CN115299527A - Method for degrading vomitoxin in DDGS feed and DDGS feed - Google Patents

Abstract

The invention provides a method for degrading vomitoxin in DDGS feed and the DDGS feed. The method comprises: inoculating Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum into wet grains and distiller's grains concentrate respectively for fermentation treatment to obtain detoxified wet grains and detoxified distiller's grains concentrate; and then drying to obtain The DDGS feed that has degraded DON; wherein, the bacterial concentration of Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum is independently 2×1010CFU/mL～4×1010CFU/mL. The above three mixed strains are used to degrade DON in wet glutinous grains and distiller's grains concentrate, respectively, so that the content of DON in the feed is lower, and the problem that DON residues in existing DDGS feeds endanger animal and human health is solved. In addition, the content of probiotics in the feed is increased, and the application value of the feed is improved.

Description

Method for degrading vomitoxin in DDGS feed and DDGS feed

technical field

The invention relates to the field of microorganisms, in particular to a method for degrading vomitoxin in DDGS feed and DDGS feed.

Background technique

With the widespread concern of consumers on food hygiene and safety and the continuous deepening of research on mycotoxins by researchers, the contamination of mycotoxins in raw materials and feeds has increasingly attracted the attention of the animal nutrition and feed industries. According to a survey, the proportion of mycotoxin contamination in feed and raw materials in China is 60% to 70%, and the proportion of vomitoxin (a common mycotoxin in food or feed, also known as deoxynivalenol DON) is close to 70%. Wang Ruojun et al. (Investigation Report on Mycotoxin Contamination of Feed and Feed Raw Materials in China, Feed Industry, 2003, 24(7): 53-54) conducted a survey of 194 feed and raw materials corn and wheat bran in 28 provinces and autonomous regions of my country. , the contamination rates of vomitoxin (type B trichothecene mycotoxin), T-2 toxin (type A trichothecene mycotoxin) and zearalenone were 50.0%, 18.1% and 26% respectively. %. Wang Jinyong et al. (2012 Chinese feed and raw material mycotoxin detection report, "Chinese Journal of Animal Husbandry", 2013 No. 4, 29-34) tested 841 feed and raw material samples from various places in my country in 2012 and found that the current feed and raw material The main mycotoxins present were deoxynivalenol, zearalenone, fumonisin and aflatoxin. Among them, the positive detection rate and average value of vomitoxin were the highest.

Vomitoxin (vomitoxin), also known as deoxynivalenol (DON), is a type B trichothecene compound with a molecular formula of C ₁₅ H ₂₀ O ₆ and a relative molecular mass of 296. The name is 3a, 7a, 15-trihydroxy-12, 13-epoxy single terminal sporo-9-en-8-one (3,7,15-trihydroxy-12,13-epoxytrichothec-9-en-8 -one) is a colorless needle-like crystal with a melting point of 151°C to 153°C and no absorption peak in ultraviolet spectrum scanning. Soluble in water, methanol, ethanol, ethyl acetate, acetone, chloroform and other solvents, insoluble in butanol, petroleum ether and n-hexane, stable in nature, with strong heat resistance, only a small amount is heated at 121°C for 25 minutes under high pressure Destruction, has strong acid resistance, but the toxicity of DON is reduced under alkaline conditions. It is reported that DON-contaminated grains can remove 70% of the toxicity in sodium carbonate solution, and can be almost completely removed for a long time. It is mainly a toxic secondary metabolite produced by Fusariurn graminearum and Fusarium culmorum in the genus Fusarium, and vomitoxin is widely found in grain and feed materials such as barley, wheat, corn and oats . Humans and animals can produce a wide range of toxic effects after accidentally eating grains contaminated by the toxin. Piglets are especially sensitive. 0.3mg/kg～0.5mg/kg of trace toxin in the feed will cause pigs to refuse to eat, decrease in growth, and reduce resistance to infectious diseases. Symptoms include severe impairment, slowed weight gain, weakened immune function, loss of muscle coordination, and vomiting. In addition, DON can accumulate in humans and animals, can induce acute or chronic diseases, and has teratogenic, neurotoxic, embryotoxic and immunosuppressive effects.

The U.S. Food and Drug Administration (FDA) requires that the content of vomitoxin in beef cattle and chicken feeds over 4 months old should not exceed 10mg/kg, and in other animal feeds should not exceed 5mg/kg; human wheat bran, flour, germ, etc. In cereal products, the concentration of DON must be less than 1mg/kg. The European Union stipulates that the maximum content of vomitoxin in grains, grain by-products and corn by-products is 8mg/kg and 12mg/kg respectively. The content of vomitoxin in pig, sheep and other animal feed should not exceed 0.9mg/kg, 2mg/kg and 5mg/kg respectively. In my country, in the "National Food Safety Standard Grain" (GB2715-2016), the limit of vomitoxin in wheat, flour, and corn is 1 mg/kg.

At present, the raw materials used by fuel ethanol production enterprises are mainly corn, and corn will inevitably have mildew during storage and transportation, resulting in corn raw materials containing mycotoxins (vomitin, zearalenone, fumonisin and aflatoxin toxin). When corn containing mycotoxins is used for fermentation to produce fuel ethanol, most of the mycotoxins will be concentrated and enriched in the by-product distiller's grains (DDGS feed) during the fermentation process. However, when the content of mycotoxins (vomitin, zearalenone and fumonisins) in DDGS feed exceeds the national limit standard, it cannot be used. DDGS feed, also known as distiller's grain protein, is popular in the feed industry because of its high protein, high available phosphorus, low phytate phosphorus, and high vitamins. As an important substitute for conventional protein feed, DDGS has greatly alleviated the lack of conventional protein resources in my country and effectively reduced production costs. However, the content of mycotoxins in DDGS is almost three times that of fermented grain materials. According to the 2010 DDGS market survey, the detection rate of zearalenone was 73%, and the detection rate of deoxynivalenol was 98%.

Microbial degradation and conversion can not only efficiently degrade and convert mycotoxins into non-toxic products, which is environmentally safe, but also has strong specificity and high conversion efficiency through the method of biological enzyme catalysis. It has become the most promising treatment technology approach in the current mycotoxin reduction technology. The toxic groups of mycotoxins are used by microorganisms to produce secondary metabolites or are decomposed and destroyed by intracellular and extracellular enzymes secreted by microorganisms, and at the same time produce non-toxic degradation products. For microorganisms, it has the characteristics of fast growth and reproduction, easy cultivation, etc., and is easy to produce on a large scale, and is very suitable for popularization and use.

