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CN-121991190-A - Bacteriocin composition prepared from lactobacillus fermentum and enterococcus faecium and application thereof

CN121991190ACN 121991190 ACN121991190 ACN 121991190ACN-121991190-A

Abstract

The invention provides a bacteriocin composition prepared from lactobacillus fermentum and enterococcus faecium and application thereof, and relates to the technical field of microorganisms. The preparation method of the bacteriocin composition comprises the following steps of (1) fermenting enterococcus faecium NMA-LF and lactobacillus fermentum L.Fermentum F6 to obtain mixed fermentation bacteria liquid, (2) centrifuging the mixed fermentation bacteria liquid, collecting supernatant, adding ammonium sulfate into the supernatant to enable the saturation degree of the ammonium sulfate in the supernatant to be 75% -85%, collecting precipitate, and (3) dissolving the precipitate, dialyzing by using a 3000-4000 Da dialysis bag, and collecting dialyzate in the dialysis bag to obtain the bacteriocin composition containing bacteriocin peptide fragments. The bacteriocin composition prepared by the invention is a bacteriocin with high-efficiency antifungal activity, can obviously inhibit verticillium dahliae, and has important significance in developing novel biological verticillium dahliae resisting preparations.

Inventors

  • WEN JING
  • Shu lun
  • YANG LAN
  • LIU JINJIANG

Assignees

  • 内蒙古农业大学

Dates

Publication Date
20260508
Application Date
20260130

Claims (10)

  1. 1. A bacteriocin composition prepared from lactobacillus fermentum and enterococcus faecium, characterized in that the preparation method of the bacteriocin composition comprises the following steps: (1) Enterococcus faecium NMA-LF and lactobacillus fermentum L.Fermentum F6 are fermented to obtain mixed fermentation bacteria liquid; (2) Centrifuging the mixed fermentation broth, collecting supernatant, adding ammonium sulfate into the supernatant to ensure that the saturation of the ammonium sulfate in the supernatant is 75% -85%, and collecting precipitate; (3) Dissolving the precipitate, dialyzing by using a dialysis bag with the speed of 3000-4000 Da, and collecting dialysate in the dialysis bag to obtain the bacteriocin composition containing the bacteriocin peptide fragment.
  2. 2. The bacteriocin composition according to claim 1, wherein in the step (1) of the preparation method of the bacteriocin composition, the fermentation time is 42-54 hours, and the viable bacteria concentration of the mixed fermentation bacteria liquid is 1 x 10 7 ~1×10 8 cfu/mL.
  3. 3. The bacteriocin composition according to claim 1, wherein the medium used for the fermentation in step (1) is a modified MRS liquid medium, and the formulation comprises peptone 10g, beef extract 10g, yeast extract 5g, lactose 10g, glucose 25 g, K 2 HPO 4 2g, diammonium citrate 2g, sodium acetate 5g, mgSO 4 0.58 g、MnSO 4 0.25 g, tween 80 mL and water 1,000 mL, and is adjusted to pH 6.5.
  4. 4. The bacteriocin composition of claim 1, wherein the temperature of the centrifugation is from 4 ℃ to 10 ℃ in step (2) of the process for preparing the bacteriocin composition.
  5. 5. The bacteriocin composition according to claim 1, wherein the pellet is dissolved in PBS buffer, the mass to volume ratio of the pellet to the PBS buffer being 1 mg:5-20 ml.
  6. 6. Use of a bacteriocin composition according to claim 1 for inhibiting verticillium dahliae or for the preparation of a product for inhibiting verticillium dahliae.
  7. 7. The verticillium dahliae inhibitor is characterized by comprising the bacteriocin composition according to any one of claims 1-6 and pharmaceutically acceptable auxiliary materials.
  8. 8. The bacteriocin composition according to any one of claims 1 to 6 or the verticillium dahliae inhibitor according to claim 7 for use in the control of verticillium wilt.
  9. 9. The use according to claim 8, wherein the verticillium wilt comprises one or more of malvaceae verticillium wilt, solanaceae verticillium wilt, leguminous verticillium wilt and cucurbitaceae verticillium wilt.
  10. 10. A method for controlling verticillium wilt, which is characterized by comprising the step of applying the bacteriocin composition according to any one of claims 1 to 6 or the verticillium dahliae inhibitor according to claim 7 to verticillium wilt plants.

