Composite leavening agent and application thereof in preparation of pomace fermented feed for pigs

Abstract

The invention provides a composite leavening agent and application thereof in preparation of a pomace fermented feed for pigs. The composite leavening agent provided by the invention comprises the following components in parts by colony forming unit: 3-60 parts of lactobacillus plantarum, 1-30 parts of saccharomyces cerevisiae and 1-30 parts of aspergillus niger. The compound leavening agent provided by the invention is used for fermenting the pericarp residues, so that the content of crude protein can be increased, the high requirement of pigs on protein in the growth and development process is met, the palatability of the pericarp residues is obviously improved, and the nutritional value of feed is increased.

Description

Technical Field

[0001] The invention relates to the field of fermentation, and in particular to a composite fermentation agent and application thereof in preparing fermented pomace feed for pigs. Background Art

[0002] In my country, a large amount of peels and residues are produced during the production and processing of citrus and pineapples. There is currently no supporting technology and solution for efficient and reasonable treatment of such peel residues in China. A large amount of peel residues are directly discarded as waste, resulting in a large amount of accumulation of peel residues, which not only wastes resources but also seriously pollutes the ecological environment. Feeding domestic pigs directly with citrus and pineapple residues mainly leads to poor palatability and unbalanced nutrition. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a composite leavening agent.

[0004] The use of composite bacterial agents (lactic acid bacteria, yeast and fungi, etc.) to ferment fruit pomace into high-protein animal feed can solve the problems of poor palatability and unbalanced nutrition in the prior art of directly feeding fruit peel pomace to domestic pigs. It can also solve the problem of waste of fruit peel pomace and pollution of the ecological environment. It is an effective way to solve the problem of fruit peel pomace. It can not only turn fruit peel pomace waste into resources, but also create economic benefits for enterprises. It has great market potential. The use of microorganisms to ferment fruit peel pomace to make fermented feed can significantly improve the palatability of fruit peel pomace and increase the pigs' intake of fruit pomace; at the same time, the composite bacterial agent can degrade the anti-nutritional factors in the fruit pomace during the fermentation process, increase the crude protein content, and significantly improve the nutritional value of the feed. In addition, after pigs eat fermented feed, they can obtain probiotics in the feed, which plays an important role in maintaining the balance of pig intestinal flora and enhancing immunity. Pineapple and citrus peel pomace are fermented by microbial fermentation.

[0005] The technical solution adopted by the present invention is as follows:

[0006] The invention provides a composite fermentation agent, which comprises, in terms of colony forming units, 3-60 parts of plant lactobacillus, 1-30 parts of brewer's yeast and 1-30 parts of aspergillus niger.

[0007] Preferably, the method comprises 3-20 parts of Lactobacillus plantarum, 1-7 parts of Saccharomyces cerevisiae and 1-10 parts of Aspergillus niger in terms of colony forming units;

[0008] Preferably, the mixture comprises 3-5 parts of Lactobacillus plantarum, 1-3 parts of Saccharomyces cerevisiae and 1-2 parts of Aspergillus niger in terms of colony forming units.

[0009] Preferably, each gram or each milliliter of the composite fermentation agent contains 3×10 plant lactobacillus. 8 -6×10 9CFU, preferably 4×10 Lactobacillus plantarum per gram or per milliliter of the composite fermentation agent. 8 -5×10 9 CFU;

[0010] Preferably, each gram or each milliliter of the composite fermentation agent contains 1×10 8 -3×10 9 CFU, preferably 1×10 Saccharomyces cerevisiae per gram or per milliliter of the composite fermentation agent. 8 -2×10 9 CFU;

[0011] Preferably, the composite fermentation agent contains 1×10 Aspergillus niger per gram or per milliliter. 8 -3×10 9 CFU, preferably 1×10 Aspergillus niger per gram or per milliliter of the composite fermentation agent. 8 -2×10 9 CFU.

[0012] Preferably, the Lactobacillus plantarum is Lactobacillus plantarum S2 strain, which is deposited in China Center for Type Culture Collection (CCTCC) with a deposit number of CCTCC NO: M 2021340;

[0013] Preferably, the brewer's yeast is a brewer's yeast (Saccharomyces cerevisiae) PF-6 strain, which is deposited in the China Center for Type Culture Collection (CCTCC) with a deposit number of CCTCC NO: M2020171;

[0014] Preferably, the Aspergillus niger is Aspergillus niger XZ-AN01 strain, which is deposited in China Center for Type Culture Collection (CCTCC) with a deposit number of CCTCC NO: M 2023298.