Microorganisms degrade and transform pollutants mainly through oxidation reactions (β-oxidation, epoxidation, nitrogen oxidation, sulfur oxidation, methyl oxidation, etc.), reduction (sulfate reduction, double bond reduction, triple bond reduction) reactions, hydrolysis reactions, and desulfurization reactions. One or more physiological and biochemical reactions such as radical reaction (dehalogenation, deamination, decarboxylation), hydroxylation reaction, esterification reaction, and metabolism (ammonia metabolism, oxime metabolism, nitrile amine metabolism) to achieve the transformation of pollutants, Degradation, mineralization, etc., change the molecular structure of pollutants, thereby reducing or removing the toxicity of pollutants. This feature of microorganisms is used to decompose and transform mycotoxins in corn distillers grains to reduce the content of mycotoxins in DDGS feed.

Microbial cells can degrade mycotoxins into non-toxic or low-toxic substances under mild conditions, and have minimal impact on the sensory properties and palatability of raw materials, so they have become a hot spot in the study of biodegradation of mycotoxins. There are three main ways for microorganisms to degrade DON: (1) ring-opening oxidation; (2) C3-OH oxidation, glycolysis, and isomerization; (3) hydration. The degradation target of DON is shown in Formula 1.

At present, the microorganisms that have been found to degrade vomitoxin include Agrobacterium, Rhizobium, Rhodotorula glutinis, Geotrichumfermentans, Metschnikowia pulcherima), Kluyveromyces marxianus, Rhodotorular ubra and Eubacterium BBSH797, microorganisms in the rumen of cattle, microorganisms in soil, microorganisms in fish viscera, and microorganisms in chicken gut. Some progress has been made in the research on the microbial degradation of DON (as shown in Table 1).

Table 1 The scavenging effect of microorganisms on vomitoxin

Soil microorganisms are the general term for bacteria, fungi, actinomycetes, and algae that live in soil. Its individuals are tiny, generally calculated in micrometers or nanometers, usually 10 ⁶ to 10 ⁹ in 1 gram of soil, and its type and quantity vary with the soil-forming environment and the depth of the soil layer. They carry out oxidation, nitrification, ammonification, nitrogen fixation, vulcanization and other processes in the soil, and promote the decomposition of soil organic matter and the transformation of nutrients. Soil microorganisms generally have the largest number of bacteria. Beneficial bacteria include nitrogen-fixing bacteria, nitrifying bacteria, and saprophytic bacteria; harmful bacteria include denitrifying bacteria. The application of organic fertilizer is beneficial to the growth and reproduction of microorganisms.

In Chinese patent CN 102485883 B, it is disclosed that microorganisms of the genus Clostridium (clostridium sp.) are used to decompose vomitoxin. The use of Bacillus cereus to decompose vomitoxin was disclosed in the journal Food Science entitled Screening and identification of a strain of Bacillus cereus degrading vomitoxin, but none of the microorganisms they used were listed as available for Safe microorganisms for feed additive use.

Although several schemes for degrading deoxynivalenol have been proposed in the prior art, facing the problem that the content of deoxynivalenol in different feeds is still high, it is necessary to improve the existing deoxynivalenol degradation schemes to further Reduce the level of vomitoxin in the feed.

Contents of the invention

The main purpose of the present invention is to provide a method for degrading vomitoxin in DDGS feed and DDGS feed to solve the problem of high content of vomitoxin in existing feed.

In order to achieve the above object, according to one aspect of the present invention, a method for degrading vomitoxin in DDGS feed is provided, the method comprising: Step S1, inoculating Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum into wet grains and Fermentation treatment in distiller's grain concentrate to obtain detoxified wet grains and detoxified distiller's grain concentrate; and step S2, mixing and drying the detoxified wet grains and detoxified distiller's grain concentrate to obtain degraded vomitoxin DDGS feed; wherein, the concentration of Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum are each independently 2×10 ¹⁰ CFU/mL～4×10 ¹⁰ CFU/mL.

Further, the inoculum volume proportions of Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum are each independently 2%-5%.

Further, the fermentation conditions in the wet grains are as follows: the rotation speed of the fermenter is 200r/min-400r/min, the oxygen ventilation rate is 1.0vvm-1.5vvm, the fermentation temperature is 28°C-37°C, and the fermentation time is 18h-24h; The fermentation conditions are as follows: the rotation speed of the fermenter is 200r/min-400r/min, the oxygen ventilation rate is 1.0vvm-1.5vvm, the fermentation temperature is 28°C-37°C, and the fermentation time is 24h-48h.

Further, before inoculating Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum, the method further includes: cultivating and obtaining subtilis subtilis with a bacterial solution concentration of 2×10 ¹⁰ CFU/mL to 4×10 ¹⁰ CFU/mL independently. Bacillus, Bacillus licheniformis and Lactobacillus plantarum; preferably, inoculate the respective thallines of Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum in shake flasks filled with 100ml～200ml medium for primary seed culture, obtaining first-class seeds; and inoculating the first-class seeds in a fermenter for fermenter culture to obtain a bacterial solution with a concentration of 2×10 ¹⁰ CFU/mL to 4×10 ¹⁰ CFU/mL; wherein, the fermented and cultured The culture conditions are: the fermentation temperature is 28°C-37°C, the fermentation time is 18h-24h, the rotation speed of the shaker flask is 150r/min-180r/min, the pH value of the medium is 6.0-7.4; The temperature is 28°C-37°C, the fermentation time is 36h-48h, the rotation speed of the fermenter is 200r/min-400r/min, the oxygen ventilation is 1.0vvm-1.5vvm, and the pH value of the medium is 6.0-7.0; preferably, a Grade seeds are inoculated in fermentors at a volume ratio of 1% to 10% for fermenter cultivation; preferably, the culture medium for fermentation and culture in shake flasks and the culture medium for fermentor cultivation are each independently: 4g to 8g of peptone, yeast Dip powder 4g~8g, glucose 10g~20g, potassium dihydrogen phosphate 5g~10g, magnesium sulfate heptahydrate 0.5g~1g, sodium chloride 5g~10g, add distilled water to 1000mL~1400mL, pH 6.0~7.4.

Further, during the fermentation process of wet grains and/or during the fermentation process of the distiller's grain concentrate, the method also includes the step of adding nutrient salts to the fermentation system; preferably, the added amount of nutrient salts is expressed as the final concentration In total, they are 0.1g/L-0.3g/L ammonium sulfate, 0.1g/L-0.3g/L urea and 0.1g/L-0.3g/L diammonium hydrogen phosphate.

