CN104543402A - Preparation method of fermentation-state iron feed additive - Google Patents

Abstract

A method for preparing a fermented iron feed additive. Firstly, the fermented substrate is prepared by using industrial and agricultural by-products such as alcohol industrial yellow water, bran, and powder slag as raw materials, and then iron-rich microorganisms are obtained through microbial screening and domestication culture, and inoculated Fermentation is carried out in the obtained fermentation substrate, and then the fermented material is dried, pulverized and packaged to obtain the product. Compared with chemically synthesized iron feed additives, the present invention uses by-products such as slag, bran, and alcohol industrial yellow water as culture materials and substrates, thereby expanding resource utilization and reducing the production cost of iron feed additives, and the prepared The bioavailability of fermented iron feed additives is more stable and the absorption rate is higher. Its iron absorption rate is above 24.7%, which is 5.7 times that of ferrous sulfate monohydrate and 1.8 times that of amino acid chelated iron.

Description

A kind of preparation method of fermented iron feed additive

technical field

The invention relates to the field of biological feed processing, in particular to a method for preparing a fermented iron feed additive by using microorganisms.

Background technique

Iron is one of the essential trace mineral elements for animals, iron deficiency is more common in young livestock and poultry, breeding livestock and so on. Iron deficiency can lead to decreased animal production performance, reduced resistance, and anemia in severe cases. Therefore, adding additional iron preparations to the feed is an important measure to meet the iron requirements of animals. However, studies have found that inorganic iron preparations (such as ferrous sulfate, ferrous chloride, etc.) have low bioavailability, and their absorption and utilization rate is less than 10%, and the rest of iron is discharged into the environment through feces, causing pollution. Studies in recent years have found that the utilization rate of organic iron preparations such as organic chelated iron preparations, heme iron, and animal feed iron is significantly higher than that of inorganic iron. This has greatly aroused researchers' interest in the study of organic iron preparations, and some organic iron preparations have been continuously developed, such as ferric citrate, ferric glucose, EDTA-FeNa, and amino acid chelated iron. However, with the deepening of research, it was found that the utilization rate of artificially synthesized organic iron was not stable, and some studies even found that the utilization rate of organic iron preparations was not as high as that of ferrous sulfate.

Microorganisms are organisms that widely exist in nature. In recent years, some types of microorganisms that are beneficial to humans and animals have been discovered and developed into health products, drugs, and feed additives.

The present invention screens available microorganisms from the microorganisms approved for use in the "Feed Additives Category Catalog (2008)" Announcement No. 1126 of the Ministry of Agriculture of the People's Republic of China, and develops fermented iron with high absorption and utilization rate through domestication and cultivation, fermentation parameter screening, etc. Feed additives.

Contents of the invention

The purpose of the present invention is to provide a method for preparing fermented iron feed additives, obtain microbial strains with strong iron-enrichment ability through screening and domestication of microorganisms, and use industrial and agricultural by-products such as alcohol industry yellow water and bran As a microbial culture substrate, the preparation of fermented iron feed additives can effectively improve the absorption and utilization rate of iron in feed additives, and greatly reduce the production cost of organic iron feed additives. At the same time, it can achieve the purpose of resource reuse and reduce environmental pollution. It also solves technical problems such as the determination of various parameters in the preparation process and the drying and packaging of fermented materials.

The technical solution adopted by the present invention to solve the problems of the technologies described above is:

A method for preparing a fermented iron feed additive. Firstly, mixing a solid raw material and a liquid raw material at a ratio of 1:1 to 2 to obtain a fermentation substrate, then inoculating microorganisms therein for fermentation, and drying the obtained material after the fermentation is completed, The product is obtained by packaging, wherein the microorganism is a microorganism with strong iron-rich ability obtained through screening and domestication. The specific preparation method includes the following steps:

1. Preparation of fermentation raw materials

The fermentation raw materials include solid raw materials and liquid raw materials, wherein the solid raw materials are composed of 5.67% iron raw materials, 27.5% powder slag, 66.5% bran, 0.12% urea, 0.15% sugar, 0.05% sodium bicarbonate %, zinc 0.01%, wherein said iron is divalent iron, and zinc is inorganic state zinc; Described liquid raw material is the alcohol industrial yellow water that directly collects from the plate frame of plate-and-frame filter press, then through filtering, After sterilization, use sodium bicarbonate or sodium hydroxide to adjust the pH to 7.2~7.5. The sterilization method is: sterilize the filtered alcohol industrial yellow water in an autoclave at 121°C for 15 ~20min, cool down.