[0015] The present invention also provides a method for preparing the composite leavening agent, which comprises the following steps: mixing the plant lactobacillus, saccharomyces cerevisiae and aspergillus niger.

[0016] Preferably, the Lactobacillus plantarum, Saccharomyces cerevisiae and Aspergillus niger are cultured separately, and the obtained bacterial liquids or bacterial powders are mixed to obtain the composite starter.

[0017] The present invention also provides the use of the composite fermentation agent or the composite fermentation agent obtained by the preparation method in fermenting feed;

[0018] Preferably, the composite fermentation agent is used in fermenting pig feed.

[0019] The present invention also provides a fermented feed, wherein the raw materials of the fermented feed include fruit residue, soybean meal and the composite fermentation agent or the composite fermentation agent obtained by the preparation method.

[0020] Preferably, the raw material of the fermented feed comprises 70-90 parts of fruit pomace, 10-30 parts of soybean meal and the composite fermentation agent, wherein the live bacteria concentration of the composite fermentation agent in the fermented feed raw material reaches 10 6 CFU / g-10 8 CFU / g;

[0021] Preferably, based on dry matter weight, the fruit pomace contains 35-45 parts of citrus pomace and 35-45 parts of pineapple pomace.

[0022] Preferably, the moisture content of the raw materials of the fermented feed is 65wt%-75wt%.

[0023] Preferably, the moisture content of the citrus residue is 70%-80%, the moisture content of the pineapple residue is 70%-80%, and the moisture content of the soybean meal is 10%-13.5%.

[0024] Preferably, the fruit residue is one or a combination of two or more of citrus residue or pineapple residue.

[0025] The present invention also provides a method for preparing the fermented feed, which comprises the following steps: mixing fruit residue, soybean meal and a composite fermentation agent and then performing anaerobic fermentation.

[0026] Beneficial effects of the technical solution of the present invention:

[0027] (1) The composite fermentation agent provided by the present invention can significantly increase the crude protein content of fruit peel residues, meet the high demand for protein of pigs during growth and development, significantly reduce the content of bitter substances such as naringin and limonin, and significantly improve the palatability of fruit peel residues; and the composite bacterial agent can effectively degrade the anti-nutritional factors in the fermentation base material, refine macromolecular substances, improve the palatability of feed, and significantly improve the nutritional value of feed. It enhances the digestion and absorption of fermented feed by pigs, has the advantages of significantly increasing the daily feed intake of pigs, reducing feed-to-weight ratio, improving pork production and quality, shortening the breeding cycle, and reducing breeding costs. In addition, after pigs eat fermented feed, they can obtain probiotics in the feed, which can improve the intestinal flora of pigs and enhance the immunity of pigs.

[0028] (2) The fermentation formula of the present invention is pure, the materials are easily available, the fermentation process is simple and mature, the fermentation site requirements are low, and the fermentation cycle is controlled within 10 days, which is suitable for large-scale factory production. In addition, no additional chemical additives are added during the fermentation process, which is green, healthy, low-cost and environmentally friendly.

[0029] (3) The present invention uses fruit residues such as citrus residues, pineapple residues, etc. and soybean meal as the main fermentation materials, which are all solid wastes generated in the process of food production and processing, with low cost and easy to obtain. By preparing fermented feed through microbial fermentation, such solid wastes can be fully utilized, turning waste into treasure, creating more economic value, and avoiding a series of social problems such as environmental pollution and waste of resources caused by direct disposal. In addition, during the fermentation process, the process is simple and easy to operate, without the need to add any additional chemical additives, further reducing labor and material costs, and can greatly explore the economic value of solid wastes, improve corporate benefits, build a green and sustainable production model, and promote high-quality development of the industry.

[0030] Strain deposit information

[0031] The Saccharomyces cerevisiae PF-6 strain in the present invention was deposited in the China Center for Type Culture Collection (CCTCC) on June 2, 2020, with a deposit number of CCTCC NO: M 2020171. The deposit address is: Wuhan University, Wuhan, China, Postal Code: 430072; Telephone: 027-68754052.

