Fermented feed protein and preparation method and application thereof

Abstract

The application discloses fermented feed protein and a preparation method and application thereof. The method utilizes a step-by-step fermentation mode, so that after moringa seed meal is fermented by aspergillus niger and rhizopus oryzae, macromolecules such as cellulose and protein are degraded into small molecules, and then enterococcus faecium inoculated can directly utilize the small molecule substances to further ferment the moringa seed meal, so that the fermentation efficiency is improved, and the nutritional value of the moringa seed meal is more effectively improved. After the moringa seed meal is fermented, sour aroma is generated, compared with single-bacterium fermentation, the content of crude protein, the content of acid-soluble protein and the activity of neutral protease are significantly improved, the fermented moringa seed meal is rich in probiotics, and becomes a high-quality feed protein.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of feed processing, and particularly relates to a fermented feed protein and a preparation method and application thereof. BACKGROUND

[0002] Feed protein is an important resource for aquaculture and livestock breeding. At present, the demand for feed protein is very large in the world, and the price of traditional feed protein such as fish meal has increased. Therefore, finding potential and high-quality feed protein is one of the important goals of the current breeding industry. Therefore, optimizing the feed formula and reducing the cost of feed are important research problems in the breeding industry. Compared with traditional feed protein, fermented feed protein has the advantages of high digestibility and high feed conversion ratio. In recent years, more and more researches on using agricultural and pastoral waste such as seed cake and cottonseed cake as raw materials to produce new fermented feed protein have been carried out, and fermented feed protein has greater development potential.

[0003] Moringa is a new multifunctional plant resource that has not been fully developed, and has the characteristics of high yield, wide adaptability, simple cultivation, strong stress resistance, etc. Moringa leaves and moringa seeds are often added to conventional feed as feed. The leaves and seeds have the effects of improving the growth performance of economic animals, improving the immune function, and improving the meat quality. After the production of moringa oil, the remaining moringa seed cake is discarded if not fully utilized, which will cause environmental pollution and great waste of resources. Moringa seed cake itself has a high crude protein content (25%-36%), but plant raw materials often contain anti-nutritional factors and are difficult to digest, and direct feeding may even cause the death of young animals. Through fermentation, microorganisms can decompose the dregs and cake materials to degrade plant protein and anti-nutritional factors and improve the nutritional value, which is an ideal method for developing moringa seed cake. There are more reports on directly using moringa leaves as feed or using moringa leaves to produce silage feed, but there are fewer reports on developing and utilizing moringa seed cake for solid-state fermentation to produce feed protein. SUMMARY

[0004] The primary purpose of the present application is to overcome the shortcomings and deficiencies of the prior art and provide a preparation method of fermented feed protein.

[0005] Another purpose of the present application is to provide fermented feed protein obtained by the above preparation method.

[0006] Still another purpose of the present application is to provide the application of the above fermented feed protein.

[0007] The purposes of the present application are achieved by the following technical solutions:

[0008] A preparation method of fermented feed protein, comprising the following steps:

[0009] (1) Moringa seed cake pretreatment: moringa seed cake is taken, crushed, sieved, and prepared for use;

[0010] (2) mixing the moringa seed meal obtained in step (1) with water, then inoculating mixed bacteria agent, mixing uniformly, sealing fermentation, obtaining fermentation product A; the mixed bacteria agent comprises Rhizopus oryzae and Aspergillus niger;

[0011] (3) inoculating Enterococcus faecalis in the fermentation product A, mixing uniformly, sealing fermentation, obtaining fermented feed protein.

[0012] The sieving in step (1) is preferably 10-20 mesh sieving; more preferably, 10 mesh sieving.

[0013] The moringa seed meal and water in step (2) are preferably mixed in a mass ratio of 54-75:25-46.

[0014] The inoculation amount of the mixed bacteria agent in step (2) is preferably 10-16 parts of mixed bacteria agent, based on 54-75 parts of the mass of the moringa seed meal; more preferably, 13-16 parts by mass.

[0015] The mixed bacteria agent in step (2) is preferably a mixed bacteria agent obtained by mixing Rhizopus oryzae and Aspergillus niger in a mass ratio of 5-8:5-8.