2. Screening and domestication of microorganisms

2.1. Preparation of iron-containing basal culture and iron-containing gradient medium

The preparation method of the iron-containing basal medium is: dissolve 5 g of beef extract, 10 g of peptone, 5 g of sodium chloride, and 100 mg of iron in distilled water and set the volume to 1 L, then adjust the pH to 7.2~7.5, and set aside;

The preparation method of the iron-containing gradient medium is: according to the above-mentioned preparation method of the iron-containing basic medium, the iron content is gradually increased by 10% on the basis of 100 mg, the total volume of the medium is 1 L, and the gradient medium is sequentially prepared for standby;

2.2. Screening of microorganisms

Inoculate the microorganisms in the “Catalogue of Feed Additives (2008)” in Bulletin No. 1126 of the Ministry of Agriculture of the People’s Republic of China in the iron-containing basal medium prepared in step 2.1 according to the inoculum amount of 5-8%, and one iron-containing basal medium Inoculate a microorganism on the culture medium, cultivate it in a constant temperature incubator at 36.5~37.2°C and 55r/min for 18 hours, record the number of various microorganisms, and the one with the largest number is selected as the microbial strain for fermentation;

2.3. Domestication and cultivation of microorganisms

Under the same culture conditions as in step 2.2, the microbial strains screened in step 2.2 were sequentially cultured in the iron-containing gradient medium prepared in step 2.1, and then the iron content in the microorganisms was determined, and those with high iron content were iron-rich Strong ability, so as to obtain microbial strains with strong iron-enriching ability, for future use.

3. Inoculation and fermentation of microorganisms

3.1. Expanded cultivation of microbial strains

Inoculate the microbial strains with strong iron-rich ability obtained through the screening of microorganisms in step 2 and domestication culture into the treated alcohol industrial yellow water for cultivation. Time 18h, thereby obtains the microbial strain liquid that is used for fermentation, standby;

3.2. Preparation of fermentation substrate

Take the microbial strain solution obtained from the expanded culture in step 3.1 for live bacteria inspection. When the number of viable bacteria reaches 1×10 ⁹ cfu/mL, mix it into the solid mixed in step 1 at a weight ratio of 5-8%. In the raw material, add the alcohol industrial yellow water processed in step 1 according to the solid-to-liquid ratio of 1:1.5, stir and mix, and then adjust the pH to 7.2 to 7.5 to obtain the fermentation substrate;

3.3. Fermentation of fermentation substrate

Put the fermentation substrate obtained in 3.2 in a constant temperature incubator at 36.5-37.2°C to ferment for 22-24 hours to obtain fermentation materials.

4. Drying and packaging of fermented materials

Put the fermented material obtained in step 3.3 in a 65°C electric heating constant temperature drying box, and keep turning the material, and take samples of the material every half an hour to measure the water content, until the water content of the material drops to 12%~14%, it is dry , and then the dried material is taken out and pulverized to obtain the finished fermented iron feed additive, which is vacuum-packed with a vacuum degree of 0.085-0.095Mpa.

Wherein, the iron raw material can be divalent iron such as ferrous sulfate monohydrate, ferrous sulfate pentahydrate, ferrous sulfate heptahydrate, ferrous chloride, etc., and the iron can be determined by searching product descriptions or laboratory measurements. content.

The sodium bicarbonate is analytically pure, and the zinc is inorganic zinc such as zinc sulfate and zinc chloride.