[0032] The Aspergillus niger XZ-AN01 strain in the present invention was deposited in the China Center for Type Culture Collection (CCTCC) on March 13, 2023, with a deposit number of CCTCC NO: M2023298, and a deposit address: Wuhan University, Wuhan, China, Postal Code: 430072; Telephone: 027-68754052. DETAILED DESCRIPTION

[0033] The invention provides a composite fermentation agent, which comprises, in terms of colony forming units, 3-60 parts of plant lactobacillus, 1-30 parts of brewer's yeast and 1-30 parts of aspergillus niger.

[0034] The composite fermentation agent is inoculated into a mixed fermentation base material containing fruit residue (such as citrus residue, pineapple residue, etc.), soybean meal and water, and fermented feed is obtained after anaerobic fermentation.

[0035] The feed prepared by fermenting fruit residue (such as citrus residue, pineapple residue, etc.) and soybean meal with the composite fermentation agent provided by the present invention can improve the palatability of the feed and significantly increase the nutritional value of the feed. It can enhance the digestion and absorption of fermented feed by pigs, significantly increase the daily feed intake of pigs, reduce the feed-to-weight ratio, improve the intestinal flora of pigs, improve the immunity of pigs, increase the yield and quality of pork, shorten the breeding cycle, and reduce the breeding cost.

[0036] The Lactobacillus plantarum S2 strain with a preservation number of CCTCC NO: M 2021340 used in the present invention was screened from the Qinghai-Tibet Plateau, has good fermentation and acid production performance, can significantly improve the palatability of feed, and can inhibit the growth of miscellaneous bacteria by lowering the environmental pH, thereby extending the storage period of fermented feed. In addition, it also has the function of improving constipation and intestinal repair; it can regulate the immune function of pigs, maintain the balance of intestinal flora and promote the absorption and utilization of nutrients.

[0037] The Saccharomyces cerevisiae PF-6 strain with the deposit number of CCTCC NO: M 2020171 used in the present invention can increase the palatability of fermented feed, consume free oxygen, promote the growth of beneficial bacteria, synthesize a variety of enzymes, and effectively degrade anti-nutritional factors in the fermentation base material.

[0038] The Aspergillus niger XZ-AN01 strain with a preservation number of CCTCC NO: M 2023298 used in the present invention has good fermentation performance, can produce acid and secrete a variety of enzymes, can cleave macromolecular organic matter and insoluble inorganic matter in the fermentation base material, is beneficial to the digestion and absorption of the fermented feed by pigs, can produce soybean peptide substances, has the effect of improving the immunity of pigs, and reduces the amount of antibiotics used in the feeding process.

[0039] In a specific embodiment of the present invention, the preparation method of the composite leavening agent comprises the following steps:

[0040] (1) Activation and expansion of strains: Take a glycerol storage tube of Lactobacillus plantarum S2 strain, inoculate the Lactobacillus plantarum S2 strain into MRS liquid culture medium, and incubate at 37°C for 10-12 hours for activation. Inoculate the S2 activated bacterial solution into MRS liquid culture medium at an inoculum volume of 1-2% and expand the culture under the same conditions until the final live bacterial concentration of Lactobacillus plantarum S2 strain reaches 10 10 CFU / mL, reserve;

[0041] Take the glycerol preservation tube of Saccharomyces cerevisiae PF-6 strain and inoculate it into YPD liquid medium. Cultivate it at 30℃ and 120r / min for 16-20h for activation. Take the activated bacterial solution of Saccharomyces cerevisiae PF-6 strain at a rate of 1-2% and inoculate it into YPD liquid medium for expansion under the same conditions. Make the final live bacterial concentration of Saccharomyces cerevisiae PF-6 strain reach 10 10 CFU / mL, reserve;

[0042] Take the Aspergillus niger XZ-AN01 strain glycerol preservation tube, inoculate it into PDA liquid culture medium, and culture it at 30°C for 24-36h for activation. Take the Aspergillus niger XZ-AN01 strain activated bacterial solution at a rate of 1-2% and inoculate it into PDA liquid culture medium containing glass beads, and culture it at 30°C, 120r / min for 24-36h for expansion, so that the final spore concentration of Aspergillus niger XZ-AN01 strain reaches 10 9 CFU / mL, for future use.

