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CN-122011106-A - Sheep colostrum, polypeptide, preparation method thereof and application of sheep colostrum and polypeptide in resisting virus and promoting repair

CN122011106ACN 122011106 ACN122011106 ACN 122011106ACN-122011106-A

Abstract

The invention provides a polypeptide, which has a sequence SVDGKENLI. The polypeptide is separated from the sheep colostrum after lactobacillus rhamnosus D8A fermentation. The invention also provides application of the polypeptide, which can be applied to preparation of medicines for inhibiting neuraminidase, resisting viruses and promoting lung repair. The invention also provides sheep colostrum which comprises the polypeptide. The invention also provides a preparation method of the sheep colostrum, which comprises the following steps of filtering the sheep colostrum, carrying out secondary homogenization on the sheep colostrum after pre-sterilization, carrying out flash evaporation sterilization on the sheep colostrum after secondary homogenization, cooling, adding fructose, carrying out sterilization, inoculating a starter comprising lactobacillus rhamnosus D8A for fermentation, and then carrying out primary homogenization, concentration and freeze-drying.

Inventors

  • YANG TAO
  • XIAO HONG
  • LIAO MINGJUAN

Assignees

  • 湖南营养树生物科技有限公司

Dates

Publication Date
20260512
Application Date
20260408

Claims (10)

  1. 1. A polypeptide, characterized in that: the polypeptide sequence is SVDGKENLI.
  2. 2. The use of a polypeptide according to claim 1, wherein: can be used for preparing medicine for inhibiting neuraminidase or Is applied to preparing antiviral drugs; is applied to medicaments for promoting lung repair.
  3. 3. A sheep colostrum, characterized in that: comprising the polypeptide of claim 1.
  4. 4. A method of preparing sheep colostrum as claimed in claim 3 wherein: the method comprises the following steps: Filtering fresh sheep colostrum, pre-sterilizing, performing secondary homogenization on the fresh sheep colostrum, performing flash evaporation sterilization on the secondary homogenized fresh sheep colostrum, cooling, adding fructose, performing primary sterilization, inoculating a starter including lactobacillus rhamnosus D8A, fermenting, performing primary homogenization, concentrating, and performing primary freeze-drying.
  5. 5. The method for preparing the sheep colostrum as claimed in claim 4, wherein: The pore diameter of the filter adopted by the filtration is 80-100 meshes; the pre-sterilization temperature is 70 ℃; the pre-sterilization time is 18s; the temperature of the secondary homogenization does not exceed 60 ℃; The primary pressure of the secondary homogenization is 15MPa, and the secondary pressure is 8MPa; The flash sterilization time is 12s; The heat source temperature of the flash sterilization is 76 ℃; The temperature of the cooling is 4 ℃; the vacuum degree of flash evaporation sterilization is 0.5MPa; the temperature of the fresh sheep colostrum in the flash evaporation sterilization process is not more than 65 ℃.
  6. 6. The method for preparing the sheep colostrum as claimed in claim 4, wherein: The addition amount of the fructose is 7-8wt%; the temperature of the first sterilization is 95-100 ℃; the first sterilization time is 30-60s; The primary homogenization pressure is 20-25MPa; The concentration proportion is 20-25% of the original volume; The first freeze-drying protective agent adopted by the first freeze-drying comprises 3-4wt% of sorbitol, 5-10wt% of trehalose, 0.2-0.5wt% of ascorbic acid, 0.8-1.2wt% of sodium glutamate and the balance of water; The temperature of the first lyophilization is from-80 ℃ to-60 ℃.
  7. 7. The method for preparing the sheep colostrum as claimed in claim 4, wherein: The inoculation amount of the starter is 0.1%; The temperature of the fermentation is 37 ℃ and the time is 16-25h; the vacuum degree of the concentration is lower than 10Torr; the temperature of the concentration is 40-45 ℃.
  8. 8. The method for preparing the sheep colostrum as claimed in claim 4, wherein: the preparation method of the starter comprises the following steps: Streaking Lactobacillus rhamnosus D8A on MRS solid culture medium, culturing at 37deg.C to form full single colony, respectively inoculating the single colony into MRS liquid culture medium, and performing two-generation serial passage activation; Inoculating 2-2.5% of activated and amplified Lactobacillus rhamnosus D8A to an optimized MRS culture medium, controlling the temperature at 36 ℃ plus or minus 0.5 ℃, the pH value at 6.8 and the dissolved oxygen content at 20-25%, and fermenting for 20-28h to obtain fermentation liquor; after fermentation, centrifuging the fermentation liquor, and discarding the supernatant to obtain bacterial mud; uniformly mixing the bacterial mud with a second freeze-drying protective agent, performing second freeze-drying until dehydration and uniform grinding are performed, and obtaining a starter; The optimized MRS culture medium comprises 11.0g of tryptone, 12.0g of beef extract, 4.0g of yeast extract powder, 25.0g of glucose, 1.5mL of Tween 80, 3.0g of dipotassium hydrogen phosphate, 1.5g of magnesium sulfate, 1.75g of manganese sulfate and 1L of water.
  9. 9. The method for preparing sheep colostrum as claimed in claim 8, wherein: The second freeze-drying protective agent adopted by the second freeze-drying comprises 10-13wt% of skim milk powder, 5-8wt% of trehalose, 3-6wt% of maltose, 2-4wt% of mannitol and the balance of water; the weight ratio of the bacterial sludge to the second freeze-drying protective agent is 1:2-2.5; the second lyophilization temperature is from-50 ℃ to-55 ℃.
  10. 10. The method for preparing sheep colostrum as claimed in claim 8, wherein: The acceleration of the centrifugation is 5000-6000g; The temperature of the centrifugation is 4-6 ℃.

