammonia ion concentration. The filtrate glucose concentration was adjusted with glucose and water. The main components of the fermentation medium are glucose 60g/L, yeast extract 10g/L, potassium dihydrogen phosphate 5g/L, magnesium sulfate 3g/L, sodium citrate 3g/L, vitamin B 150mg/L, vitamin B6 310mg/L, Vitamin B12 20mg/L, biotin 20mg/L. The pH of the medium is 6.8, and the culture temperature is 25°C. The DHA-producing microorganism was Schizochytrium Aurantiochy trium sp. SD116 (preserved in the General Microorganism Center of China Committee for the Collection of Microorganisms, and its preservation number is CGMCC No: 6208). The initial inoculum size is 0.5g (0.1-0.6g) dry weight per liter, cultured on a shaking table for 72 hours, and the rotation speed is 200rpm. After the cultivation is finished, the fermentation culture liquid is vacuum freeze-dried and the dried solid is crushed to obtain the DHA-rich livestock and poultry feed additive.

Table 1 Nutrient composition table (wt%) of the gained DHA-rich feed of the present invention

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Xylooligosaccharide 8 7 6 8 8 8 8 DHA 30 twenty two twenty four twenty one 20 28 25 protein 49 52 51 55 48 40 53 Cellooligosaccharide 3 3 2 1 2 5 4

Claims (10)

1. The technique of producing DHA-rich livestock and poultry feed additives by using dross materials is characterized in that: comprising the following steps: ①Material pretreatment: uniformly mix the dross material to be treated with water to obtain a mixed material, adjust the pH value of the mixed material to 3-8; the mass ratio of dry dregs and water in the dregs material is 1 :3-1:50; The dregs-like material is starch dregs or pomace or a combination of the two; ②Hydrothermal treatment: transfer the mixed material prepared in step ① into a container, and slowly heat it up to T1 under agitation; keep it warm at T1 for 1-180 minutes, and then quickly cool it down to T2 to obtain a hydrothermal distiller Slag; the T1 is 120-230°C, and the T2 is 20-80°C; ③Enzymatic hydrolysis treatment: adjust the temperature of the hydrothermal dregs to 20-90°C and the pH value to 3-8; then add glucoamylase, xylanase, and cellulase to the hydrothermal dregs to react for 48 After -72 hours, add protease and react for 2-24 hours to obtain enzymatic hydrolysis material; ④Liquid-solid separation: separate the solid in the enzymolysis material from the liquid, and the separation method is centrifugation, pressing or filtration; ⑤ DHA fermentation: adjust the concentration and ratio of carbon source and nitrogen source in the liquid phase after liquid-solid separation, add essential nutrients, and then inoculate DHA-producing microorganisms for microbial fermentation to obtain microbial fermentation liquid; ⑥Drying and crushing: drying and crushing the microbial fermentation broth to obtain solid feed additives. 2. The process for producing DHA-rich livestock and poultry feed additives using dross materials according to claim 1, characterized in that: the enzymatic hydrolysis treatment method in step ③ is adding hydrothermal dregs to the enzyme solution in batches wherein, the enzyme solution is a mixed enzyme solution of glucoamylase, xylanase and cellulase; after reacting for 48-72 hours, protease is added and reacted for 2-24 hours to obtain the enzymolysis material. 3. The process of producing DHA-rich livestock and poultry feed additives using dross materials according to claim 1, characterized in that: the DHA-producing microorganisms described in step 5 are Schizochytrium, Thraustochytrium Any one or any mixed population of the genus Cryptidomyces, Cryptidomyces, Ukenshichytrium, Shewanella and Mortierella. 4. according to any one of claims 1-3, the process of producing DHA-rich livestock and poultry feed additives using dross materials, is characterized in that: the addition of step 3. said glucoamylase is per gram dry Add 0.02-200 AGU of enzyme to the dregs; the xylanase is endo-1,4-β xylanase, and the amount of xylanase added is 10 ^-1 per gram of dregs ×10 ⁴ IU of xylanase; the cellulase is an enzyme with cellobiohydrolase activity and an enzyme with endoglucanase activity and β-glucanase activity, and the cellulase The addition amount of the protease is 0.1-100 FPU enzyme per gram of dry residue solid; the addition amount of protease is 1×10 ^-4 -1×10 ² LAPU enzyme per gram of dry residue solid. 5. The process for producing DHA-rich livestock and poultry feed additives using dross materials according to claim 4, characterized in that: the glucoamylase described in step ③ is α-1,4-glucohydrolase; The xylanase is endo-1,4-beta xylanase of GH10 or GH11; the enzyme with cellobiohydrolase activity includes cellobiohydrolase I and cellobiohydrolase II; The protease is acid protease. 6. The process for producing DHA-rich livestock and poultry feed additives using dross materials according to claim 1, characterized in that: the mass ratio of dregs materials to water in the step ① is 1:3-1 :10. 7. the process of producing DHA-rich livestock and poultry feed additives using dross materials according to claim 2, characterized in that: the microbial fermented liquid in the step 6. is a mixed liquid of multiple microbial fermented liquids; The drying method is freeze drying, vacuum drying, hot air drying or spray drying. 8. The process of producing DHA-rich livestock and poultry feed additives using dross materials according to claim 2, characterized in that: in the step ⑥, a single microbial fermentation liquid is dried and pulverized and then mixed to obtain a solid feed Additive; the drying method is freeze drying, vacuum drying, hot air drying or spray drying. 9. The DHA-rich livestock and poultry feed additive produced by the process according to claim 1 is characterized in that: in parts by mass, it comprises 40-55 parts of protein, 20-30 parts of DHA, 8-10 parts of wood oligo Sugar and 1-5 parts of cellooligosaccharide. 10. the purposes of the DHA-rich livestock and poultry feed additive that adopts the process production described in claim 1, it is characterized in that: be used as the feed additive of livestock and poultry, aquaculture animal and companion animal; Described livestock and poultry comprises cattle, Pigs, chickens, ducks and geese, the aquaculture animals include shrimp and fish; the companion animals are cats and dogs.