[0043] In a specific embodiment of the present invention, the three fermentation bacteria may be further freeze-dried to prepare bacterial powder for preparing the composite starter.

[0044] (2) Preparation of composite starter: After microscopic counting of the culture fluids of the reserved Lactobacillus plantarum S2 strain, Saccharomyces cerevisiae PF-6 strain and Aspergillus niger XZ-AN01 strain, or counting of the freeze-dried bacteria (spore) powders thereof, a composite starter is prepared containing 3-60 parts of Lactobacillus plantarum, 1-30 parts of Saccharomyces cerevisiae and 1-30 parts of Aspergillus niger in terms of colony forming units.

[0045] In a specific embodiment of the present invention, the method for preparing fermented feed comprises the following steps:

[0046] The moisture content of citrus residue, pineapple residue and soybean meal was determined according to the method in GB / T 6435-2014. The materials were weighed at a ratio of 35-45 parts of citrus residue: 35-45 parts of pineapple residue: 10-30 parts of soybean meal. After fully mixing, a mixed material with the corresponding moisture content was prepared and set aside.

[0047] After the composite fermentation agent and mixed fermentation materials are prepared, they can be inoculated to prepare the fermented feed. The specific preparation method is as follows:

[0048] (1) Mixing the compound fermentation agent and the mixed material: Spray or sprinkle the compound fermentation agent evenly into the mixed material to make the live bacteria concentration of the compound fermentation agent in the mixed material reach 10 6 CFU / g-10 8 CFU / g, stir the mixed material and the composite fermentation agent until the two are evenly mixed and wait for fermentation.

[0049] (2) Anaerobic fermentation: Transfer the mixed fermentation materials to an anaerobic fermentation bag (≥20 threads) with a one-way exhaust valve, seal the bag and remove the air in the bag as much as possible, then place the fermentation bag in a fermentation room at 25-30°C for static fermentation for 7-10 days. During the fermentation process, check the fermentation bag regularly for bloating and manually intervene to exhaust if necessary.

[0050] The source information of the reagents and instruments used in the present invention is shown in Tables 1 and 2 below.

[0051] Table 1 Reagents used in the present invention

[0052]

[0053] Table 2 Instruments used in the present invention

[0054] Instrument Name Manufacturer model Constant temperature incubator Qingdao Haier Biomedical Co., Ltd. HZP-168 Biological Safety Cabinets Qingdao Haier Biomedical Co., Ltd. HR1500-IIA2-E Medical Refrigerator Qingdao Haier Biomedical Co., Ltd. HYC-509F Shaking incubator Shanghai Zhichu Instrument Co., Ltd. ZQZY-98CV

[0055] The Lactobacillus plantarum S2 strain is deposited in China Center for Type Culture Collection (CCTCC) with a deposit number of CCTCC NO: M 2021340. The deposit address is: Wuhan University, Wuhan, China, zip code: 430072; telephone: 027-68754052. The strain has been disclosed in the prior art CN 113755360 A.

[0056] Saccharomyces cerevisiae PF-6 strain was collected from Yichang, Hubei, and identified as Saccharomyces cerevisiae by 26s rRNA sequencing. The strain was deposited in the China Center for Type Culture Collection (CCTCC) with the deposit number CCTCCNO:M 2020171. The deposit address is: Wuhan University, Wuhan, China, Postal Code: 430072; Tel: 027-68754052.

[0057] Aspergillus niger XZ-AN01 strain was collected from Gangjiu Village, Payang Town, Zhongba County, Shigatse City, Tibet, and identified as Aspergillus niger by 18s rRNA sequencing. The strain was deposited in China Center for Type Culture Collection (CCTCC) with the deposit number CCTCC NO:M 2023298. The deposit address is: Wuhan University, Wuhan, China, Postal Code: 430072; Tel: 027-68754052.

[0058] The EM bacteria used in Comparative Example 8 were commercially available strains purchased from JD.com (website: https: / / item.jd.com / 53189619226.html?cu=true&utm_source=www.baidu.com&utm_medium=tuiguang&utm_campaign=t_1003608409_&utm_term=ec4500bd27f24b458121e75822eec315#crumb-wrap);

[0059] The Lactobacillus delbrueckii subspecies bulgaricus CICC 6047 used in Comparative Example 9 was purchased from the China Industrial Microbiological Culture Collection Administration Center.

