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CN-121975677-A - Mutation common Sha Genliu bacterium for producing beta-1, 3-glucan and application thereof

CN121975677ACN 121975677 ACN121975677 ACN 121975677ACN-121975677-A

Abstract

The invention discloses a mutant common Sha Genliu strain for high yield of beta-1, 3-glucan, and a preparation method and application thereof, belonging to the technical field of biology. The strain is common Sha Genliu bacteria RSFBMT-41666, and the preservation number is CGMCC No.36520. The preparation method comprises the steps of screening and obtaining a common Sha Genliu fungus wild strain A414 from soil, carrying out combined mutagenesis by 12C6 + heavy ion beam irradiation and low-temperature plasma, and carrying out Congo red identification flat plate primary screening and shake flask fermentation secondary screening. The mutant strain takes glucose as a main carbon source, the yield of the fermentation product beta-1, 3-glucan reaches 31.4g/L, the purity is improved by 56% compared with a wild strain, and the mutant strain has 95.40%, excellent water solubility and special rheological property. The invention solves the problems of high carbon source cost and low glucose utilization efficiency of the existing strain, reduces the industrial production cost, and has wide application prospect in the fields of foods, medicines and cosmetics.

Inventors

  • ZENG YAN
  • QIU RONGHUI
  • ZHAO SHUJING
  • CHEN PENG
  • ZHU YUEMING
  • MEN YAN
  • YANG JIANGANG
  • SUN YUANXIA

Assignees

  • 中国科学院天津工业生物技术研究所

Dates

Publication Date
20260505
Application Date
20251230

Claims (10)

  1. 1. A common Sha Genliu bacterial mutant RSFBMT-41666 is characterized in that the preservation number is CGMCC No.36520.
  2. 2. A method of making the pulvis-a-vis Sha Genliu mutant RSFBMT-41666 of claim 1, comprising the steps of: s1, screening a soil sample to obtain a wild strain of the common Sha Genliu strain; s2, carrying out 12 C 6+ heavy ion beam irradiation treatment on the wild plants; s3, carrying out low-temperature plasma radiation treatment on the irradiated strain; S4, primarily screening on a Congo red identification plate with glucose as a unique carbon source, and selecting mutant strains generating deep red halos; S5, carrying out shaking fermentation and re-screening to obtain mutant strains.
  3. 3. The method according to claim 2, wherein the irradiation dose of 12 C 6+ heavy ion beams is 0-100Gy, preferably the radio frequency power of the low-temperature plasma is 120W, the low-temperature plasma irradiation treatment time is 0-120s, preferably the low-temperature plasma irradiation treatment time is 80-100s, preferably the culture condition of the primary screen is 27-32 ℃ and is cultivated in a dark place for 36-84h, preferably the culture condition of the primary screen is 28-30 ℃ and is cultivated in a dark place for 60-72h.
  4. 4. Use of the mutant strain RSFBMT-41666 of the strain p Sha Genliu of claim 1 or the mutant strain prepared by the method of any one of claims 2-3 for the preparation of beta-1, 3-glucan, preferably comprising the use of the prepared beta-1, 3-glucan in the field of food, medicine or cosmetics.
  5. 5. A method for producing β -1, 3-glucan comprising culturing the mutant strain RSFBMT-41666 of claim 1 by fermentation, optionally further comprising the step of collecting or isolating the β -1, 3-glucan produced.
  6. 6. The method according to claim 5, wherein the fermentation medium contains glucose as a carbon source in an amount of 2-10% by mass, more preferably 4-8% by mass.
  7. 7. The method according to claim 6, wherein the fermentation medium further comprises a nitrogen source, dipotassium hydrogen phosphate, magnesium sulfate and an antifoaming agent, the nitrogen source being selected from an organic nitrogen source or an inorganic nitrogen source, preferably the organic nitrogen source is peptone, preferably the inorganic nitrogen source is ammonium sulfate.
  8. 8. The method according to claim 7, wherein the peptone is 0.1-2% by mass, the ammonium sulfate is 0.1-2% by mass, the dipotassium hydrogen phosphate is 0.1-1% by mass, the magnesium sulfate is 0.01-0.2% by mass, the defoaming agent is 0.001-0.15% by mass, preferably the peptone is 0.3-1% by mass, the ammonium sulfate is 0.1-1% by mass, the dipotassium hydrogen phosphate is 0.2-0.4% by mass, the magnesium sulfate is 0.05-0.1% by mass, and the defoaming agent is 0.005-0.01% by mass.
  9. 9. The method according to claim 5, wherein the fermentation culture is inoculated at an amount of 1% -15%, the fermentation is carried out at 25-35 ℃,0.05-0.2MPa, the ventilation is 0.2-1.5vvm, preferably 5% -8%, the fermentation is carried out at 28-32 ℃,0.08-0.1MPa, and the ventilation is 0.6-0.8 vvm.
  10. 10. The method according to claim 5, wherein the pH is controlled to be 6.5-7.5, preferably 6.8-7.0, preferably not less than 80h, preferably not less than 90h, preferably not less than 96h, by feeding potassium hydroxide solution during fermentation.

