Poultry probiotic preparation prepared by fermenting selenium-resistant duck-origin lactobacillus plantarum

Abstract

The invention provides a poultry probiotic preparation prepared by fermenting selenium-resistant duck-origin lactobacillus plantarum. The poultry probiotic preparation is prepared by inoculating duck-origin lactobacillus plantarum with high selenium ion loading capacity into a culture medium and fermenting, the duck-origin lactobacillus plantarum with high load of selenium ions has the preservation number of CGMCC (China General Microbiological Culture Collection Center) No.30182. The high-load selenium duck-origin lactobacillus plantarum obtained by domesticating and screening by adopting a method for gradually increasing the concentration of selenium ions in a culture medium contains small peptides, small molecular organic acids, digestive enzymes and the like. As the antibacterial peptide is rich in targeted antibacterial peptide, the antibacterial peptide has an obvious inhibition effect on harmful bacteria such as escherichia coli, salmonella, riemerella anatipestifer and the like. Other bioactive substances such as digestive enzyme contained in the feed can promote the growth and development of poultry and improve the product quality.

Description

Technical Field

[0001] The invention belongs to the technical field of biological product preparation, and specifically relates to a probiotic preparation for poultry prepared by fermenting selenium-resistant duck-derived Lactobacillus plantarum. Background Art

[0002] In poultry farming, it is common to see a decline in animal growth performance and immune health due to selenium deficiency in feed. Therefore, in order to improve the animal's absorption metabolism, growth and development, immunity and clinical health functions, it is necessary to meet the animal's need for selenium and prevent the occurrence of selenium deficiency, which is also an important measure in modern animal husbandry production. At present, selenium supplements are divided into inorganic selenium and organic selenium according to the different forms of selenium metabolism in the body.

[0003] Inorganic selenium refers to inorganic selenium compounds, including selenides Se in different valence states. 4+ (Selenite), selenate Se 6+ (selenate), Se 0 (elemental selenium) and Se 2- (Selenium compounds), etc. Sodium selenite is currently the most widely used and generally accepted inorganic selenium additive in the world. However, the selenite ions in inorganic selenium are easily oxidized, have extremely low biological absorption and utilization rates, and are toxic to the body, resulting in poor selenium deposition and storage capacity in the body. Therefore, it may cause potential toxic effects on animals and pollute the environment. Organic selenium refers to the organic compounds and biologically active macromolecules containing selenium produced by combining selenium and amino acids through biological metabolic activities in an organism. Therefore, compared with inorganic selenium, organic selenium has the advantages of low toxic side effects, low-volume high efficiency, and easy absorption and utilization by the animal body, and has significant advantages in enhancing the body's antioxidant properties, immune function, and resistance to heat stress. Therefore, exploring a method that can not only promote the normal growth and development of poultry, but also maintain intestinal health and increase selenium absorption rate is of great significance to the precision of poultry farming nutrition and the maintenance of a good ecological cycle. Summary of the invention

[0004] The invention provides a probiotic preparation for poultry prepared by fermenting selenium-resistant duck-derived Lactobacillus plantarum, thereby making up for the deficiencies of the prior art.

[0005] The present invention first provides a poultry probiotic preparation prepared by fermenting selenium-resistant duck-derived Lactobacillus plantarum, which is a high-load selenium ion (Se 4+ ) is inoculated into a culture medium for fermentation;

[0006] The high load selenium ion (Se 4+) is a duck-derived Lactobacillus plantarum (LP), which is specifically recorded in an embodiment of the present invention. It was deposited at the General Microbiology Center of the China Microbiological Culture Collection Committee, Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing on March 28, 2024, with a deposit number of CGMCC No.30182.

[0007] The fermentation medium preferably has the following composition: 10 g / L peptone, 10 g / L beef powder, 5 g / L yeast powder, 20 g / L glucose, 0.1 g / L magnesium sulfate, 5 g / L sodium acetate, 2 g / L ammonium citrate, 2 g / L dipotassium hydrogen phosphate, 0.05 g / L manganese sulfate, 1 g / L Tween 80, and a pH value of 6.2±0.2.