[0060] Example 1

[0061] (1) Preparation of mixed fermentation material: Weigh 4 kg of citrus residue, 4 kg of pineapple residue and 2 kg of soybean meal, mix them evenly, and obtain 10 kg of mixed fermentation material with a moisture content of 65 wt%.

[0062] (2) Preparation of composite starter: The plant lactobacillus S2 strain, cerevisiae PF-6 strain and Aspergillus niger XZ-AN01 strain obtained after expansion were added to a final concentration of 3×10 9 CFU / mL:1×10 9 CFU / mL:1×10 9 CFU / mL were mixed to prepare a composite fermentation agent.

[0063] (3) Fermentation of the mixed material: 100 mL of the composite fermentation agent was inoculated into the mixed material, and after mixing evenly, the mixture was transferred into an anaerobic fermentation bag for anaerobic fermentation. The fermentation cycle was 10 days.

[0064] Example 2

[0065] The composite fermentation agent in Example 1 was changed to Lactobacillus plantarum S2 strain, Saccharomyces cerevisiae PF-6 strain and Aspergillus niger XZ-AN01 strain at a final concentration of 3×10 8 CFU / mL:3×10 9 CFU / mL:1×10 8 CFU / mL for mixing and set aside, and the other implementation steps remain unchanged.

[0066] Example 3

[0067] The composite fermentation agent in Example 1 was changed to Lactobacillus plantarum S2 strain, Saccharomyces cerevisiae PF-6 strain and Aspergillus niger XZ-AN01 strain at a final concentration of 6×10 9 CFU / mL:1×10 8 CFU / mL:3×10 9 CFU / mL for mixing and set aside, and the other implementation steps remain unchanged.

[0068] Example 4

[0069] The composite fermentation agent in Example 1 was changed to Lactobacillus plantarum S2 strain, Saccharomyces cerevisiae PF-6 strain and Aspergillus niger XZ-AN01 strain at a final concentration of 4×10 8 CFU / mL:3×10 8 CFU / mL:1×10 8 CFU / mL for mixing and set aside, and the other implementation steps remain unchanged.

[0070] Example 5

[0071] The composite fermentation agent in Example 1 was changed to Lactobacillus plantarum S2 strain, Saccharomyces cerevisiae PF-6 strain and Aspergillus niger XZ-AN01 strain at a final concentration of 5×10 8 CFU / mL:1×10 8 CFU / mL:2×10 8 CFU / mL for mixing and set aside, and the other implementation steps remain unchanged.

[0072] Example 6

[0073] The composite fermentation agent in Example 1 was changed to Lactobacillus plantarum S2 strain, Saccharomyces cerevisiae PF-6 strain and Aspergillus niger XZ-AN01 strain at a final concentration of 2×10 9 CFU / mL:7×10 8 CFU / mL:1×10 9 CFU / mL for mixing and set aside, and the other implementation steps remain unchanged.

[0074] Comparative Example 1

[0075] The composite fermentation agent in Example 1 was changed to Lactobacillus plantarum S2 strain and Saccharomyces cerevisiae PF-6 strain at a final concentration of 3×10 9 CFU / mL:1×10 9 CFU / mL for mixing and set aside, and the other implementation steps remain unchanged.

[0076] Comparative Example 2

[0077] The composite fermentation agent in Example 1 was changed to Lactobacillus plantarum S2 strain and Aspergillus niger XZ-AN01 strain at a final concentration of 3×10 9 CFU / mL:1×10 9 CFU / mL for mixing and set aside, and the other implementation steps remain unchanged.

[0078] Comparative Example 3

[0079] The composite fermentation agent in Example 1 was changed to Lactobacillus plantarum S2 strain, and the live bacteria concentration was 3×10 9 CFU / mL, and the rest of the implementation steps remain unchanged.

[0080] Comparative Example 4

[0081] In Example 1, the mixed material is naturally fermented without inoculating a fermentation agent, that is, steps (3) and (4) are directly carried out.

[0082] Comparative Example 5

[0083] The composite fermentation agent in Example 1 was changed to plant lactobacillus S2 strain and cerevisiae PF-6 strain at a final concentration of 1×10 9 CFU / mL:1×109 CFU / mL were mixed, and the other steps remained unchanged.