Compared with prior art, the beneficial effect of the present invention is:

(1) Compared with chemically synthesized organic iron feed additives, the present invention uses by-products such as slag, bran, and alcohol industry yellow water as culture materials and substrates, thereby expanding resource utilization and reducing the production of iron feed additives. cost;

(2) Compared with chemically synthesized organic iron feed additives, the fermented iron feed additives prepared by the present invention have more stable bioavailability and higher absorption rate. The Caco-2 epithelial cell absorption model is used to find that the absorption rate is between More than 24.7%, while the absorption rate of inorganic ferrous sulfate (monohydrate) is 4.33% at present, the absorption rate of amino acid chelated iron (compound amino acid, commercially available) is 13.6%, therefore, the fermented state iron feed additive prepared by the present invention The iron absorption rate is 5.7 times and 1.8 times that of ferrous sulfate monohydrate and amino acid chelated iron, respectively;

(3) The present invention is more targeted by screening and domesticating microorganisms, improves the efficiency of microbial fermentation, and ensures a higher iron absorption rate in fermented iron feed additives;

(4) Provides a series of method steps for producing fermented iron feed additives based on industrial and agricultural by-products such as yellow water and bran in the alcohol industry, including the composition and proportion of solid materials, control of chemical properties of culture materials, fermentation parameters screening etc.

Detailed ways

The present invention will be further described below through specific examples and relevant test examples.

Embodiment 1: A kind of preparation method of fermented state iron feed additive, comprises the preparation of fermented raw material, the screening of microorganism and domestication culture, the inoculation fermentation of microorganism and the drying and packing of fermented material, and described preparation method comprises the following concrete steps:

1. Preparation of fermentation raw materials

The fermentation raw materials include solid raw materials and liquid raw materials.

Solid raw materials include iron raw materials, powder slag, bran, urea, sugar, sodium bicarbonate and zinc as nutritional supplements, wherein the iron raw material is ferrous sulfate monohydrate, which is determined by looking up product descriptions or laboratory measurements Iron content; powder slag is potato flour slag, air-dried basis, crude protein content 22.5%; bran is wheat bran, air-dried basis, crude protein content 15.3%; urea is a commercially available product, and it is required not to agglomerate or deliquescence before use; Sugar can be white granulated sugar, brown sugar, molasses, etc.; sodium bicarbonate is analytically pure; zinc is zinc sulfate. According to the weight percentage of solid raw materials, the above solid raw materials are mixed evenly for later use. The specific ratios are: iron raw materials (calculated as iron) 5.67%, powder residue 27.5%, bran 66.5%, urea 0.12%, sugar 0.15%, carbonic acid Sodium hydrogen 0.05%, zinc (calculated as zinc) 0.01%.

The liquid raw material is the alcohol industrial yellow water directly collected from the plate and frame of the plate and frame filter press, which is filtered and sterilized in a sealed container, and then the pH is adjusted to 7.2 by using sodium bicarbonate or sodium hydroxide. Store in a refrigerator for later use, wherein the sterilization method is: sterilize alcohol industrial yellow water at 121° C. for 15 minutes in an autoclave, and cool.

2. Screening and domestication of microorganisms

2.1. Preparation of iron-containing basal culture and iron-containing gradient medium

The preparation method of the iron-containing basal medium is: dissolve 5 g of beef extract, 10 g of peptone, 5 g of sodium chloride, and 100 mg of iron in distilled water, and set the volume to 1 L, then adjust the pH to 7.2, and set aside;

The preparation method of the iron-containing gradient medium is: according to the above-mentioned preparation method of the iron-containing basic medium, the iron content is gradually increased by 10% on the basis of 100 mg, the total volume of the medium is 1 L, and the iron gradient medium is successively prepared for standby;

2.2. Screening of microorganisms

Inoculate the microorganisms in the "Feed Additive Variety Catalog (2008)" announced by the Ministry of Agriculture of the People's Republic of China No. 1126 into the iron-containing basal medium prepared in step 2.1 at an inoculation ratio of 5%. After culturing in a constant temperature incubator for 18 hours, the number of various microorganisms was recorded, and those with the largest number were selected as microbial strains for fermentation. According to calculations, the number of Bacillus subtilis was the largest and were screened as microbial strains for fermentation.

2.3. Domestication and cultivation of microorganisms

Under the same culture conditions, the Bacillus subtilis screened in step 2.2 is successively cultivated in the iron-containing gradient medium prepared in step 2.1, and the number of Bacillus subtilis that can survive and reproduce under a certain high iron concentration is counted by plate counting , the greater the survival and reproduction number, the stronger the iron resistance; at the same time, centrifuge at 3000r/min to obtain Bacillus subtilis, and after traditional wet digestion, use inductively coupled plasma mass spectrometry (ICP-MS) to determine Bacillus subtilis Iron content in the bacillus, high iron content means strong iron-enriching ability, thereby obtaining Bacillus subtilis strains with strong iron-enriching ability for future use.