Further, step S2 includes: mixing the detoxified wet grains and the detoxified distiller's grains concentrate at a mass ratio of 4 to 6:1, drying the detoxified wet grains mixture, and controlling the decrease in the content of dry matter. To less than 15%, get the DDGS feed that has degraded vomitoxin.

Further, the dry matter concentration of the detoxified distiller's grains is 62%-65%, and the dry matter concentration of the concentrated distiller's grains is 27%-30%.

Further, the drying temperature is 80°C-200°C, and the drying time is 4h-48h.

According to another aspect of the present invention, there is provided a DDGS feed obtained by degrading any one of the above methods for degrading the deoxynivalenol in the DDGS feed, and the content of the deoxynivalenol in the DDGS feed is below 1 mg/kg.

Applying the technical scheme of the present invention, by using the above-mentioned three mixed strains to degrade the vomitoxin in the wet grains and distiller's grains concentrate, not only the content of vomitoxin in the feed is lower, but also the method of degrading the toxin is beneficial to the feed and The environment is not polluted, which effectively solves the problems existing in traditional detoxification methods. Moreover, the microorganisms used in the method meet the requirements of microbial feed additives, which not only solves the problem that the vomitoxin residue in the existing DDGS feed endangers animals and human health, but also improves the content of probiotics in the feed and improves the application of the feed. value.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below in conjunction with examples.

As mentioned in the background art, the content of vomitoxin in the existing feed is the highest, and its degradation efficiency is still relatively low. In order to further reduce the content of deoxynivalenol in the feed and improve the quality of the feed, the inventors of the present application improved the deoxynivalenol degradation scheme by using the existing microbial strains capable of degrading the deoxynivalenol, and provided a scheme with stronger degradation ability ,details as follows.

In this application, three safe microorganisms that can be clearly used for feed addition are used to degrade vomitoxin, namely Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum. The inventors have found through research that the mixed culture of these three strains under the same culture conditions can all obtain higher reproductive ability, and have a stronger ability to degrade deoxynivalenol, so the degradation efficiency of deoxynivalenol is also higher.

Based on the above research results, in a typical implementation of the present application, a method for degrading vomitoxin in DDGS feed is provided, the method includes: Step S1, Bacillus subtilis, Bacillus licheniformis and plant Lactobacillus is inoculated in the wet grains and concentrated distiller's grains respectively for fermentation treatment to obtain detoxified wet grains and detoxified distiller's grains concentrated liquid; and step S2, mixing and drying the detoxified wet grains and the detoxified distiller's grains concentrated liquid Dry treatment to obtain DDGS feed that has degraded vomitoxin; wherein, the concentration of Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum are each independently 2×10 ¹⁰ CFU/mL～4×10 ¹⁰ CFU/mL.

The method for degrading deoxynivalenol in DDGS feed of the present application uses the above-mentioned three mixed strains to degrade the deoxynivalenol in the wet grains and distiller's grain concentrate, not only makes the content of deoxynivalenol in the feed lower, but also degrades the toxin The method has no pollution to the feed and the environment, and effectively solves the problems existing in the traditional detoxification method. And the microorganisms used in this method meet the requirements of microbial feed additives allowed to be added in the Ministry of Agriculture Announcement No. 2045 "Catalogue of Feed Additives (2013)", which not only solves the residual hazard of vomitoxin in the existing DDGS feed Animal and human health problems, and increase the content of probiotics in feed, improve the application value of feed.

The above-mentioned method for degrading vomitoxin in DDGS feed provided by this application, because in the fuel ethanol production process, can produce a large amount of distiller's grains supernatant (clear liquid after centrifugation of fermented mature mash), most of them are produced after evaporation and concentration Distiller's grain concentrate, wet grains and distiller's grain concentrate are mixed, evaporated and dried to produce distiller's grain protein feed (DDGS feed). Therefore, the method of degrading DON in DDGS feed needs two ways to cooperate to achieve the purpose of degrading DON in DDGS feed. One approach is to add a high-density mixed bacterial solution to the wet grains for fermentation treatment to achieve the purpose of degrading the water-soluble vomitoxin dissolved in the wet grains. Another approach is to add a high-density mixed bacterial solution to the concentrated distiller's grains for fermentation to achieve the purpose of degrading the non-water-soluble vomitoxin in the concentrated distiller's grains. After being treated by the above two methods, the wet grains and distiller's grain concentrate are dried together to produce distiller's grain protein feed, which can achieve the purpose of degrading the vomitoxin in DDGS feed.

The Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum used in the method all belong to probiotics, and Bacillus subtilis can promote the growth of animals and synthesize multiple enzymes and multiple B vitamins in animals, thereby improving feed digestion and absorption utilization rate. Bacillus licheniformis can produce a variety of active enzymes, such as protease, amylase, lipase, pectinase, glucanase, cellulase, etc., and can also produce a variety of enzymatic factors to enhance the activity of animal digestive enzymes. Lactobacillus plantarum has a wide range of probiotic effects, which can improve the growth rate of animals and the body's immunity, reduce the body's cholesterol content, synthesize unsaturated fatty acids and polysaccharides, and reduce oxidative stress. In the mixed bacterial liquid in the form of bacterial liquid with a high concentration range of 2×10 ¹⁰ CFU/mL to 4×10 ¹⁰ CFU/mL, the bacterial biomass is relatively high, and the ability and efficiency of degrading toxins in feed are relatively high .

Bacillus subtilis is a kind of soil microorganism belonging to the genus Bacillus. Its single cell is 0.7μm～0.8μm×2μm～3μm, and its color is uniform. Uncapsulated, with periosteum flagella, able to move. Gram-positive bacteria, spores 0.6μm～0.9μm×1.0μm～1.5μm, oval to columnar, located in the center of the bacterium or slightly biased, the bacterium does not expand after spore formation. The surface of the colony is rough and opaque, stained white or yellowish, and often forms wrinkles when growing in liquid medium. Aerobic bacteria. It can use protein, various sugars and starch to decompose tryptophan to form indole. It is widely used in genetic research, and the synthesis pathway and regulation mechanism of purine nucleotides in this strain have been studied clearly. Widely distributed in soil and decaying organic matter, it is easy to reproduce in withered grass juice, hence the name.