[0016] The Rhizopus oryzae in step (2) is preferably in the logarithmic growth phase or stationary phase; more preferably, it is prepared by the following steps: inoculating the preserved Rhizopus oryzae spores on a plate for activation, then inoculating in a seed culture medium, and oscillating culture to obtain Rhizopus oryzae culture solution in the logarithmic growth phase or stationary phase.

[0017] The culture medium used in the plate activation is preferably potato dextrose agar medium (PDA).

[0018] The time for the plate activation is preferably 40-50 h; more preferably, 48 h.

[0019] The seed culture medium is preferably potato dextrose broth (PDB).

[0020] The rotation speed of the oscillating culture is preferably 110-130 rpm; more preferably, 120 rpm.

[0021] The temperature of the oscillating culture is preferably 28-32℃; more preferably, 30℃.

[0022] The time of the oscillating culture is preferably 10-14 h.

[0023] The Rhizopus oryzae strain amount in step (2) is preferably 0.8-0.9 mg / mL of Rhizopus oryzae bacteria solution; more preferably, 0.87 mg / mL of Rhizopus oryzae bacteria solution.

[0024] The Aspergillus niger in step (2) is preferably in logarithmic growth phase or stationary phase; more preferably prepared by the following steps: inoculating the preserved Aspergillus niger strain on a plate for activation, then inoculating on a seed culture medium, and oscillating culture to obtain Aspergillus niger culture solution in logarithmic growth phase or stationary phase.

[0025] The culture medium used in the plate activation is preferably potato dextrose agar medium (PDA).

[0026] The time of the plate activation is preferably 40-50 h; more preferably 48 h.

[0027] The seed culture medium is preferably potato dextrose broth (PDB).

[0028] The rotation speed of the oscillating culture is preferably 110-130 rpm; more preferably 120 rpm.

[0029] The temperature of the oscillating culture is preferably 28-32℃; more preferably 30℃.

[0030] The time of the oscillating culture is preferably 20-26 h.

[0031] The Aspergillus niger in step (2) is preferably Aspergillus niger culture solution with a strain amount of 3-4 mg / mL; more preferably Aspergillus niger culture solution with a strain amount of 3.7 mg / mL.

[0032] The fermentation temperature after inoculating the mixed bacterial agent in step (2) is preferably 28-32℃; more preferably 30℃.

[0033] The fermentation time after inoculating the mixed bacterial agent in step (2) is preferably 32-42 h.

[0034] The inoculation amount of Enterococcus faecium in step (3) is preferably 5-8 parts by mass based on 54-75 parts by mass of the Moringa oleifera seed meal; more preferably 7-8 parts by mass.

[0035] The Enterococcus faecium in step (3) is preferably in logarithmic growth phase or stationary phase; more preferably prepared by the following steps: inoculating the preserved Aspergillus niger strain on a plate for activation, then inoculating on a seed culture medium, and oscillating culture to obtain Enterococcus faecium culture solution in logarithmic growth phase or stationary phase.

[0036] The culture medium used in the plate activation is preferably MRS medium.

[0037] The time of the plate activation is preferably 40-50 h; more preferably 48 h.

[0038] The seed culture medium is preferably MRS medium.

[0039] The rotation speed of the oscillation culture is preferably 110-130 rpm, more preferably 120 rpm.

[0040] The temperature of the oscillation culture is preferably 28-32℃, more preferably 30℃.

[0041] The time of the oscillation culture is preferably 12-16 h.

[0042] The Enterococcus faecium in step (3) has an OD 600 value of 0.7-0.8, more preferably an OD 600 value of 0.76.

[0043] The fermentation temperature after inoculating the Enterococcus faecium in step (3) is preferably 28-32℃, more preferably 30℃.

[0044] The fermentation time after inoculating the Enterococcus faecium in step (3) is preferably 32-42 h.

[0045] A fermented feed protein is prepared by the above method for preparing a fermented feed protein.

[0046] The fermented feed protein has a crude protein content of 40-50%, an acid-soluble protein content of 9-11%, and a neutral protease activity of 700-850 U / g.

[0047] The above fermented feed protein is used in the preparation of a feed.