Description

Mutation common Sha Genliu bacterium for producing beta-1, 3-glucan and application thereof Technical Field The invention belongs to the technical field of biology, and particularly relates to a strain for producing water-soluble beta-1, 3-glucan and application thereof. Background Beta-1, 3-glucan is a natural polysaccharide with various biological activities such as immunoregulation, anti-tumor, antioxidation and the like. The solubility of the strain directly affects the bioavailability and has important significance for the application of the strain in the fields of foods, medicines, functional materials and the like, （Wang X , Ma L , Wang Y ,et al.Water-soluble β-glucan from G. lucidum as a potential functional food ingredient with gut microbiota-regulating and immune-enhancing activities[J].International Journal of Biological Macromolecules, 2025, 319(Part1).）. common Sha Genliu strain (Rhizobium pusense) is regarded as a beta-1, 3-glucan fermentation production strain with great potential, and the strain can secrete beta-glucan with good water solubility and antibacterial activity （Zhang B , Zhao W , Song D ,et al.Regulatory effect of β-glucan secreted by Rhizobium pusense on triglyceride metabolism and their relationships with the modulation of intestinal microbiota in mice fed a high-fat diet[J].Food & Function, 2024, 15(17): 8759-8774.）. However, in the prior art, sucrose is generally used as a main carbon source for producing beta-1, 3-glucan by fermenting the rhizobium prabase, patent CN112358985A (publication date 2021.02.12) discloses the rhizobium prabase Sha Genliu and application thereof in preparing water-soluble beta-1, 3-glucan, CN118599711A (publication date 2024.09.06) discloses the rhizobium prabase and application thereof in preparing beta-1, 3-glucan, and CN120682984A (publication date 2025.09.23) discloses the rhizobium prabase Sha Genliu and application thereof in preparing selenium-enriched beta-1, 3/alpha-1, 3-glucan fermentation liquor. Although sucrose can be effectively utilized by the strain, the cost of raw materials is high, and the market competitiveness of related products is severely restricted. In contrast, glucose has wide sources and low price, and is a substitute carbon source with more industrialized advantages. However, the metabolic efficiency of glucose utilization by wild-type or existing strains of the genus Sha Genliu is generally low. In addition, the wild strain obtained by separating in nature generally has the problems of low yield, unstable product quality and the like, while the traditional natural breeding has low spontaneous mutation rate and limited mutation amplitude, so that the requirements of industrial production on high-yield and high-efficiency strains are difficult to meet. Therefore, it is necessary to change the genetic characteristics of the strain by means of artificial mutation breeding to obtain a high-yield mutant strain excellent in performance. Heavy ion mutagenesis directly acts on organisms through high-energy heavy ion beams to cause DNA double-strand break, base substitution and other damages, and plasma mutagenesis indirectly acts on cytogenetic materials through low-temperature plasma discharge to generate active particles (such as free radicals, ions, ultraviolet rays and the like) to induce diversified mutation. The two physical mutagenesis modes are used as important strain improvement means and are widely applied to the field of microorganism breeding, but related reports of applying the two physical mutagenesis modes to common Sha Genliu strain mutagenesis breeding are not yet seen at present. Therefore, combining two physical radiation breeding technologies of heavy ion mutagenesis and plasma mutagenesis, carrying out directional screening and transformation on the metabolic pathway of the common Sha Genliu bacteria to obtain mutant strains which preferentially utilize glucose and highly produce water-soluble beta-1, 3-glucan, has important significance for reducing production cost and promoting the large-scale application of the product, and is also beneficial to expanding the application of the physical radiation mutagenesis technology in the field of biological manufacturing. Disclosure of Invention In order to solve the problems in the prior art, the invention screens and obtains the common Sha Genliu bacteria capable of producing the water-soluble beta-1, 3-glucan by utilizing low-cost glucose from soil, and then the common Sha Genliu bacteria are subjected to mutagenesis to select and breed a high-yield bacteria (RSFBMT-41666) which is preserved in China general microbiological culture collection center (CGMCC) at 11 and 6 of 2025. In one aspect, the invention provides a mutant strain RSFBMT-41666 of general Sha Genliu bacteria, which has a preservation number of CGMCC No.36520, is preserved in China general microbiological culture Collection center (CGMCC) at the date of 2025, 11 and 6, and is classified and named