Degrading the vomitoxin by the compound strain containing Bacillus subtilis has the following beneficial effects, including 1) promoting the growth of animals and synthesizing various enzymes and various B vitamins in animals, thereby improving the utilization rate of feed digestion and absorption. 2) Inhibit pathogenic bacteria, subtilis fungi, polymyxin, nystatin, gramicidin and other antibacterial active substances produced by the bacteria, which are pathogenic to pathogenic bacteria or endogenous infections in animals Bacteria have obvious inhibitory effect. 3) Improve immunity, stimulate the growth and development of animal immune organs, increase the level of immunoglobulin and antibodies, and improve the body's immunity. 4) Relieve stress, slow down the stress response of animals caused by various reasons. 5) Regulate the intestinal balance, establish the dominant beneficial bacteria in the intestinal tract, and adjust the micro-ecological balance in the digestive tract. 6) Improve the feed environment, reduce fecal odor and harmful gas emissions.

Bacillus licheniformis is a Gram-positive bacillus and belongs to soil microorganisms. A single cell is 0.8 μm×1.5 μm to 3.5 μm. The shape and arrangement of the cells are rod-shaped and solitary. The colony on the gravy medium was flat, with irregular edges, white, rough and wrinkled surface, and the diameter of the colony was 3 mm after 24 hours.

Bacillus licheniformis can produce antibacterial active substances, kill pathogenic bacteria, and has a unique mechanism of biological oxygen capture, which can inhibit the growth and reproduction of pathogenic bacteria and promote the growth of beneficial bacteria. Bacillus licheniformis can produce a variety of active enzymes, such as protease, amylase, lipase, pectinase, glucanase, cellulase, etc., and can also produce a variety of enzymatic factors to enhance the activity of animal digestive enzymes. Bacillus licheniformis can produce stress-resistant endospores under certain conditions, and can produce lipopeptides, peptides, phospholipids, polyenes and amino acids and other antibiotics, which have a good inhibitory effect on various pathogenic bacteria .

Bacillus licheniformis can also produce a variety of nutrients such as vitamins, amino acids, organic acids, growth-promoting factors, etc., participate in the metabolism of animal bodies, and provide nutrients for the body. Bacillus licheniformis can regulate the balance of animal intestinal flora, improve the intestinal micro-ecological environment, promote animal growth, reduce the occurrence of animal intestinal diseases, and improve the disease resistance of animal organisms. At the same time, it can also play various roles such as immunosuppression, competitive adsorption and synthesis of antibacterial substances. Bacillus licheniformis can stimulate the growth and development of animal immune organs, activate lymphocytes, increase the level of immunoglobulin and antibodies, enhance cellular immunity and humoral immunity, and improve the body's immunity. In addition, Bacillus licheniformis for feed has the functions of antagonizing intestinal pathogenic bacteria, maintaining and regulating the intestinal microecological balance, enhancing the disease resistance and immunity of animals, effectively improving the conversion rate of feed, and increasing the yield of livestock and poultry products. Production.

Lactobacillus plantarum belongs to the genus Lactobacillus, Rectobacillus round-terminal, usually 0.9 μm ~ 1.2 μm × 3.0 μm ~ 8.0 μm, single, paired or short chain. Usually lacks flagella, but is able to move. Gram positive, non-spore forming. Facultative anaerobic, surface colony diameter about 3mm, raised, round, smooth surface, dense, white color, occasionally light yellow or dark yellow. It is a chemoheterotrophic bacterium that can grow at 15°C, and usually the optimum growth temperature is 30°C to 35°C.

Lactobacillus plantarum produces various antibacterial substances such as organic acids, bacteriocins, hydrogen peroxide and diacetyl, and promotes nutrient absorption and other functions, which can improve the balance of intestinal microbial flora and enhance the body's immunity. Lactobacillus plantarum has a wide range of prebiotic effects, such as improving animal growth rate and body immunity, reducing body cholesterol levels, synthesizing unsaturated fatty acids and polysaccharides, and reducing oxidative stress. It is widely used in the fields of food fermentation and micro-ecological preparations, and is one of the microbial feed additives allowed to be added in the Ministry of Agriculture Announcement No. 2045 "Catalogue of Feed Additives (2013)". French scientist Niderkorn tested the removal effect of 29 strains of bacteria on mycotoxins and found that all lactic acid bacteria have the ability to remove vomitoxin. The realization of the function of lactic acid bacteria to degrade vomitoxin requires a certain number of viable bacteria.

In the above method, the mixed bacterial solution formed by three kinds of bacteria not only has a synergistic effect on the degradation of vomitoxin in the feed, but also can degrade other possible toxins in the feed, so that the toxin in the processed feed The content is lower, and because the above-mentioned bacterial species belong to the probiotics beneficial to humans and animals, the nutritional value of the obtained feed is higher.

In the above method, the inoculation ratio of inoculating each bacterium in the wet grains and distiller's grains concentrate is preferably 2%-5% by volume.

In the above method of the present application, the specific conditions for fermenting wet grains and distiller's grain concentrate to degrade vomitoxin are the propagation conditions of mixed microbial strains, and all conditions that are conducive to the maximum reproduction of the above mixed strains are conducive to Achieve efficient degradation of vomitoxin.

In a preferred embodiment of the present application, the fermentation conditions in the wet grains are: the rotation speed of the fermenter is 200r/min-400r/min, the oxygen ventilation rate is 1.0vvm-1.5vvm, the fermentation temperature is 28°C-37°C, and the fermentation The time is 18h-24h; preferably, the fermentation conditions of distiller's grain concentrate are: the rotation speed of the fermenter is 200r/min-400r/min, the oxygen ventilation is 1.0vvm-1.5vvm, the fermentation temperature is 28°C-37°C, and the fermentation time is 24h- 48h; more preferably, during the fermentation process of wet grains and/or during the fermentation process of the distiller's grain concentrate, it also includes the step of adding nutrient salts to the fermenter, further preferably, the nutrient salts are 0.1g/ L-0.3g/L ammonium sulfate, 0.1g/L-0.3g/L urea and 0.1g/L-0.3g/L diammonium hydrogen phosphate.

The wet grains and distiller's grains concentrate are fermented under the above-mentioned optimal conditions, so that the above-mentioned mixed bacteria can reproduce in a large amount, and then efficiently degrade the vomitoxin in the wet grains and distiller's grains concentrate, which greatly reduces the processing time. After reducing the content of vomitoxin in the feed, and correspondingly increasing the content of probiotics in the feed, the feed has more application value.