[0048] The present application has the following advantages and effects relative to the prior art:

[0049] The method of the present application uses a step-by-step fermentation method by screening reasonable microbial species and inoculation methods. After the moringa seed meal is fermented by Aspergillus niger and Rhizopus oryzae, macromolecules such as cellulose and protein are degraded into small molecules. The inoculated Enterococcus faecium can directly utilize the small molecules to further ferment the moringa seed meal, thereby improving the fermentation efficiency and more effectively improving the nutritional value of the moringa seed meal. After the moringa seed meal is fermented, an acid aroma is produced. Compared with single-bacterium fermentation, the crude protein content, acid-soluble protein content, and neutral protease activity are significantly improved, and the fermented moringa seed meal is rich in probiotics and becomes a high-quality feed protein. DETAILED DESCRIPTION

[0050] The present application will be further described in detail below with reference to examples, but the embodiments of the present application are not limited thereto.

[0051] The Enterococcus faecium used in the embodiment of the application is preserved Enterococcus faecium, a ring of Enterococcus faecium is scraped and inoculated on a MRS medium plate for activation, and cultured for 2 days; then a ring of the activated Enterococcus faecium is scraped and inoculated in 50 mL of MRS liquid medium for culture at 37°C and 120 rpm for 12-16 h, and the OD600 value is measured to be 0.76 (diluted 3 times).

[0052] The Rhizopus used in the embodiment of the application is preserved Rhizopus, a ring of Rhizopus mycelium is scraped and inoculated on a PDA plate for activation, and cultured for 2 days; a 5 mm agar puncher is used to punch, and 2 holes of agar with mycelium are inoculated in 50 mL of PDB liquid medium for culture at 30°C and 120 rpm for 10-14 h, and the strain amount is measured to be 0.87 mg / mL.

[0053] The Aspergillus niger used in the embodiment of the application is preserved Aspergillus niger, a ring of Aspergillus niger mycelium is scraped and inoculated on a PDA plate for activation, and cultured for 2 days; a 5 mm agar puncher is used to punch, and 2 holes of agar with mycelium are inoculated in 50 mL of PDB liquid medium for culture at 30°C and 120 rpm for 20-26 h, and the strain amount is measured to be 3.7 mg / mL.

[0054] The Saccharomyces cerevisiae used in the comparative example of the application is preserved Saccharomyces cerevisiae, a ring of Saccharomyces cerevisiae is scraped and inoculated on a YPD medium plate by the plate streaking method for activation, and cultured for 48 h; a ring of the activated Saccharomyces cerevisiae is scraped and inoculated in 50 mL of YPD medium for culture at 30°C and 120 rpm for 12 h, and the OD600 value is measured to be 0.686 (diluted 6 times).

[0055] The microorganisms involved in the embodiment or the comparative example of the application are as follows:

[0056] Rhizopus A: Rhizopus oryzae E20360, which has been disclosed in NCBI, and the accession number is MK267423.1;

[0057] Rhizopus B: Rhizopus GIM 3.130, which can be purchased from Guangdong Microbial Culture Collection Center;

[0058] Aspergillus niger A: Aspergillus niger, which has been disclosed in NCBI, and the accession number is MN474007;

[0059] Aspergillus niger B: Aspergillus niger GIM 3.462, which can be purchased from Guangdong Microbial Culture Collection Center;

[0060] Enterococcus faecium A: Enterococcus faecium A1, which has been disclosed in NCBI, and the accession number is MN474019;

[0061] Enterococcus faecium B: Enterococcus faecium GIM 1.391, which can be purchased from Guangdong Microbial Culture Collection Center;

[0062] Saccharomyces cerevisiae: purchased from Angel Yeast Co., Ltd.

[0063] The crude protein content was determined by the method described in the literature "Zhang Houfeng, Zhang Shuping. Discussion on shortening the digestion time of Kjeldahl nitrogen determination [J]. China Animal Husbandry and Veterinary Medicine, 2008 (9): 157-158."

[0064] The acid-soluble protein content was determined by the method described in the literature "Hou Nannan, Xie Quanxi, Lei Chunhong, et al. Effect of solid-state fermentation of compound probiotics on nutritional quality of soybean meal [J]. China Feed, 2018."

[0065] The neutral protease activity was determined according to the national standard GB / T 28715-2012.

[0066] Preparation of moringa seed meal: Moringa seed meal was taken, crushed, and passed through a 10-mesh sieve for standby.