[0008] The culture temperature is 35.5-38.5°C, preferably 37°C; the culture time is 20-27h, preferably 24h.

[0009] The present invention also provides a small peptide with antibacterial effect, wherein the small peptide is separated and prepared from the above-mentioned probiotic preparation.

[0010] The amino acid sequence of the small peptide is SEQ ID NO: 1 or SEQ ID NO: 2.

[0011] The poultry probiotic preparation provided by the present invention can be used to prepare antibacterial products or feed additives to promote the growth and development of poultry.

[0012] The present invention provides a feed for livestock and poultry breeding, wherein the feed contains the above-mentioned probiotic preparation for poultry.

[0013] The method of the present invention is to gradually increase the selenium ion (Se 4+ ) concentration method to obtain high-load selenium duck-derived plant lactobacillus, which not only has the probiotic advantages of duck-derived plant lactobacillus, but also can improve intestinal selenium absorption rate and reduce selenium ion (Se 4+ ) to the environment. At the same time, the domesticated and bred high-load selenium duck-derived Lactobacillus plantarum produces a lot of postbiotics, including small peptides (antimicrobial peptides), small molecule organic acids, digestive enzymes, etc. Because it is rich in targeted antimicrobial peptides, it has a significant inhibitory effect on harmful bacteria such as Escherichia coli, Salmonella, and Riemerella anatipestifer. The digestive enzymes and other bioactive substances contained can promote the growth and development of poultry and improve product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 :The effect of high-load selenium ion acclimation on the growth of Lactobacillus plantarum,

[0015] Figure 2:The effect of high-load selenium ion acclimation on the selenium content of Lactobacillus plantarum,

[0016] Figure 3 :PTGGTPTSDHAATDKVNLNTADVAALQTLS sequence secondary mass spectrum

[0017] Figure 4 :STGVTLADGGEGTSEAFLANQRGGRWEYAM sequence secondary mass spectrum

[0018] Figure 5 :PTGGTPTSDHAATDKVNLNTADVAALQTLS sequence small peptide structure diagram

[0019] Figure 6 :STGVTLADGGEGTSEAFLANQRGGRWEYAM sequence small peptide structure diagram

[0020] Figure 7 , 8 9: Effect of high-load selenium ion duck-derived Lactobacillus plantarum postbiotics on antibacterial effects

[0021] Fig.10 :Flow cytometry of E. coli (postbiotics added at 1:4)

[0022] Fig.11 :Salmonella flow cytometry (postbiotics 1:4 addition)

[0023] Fig.12 :Flow cytometry of Riemerella (postbiotics added at a ratio of 1:4)

[0024] Fig.13 :Morphology of high-load selenium ion duck-derived Lactobacillus plantarum postbiotics inhibiting Escherichia coli (postbiotics added in a ratio of 1:4)

[0025] Fig.14 :High-load selenium ion duck-derived Lactobacillus plantarum postbiotics inhibit Riemerella morphology (postbiotics 1:4 addition)

[0026] Fig.15 :Effects of high-selenium-load duck-derived Lactobacillus plantarum postbiotics on fatty acids in breast muscle of duck meat DETAILED DESCRIPTION

[0027] The invention screens the selenium ion-loaded 4+ ) is used as the strain to ferment and prepare bacterial preparations. The prepared bacterial preparations are rich in functional antimicrobial peptides, which have the effects of inhibiting the reproduction of harmful bacteria and promoting their cell apoptosis. At the same time, they have the effects of promoting growth and development, improving slaughter performance, improving meat quality, increasing the body's antioxidant capacity, and improving intestinal mucosal immunity.

[0028] The fermentation strain used is a high-load selenium duck-derived Lactobacillus plantarum, which was deposited on March 28, 2024 at the General Microbiology Center of the China Microbiological Culture Collection Administration, Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with the deposit number CGMCC No. 30182.