Description

Bacteriocin composition prepared from lactobacillus fermentum and enterococcus faecium and application thereof Technical Field The invention belongs to the technical field of microorganisms, and particularly relates to a bacteriocin composition prepared from lactobacillus fermentum and enterococcus faecium and application thereof. Background Bacteriocins are a class of polypeptides or precursor polypeptides with bacteriostatic activity that are produced by certain bacteria during metabolism via the ribosome synthesis mechanism. Bacteriocins produced by bacteria can inhibit not only homologous or related organisms of the bacteria, but also other various spoilage microorganisms or food-borne pathogenic bacteria. Most bacteriocins are produced by food-grade lactobacillus, and inhibit protein synthesis by perforation and inhibition of peptidoglycan synthesis on target cells, interaction with ribosome or tRNA, and direct degradation of target cell DNA, thereby achieving antibacterial effect At present, prevention and control means for fungal pollution mainly depend on chemical synthesis of bactericides, preservatives and antifungal drugs. The chemical bactericide is widely used in agricultural production, and the benzoic acid and sorbic acid chemical preservatives applied in the food industry can inhibit the growth of fungi in a short period of time, but long-term abuse has raised a series of outstanding problems that firstly, the drug resistance of fungi rapidly evolves, the prevention and control effect of the drugs is continuously reduced, the drug dosage is required to be continuously improved or novel drugs are developed to form vicious circle, secondly, the residues of the chemical drugs in crops and foods and the enrichment of the chemical agents in the environment can destroy ecological balance, harm human and animal endocrine systems, immune systems and the like, and thirdly, the application range of part of the chemical preservatives is limited, and the chemical preservatives are easy to decompose and lose efficacy under special processing or storage conditions such as high temperature, acidity and the like. Therefore, the development of a novel antifungal agent which is safe, efficient and environmentally friendly has become a key problem to be solved. Based on the existing research foundation, the bacteriocin with high-efficiency antifungal activity is further screened, and the method has important significance in developing novel biological antifungal preparations. Disclosure of Invention The invention mainly aims to provide a bacteriocin composition prepared from lactobacillus fermentum and enterococcus faecium and application thereof, which can obviously inhibit verticillium dahliae and has great application potential for preventing and treating verticillium wilt. The invention provides a bacteriocin composition prepared from lactobacillus fermentum and enterococcus faecium, and a preparation method of the bacteriocin composition comprises the following steps of: (1) Enterococcus faecium NMA-LF and lactobacillus fermentum L.FermentumF6 are fermented to obtain mixed fermentation bacteria liquid; (2) Centrifuging the mixed fermentation broth, collecting supernatant, adding ammonium sulfate into the supernatant to ensure that the saturation of the ammonium sulfate in the supernatant is 75% -85%, and collecting precipitate; (3) Dissolving the precipitate, dialyzing by using a dialysis bag with the speed of 3000-4000 Da, and collecting dialysate in the dialysis bag to obtain the bacteriocin composition containing the bacteriocin peptide fragment. Preferably, in the step (1) of the preparation method of the bacteriocin composition, the fermentation time is 42-54 h, and the viable bacteria concentration of the mixed fermentation bacteria liquid is 1×10 7~1×108 cfu/mL. Preferably, in the step (1) of the preparation method of the bacteriocin composition, the culture medium adopted by the fermentation is a modified MRS liquid culture medium, and the formulation comprises peptone 10g, beef extract 10g, yeast extract 5 g, lactose 10g, glucose 25 g, K 2HPO4 2 g, diammonium citrate 2 g, sodium acetate 5 g, mgSO 40.58 g、MnSO4 0.25 g, tween 80 mL and water 1,000 mL, and the pH is adjusted to 6.5. Preferably, in the step (2) of the preparation method of the bacteriocin composition, the temperature of the centrifugation is 4 ℃ to 10 ℃. Preferably, the precipitate is dissolved by using PBS buffer, and the mass-volume ratio of the precipitate to the PBS buffer is 1 mg:5-20 mL. The invention also provides application of the bacteriocin composition in inhibiting verticillium dahliae or preparing a product for inhibiting verticillium dahliae. The invention also provides a verticillium dahliae inhibitor, which comprises the bacteriocin composition and auxiliary materials acceptable in agro-pharmacy. The invention also provides an application of the bacteriocin composition or the verticillium dahliae inhibitor in controll