[0067] Example 1

[0068] Take 54 parts by mass of moringa seed meal, add 46 parts by mass of water, inoculate 16 parts by mass of mixed bacteria of Rhizopus oryzae A and Aspergillus niger A (mass ratio 1:1), and seal fermentation at 30°C for 38h; then inoculate 8 parts by mass of Enterococcus faecium A, mix evenly, and seal fermentation at 30°C for 34h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method were 40.61%, 9.34%, and 752.35U / g, respectively.

[0069] Example 2

[0070] Take 75 parts by mass of moringa seed meal, add 25 parts by mass of water, inoculate 14 parts by mass of mixed bacteria of Rhizopus oryzae A and Aspergillus niger A (mass ratio 1:1), and seal fermentation at 30°C for 40h; then inoculate 6 parts by mass of Enterococcus faecium A, mix evenly, and seal fermentation at 30°C for 32h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method were 41.88%, 9.64%, and 849.74U / g, respectively.

[0071] Example 3

[0072] Take 50 parts by mass of Moringa oleifera seed meal, add 50 parts by mass of water, inoculate with 13 parts by mass of mixed bacteria of Rhizopus oryzae A and Aspergillus niger A (mass ratio 1:1), seal and ferment at 30°C for 36 hours; then inoculate with 7 parts by mass of Enterococcus faecalis A, mix uniformly, and seal and ferment at 30°C for 36 hours. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 46.78%, 10.64%, and 711.93 U / g, respectively.

[0073] Example 4

[0074] Take 65 parts by mass of Moringa oleifera seed meal, add 35 parts by mass of water, inoculate with 13 parts by mass of mixed bacteria of Rhizopus oryzae A and Aspergillus niger A (mass ratio 1:1), mix uniformly, and seal and ferment at 30°C for 36 hours; then inoculate with 7 parts by mass of Enterococcus faecalis A, mix uniformly, and seal and ferment at 30°C for 36 hours. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 44.5%, 9.55%, and 744.95 U / g, respectively.

[0075] Example 5

[0076] Take 65 parts by mass of Moringa oleifera seed meal, add 35 parts by mass of water, inoculate with 13 parts by mass of mixed bacteria of Rhizopus oryzae B and Aspergillus niger A (mass ratio 1:1), mix uniformly, and seal and ferment at 30°C for 36 hours; then inoculate with 7 parts by mass of Enterococcus faecalis A, mix uniformly, and seal and ferment at 30°C for 36 hours. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 43.33%, 9.56%, and 701.80 U / g, respectively.

[0077] Example 6

[0078] Take 65 parts by mass of Moringa oleifera seed meal, add 35 parts by mass of water, inoculate with 13 parts by mass of mixed bacteria of Rhizopus oryzae A and Aspergillus niger B (mass ratio 1:1), mix uniformly, and seal and ferment at 30°C for 36 hours; then inoculate with 7 parts by mass of Enterococcus faecalis A, mix uniformly, and seal and ferment at 30°C for 36 hours. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 42.87%, 8.91%, and 677.52 U / g, respectively.

[0079] Example 7

[0080] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 13 parts by mass of mixed bacteria of Rhizopus oryzae A and Aspergillus niger A (mass ratio 1:1), mix uniformly, seal and ferment at 30°C for 36h; then inoculate 7 parts by mass of Enterococcus faecium B, mix uniformly, seal and ferment at 30°C for 36h. The crude protein content, acid-soluble protein content and neutral protease activity of the feed protein prepared by the above method are 44.56%, 8.95% and 760.31U / g, respectively.

[0081] Example 8

[0082] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 13 parts by mass of mixed bacteria of Rhizopus oryzae B and Aspergillus niger B (mass ratio 1:1), mix uniformly, seal and ferment at 30°C for 36h; then inoculate 7 parts by mass of Enterococcus faecium A, mix uniformly, seal and ferment at 30°C for 36h. The crude protein content, acid-soluble protein content and neutral protease activity of the feed protein prepared by the above method are 42.18%, 9.56% and 685.78U / g, respectively.

[0083] Example 9

[0084] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 13 parts by mass of mixed bacteria of Rhizopus oryzae B and Aspergillus niger A (mass ratio 1:1), mix uniformly, seal and ferment at 30°C for 36h; then inoculate 7 parts by mass of Enterococcus faecium B, mix uniformly, seal and ferment at 30°C for 36h. The crude protein content, acid-soluble protein content and neutral protease activity of the feed protein prepared by the above method are 41.97%, 9.45% and 740.74U / g, respectively.