Specifically: the fermentation treatment steps in the wet grains are as follows: take Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum with a concentration of 2×10 ¹⁰ CFU/mL to 4×10 ¹⁰ CFU/mL, and use 2%~ 5% was inoculated in wet grain fermentation tanks for fermentation and cultivation. The fermentation conditions were: rotation speed 200r/min-400r/min, ventilation rate 1.0vvm-1.5vvm, natural pH value, fermentation temperature 28°C-37°C, fermentation culture 18h ~24h, in the fermentation process, a certain amount of nutrient salt needs to be added in order to promote the growth of microorganisms (preferably, the added amount of nutrient salt, in terms of final concentration, is respectively ammonium sulfate of 0.1g/L～0.3g/L, 0.1g/L L～0.3g/L urea and 0.1g/L～0.3g/L diammonium hydrogen phosphate).

The fermentation treatment steps in distiller's grain concentrate are as follows: take Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum with a concentration of 2×10 ¹⁰ CFU/mL to 4×10 ¹⁰ CFU/mL, and use 5% to 10% Proportionally inoculated in distiller's grain concentrate fermenter for fermentation and cultivation, the fermentation conditions are: rotation speed 200r/min~400r/min, ventilation rate 1.0vvm~1.5vvm, natural pH value, fermentation temperature 28℃~37℃, fermentation cultivation 24h~ 48h, during the fermentation process, a certain amount of nutrient salt needs to be added to promote the growth of microorganisms. Among them, the added amount of nutrient salt is 0.1g/L-0.3g/L ammonium sulfate, 0.1g/L-0.3g/L urea, 0.1g/L-0.3g/L diammonium hydrogen phosphate.

In order to further extend the storage time of the feed after the microbial agent has degraded vomitoxin and improve the storage and transportation conditions of the feed, in a preferred embodiment of the present application, step S2 includes: detoxified wet grains and detoxified distiller's grains The concentrate is mixed according to the mass ratio of 4-6:1; and then the detoxified wet grains mixture is dried to reduce the water content to below 15%, so as to obtain the DDGS feed which has degraded the vomitoxin. Preferably, the dry matter content in the detoxified wet grains is 62wt%-65wt%, and the dry matter content in the detoxified distiller's grains concentrate is 27wt%-30wt%. Preferably, the drying temperature is 80°C-200°C, and the drying time is 4h-48h.

In the second typical embodiment of the present application, a DDGS feed degraded by the above-mentioned degradation method is provided, and the content of vomitoxin in the DDGS feed is below 1 mg/kg. Compared with the DDGS feed in the prior art, the content of vomitoxin therein is greatly reduced, and the edible safety of the feed is improved.

It should be noted that, before the above-mentioned three kinds of bacterial species are mixed and degraded to deoxynivalenol, they need to be cultured at a high density individually or mixed to obtain the above-mentioned high concentration. The specific steps can be obtained by optimizing and adjusting each culture condition on the basis of the existing bacillus culture conditions. In a preferred embodiment of the present application, the step of obtaining the above-mentioned bacterial solution with a concentration of 2×10 ¹⁰ CFU/mL to 4×10 ¹⁰ CFU/mL through high-density culture includes: inoculating the bacteria in a container containing 100ml- Cultivate primary seeds in shake flasks with 200ml of medium, and inoculate primary seeds in fermentors for fermentation to obtain 2×10 ¹⁰ CFU/mL～4×10 ¹⁰ CFU/mL bacterial liquid; , the culture conditions of the fermentation culture in the shake flask are: fermentation temperature 28 ℃～37 ℃, fermentation time 18h～24h, the rotating speed of the shake flask is 150r/min～180r/min, the pH value of the medium is 6.0～7.4; The culture conditions for cultivation are: fermentation temperature 28℃～37℃, fermentation time 36h～48h, rotation speed of fermenter 200r/min～400r/min, oxygen ventilation 1.0vvm～1.5vvm, medium pH value 6.0～ 7.0.

Under the above-mentioned preferred culture conditions, the fermenter culture can obtain the bacterial liquid with the above-mentioned high density of the present application, so that under the same bacterial liquid dosage, the degradation efficiency of toxins in the feed is high, and the nutritional value of the treated feed is high.

In the above-mentioned step of inoculating the primary seeds in the fermenter for cultivation, the specific inoculation ratio can be reasonably adjusted according to the actual bacterial concentration of the primary seeds. In a preferred embodiment of the present application, the primary seeds are inoculated in a fermenter at a volume ratio of 1% to 10% for fermentation in a fermenter to obtain a microbial agent. The inoculation at a volume ratio of 1% to 10% can make the fermentation speed in the fermenter fast and the fermentation efficiency high.

In the steps of primary seed cultivation and fermenter cultivation of the mixed strains of the present application, it can be obtained by rationally adding or adjusting carbon sources, nitrogen sources and other nutrient elements on the basis of the culture medium of a single strain. In a preferred embodiment of the present application, the medium for fermentation culture in shake flasks and the culture medium for fermentor tank culture are each independently: 4g-8g of peptone, 4g-8g of yeast extract powder, 10g-20g of glucose, diphosphate Potassium hydrogen 5g~10g, magnesium sulfate heptahydrate 0.5g~1g, sodium chloride 5g~10g, add distilled water to 1000mL~1400mL, pH value 6.0~7.4.

In one of the most preferred embodiments of the present application, the high-density culture method of the above-mentioned Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum is specifically: under sterile conditions, use the inoculation loop to pick 3 to 5 rings respectively Bacteria are inoculated in 100ml~200ml medium for shake flask fermentation culture (first-level seed culture). The value is 6.0-7.4. Inoculate the first-grade seeds cultivated above in a fermenter at a ratio of 1% to 10% for high-density cultivation of Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum. The cultivation conditions are: fermentation temperature 28°C-37°C, fermentation The time is 36h~48h, the rotation speed is 200r/min~400r/min, the ventilation rate is 1.0vvm~1.5vvm, the pH value is 6.0~7.0, and the final concentration of each bacterial solution reaches 2×10 ¹⁰ CFU/mL~4×10 ¹⁰ CFU/mL. The fermented seed medium is composed of the following components: peptone 4g-8g, yeast extract powder 4g-8g, glucose 10g-20g, potassium dihydrogen phosphate 5g-10g, magnesium sulfate heptahydrate 0.5g-1g, sodium chloride 5g-10g , add distilled water to 1000mL ~ 1400mL, pH 6.0 ~ 7.4. The fermenter culture medium is composed of the following components: peptone 4g-8g, yeast extract powder 4g-8g, glucose 10g-20g, potassium dihydrogen phosphate 5g-10g, magnesium sulfate heptahydrate 0.5g-1g, sodium chloride 5g-10g , add distilled water to 1000mL ~ 1400mL, pH 6.0 ~ 7.4.