[0029] The culture medium used in the embodiment of the present invention is specifically composed of: peptone 10g / L, beef powder 10g / L, yeast powder 5g / L, glucose 20g / L, magnesium sulfate 0.1g / L, sodium acetate 5g / L, ammonium citrate 2g / L, dipotassium hydrogen phosphate 2g / L, manganese sulfate 0.05g / L, Tween 80 1g / L, pH 6.2±0.2.

[0030] The culture temperature for fermenting duck-derived Lactobacillus plantarum is 35.5-38.5°C, and the culture time is 20-27 hours.

[0031] The present invention is described in detail below with reference to specific implementation cases.

[0032] Example 1: Cultivation and domestication of duck-derived Lactobacillus plantarum with high selenium ion loading

[0033] The Se content in the culture medium was gradually increased. 4+ concentration; after the domesticated strains are continuously cultured for several generations, the plant morphology, enzyme activity, small peptides, amino acids, antibacterial effects, etc. are compared with those of the plant lactobacillus before domestication to further determine the characteristics of the plant lactobacillus after domestication, and it can be stably propagated. Finally, plant lactobacillus (Lactobacillus plantarum, LP) that can tolerate high concentrations of sodium selenite (280 mg / L) was domesticated and cultivated, and was deposited at the General Microbiology Center of the China Microbiological Culture Collection Administration Committee, Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, on March 28, 2024, with a deposit number of CGMCC NO.30182.

[0034] The domesticated selenium-rich duck-derived Lactobacillus plantarum has the ability to load selenium ions. When the amount of selenium ions added is 280.0 mg / L, the organic selenium content of the bacteria is 21.60 ug / L, which is greater than the selenium content of ordinary duck-derived Lactobacillus plantarum ( Figure 1 , Figure 2 ).

[0035] Example 2: Preparation method and effective component analysis of high-load selenium duck-derived Lactobacillus plantarum postbiotics

[0036] 1) Preparation method of postbiotics: plant lactobacillus with a preservation number of CGMCC NO.30182 is inoculated into the culture medium for fermentation, and the culture temperature is 35.5-38.5°C; the culture time is 20-27h. After the fermentation liquid is centrifuged at 6000r / min for 6-12 minutes, it is filtered with a 0.22μm water filter membrane, and the filtrate is the prepared postbiotic preparation. The specific composition of the culture medium is as follows: peptone 10g / L, beef powder 10g / L, yeast powder 5g / L, glucose 20g / L, magnesium sulfate 0.1g / L, sodium acetate 5g / L, ammonium citrate 2g / L, potassium dihydrogen phosphate 2g / L, manganese sulfate 0.05g / L, Tween 80 1g / L, pH 6.2±0.2.

[0037] 2) Analysis of effective components of postbiotics: The content of amylase in the postbiotics of the fermentation product of duck-derived plant lactobacillus after domestication was 0.26U / mL, which was 18.18% higher than that before domestication; the content of lipase was 48.66U / L, which was 29.24% higher than that before domestication; the content of small peptides was 23.09mg / mL, which was 8.45% higher than that before domestication; the content of L-lactic acid was 17.45mg / mL, which was 19.44% higher than that before domestication; the content of acetic acid was 0.42mg / mL, which was 13.51% higher than that before domestication; the content of propionic acid was 0.22mg / mL, which was 22.22% higher than that before domestication; and the content of butyric acid was 0.21mg / mL, which was 31.25% higher than that before domestication.

[0038] Example 3: Sequence analysis of small peptides in duck-derived Lactobacillus plantarum postbiotics before and after domestication

[0039] 1) Small peptide sequence analysis method: A commercial company was commissioned to perform protein shotgun identification analysis on duck-derived plant lactobacillus and duck-derived plant lactobacillus with high selenium ion load. The experimental method was to add an appropriate amount of 0.1% TFA to the sample, mix well, centrifuge at 20000g for 5min, take the supernatant, transfer to a 10KD ultrafiltration centrifuge tube, and centrifuge at 12000g for 15min. Add 200μL 0.1% TFA and centrifuge at 12000g for 15min, repeat twice, collect the filtrate, desalt with C18 StageTip, and vacuum dry. After drying, the peptides were re-dissolved with 0.1% FA, and the peptide concentration was determined for LC-MS analysis. An appropriate amount of peptides was taken from each sample and chromatographically separated using the nanoliter flow rate Easy nL C1200 chromatography system (Thermo Scientific). After the sample was injected into the Trap Column, it was gradient separated through the chromatographic analysis column at a flow rate of 300nl / min. After peptide separation, DDA (data-dependent acquisition) mass spectrometry analysis was performed using a Q-Exactive HF-X mass spectrometer (Thermo Scientific), and the mass spectrometry database search software MaxQuant 2.4.14.0 was used for retrieval.