[0085] Example 10

[0086] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 13 parts by mass of mixed bacteria of Rhizopus oryzae A and Aspergillus niger B (mass ratio 1:1), mix uniformly, seal and ferment at 30°C for 36h; then inoculate 7 parts by mass of Enterococcus faecium B, mix uniformly, seal and ferment at 30°C for 36h. The crude protein content, acid-soluble protein content and neutral protease activity of the feed protein prepared by the above method are 42.55%, 9.33% and 666.20U / g, respectively.

[0087] Example 11

[0088] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 13 parts by mass of mixed bacteria of Rhizopus oryzae B and Aspergillus niger B (mass ratio 1:1), mix uniformly, seal fermentation at 30°C for 36h; then inoculate 7 parts by mass of Enterococcus faecalis B, mix uniformly, seal fermentation at 30°C for 36h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 44.06%, 8.85%, and 684.87U / g, respectively.

[0089] Comparative Example 1

[0090] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, mix uniformly, sterilize, then add 20 parts by mass of water, seal for 72h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 35.38%, 5.10%, and 13.91U / g, respectively.

[0091] Comparative Example 2

[0092] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 20 parts by mass of Enterococcus faecalis A, mix uniformly, seal fermentation at 30°C for 72h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 31.77%, 4.52%, and 11.11U / g, respectively.

[0093] Comparative Example 3

[0094] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 20 parts by mass of Saccharomyces cerevisiae, mix uniformly, seal fermentation at 30°C for 72h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 35.17%, 4.59%, and 92.59U / g, respectively.

[0095] Comparative Example 4

[0096] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 20 parts by mass of Rhizopus oryzae A, mix uniformly, seal fermentation at 30°C for 72h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 38.16%, 8.17%, and 266.67U / g, respectively.

[0097] Comparative Example 5

[0098] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 20 parts by mass of Aspergillus niger A, mix uniformly, seal fermentation at 30°C for 72h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 38.64%, 6.46%, and 114.81U / g, respectively.

[0099] Comparative Example 6

[0100] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 10 parts by mass of Aspergillus niger A, mix uniformly, seal fermentation at 30°C for 36h; then inoculate 10 parts by mass of Enterococcus faecium A, mix uniformly, seal fermentation at 30°C for 36h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 38.23%, 6.85%, and 503.29U / g, respectively.

[0101] Comparative Example 7

[0102] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 10 parts by mass of Rhizopus oryzae A, mix uniformly, seal fermentation at 30°C for 36h; then inoculate 10 parts by mass of Enterococcus faecium A, mix uniformly, seal fermentation at 30°C for 36h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 39.75%, 5.94%, and 392.38U / g, respectively.

[0103] Comparative Example 8

[0104] Take 65 parts by mass of moringa seed meal, add 35 parts by mass of water, inoculate 20 parts by mass of mixed bacteria of Rhizopus oryzae A and Aspergillus niger A (mass ratio 1:1), mix uniformly, seal fermentation at 30°C for 72h. The crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the above method are 40.02%, 7.61%, and 513.34U / g, respectively.

[0105] The crude protein content, acid-soluble protein content, and neutral protease activity of Comparative Examples 1-8 are compared with Example 4, and the results are shown in Table 1. It can be seen that the crude protein content, acid-soluble protein content, and neutral protease activity of the feed protein prepared by the method of the present application are significantly higher than those of the comparative examples.

[0106] Table 1 result comparison

[0107]