3, the inoculation fermentation of described microorganism comprises the following steps:

3.1. Expanded cultivation of microbial strains

Inoculate the bacillus subtilis strains that have been domesticated and cultivated in step 2.3 in the proportion of 5% in the alcohol industrial yellow water obtained from the treatment in step 1 for cultivation, the cultivation temperature is 36.5°C, and the cultivation time is 18h, so as to obtain subtilis for fermentation Bacillus seed liquid, spare;

3.2. Preparation of fermentation substrate

Take the Bacillus subtilis seed liquid obtained in 3.1 for live bacteria inspection. When the number of viable bacteria reaches 1×10 ⁹ cfu/mL, mix it into the solid raw material prepared in step 1 at a ratio of 5%, and mix it according to the solid-liquid ratio Add the alcohol industrial yellow water processed in step 1 at a ratio of 1:1.5, stir and mix, then adjust the pH to 7.2 to obtain the fermentation substrate;

3.3. Fermentation of fermentation substrate

Put the fermentation substrate obtained in 3.2 in a constant temperature incubator at 36.5° C. to ferment for 22 hours to obtain fermentation materials.

4. Drying and packaging of fermented materials

Put the fermented material obtained in step 3.3 in a 65°C electric constant temperature drying box, and constantly turn the material, and take samples every half an hour to measure the water content until the material loses 12% of the moisture, then dry the material Take out and pulverize, and pass through an 80-mesh sieve to obtain the finished fermented zinc feed additive, which is vacuum-packed with a composite film in units of 1000 g, and the vacuum degree is 0.085Mpa.

Embodiment 2: A kind of preparation method of fermented state iron feed additive, comprises the preparation of fermentation raw material, the screening of microorganism and domestication culture, the inoculation fermentation of microorganism and the drying and packing of fermented material, described preparation method comprises the following steps:

1. Preparation of fermentation raw materials

The fermentation raw materials include solid raw materials and liquid raw materials.

Solid raw materials include iron raw materials, powder slag, bran, urea, sugar, sodium bicarbonate and zinc as nutritional supplements, among which, the iron raw material is ferrous sulfate pentahydrate, which is determined by looking up product descriptions or laboratory measurements Iron content; powder slag is potato flour slag, air-dried basis, crude protein content 22.5%; bran is wheat bran, air-dried basis, crude protein content 15.3%; urea is a commercially available product, and it is required not to agglomerate or deliquescence before use; Sugar can be white granulated sugar, brown sugar, molasses, etc.; sodium bicarbonate is analytically pure; zinc is zinc sulfate. According to the weight percentage of solid raw materials, the above solid raw materials are mixed evenly for later use. The specific ratios are: iron raw materials (calculated as iron) 5.67%, powder residue 27.5%, bran 66.5%, urea 0.12%, sugar 0.15%, carbonic acid Sodium hydrogen 0.05%, zinc (calculated as zinc) 0.01%.

The liquid raw material is the alcohol industrial yellow water directly collected from the plate and frame of the plate and frame filter press, which is filtered and sterilized in a sealed container, and then the pH is adjusted to 7.5 by using sodium bicarbonate or sodium hydroxide. Store in a refrigerator for later use, wherein the sterilization method is as follows: sterilize alcohol industrial yellow water at 121° C. for 20 minutes in an autoclave, and cool.

2. Screening and domestication of microorganisms

2.1. Preparation of iron-containing basal culture and iron-containing gradient medium

The preparation method of the iron-containing basal medium is: dissolving 5 g of beef extract, 10 g of peptone, 5 g of sodium chloride, and 100 mg of iron in distilled water, and set the volume to 1 L, then adjust the pH to 7.5, and set aside;

The preparation method of the iron-containing gradient medium is: according to the above-mentioned preparation method of the iron-containing basic medium, the iron content is gradually increased by 10% on the basis of 100 mg, the total volume of the medium is 1 L, and the iron gradient medium is successively prepared for standby;

2.2. Screening of microorganisms

Inoculate the microorganisms in the "Feed Additives Category Catalog (2008)" in Bulletin No. 1126 of the Ministry of Agriculture of the People's Republic of China into the iron-containing basal medium prepared in step 2.1 at an inoculation ratio of 8%. After culturing in a constant temperature incubator for 18 hours, the number of various microorganisms was recorded, and those with the largest number were selected as microbial strains for fermentation. According to calculations, the number of Bacillus subtilis was the largest and were screened as microbial strains for fermentation.