The beneficial effects of the present application will be further described below in conjunction with specific embodiments. The strains used in the following examples are all commercial strains purchased from China Industrial Microbiology Culture Collection Center (CICC). Specific information is as follows:

Bacillus subtilis: (Bacillus subtilis), the deposit numbers are CICC 10089 and CICC20445 respectively.

Bacillus licheniformis: (Bacillus licheniformis), the deposit numbers are CICC 20446 and CICC20514.

Lactobacillus plantarum: (Lactobacillus plantarum), the preservation number is CICC 6002.

It should be noted that the detection method for the content of deoxynivalenol in the following examples is to use the deoxynivalenol (DON) ELISA rapid detection kit (this kit adopts the indirect competitive ELISA method, and the deoxynivalenol is pre-coated on the microwell strip of the microtiter plate. The antigen, DON in the sample and the pre-coated antigen on the microwell strip compete with the anti-DON antibody (anti-reagent), and at the same time, the DON antibody is combined with the enzyme-labeled secondary antibody (enzyme-labeled substance), and the color is developed by the TMB substrate , the absorbance value of the sample is negatively correlated with the amount of vomitoxin contained in it. Compared with the standard curve and multiplied by the corresponding dilution factor, the content of vomitoxin in the sample can be obtained. Relevant detection reagents were purchased from Beijing Huaan Maike Biotechnology Co., Ltd. company) to measure.

Embodiment 1 The high-density culture method of Bacillus subtilis of the present invention

Under aseptic conditions, use the inoculation loop to pick 5 rings of two kinds of Bacillus subtilis and inoculate them in 100ml medium (300ml Erlenmeyer flask), and carry out shake flask fermentation culture (first-level seed culture). The culture conditions are: fermentation temperature 37°C , fermentation time 24h, rotation speed 180r/min, pH value 7.0. The first-grade seeds cultivated above were inoculated in a fermenter at a ratio of 10% to carry out high-density culture of Bacillus subtilis. The culture conditions were: fermentation temperature 37°C, fermentation time 48h, rotation speed 200r/min, ventilation rate 1.5vvm, pH The value is 7.0. After the fermentation is finished, the fermentation broth is stored in a refrigerator at 4°C for later use. The plate counting method is used. After diluting 1mL of fermentation broth by 10 ^-9 times, after 24 hours of cultivation at 37°C, the number of colonies grown on the plate is counted: CICC 10089 reaches 3.8×10 ¹⁰ CFU/mL and CICC 20445 reached 3.5×10 ¹⁰ CFU/mL.

Among them, the shake flask fermentation medium is composed of the following components: peptone 4g, yeast extract powder 4g, glucose 10g, potassium dihydrogen phosphate 5g, magnesium sulfate heptahydrate 0.5g, sodium chloride 5g, add distilled water to 1000mL, pH 7.0. The fermentor medium is composed of the following components: 16g of peptone, 16g of yeast extract powder, 40g of glucose, 20g of sodium chloride, 20g of potassium dihydrogen phosphate, 2g of magnesium sulfate heptahydrate, 2000mL of distilled water, and a pH value of 7.0.

The high-density culture method of embodiment 2 bacillus licheniformis of the present invention

Under sterile conditions, use the inoculation loop to pick 5 rings of two kinds of Bacillus licheniformis and inoculate them in 100ml culture medium (300ml Erlenmeyer flask), and carry out shaking flask fermentation culture (first-level seed culture). The culture conditions are: fermentation temperature 37°C , fermentation time 24h, rotation speed 180r/min, pH value 7.0. The first-grade seeds cultivated above were inoculated in a fermenter at a ratio of 10% to carry out high-density culture of Bacillus licheniformis. The culture conditions were: fermentation temperature 37°C, fermentation time 48h, rotation speed 400r/min, ventilation rate 1.5vvm, pH The value is 7.0. After the fermentation is finished, the fermentation broth is stored in a refrigerator at 4°C for later use. The plate counting method is used. After diluting 1mL of fermentation broth by 10 ^-9 times, count the number of colonies grown on the plate after 24 hours of cultivation at 37°C. CICC20446 reaches 2.7×10 ¹⁰ CFU/mL, and CICC20514 reaches 2.8×10 ¹⁰ CFU/mL.

Among them, the shake flask fermentation medium is composed of the following components: peptone 4g, yeast extract powder 4g, glucose 10g, potassium dihydrogen phosphate 5g, magnesium sulfate heptahydrate 0.5g, sodium chloride 5g, add distilled water to 1000mL, pH 7.0. The fermentor medium is composed of the following components: 16g of peptone, 16g of yeast extract powder, 40g of glucose, 20g of sodium chloride, 20g of potassium dihydrogen phosphate, 2g of magnesium sulfate heptahydrate, 2000mL of distilled water, and a pH value of 7.0.

Embodiment 3 The high-density cultivation method of plantarum lactobacillus of the present invention

Under sterile conditions, use the inoculation loop to pick 5 rings of Lactobacillus plantarum and inoculate them in 100ml culture medium (300ml Erlenmeyer flask), and carry out shake flask fermentation culture (first-level seed culture). The culture conditions are: fermentation temperature 30°C, fermentation The time is 24 hours, the rotation speed is 180r/min, and the pH value is 6.2. The first-grade seeds cultivated above were inoculated in a fermenter at a ratio of 10% for high-density cultivation of Lactobacillus plantarum. The cultivation conditions were: fermentation temperature 30°C, fermentation time 48h, rotation speed 200r/min, ventilation rate 1.5vvm, pH The value is 6.2. After the fermentation is finished, the fermentation broth is stored in a refrigerator at 4°C for later use. The plate counting method was adopted. After 1 mL of fermentation broth was diluted 10 ^-9 times, after 24 hours of incubation at 30°C, the number of colonies grown on the plate was counted to reach 2.6×10 ¹⁰ CFU/mL.

Among them, the shake flask fermentation medium is composed of the following components: peptone 4g, yeast extract powder 4g, glucose 10g, potassium dihydrogen phosphate 5g, magnesium sulfate heptahydrate 0.5g, sodium chloride 5g, add distilled water to 1000mL, pH 6.2. The fermentor medium is composed of the following components: 16g of peptone, 16g of yeast extract powder, 40g of glucose, 20g of sodium chloride, 20g of potassium dihydrogen phosphate, 2g of magnesium sulfate heptahydrate, 2000mL of distilled water, and a pH value of 6.2.