[0108] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A method for preparing fermented feed protein, characterized in that: The steps include: (1) Pretreatment of Moringa seed meal: Take Moringa seed meal, crush it, sieve it, and set aside; (2) mixing the Moringa seed meal obtained in step (1) with water, then inoculating a mixed bacterial agent, mixing evenly, sealing and fermenting to obtain a fermentation product A; the mixed bacterial agent includes Rhizopus oryzae and Aspergillus niger; (3) Inoculating Enterococcus faecium into the fermentation product A, mixing evenly, sealing and fermenting to obtain fermented feed protein; The inoculation amount of the mixed bacterial agent described in step (2) is: based on 54 to 75 parts by mass of Moringa seed meal, 10 to 16 parts of the mixed bacterial agent are inoculated; The mixed bacterial agent described in step (2) is a mixed bacterial agent obtained by mixing Rhizopus oryzae and Aspergillus niger in a mass ratio of 5-8:5-8; The inoculation amount of Enterococcus faecium described in step (3) is: based on 54 to 75 parts by mass of Moringa seed meal, 5 to 8 parts of Enterococcus faecium are inoculated; The Rhizopus oryzae is Rhizopus oryzae GIM 3.130, purchased from Guangdong Provincial Microbial Culture Collection Center; The Aspergillus niger is Aspergillus niger GIM 3.462, which was purchased from Guangdong Provincial Microbiological Culture Collection Center; The Enterococcus faecium is Enterococcus faecium GIM 1.391, which was purchased from Guangdong Provincial Microbiological Culture Collection Center.

2. The method for preparing fermented feed protein according to claim 1, wherein: The moringa seed meal and water described in step (2) are mixed in a mass ratio of 54-75:25-46.

3. The method for preparing fermented feed protein according to claim 1, wherein: The Rhizopus oryzae described in step (2) is prepared by the following steps: inoculating the stored Rhizopus oryzae seeds on a plate for activation, then inoculating them on a seed culture medium, and culturing them with shaking to obtain a Rhizopus oryzae culture solution in a logarithmic growth phase or a stationary phase; The culture medium used for the plate activation is PDA; The activation time of the plate is 40 to 50 hours; The seed culture medium is PDB; The rotation speed of the shaking culture is 110-130 rpm; The shaking culture temperature is 28-32°C; The shaking culture time is 10 to 14 hours; The Rhizopus oryzae described in step (2) is a Rhizopus oryzae liquid with a strain amount of 0.8 to 0.9 mg / mL.

4. The method for preparing fermented feed protein according to claim 1, wherein: The Aspergillus niger described in step (2) is prepared by the following steps: inoculating the preserved Aspergillus niger seeds on a plate for activation, then inoculating them on a seed culture medium, and culturing them with shaking to obtain an Aspergillus niger culture solution in a logarithmic growth phase or a stationary phase; The culture medium used for the plate activation is PDA; The activation time of the plate is 40 to 50 hours; The seed culture medium is PDB; The rotation speed of the shaking culture is 110-130 rpm; The shaking culture temperature is 28-32°C; The shaking culture time is 20 to 26 hours; The Aspergillus niger described in step (2) is an Aspergillus niger liquid with a strain amount of 3 to 4 mg / mL.

5. The method for preparing fermented feed protein according to claim 1, wherein: The Enterococcus faecium described in step (3) is prepared by the following steps: inoculating the stored Enterococcus faecium species on a plate for activation, then inoculating it on a seed culture medium, and culturing it with shaking to obtain a culture solution of Enterococcus faecium in a logarithmic growth phase or a stationary phase; The culture medium used for the plate activation is a lactic acid bacteria culture medium; The activation time of the plate is 40 to 50 hours; The seed culture medium is a lactic acid bacteria culture medium; The rotation speed of the shaking culture is 110-130 rpm; The shaking culture temperature is 28-32°C; The shaking culture time is 12 to 16 hours; The Enterococcus faecium described in step (3) is OD 600 Enterococcus faecium liquid with a value of 0.7 to 0.

8.

6. The method for preparing fermented feed protein according to claim 1, characterized in that: The sealed fermentation after inoculation of the mixed bacterial agent in step (2) is carried out at a fermentation temperature of 28 to 32°C; The sealed fermentation after inoculation of the mixed bacterial agent in step (2) is carried out for 32 to 42 hours; The sealed fermentation after inoculation with Enterococcus faecium in step (3) is carried out at a fermentation temperature of 28 to 32°C; The sealed fermentation after inoculation with Enterococcus faecium in step (3) has a fermentation time of 32 to 42 hours.

7. A fermented feed protein, characterized in that: The fermented feed protein is prepared by the method for preparing the fermented feed protein according to any one of claims 1 to 6.

8. The fermented feed protein according to claim 7, characterized in that: The crude protein content of the fermented feed protein is 40-50%, the acid-soluble protein content is 9-11%, and the neutral protease activity is 700-850 U / g.

9. Use of the fermented feed protein according to claim 7 or 8 in preparing feed.

Images