2.3. Domestication and cultivation of microorganisms

Under the same culture conditions, the Bacillus subtilis screened in step 2.2 is successively cultivated in the iron-containing gradient medium prepared in step 2.1, and the number of Bacillus subtilis that can survive and reproduce under a certain high iron concentration is counted by plate counting , the greater the survival and reproduction number, the stronger the iron resistance; at the same time, centrifuge at 3000r/min to obtain Bacillus subtilis, and after traditional wet digestion, use inductively coupled plasma mass spectrometry (ICP-MS) to determine Bacillus subtilis Iron content in the bacillus, high iron content means strong iron-enriching ability, thereby obtaining Bacillus subtilis strains with strong iron-enriching ability for future use.

3, the inoculation fermentation of described microorganism comprises the following steps:

3.1. Expanded cultivation of microbial strains

Inoculate the Bacillus subtilis strains that have been domesticated and cultivated in step 2.3 in the proportion of 8% in the alcohol industrial yellow water obtained from the treatment in step 1 for cultivation, the cultivation temperature is 37.2°C, and the cultivation time is 18h, so as to obtain subtilis for fermentation Bacillus seed liquid, spare;

3.2. Preparation of fermentation substrate

Take the Bacillus subtilis seed liquid obtained in 3.1 to check for viable bacteria. When the number of viable bacteria reaches 1×10 ⁹ cfu/mL, mix it into the solid raw material prepared in step 1 at a ratio of 8%, and mix it according to the solid-liquid ratio Add the alcohol industrial yellow water processed in step 1 in a ratio of 1:1.5, stir and mix well, then adjust the pH to 7.5 to obtain the fermentation substrate;

3.3. Fermentation of fermentation substrate

The fermentation substrate obtained in 3.2 was placed in a constant temperature incubator at 37.2°C to ferment for 24 hours to obtain fermentation materials.

4. Drying and packaging of fermented materials

Place the fermented material obtained in step 3.3 in a 65°C electric heating constant temperature drying box, and keep turning the material, and take samples every half an hour to measure the water content, until the material loses 14% of the water, then it is dried, and then the dried material Take out and pulverize, and pass through an 80-mesh sieve to obtain the finished fermented zinc feed additive, which is vacuum-packed with a composite film in units of 1000 g, and the vacuum degree is 0.095Mpa.

Embodiment 3: A kind of preparation method of fermented state iron feed additive, comprises the preparation of fermentation raw material, the screening of microorganism and domestication culture, the inoculation fermentation of microorganism and the drying and packing of fermented material, described preparation method comprises the following specific steps:

1. Preparation of fermentation raw materials

The fermentation raw materials include solid raw materials and liquid raw materials.

Solid raw materials include iron raw materials, powder slag, bran, urea and sugar, sodium bicarbonate and zinc as nutritional supplements. Among them, the iron raw material is ferrous chloride, and the iron raw materials can be determined by looking up product descriptions or laboratory determination methods. content; powder residue is potato flour residue, air-dried basis, crude protein content 22.5%; bran is wheat bran, air-dried basis, crude protein content 15.3%; It can be white sugar, brown sugar, molasses, etc.; sodium bicarbonate is analytically pure; zinc is zinc chloride. According to the weight percentage of solid raw materials, the above solid raw materials are mixed evenly for later use. The specific ratios are: iron raw materials (calculated as iron) 5.67%, powder residue 27.5%, bran 66.5%, urea 0.12%, sugar 0.15%, carbonic acid Sodium hydrogen 0.05%, zinc (calculated as zinc) 0.01%.

The liquid raw material is the alcohol industrial yellow water collected directly from the plate and frame of the plate and frame filter press, which is filtered and sterilized in a sealed container, and then the pH is adjusted to 7.3 by using sodium bicarbonate or sodium hydroxide. Store in a refrigerator for later use, wherein the sterilization method is: sterilize alcohol industrial yellow water at 121° C. for 18 minutes in an autoclave, and cool.