[0040] 2) Small peptide sequence analysis results:

[0041] Figure 3 As shown, the amino acid sequence of a small peptide with antibacterial effect from Lactobacillus plantarum postbiotics from ducks before domestication is: PTGGTPTSDHAATDKVNLNTADVAALQTLS (SEQ ID NO: 1), with a relative molecular mass of 2965.46. Figure 4 As shown, the amino acid sequence of a small peptide with antibacterial effect of a high-selenium ion-loaded duck-derived Lactobacillus plantarum postbiotic is STGVTLADGGEGTSEAFLANQRGGRWEYAM (SEQ ID NO: 2), with a relative molecular mass of 3130.44. Figure 5 is a structural diagram of a small peptide having an amino acid sequence of SEQ ID NO: 1; Figure 6 It is a structural diagram of a small peptide having an amino acid sequence of SEQ ID NO: 2.

[0042] 3) Analysis of antibacterial effect of small peptides:

[0043] After synthesizing the small peptides with the sequence of SEQ ID NO:1 and the sequence of SEQ ID NO:2, dilute them with MRS medium so that the total amount of the solution is consistent with the initial fermentation volume. Take the same content of small peptides and harmful bacteria to inhibit the growth of duck harmful bacteria (Escherichia coli, Riemerella anatipestifer, Salmonella) to verify the in vitro antibacterial activity of artificial synthetic peptides against harmful bacteria. After filtering and sterilizing the synthetic peptides through a 0.22μm water membrane, add them to a 96-well plate, set the medium with normal inoculation of harmful bacteria and no antimicrobial peptides as a control, put them into a microbial growth analyzer (enzyme reader) for growth curve determination, culture at 37°C for 12 to 16h, and measure the absorbance at a wavelength of 600nm.

[0044] Table 1: Inhibition rate of synthetic small peptides on harmful bacteria

[0045]

[0046] The results in Table 1 show that both small peptides have obvious antibacterial effects; compared with the antibacterial effect of the small peptide produced by duck-derived Lactobacillus plantarum before domestication, the antibacterial effect of the small peptide produced by duck-derived Lactobacillus plantarum with high selenium ion load after domestication is better.

[0047] Example 4: Comparison of the antibacterial effects of duck-derived Lactobacillus plantarum postbiotics before and after domestication

[0048] Undomesticated duck-derived Lactobacillus plantarum and the high-load selenium duck-derived Lactobacillus plantarum postbiotics of Example 1 were used to test the inhibition of the growth of duck harmful bacteria (Escherichia coli, Riemerella anatipestifer, and Salmonella). After the two strains of Lactobacillus plantarum were cultured in MRS broth for 24 hours, the supernatant (metabolites) were taken and mixed with the broth culture medium containing harmful bacteria in proportion (the ratio of supernatant: harmful bacteria was 1:4 and 1:9), and the growth curve was measured after being placed in a microbial growth analyzer (enzyme reader) for 36 hours.

[0049] Figure 7 , Figure 8 , Fig. 9 The results of the antibacterial test showed that when the addition ratio with harmful bacteria was 1:4, the postbiotics of the two strains of bacteria had significant antibacterial effects, and kept the harmful bacteria in a non-growth state for 15 consecutive hours. This shows that duck-derived plant lactobacillus postbiotics have a significant inhibitory effect on Escherichia coli, Riemerella anatipestifer, and Salmonella, and the high-load selenium duck-derived plant lactobacillus has a better inhibitory effect. When the addition ratio with harmful bacteria was 1:9, duck-derived plant lactobacillus and high-load selenium duck-derived plant lactobacillus postbiotics could delay the time when Riemerella anatipestifer entered the exponential growth phase, and could significantly inhibit the growth vitality of Riemerella anatipestifer; high-load selenium duck-derived plant lactobacillus postbiotics could delay the time when Salmonella entered the exponential growth phase, and had a certain antibacterial effect; duck-derived plant lactobacillus and high-load selenium duck-derived plant lactobacillus postbiotics had no obvious inhibitory effect on Escherichia coli when added at a ratio of 1:9.