Embodiment 4 The method of the present invention for degrading vomitoxin in DDGS feed

Fermentation treatment of mixed microbial cultures of wet grains: take Bacillus subtilis solution (CICC 10089) with a concentration of 3.8×10 ¹⁰ CFU/mL, Bacillus licheniformis (CICC 20446) with a concentration of 2.7×10 ¹⁰ CFU/mL, Lactobacillus plantarum The liquid concentration was 2.6×10 ¹⁰ CFU/mL, and they were co-inoculated in wet grain fermentation tanks at the ratio of 2%, 2% and 5% respectively for fermentation and cultivation. The fermentation conditions were: rotation speed 200r/min, ventilation rate 1.0vvm, natural The pH value, the fermentation temperature was 37°C, and the fermentation was cultivated for 24 hours. After the fermentation, the fermentation broth was stored in a refrigerator at 4°C for later use. Wherein, the nutrient salt added in the fermentation process consists of the following components: 0.2g/L ammonium sulfate, 0.1g/L urea, and 0.3g/L diammonium hydrogen phosphate.

Fermentation treatment of distiller's grains concentrated liquid with mixed microbial liquid: take Bacillus subtilis liquid (CICC 10089) concentration of 3.8×10 ¹⁰ CFU/mL, Bacillus licheniformis liquid (CICC 20446) concentration of 2.7×10 ¹⁰ CFU/mL, vegetable milk The concentration of the bacillus liquid is 2.6×10 ¹⁰ CFU/mL, and they are co-inoculated in the distiller's grain concentrate fermenter at the ratio of 5%, 5% and 10%, respectively, for fermentation and cultivation. The fermentation conditions are: rotation speed 400r/min, ventilation volume 1.5vvm , natural pH value, fermentation temperature 37°C, fermentation culture for 48 hours, after fermentation, the fermentation broth was stored in a 4°C refrigerator for later use. Wherein, the nutrient salt added in the fermentation process consists of the following components: 0.1g/L ammonium sulfate, 0.2g/L urea, and 0.1g/L diammonium hydrogen phosphate.

Preparation of detoxified vomitoxin DDGS feed: After the above two ways of treatment, the detoxified wet grains and the detoxified distiller's grains concentrate are mixed according to the mass ratio of 4:1, wherein the dry matter concentration in the detoxified wet grains is 62% to 65%, and the dry matter content of the detoxified distiller's grains concentrate is 27% to 30%. Then dry it in an oven at 100° C. for 24 hours to reduce the moisture content to below 15%, so that the DDGS feed that has degraded the deoxynivalenol can be obtained, and the content of the deoxynivalenol in the DDGS feed is below 1 mg/kg.

Embodiment 5 The method of the present invention to degrade vomitoxin in DDGS feed

Fermentation treatment of mixed microbial broth of wet grains: take Bacillus subtilis solution (CICC 20445) with a concentration of 3.5×10 ¹⁰ CFU/mL, Bacillus licheniformis (CICC 20514) with a concentration of 2.8×10 ¹⁰ CFU/mL, Lactobacillus plantarum Liquid (CICC6002) with a concentration of 2.6×10 ¹⁰ CFU/mL was co-inoculated in wet grain fermentation tanks at the ratio of 2%, 2% and 5% respectively for fermentation and cultivation. The fermentation conditions were: rotation speed 200r/min, ventilation rate 1.0 vvm, natural pH value, fermentation temperature 37°C, fermentation culture for 24 hours, after fermentation, the fermentation broth was stored in a 4°C refrigerator for later use. Wherein, the nutrient salt added in the fermentation process consists of the following components: 0.2g/L ammonium sulfate, 0.1g/L urea, and 0.3g/L diammonium hydrogen phosphate.

Fermentation treatment of distiller's grains concentrated liquid with mixed microbial liquid: take Bacillus subtilis liquid (CICC 20445) concentration of 3.5×10 ¹⁰ CFU/mL, Bacillus licheniformis liquid (CICC 20514) concentration of 2.8×10 ¹⁰ CFU/mL, plant milk The concentration of the bacillus liquid (CICC6002) was 2.6×10 ¹⁰ CFU/mL, and they were co-inoculated in the distiller's grain concentrate fermenter at the ratio of 5%, 5% and 10% respectively for fermentation. The fermentation conditions were: rotation speed 400r/min, ventilation The volume is 1.5vvm, the natural pH value, the fermentation temperature is 37°C, and the fermentation is cultivated for 48 hours. After the fermentation is completed, the fermentation broth is stored in a 4°C refrigerator for later use. Wherein, the nutrient salt added in the fermentation process consists of the following components: 0.1g/L ammonium sulfate, 0.2g/L urea, and 0.1g/L diammonium hydrogen phosphate.

Preparation of detoxified DDGS feed: After being treated by the above two methods, the detoxified wet grains and the detoxified distiller's grains concentrate are mixed according to the mass ratio of 6:1, wherein the dry matter content in the detoxified wet grains is 62% to 65%, and the dry matter content in the detoxified distiller's grain concentrate is 27% to 30%. Then dry it in an oven at 80° C. for 48 hours to reduce the moisture content to below 15%, and then obtain the DDGS feed that has degraded the deoxynivalenol, and achieve the content of the deoxynivalenol in the DDGS feed below 1 mg/kg.

Comparative example 1

The difference from Example 5 is that in the raw material of wet grains and distiller's grains concentrate with 1.2 mg/kg vomitoxin artificially added, the concentration of Bacillus subtilis liquid (CICC 20445) is 1.5×10 ⁷ CFU/mL, and the concentration of Bacillus licheniformis liquid (CICC20514) was inoculated at a concentration of 1.8×10 ⁷ CFU/mL, and the concentration of Lactobacillus plantarum was 1.6×10 ⁷ CFU/mL, and the wet grains and distiller's grain concentrate were fermented respectively.

After testing, the content of vomitoxin in DDGS feed was 0.8mg/kg.

Comparative example 2

The difference from Example 5 is that only two kinds of bacteria are used for inoculation in the raw material of wet grains and distiller's grains concentrate with artificially added 1.2 mg/kg vomitoxin, and the concentration of Bacillus subtilis liquid (CICC 20445) is 3.5×10 ¹⁰ CFU/mL, Bacillus licheniformis solution (CICC 20514) 2.8×10 ¹⁰ CFU/mL for inoculation.