Description

Sheep colostrum, polypeptide, preparation method thereof and application of sheep colostrum and polypeptide in resisting virus and promoting repair Technical Field The invention relates to the field of polypeptides, in particular to a polypeptide obtained by fermentation of sheep colostrum with neuraminidase inhibiting function and application of the polypeptide. The invention also relates to the sheep colostrum and the preparation method thereof. Background The polypeptide in the fermented goat colostrum is a functional component with various biological activities, is mainly released from goat colostrum protein through a microbial fermentation process, and has wide potential in promoting health. The goat milk is rich in high-quality proteins such as alpha-, beta-and kappa-casein, and the proteins are gradually hydrolyzed by protease produced by microorganisms in the fermentation process of probiotics such as kefir, lactobacillus and the like to generate bioactive polypeptide with specific amino acid sequence. This process mimics the human digestive mechanism but more efficiently releases functional short peptide fragments. Several researches show that the polypeptide separated from the goat fermented milk can effectively reduce the TNF-alpha level of the mouse tumor necrosis factor, which indicates that the goat fermented milk has anti-inflammatory capability. In particular, the polypeptide in the fermented goat milk of the composite strain added with lactobacillus acidophilus and bifidobacterium has strong anti-inflammatory performance. The polypeptide types separated from the goat colostrum and the fermented milk are generally more than those separable from the cow milk, and the polypeptide types in the goat fermented milk are obviously more after probiotics are added. This suggests that the goat milk base is more suitable for developing functional fermented dairy products with high active peptide content. Jianpeng Li et al disclose a polypeptide PGEKGPSGEAGTAGPPGTPGPQGL in A Novel Natural Influenza A H1N1 Virus Neuraminidase Inhibitory Peptide Derived from Cod Skin Hydrolysates and Its Antiviral Mechanism. The natural peptide can effectively inhibit influenza A H1N1 virus by competitively binding to Neuraminidase (NA). Experiments show that the EC50 of the strain is 471+/-12 mug/mL, can obviously reduce virus replication in a cell model, and plays a role in early infection. However, this polypeptide is easily decomposed by pepsin. Disclosure of Invention The first object of the present invention is to provide a polypeptide isolated from a feta fermented by lactobacillus rhamnosus D8A, which has an antiviral function. A second object of the present invention is to provide the use of said polypeptide in the antiviral field. It is a third object of the present invention to provide a sheep colostrum comprising the polypeptide. The fourth object of the invention is to provide a preparation method of the sheep colostrum. The invention is realized by the following technical scheme: The invention provides a polypeptide, the sequence of which is SVDGKENLI. The polypeptide can be applied to preparing medicines for inhibiting neuraminidase, or antiviral medicines or medicines for promoting lung repair. The invention provides sheep colostrum, which contains the polypeptide. A preparation method of sheep colostrum comprises the following steps: Filtering fresh sheep colostrum, performing secondary homogenization on the fresh sheep colostrum after pre-sterilization, performing flash evaporation sterilization on the fresh sheep colostrum after secondary homogenization, and cooling; Adding fructose into sterilized feta colostrum, sterilizing for the first time, inoculating starter including Lactobacillus rhamnosus D8A, fermenting, homogenizing, concentrating, and lyophilizing. The pore diameter of the filter adopted by the filtration is 80-100 meshes; the pre-sterilization temperature is 70 ℃; the pre-sterilization time is 18s; the temperature of the secondary homogenization does not exceed 60 ℃; The primary pressure of the secondary homogenization is 15MPa, and the secondary pressure is 8MPa; The flash sterilization time is 12s; The heat source temperature of the flash sterilization is 76 ℃; The temperature of the cooling is 4 ℃; the vacuum degree of flash evaporation sterilization is 0.5MPa; the temperature of the fresh sheep colostrum in the flash evaporation sterilization process is not more than 65 ℃. The addition amount of the fructose is 7-8wt%; the temperature of the first sterilization is 95-100 ℃; the first sterilization time is 30-60s; The primary homogenization pressure is 20-25MPa; the concentration proportion is 20% -25% of the original volume; The first freeze-drying protective agent adopted by the first freeze-drying comprises 3-4wt% of sorbitol, 5-10wt% of trehalose, 0.2-0.5wt% of ascorbic acid, 0.8-1.2wt% of sodium glutamate and the balance of water; The temperature of the first lyophilization is from