[0050] Fig.10 , Fig.11 , Fig.12 The results of flow cytometry and Table 2 show that when the addition ratio with harmful bacteria is 1:4, the apoptosis rate of harmful bacteria is significantly increased, indicating that duck-derived Lactobacillus plantarum postbiotics have a significant inhibitory effect on Escherichia coli, Riemerella anatipestifer, and Salmonella, and the antibacterial effect of duck-derived Lactobacillus plantarum postbiotics with high selenium ion load is better than that of ordinary duck-derived Lactobacillus plantarum postbiotics.

[0051] Table 2: Effect of high-load selenium ion duck-derived Lactobacillus plantarum postbiotics on the apoptosis rate of harmful bacteria

[0052]

[0053] Depend on Fig.13 , 14It can be seen that the scanning electron microscope images of the same magnification show that the Escherichia coli and Riemerella anatipestifer are intact; when the supernatant of duck-derived Lactobacillus plantarum with high load of selenium ions (postbiotics) was added at a ratio of 1:4 to the harmful bacteria, and the two harmful bacteria were cultured for the same time, both Escherichia coli and Riemerella anatipestifer showed shrinkage, rupture and distortion, indicating that the postbiotics of Lactobacillus plantarum with high load of selenium ions can not only inhibit the growth of Escherichia coli and Riemerella anatipestifer, but also cause the bacteria to rupture.

[0054] Example 5: High load of selenium ions (Se 4+ ) Effects of duck-derived Lactobacillus plantarum postbiotics on the growth and development of broiler ducks

[0055] In this experiment, 120 male Beijing ducks aged one day were randomly divided into five groups, with four replicates in each group and six ducks in each replicate. Four treatment groups and one control group were used in this experiment. The bacterial concentration in the probiotic preparation was 1×10 9 CFU / mL, 4L of bacterial liquid was added per ton of basic feed. CON group (control group): fed with a basic diet (the composition of the basic diet is shown in Table 3); Group I: added conventional unfortified duck-derived Lactobacillus plantarum on the basis of the basic diet; Group II: added the high-load selenium duck-derived Lactobacillus plantarum fermentation liquid of Example 1 on the basis of the basic diet; Group III: added high-load selenium duck-derived Lactobacillus plantarum postbiotics on the basis of the basic diet; Group IV: added high-load selenium duck-derived Lactobacillus plantarum cells on the basis of the basic diet. The experimental feeding period was 42 days, and after the end of 42 days, slaughter and sampling were carried out. The feeding experiments of Examples 4, 5, 6, 7, and 8 are the same.

[0056] Table 3: Basic feed composition of broiler ducks %

[0057]

[0058]

[0059] 1 Vitamin premix and trace element premix provide VA 12 000IU, VD3 2 500IU, VE 20mg, VK3 3mg, VB1 3mg, VB2 8mg, VB6 7mg, VB 12 0.3mg, D-pantothenic acid 20mg, niacin 50mg, folic acid 1.5mg, biotin 0.1mg, copper (as copper sulfate) 9mg, zinc (as zinc sulfate) 110mg, iron (as ferrous sulfate) 100mg, iron (as ferrous sulfate) 100mg, iodine (as potassium iodide) 0.6mg.

[0060] 2 Metabolizable energy is a calculated value, and the others are measured values.

[0061] Table 4: Growth performance of 42-day-old broiler ducks

[0062]

[0063]

[0064] Note: Data in the same row with different lowercase letters indicate significant differences (P<0.05), while data with the same lowercase letters or no letters indicate no significant differences (P>0.05).