After testing, the content of vomitoxin in DDGS feed was 0.6mg/kg.

From the above description, it can be seen that the above-mentioned embodiments of the present invention have achieved the following technical effects:

(1) The Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum used in this application are all proved to be microorganisms capable of degrading vomitoxin, and the above-mentioned microorganisms are all in line with the Ministry of Agriculture Announcement No. 2013) "Requirements for microbial feed additives allowed to be added.

(2) Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum used in the application all belong to probiotics, Bacillus subtilis can promote animal growth and synthesize multiple enzyme substances and multiple B vitamins in the animal body, thereby improving feed Digestion and absorption utilization. Bacillus licheniformis can produce a variety of active enzymes, such as protease, amylase, lipase, pectinase, glucanase, cellulase, etc., and can also produce a variety of enzymatic factors to enhance the activity of animal digestive enzymes. Lactobacillus plantarum has a wide range of probiotic effects, which can improve the growth rate of animals and the body's immunity, reduce the body's cholesterol content, synthesize unsaturated fatty acids and polysaccharides, and reduce oxidative stress.

(3) The method for degrading vomitoxin by Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum of the present application is simple to operate, does not pollute feed and the environment, and effectively solves the problems existing in traditional detoxification methods.

(4) The Bacillus subtilis, Bacillus licheniformis and Lactobacillus plantarum used in this application have high biological activity, and after high-density culture, the concentration of each bacterial solution can reach 2×10 ¹⁰ CFU/mL～4×10 ¹⁰ CFU/mL mL, to achieve the purpose of efficiently degrading the vomitoxin in DDGS feed, and to achieve the content of vomitoxin in DDGS feed below 1mg/kg.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of this application shall be included within the protection scope of this application.

Claims (10)

1. A method of degrading emetic toxin in DDGS feed, comprising:

s1, respectively inoculating bacillus subtilis, bacillus licheniformis and lactobacillus plantarum into the wet grains and the distiller 'S grains concentrated solution for fermentation treatment to obtain detoxified wet grains and detoxified distiller' S grains concentrated solution; and

s2, mixing and drying the detoxified wet grains and the detoxified distilled grain concentrated solution to obtain the DDGS feed degraded with vomitoxin;

wherein the bacterial liquid concentrations of the bacillus subtilis, the bacillus licheniformis and the lactobacillus plantarum are respectively and independently 2 multiplied by 10 ¹⁰ CFU/mL～4×10 ¹⁰ CFU/mL。

2. The method according to claim 1, wherein the inoculation volume ratio of the bacterial liquid of the bacillus subtilis, the bacillus licheniformis and the lactobacillus plantarum is 2-5% respectively and independently.

3. The method of claim 1, wherein the fermentation conditions in the wet stillage are: the rotating speed of the fermentation tank is 200 r/min-400 r/min, the oxygen ventilation amount is 1.0 vvm-1.5 vvm, the fermentation temperature is 28-37 ℃, and the fermentation time is 18-24 h;

the fermentation conditions in the vinasse concentrated solution are as follows: the rotating speed of the fermentation tank is 200 r/min-400 r/min, the oxygen ventilation amount is 1.0 vvm-1.5 vvm, the fermentation temperature is 28 ℃ -37 ℃, and the fermentation time is 24 h-48 h.

4. The method of claim 1, wherein prior to inoculating the bacillus subtilis, the bacillus licheniformis, and the lactobacillus plantarum, the method further comprises: culturing and obtaining bacterial liquid concentrationDegree is each independently 2X 10 ¹⁰ CFU/mL～4×10 ¹⁰ CFU/mL of the Bacillus subtilis, bacillus licheniformis, and Lactobacillus plantarum;

preferably, the respective thalli of the bacillus subtilis, the bacillus licheniformis and the lactobacillus plantarum are inoculated into a shake flask containing 100 ml-200 ml of culture medium for primary seed culture to obtain primary seeds; and

inoculating the first-stage seeds into a fermentation tank for fermentation tank culture to obtain the seed with the concentration of 2 multiplied by 10 ¹⁰ CFU/mL～4×10 ¹⁰ CFU/mL bacterial liquid;

wherein the culture conditions of the fermentation culture in the shake flask are as follows: the fermentation temperature is 28-37 ℃, the fermentation time is 18-24 h, the rotation speed of the shake flask is 150-180 r/min, and the pH value of the culture medium is 6.0-7.4; the culture conditions of the fermentation tank culture are as follows: the fermentation temperature is 28-37 ℃, the fermentation time is 36-48 h, the rotating speed of the fermentation tank is 200-400 r/min, the oxygen ventilation amount is 1.0-1.5 vvm, and the pH value of the culture medium is 6.0-7.0.

5. The method of claim 4, wherein the primary seeds are inoculated into a fermentor for the fermentor culture at a volume ratio of 1% to 10%.

6. The method according to claim 4, wherein the medium of the fermentation culture in the shake flask and the medium of the fermenter culture are each independently: 4-8 g of peptone, 4-8 g of yeast extract, 10-20 g of glucose, 5-10 g of monopotassium phosphate, 0.5-1 g of magnesium sulfate heptahydrate, 5-10 g of sodium chloride, adding distilled water to 1000-1400 mL, and adjusting the pH value to 6.0-7.4.

7. The method of claim 3, wherein during the fermentation treatment of the wet stillage and/or during the fermentation treatment of the stillage concentrate, the method further comprises the step of adding nutrient salts to the fermentation system;

preferably, the addition amounts of the nutrient salts are 0.1-0.3 g/L of ammonium sulfate, 0.1-0.3 g/L of urea and 0.1-0.3 g/L of diammonium hydrogen phosphate in terms of final concentration respectively.

8. The method according to claim 1, wherein the step S2 comprises:

mixing the detoxified wet grains and the detoxified concentrated solution of the lees according to the mass ratio of 4-6:1 to obtain a detoxified wet grain mixture;

and drying the detoxified wet grain mixture to reduce the water content to below 15 percent to obtain the DDGS feed with degraded vomitoxin.

9. The method of claim 8, wherein the dry matter content of the detoxified wet grains is 62-65 wt% and the dry matter content of the detoxified distillers' grains concentrate is 27-30 wt%.

10. The DDGS feed degraded by the method for degrading the vomitoxin in the DDGS feed according to any one of claims 1 to 9, wherein the content of the vomitoxin in the DDGS feed is less than 1mg/kg.