[0084] Comparative Example 6

[0085] The composite fermentation agent in Example 1 was changed to plant lactobacillus S2 strain and cerevisiae PF-6 strain at a final concentration of 3×10 9 CFU / mL:3×10 9 CFU / mL were mixed, and the other steps remained unchanged.

[0086] Comparative Example 7

[0087] The composite fermentation agent in Example 1 was changed to plant lactobacillus S2 strain and cerevisiae PF-6 strain at a final concentration of 1×10 9 CFU / mL:3×10 9 CFU / mL were mixed, and the other steps remained unchanged.

[0088] Comparative Example 8

[0089] The composite fermentation agent in Example 1 was replaced with EM bacteria purchased on the market (EM bacteria strain 2.0 for Nanhua Qianmu breeding), with an inoculation amount of 1%, and the other implementation steps remained unchanged.

[0090] Comparative Example 9

[0091] The composite starter in Example 1 was replaced with Lactobacillus delbrueckii subspecies bulgaricus CICC 6047, Saccharomyces cerevisiae PF-6 strain, and Aspergillus niger XZ-AN01 strain at a rate of 3×10 9 CFU / mL:1×10 9 CFU / mL:1×10 9 CFU / mL for mixing and set aside, and the other implementation steps remain unchanged.

[0092] The fermented feeds prepared in the above Examples 1 to 6 and Comparative Examples 1 to 9 were sampled and tested, wherein the crude protein in the feed was determined by the Kjeldahl method according to GB / T 6432-2018, the moisture content in the feed was determined by GB / T 6435-2014, the ash content in the feed was determined by GB / T 6438-2007, the pH quality in the feed was determined by DB15 / T 1458-2018, the protein in the feed was determined by DB13 / T1098-2009, the crude fat in the feed was determined by GB / T 6433-2006, and the crude fiber content in the feed was determined by the filtration method according to GB / T 6434-2006.

[0093] The data shown in Table 3 and Table 4 were obtained:

[0094] Table 3 Detection of relevant indicators of fermented feed in Example

[0095]

[0096]

[0097] Table 4 Comparative Examples of Fermented Feed Related Index Detection

[0098]

[0099] It can be seen from Table 3 and Table 4 that the true protein content of the fermented feed prepared in Examples 1-6 is significantly higher than that in the comparative example, and in all the examples and comparative examples, the true protein content of the fermented feed prepared by inoculating the composite starter in Example 1 is the highest and the crude fiber content is the lowest, indicating that the plant lactobacillus S2 strain, the cerevisiae PF-6 strain and the Aspergillus niger XZ-AN01 strain are 3×10 9 CFU / mL:1×10 9

[0100] CFU / mL:1×10 9 CFU / mL are mixed to prepare a composite fermentation agent for fermenting pomace fermented feed, which can significantly improve the nutritional value of the fermented feed.

[0101] The fermented feed was fed, and 40 healthy piglets with an average weight of 15-20 kg were selected and randomly divided into 15 groups of 10 pigs each. Experimental groups 1 to 6 were fed with the feeds of Examples 1 to 6, respectively, and experimental groups 7 to 15 were fed with the feeds of Comparative Examples 1 to 9, respectively. The feeding was continued for 30 days, and other feeding conditions were the same. The feeding effects are shown in Tables 5 and 6 below:

[0102] Table 5 Example fermented feed feeding experiment

[0103]

[0104]

[0105] Table 6 Comparative Example Fermented Feed Feeding Experiment

[0106]

[0107] It can be concluded from Tables 4 and 5 above that the total feed intake of piglets fed with the feed in Examples 1 to 6 is significantly higher than that in the control example, indicating that the palatability of the fermented feed is better and the piglets are willing to eat it. The weight gain of the piglets in Example 1 is significantly higher than that of the piglets in other examples and control examples, and the number of illnesses is significantly reduced, indicating that the inoculation of the composite fermentation agent can increase pork production, and can effectively enhance the immunity of piglets and reduce the incidence of disease. In addition, the feed-to-meat ratio of Example 1 is significantly lower than that of other examples and control examples, indicating that the nutritional value of the pomace is significantly improved after fermentation with the composite fermentation agent, which can promote the rapid growth of piglets and reduce feeding costs. Comprehensively comparing Examples 1-6 and Comparative Examples 1-9, it can be seen that the Lactobacillus plantarum S2 strain, the Saccharomyces cerevisiae PF-6 strain and the Aspergillus niger XZ-AN01 strain are fermented at a rate of 3×10 9 CFU / mL:1×10 9 CFU / mL:1×10 9 CFU / mL mixed to prepare a composite fermentation agent has the best effect.