[0065] As shown in Table 4, the ADG, ADFI, and F / G of each group in the 1-21d experiment were not significantly different from those of the CON group (P < 0.05). The average daily weight gain of the 22-42d group II and group III was significantly higher than that of the CON group (P < 0.05), and the feed-to-weight ratio was significantly lower (P < 0.05). The average daily weight gain of the 1-42d group II and group III was significantly higher than that of the CON group (P < 0.05), and the feed-to-weight ratio of the 2, 3, and 4 groups was significantly lower than that of the CON group (P < 0.05). The results of the experimental groups II and III were better than those of the group IV, which only added high-load selenium plant lactobacillus pure bacteria to the diet, indicating that the digestive enzymes in the postbiotics played an intervention role in the growth performance of meat ducks, indicating that the domesticated high-load selenium duck-derived plant lactobacillus postbiotics can improve the feed conversion rate of meat ducks.

[0066] Example 6: High load of selenium ions (Se 4+ ) Effects of duck-derived Lactobacillus plantarum postbiotics on slaughter performance of broiler ducks

[0067] Table 5: Slaughter performance of 42-day-old meat ducks

[0068]

[0069]

[0070] As shown in Table 5, the half-eviscerated rate of groups II, III, and IV was significantly higher than that of group CON (P < 0.05), and the slaughter rate of group II was significantly higher than that of group CON (P < 0.05). The eviscerated rate, breast muscle rate, and leg muscle rate of each experimental group showed an upward trend (P > 0.05). 4+ ) Duck-derived Lactobacillus plantarum postbiotics have the effect of improving the slaughter performance of meat ducks.

[0071] Example 7: High load of selenium ions (Se 4+ ) Effects of duck-derived Lactobacillus plantarum postbiotics on duck meat quality

[0072] Table 6: Quality index of 42-day-old duck meat

[0073]

[0074] As shown in Table 6, compared with the CON group, the pH of group II was significantly increased (P < 0.05), and the redness a* value of group III was significantly increased (P < 0.05). The cooking loss of group IV was significantly reduced (P < 0.05). There were no significant differences in the brightness L* value, yellowness b* value, drip loss, and shear force of the experimental groups (P > 0.05). This indicates that the addition of domesticated loaded selenium ions (Se 4+ ) Duck-derived Lactobacillus plantarum postbiotics can increase the pH of duck breast muscle, increase the redness of the meat, improve the color of duck meat, and increase the water-binding capacity of the meat.

[0075] Example 8: High load of selenium ions (Se 4+ ) Effects of duck-derived Lactobacillus plantarum postbiotics on antioxidant indices of meat ducks

[0076] Table 7: Antioxidant index of 42-day-old meat ducks

[0077]

[0078] In animals, selenium circulates and functions mainly in the form of selenoproteins, catalyzing glutathione into oxidized glutathione, and is an effective antioxidant element in animals. The antioxidant system plays an important role in maintaining the health of the body. As an important component of the antioxidant system, the activity of antioxidant enzymes can reflect the body's antioxidant capacity. As shown in Table 7, compared with the CON group, group II was able to significantly increase the total serum superoxide dismutase activity (P < 0.05), reduce the content of malondialdehyde, and the total superoxide dismutase activity of group I was also increased. The glutathione peroxidase activity of group III was significantly higher than that of the control group (P < 0.05), and the activity of group II was also increased. This indicates that high load of selenium ions (Se 4+ ) Plant Lactobacillus postbiotics can increase the activity of total superoxide dismutase, scavenge peroxide free radicals, and improve the body's antioxidant capacity.

[0079] Example 9: High load of selenium ions (Se 4+ ) Effects of duck-derived Lactobacillus plantarum postbiotics on intestinal immune parameters of broiler ducks

[0080] Table 8: Intestinal immune index table of 42-day-old meat ducks (μg / ml)

[0081]

[0082] As the system that directly contacts the animal body with the outside world, the intestine has long been in contact with various pathogenic microorganisms, and naturally becomes the first barrier to resist the invasion of pathogenic microorganisms through the digestive tract. The intestinal mucosal immune system is the material basis of this barrier. As shown in Table 8, compared with the CON group, the levels of IgA and IgG in the jejunal mucosa of the meat ducks in the experimental group were significantly increased (P < 0.05), and the IgM content showed an increasing trend (P > 0.05), indicating that the high load of selenium ions (Se 4+ ) Lactobacillus plantarum postbiotics have a positive effect on improving intestinal mucosal immunity.