2. Screening and domestication of microorganisms

2.1. Preparation of iron-containing basal culture and iron-containing gradient medium

The preparation method of the iron-containing basal medium is: dissolve 5 g of beef extract, 10 g of peptone, 5 g of sodium chloride, and 100 mg of iron in distilled water, and set the volume to 1 L, then adjust the pH to 7.3, and set aside;

The preparation method of the iron-containing gradient medium is: according to the above-mentioned preparation method of the iron-containing basic medium, the iron content is gradually increased by 10% on the basis of 100 mg, the total volume of the medium is 1 L, and the iron gradient medium is successively prepared for standby;

2.2. Screening of microorganisms

Inoculate the microorganisms in the "Feed Additives Category Catalog (2008)" in Bulletin No. 1126 of the Ministry of Agriculture of the People's Republic of China into the iron-containing basal medium prepared in step 2.1 at an inoculation ratio of 7%. After culturing in a constant temperature incubator for 18 hours, the number of various microorganisms was recorded, and those with the largest number were selected as microbial strains for fermentation. According to calculations, the number of Bacillus subtilis was the largest and were screened as microbial strains for fermentation.

2.3. Domestication and cultivation of microorganisms

Under the same culture conditions, the Bacillus subtilis screened in step 2.2 is successively cultivated in the iron-containing gradient medium prepared in step 2.1, and the number of Bacillus subtilis that can survive and reproduce under a certain high iron concentration is counted by plate counting , the greater the survival and reproduction number, the stronger the iron resistance; at the same time, centrifuge at 3000r/min to obtain Bacillus subtilis, and after traditional wet digestion, use inductively coupled plasma mass spectrometry (ICP-MS) to determine Bacillus subtilis Iron content in the bacillus, high iron content means strong iron-enriching ability, thereby obtaining Bacillus subtilis strains with strong iron-enriching ability for future use.

3, the inoculation fermentation of described microorganism comprises the following steps:

3.1. Expanded cultivation of microbial strains

Inoculate the bacillus subtilis strains that have been domesticated and cultivated in step 2.3 in the proportion of 7% in the alcohol industrial yellow water obtained from the treatment in step 1 for cultivation, the cultivation temperature is 36.8°C, and the cultivation time is 18h, so as to obtain subtilis for fermentation Bacillus seed liquid, spare;

3.2. Preparation of fermentation substrate

Take the Bacillus subtilis seed liquid obtained in 3.1 for live bacteria inspection. When the number of viable bacteria reaches 1×10 ⁹ cfu/mL, mix it into the solid raw material prepared in step 1 at a ratio of 7%, and mix it according to the solid-liquid ratio Add the alcohol industrial yellow water processed in step 1 in a ratio of 1:1.5, stir and mix, then adjust the pH to 7.3 to obtain the fermentation substrate;

3.3. Fermentation of fermentation substrate

The fermentation substrate obtained in 3.2 was placed in a constant temperature incubator at 36.8° C. to ferment for 23 hours to obtain fermentation materials.

4. Drying and packaging of fermented materials

Place the fermented material obtained in step 3.3 in a 65°C electric heating constant temperature drying box, and constantly turn the material, take samples every half an hour to measure the water content, until the material loses 13% of the water, it is dry, and then the dried material Take out and pulverize, and pass through an 80-mesh sieve to obtain the finished fermented zinc feed additive, which is vacuum-packed with a composite film in units of 1000g, and the vacuum degree is 0.09Mpa.

Test example: Caco-2 epithelial cell absorption model was used to study and find that the iron absorption rate of the fermented iron feed additive prepared by the present invention is above 24.7%, the absorption rate of inorganic ferrous sulfate (monohydrate) is 4.33%, and the amino acid chelation Iron (compound amino acid, commercially available) is 13.6%. Therefore, the iron absorption rate of the fermented iron feed additive prepared by the present invention is 5.7 times and 1.8 times that of ferrous sulfate monohydrate and amino acid chelated iron.