[0108] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A composite leavening agent, characterized in that: Calculated by colony forming units, the composition comprises 3-60 parts of plant lactobacillus, 1-30 parts of brewer's yeast and 1-30 parts of aspergillus niger.

2. The composite leavening agent according to claim 1, characterized in that Calculated by colony forming units, it contains 3-20 parts of Lactobacillus plantarum, 1-7 parts of Saccharomyces cerevisiae, and 1-10 parts of Aspergillus niger; Preferably, the mixture comprises 3-5 parts of Lactobacillus plantarum, 1-3 parts of Saccharomyces cerevisiae and 1-2 parts of Aspergillus niger in terms of colony forming units.

3. The composite leavening agent according to claim 1 or 2, characterized in that: Each gram or milliliter of the composite fermentation agent contains 3×10 plant lactobacillus. 8 -6×10 9 CFU, preferably 4×10 Lactobacillus plantarum per gram or per milliliter of the composite fermentation agent. 8 -5×10 9 CFU; Preferably, each gram or each milliliter of the composite fermentation agent contains 1×10 8 -3×10 9 CFU, preferably 1×10 Saccharomyces cerevisiae per gram or per milliliter of the composite fermentation agent. 8 -2×10 9 CFU; Preferably, the composite fermentation agent contains 1×10 Aspergillus niger per gram or per milliliter. 8 -3×10 9 CFU, preferably 1×10 Aspergillus niger per gram or per milliliter of the composite fermentation agent. 8 -2×10 9 CFU.

4. The composite leavening agent according to any one of claims 1 to 3, characterized in that: The plant lactobacillus is a plant lactobacillus (Lactobacillus plantarum) S2 strain, which is deposited in the China Center for Type Culture Collection (CCTCC) with a deposit number of CCTCC NO: M 2021340; Preferably, the brewer's yeast is a Saccharomyces cerevisiae PF-6 strain, which is deposited in the China Center for Type Culture Collection (CCTCC) with a deposit number of CCTCC NO: M 2020171; Preferably, the Aspergillus niger is Aspergillus niger XZ-AN01 strain, which is deposited in China Center for Type Culture Collection (CCTCC) with a deposit number of CCTCC NO: M2023298.

5. The method for preparing the composite leavening agent according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: mixing the plant lactobacillus, brewer's yeast and aspergillus niger.

6. The preparation method according to claim 5, characterized in that: The plant lactobacillus, saccharomyces cerevisiae and Aspergillus niger are cultured separately, and the obtained bacterial liquids or bacterial powders are mixed to obtain the composite starter.

7. Use of the composite starter according to any one of claims 1 to 4 or the composite starter obtained by the preparation method according to claim 5 or 6 in fermented feed; Preferably, the composite fermentation agent is used in fermenting pig feed.

8. A fermented feed, characterized in that: The raw materials of the fermented feed include fruit residue, soybean meal and the composite fermentation agent described in any one of claims 1 to 4 or the composite fermentation agent obtained by the preparation method described in claim 5 or 6.

9. The fermented feed according to claim 8, characterized in that The raw materials of the fermented feed include 70-90 parts of fruit pomace, 10-30 parts of soybean meal and the composite fermentation agent, wherein the live bacteria concentration of the composite fermentation agent in the fermented feed raw materials reaches 10 6 CFU / g-10 8 CFU / g; Preferably, based on dry matter weight, the fruit pomace contains 35-45 parts of citrus pomace and 35-45 parts of pineapple pomace.

10. The fermented feed according to claim 8 or 9, characterized in that: The moisture content of the raw materials of the fermented feed is 65wt%-75wt%.

11. The fermented feed according to any one of claims 8 to 10, characterized in that: The fruit residue is one or a combination of two or more of citrus residue and pineapple residue.

12. The method for preparing a fermented feed according to any one of claims 8 to 10, characterized in that: The preparation method comprises the following steps: mixing fruit residue, soybean meal and a composite fermentation agent and then performing anaerobic fermentation.

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