[0083] Example 10: High load of selenium ions (Se 4+ ) Effects of duck-derived Lactobacillus plantarum postbiotics on fatty acids in breast muscle of duck meat

[0084] Table 9: Fatty acid composition of breast muscle of 42-day-old duck

[0085]

[0086]

[0087] The proportion of fatty acid content is an important indicator for evaluating the nutritional value of meat quality, as shown in Table 9. Fig.15 It can be seen that compared with the CON group, the C18:0 content of group III was significantly reduced (P < 0.05), and the C18:1n9c and C18:3n6 contents were extremely significantly increased (P < 0.01), which led to an extremely significant increase in MUFA content (P < 0.01), thereby optimizing the fatty acid structure. The C20:3n6 content of group I was also increased (P < 0.05), and the fatty acid composition of the other groups was not significantly different from that of the CON group (P > 0.05). This shows that high load of selenium ions (Se 4+ ) Lactobacillus plantarum postbiotics also have a positive effect on improving the fatty acid composition of meat ducks.

[0088] In summary, the method of gradually increasing the selenium ion (Se 4+ ) concentration method to obtain high-load selenium duck-derived Lactobacillus plantarum, which not only has the probiotic advantages of duck-derived Lactobacillus plantarum, but also has the ability to load high selenium ions, which can improve the intestinal selenium absorption rate and reduce selenium ions (Se 4+ ) to the environment. At the same time, the domesticated and bred high-load selenium duck-derived Lactobacillus plantarum produces a lot of postbiotics, including small peptides (antimicrobial peptides), small molecule organic acids, digestive enzymes, etc. Because it is rich in targeted antimicrobial peptides, it has a significant inhibitory effect on harmful bacteria such as Escherichia coli, Salmonella, and Riemerella anatipestifer. The digestive enzymes and other bioactive substances contained can promote the growth and development of poultry and improve product quality.

Claims

1. A poultry probiotic preparation prepared by fermentation of selenium-resistant duck-derived Lactobacillus plantarum, characterized in that: The poultry probiotic preparation is prepared by inoculating duck-derived plant lactobacillus with high selenium ion load into a culture medium for fermentation. The duck-derived plant lactobacillus with high selenium ion load has a preservation number of CGMCC No.30182.

2. The probiotic preparation for poultry according to claim 1, characterized in that The composition of the culture medium is as follows: peptone 10g / L, beef powder 10g / L, yeast powder 5g / L, glucose 20g / L, magnesium sulfate 0.1g / L, sodium acetate 5g / L, ammonium citrate 2g / L, dipotassium hydrogen phosphate 2g / L, manganese sulfate 0.05g / L, Tween 80 1g / L, pH value 6.2±0.

2.

3. The probiotic preparation for poultry according to claim 1, characterized in that The fermentation temperature is 35.5-38.5°C and the culture time is 20-27h.

4. The probiotic preparation for poultry according to claim 1, characterized in that The fermentation temperature is 37°C and the culture time is 24h.

5. A small peptide with antibacterial effect, characterized in that: The small peptide is separated and prepared from the poultry probiotic preparation according to claim 1.

6. The small peptide according to claim 5, characterized in that The amino acid sequence of the small peptide is SEQ ID NO: 1 or SEQ ID NO:

2.

7. Use of the small peptide according to claim 5 in the preparation of antibacterial products.

8. Use of the probiotic preparation for poultry according to claim 1 in the preparation of antibacterial products or feed additives.

9. A feed for poultry breeding, wherein the probiotic preparation for poultry according to claim 1 is added to the feed.

10. The poultry feed according to claim 9, characterized in that: The small peptide according to claim 5 is also added to the feed.

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