Claims (4)

1. the preparation method of state iron feed additive of fermenting, first, solid material and liquid charging stock are mixed to get fermentation substrate with the ratio of 1:1 ~ 2, microbe inoculation ferments wherein again, the dry materials will obtained after fermentation, packaging i.e. obtained product, described liquid charging stock is the alcohol industry yellow water directly collected from the sheet frame of plate and frame filter press, then after filtration, after sterilizing, pH is adjusted to 7.2 ~ 7.5 and obtains, it is characterized in that: described solid material is according to percentage by weight, it consists of: iron 5.67%, granulated slag 27.5%, wheat bran 66.5%, urea 0.12%, sugar 0.15%, sodium acid carbonate 0.05%, zinc 0.01%, wherein said iron is divalent state iron, zinc is inorganic zinc, described microorganism is through the strong microorganism of the rich iron ability of screening and domestication cultivation obtains, screening and the domestication and culture method of microorganism are as follows:

(1) preparation is cultivated and iron content gradient media containing iron base

The method for making of iron content basal medium is: beef extract 5g, peptone 10g, sodium chloride 5g, iron 100mg are dissolved in distilled water, and are settled to 1L, then adjusts pH to 7.2 ~ 7.5, for subsequent use;

The method for making of iron content gradient media is: according to the method for making of above-mentioned iron content basal medium, iron content is increased progressively 10% successively on the basis of 100mg, and the cumulative volume of culture medium is 1L, configures gradient media successively for subsequent use;

(2) screening of microorganism

By the microorganism in No. 1126, The Ministry of Agriculture of the People's Republic of China, MOA bulletin " feed addictive kind catalogue (2008) " according to 5 ~ 8% inoculum concentration, be seeded in the iron content basal medium prepared by step (1) respectively, and an iron content basal medium inoculates a kind of microorganism, 36.5 ~ 37.2 DEG C, cultivate 18h in the constant incubator of 55r/min after, record various micro organism quantity, the screened microorganism fungus kind as fermentation of the maximum person of quantity;

(3) domestication of microorganism is cultivated

Under the condition of culture same with step (2), the microorganism fungus kind that step (2) is screened is incubated at successively in iron content gradient media prepared in step (1), then iron content in microorganism is measured, iron content height person is that rich iron ability is strong, thus obtain the strong microorganism fungus kind of rich iron ability, for subsequent use.

2. the preparation method of a kind of state iron feed additive that ferments according to claim 1, is characterized in that: the inoculation fermentation method of described microorganism is as follows:

(1) expansion of microorganism fungus kind is cultivated

By cultivate through the screening of microorganism and domestication the strong microorganism fungus kind of the rich iron ability that obtains be inoculated in described process after alcohol industry yellow water in cultivate, its inoculum concentration is 5 ~ 8%, cultivation temperature is 36.5 ~ 37.2 DEG C, incubation time is 18h, thus the microorganism fungus kind liquid obtained for fermenting, for subsequent use;

(2) fermentation substrate is prepared

Viable bacteria inspection is carried out, when viable count reaches 1 × 10 to through expanding the microorganism fungus kind liquid cultivating gained ⁹during cfu/mL, by its according to 5 ~ 8% inoculum concentration be seeded in mixed solid material, and according to solid-to-liquid ratio 1:1.5 ratio add described alcohol industry yellow water process, stir and evenly mix, then adjustment pH to 7.2 ~ 7.5 obtain fermentation substrate;

(3) fermentation of fermentation substrate

Described fermentation substrate is placed in the interior fermentation of the constant incubator 22 ~ 24h of 36.5 ~ 37.2 DEG C, obtains fermentation materials.

3. the preparation method of a kind of state iron feed additive that ferments according to claim 2, it is characterized in that: carrying out the dry method with packing to the fermentation materials of gained is be placed in by the fermentation materials of gained in 65 DEG C of Constant Temp. Ovens, and continuous turning over materials, at interval of half an hour, sampling and measuring water content is carried out to material, be down to 12% ~ 14% to material moisture and be drying, then dried material is taken out and pulverize, thus obtain fermentation state iron feed additive finished product, and vacuum packaging, vacuum is 0.085 ~ 0.095Mpa.

4. the preparation method of a kind of state iron feed additive that ferments according to claim 1, it is characterized in that: the sterilizing methods of described alcohol industry yellow water be by the alcohol industry yellow water after filtering in high-pressure sterilizing pot under 121 DEG C of conditions sterilizing 15 ~ 20min, cooling.