Saccharomyces cerevisiae and method for producing a culture of saccharomyces cerevisiae

Abstract

The present application relates to the technical field of yeast culture preparation, and particularly relates to a saccharomyces cerevisiae and a saccharomyces cerevisiae culture production method. The saccharomyces cerevisiae is saccharomyces cerevisiae, which is preserved in the China General Microbiological Culture Collection Center with a strain number of WJ13 and a registration number of CGMCC No. 31754. The saccharomyces cerevisiae culture production method comprises the following steps: grafting tyrosine and chitosan; preparing a composite gel; and adding the composite gel into a culture solution for culture to obtain a saccharomyces cerevisiae culture. In the present application, tyrosine is grafted with chitosan. After the grafting of tyrosine onto chitosan, the tyrosine grafting can increase the intermolecular crosslinking of chitosan, thereby improving the mechanical strength and stability of the gel scaffold. In addition, the tyrosine grafting can increase the hydrophobicity and affinity of the chitosan surface, which is helpful for the adhesion and proliferation of the saccharomyces cerevisiae, thereby improving the content of small molecular protein and organic acid and other nutritional ingredients in the culture.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of yeast culture preparation, in particular to a saccharomyces cerevisiae and a saccharomyces cerevisiae culture production method. BACKGROUND

[0002] Saccharomyces cerevisiae is a single-cell fungus belonging to the genus Saccharomyces, which is a single-cell fungus that can grow under aerobic and anaerobic conditions. Under aerobic conditions, it mainly performs respiration, completely oxidizing sugars to carbon dioxide and water; under anaerobic conditions, it performs fermentation, converting sugars to ethanol and carbon dioxide, and is widely used in the food and beverage industry. Saccharomyces cerevisiae culture refers to a mixture of saccharomyces cerevisiae cells and their metabolites cultured in a specific medium. The composition and properties of the culture depend on the culture conditions such as medium composition, temperature, pH, aeration rate and culture time. Saccharomyces cerevisiae culture contains a large number of saccharomyces cerevisiae cells, which are one of the main components of the culture, as well as the metabolites of saccharomyces cerevisiae, including ethanol, proteins, carbon dioxide, organic acids, amino acids, vitamins, polysaccharides, etc. Saccharomyces cerevisiae culture is rich in proteins, vitamins and minerals, and is a high-quality protein supplement, widely used in wine making, animal feed, seasoning and other fields.

[0003] Saccharomyces cerevisiae culture can be produced by solid fermentation and liquid fermentation. Solid fermentation uses natural substrates as carbon and nitrogen sources, or inert substrates as solid supports, and the fermentation process has no or nearly no flowing water. Liquid fermentation involves inoculating saccharomyces cerevisiae into a liquid medium for fermentation, which is widely used in industrial production and has high production efficiency and controllability. Solid fermentation has the characteristics of water and energy saving, but the cycle is longer and the overall engineering technology is relatively backward, with low automation, so it is less used in industry. Liquid fermentation has a shorter cycle and is more suitable for large-scale production. In addition, by precisely controlling temperature and other conditions, the fermentation process can be optimized. However, a variety of metabolites are produced during liquid fermentation, although these metabolites are not toxic, a large amount of metabolites will occupy the proportion of nutrients in saccharomyces cerevisiae culture, thereby reducing the nutritional value of saccharomyces cerevisiae culture and lowering the economic value of saccharomyces cerevisiae culture. Therefore, the present application provides a saccharomyces cerevisiae and a saccharomyces cerevisiae culture production method, which promotes the growth and development of saccharomyces cerevisiae by adding a composite gel, thereby increasing the proportion of nutritional ingredients in saccharomyces cerevisiae culture and improving the nutritional and economic value. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application aims to provide a saccharomyces cerevisiae and a saccharomyces cerevisiae culture production method.

[0005] A saccharomyces cerevisiae culture production method, comprising the following steps:

[0006] S1: grafting tyrosine with chitosan

[0007] Chitosan is added to an ice acetic acid solution to form a chitosan solution by stirring, tyrosine is added to an ethanol solution, and the tyrosine is added to the chitosan solution, stirring, standing for reaction, dialysis, to obtain tyrosine grafted chitosan;

[0008] S2: preparing a composite gel

[0009] Kaolin is crushed and sieved, and is added to a sulfuric acid solution, then a citric acid solution is added, and after reaction, the modified kaolin is obtained by drying, xanthan gum, modified kaolin and tyrosine grafted chitosan are dissolved in ultrapure water, and after reaction, crosslinking treatment is performed, and the composite gel is obtained.

[0010] S3: adding the composite gel to a culture solution for culture to obtain a saccharomyces cerevisiae culture

[0011] After the saccharomyces cerevisiae is purified, it is inoculated in a YPD culture medium, the composite gel is added to the YPD culture medium, and the YPD culture medium is cultured in a constant temperature incubator, and is inoculated in a solid state fermentation substrate for fermentation, and finally is naturally air dried, crushed, to obtain a saccharomyces cerevisiae culture.

[0012] The saccharomyces cerevisiae is Saccharomyces cerevisiae, which was preserved in the China General Microbiological Culture Collection Center on August 27, 2024, with a strain number of WJ13 and a registration number of CGMCC No. 31754.

[0013] Further, step S1 of grafting tyrosine with chitosan comprises the following steps:

[0014] 1-2 parts by mass of chitosan are added to 45-50 parts by mass of a 2% ice acetic acid solution, stirring for 10-15 min to form a chitosan solution, 1-2 parts by mass of tyrosine are added to 45-50 parts by mass of a 60wt% ethanol solution, and the tyrosine is added to the chitosan solution, the pH is adjusted to 4-5, stirring for 10-15 min, then standing for reaction in a dark environment for 10-11 h, the product is placed in a dialysis bag, dialysis in ultrapure water with a pH of 5.5-6 for 24-25 h, dialysis in ultrapure water with a pH of 7-7.5 for 4-4.5 h, and finally freeze-drying at -20℃ for 12-13 h, to obtain tyrosine grafted chitosan.

[0015] Further, step S2 of preparing a composite gel comprises the following steps:

[0016] Put 10-15 parts by mass of kaolin into a high-speed universal pulverizer and crush for 1-2 s, and sieve through a 200-mesh screen, and add to 15-20 parts by mass of a sulfuric acid solution, and then add 6-10 parts by mass of a citric acid solution, and stir at a rotation speed of 100-120 r / min for 20-25 min, and then seal and stand for reaction for 4-5 h, and then put into a high-temperature oven at 95-100 DEG C and dry for 2-2.5 h, and then dry in an oven at 105-110 DEG C for 12-13 h, to obtain modified kaolin; dissolve 2% by mass of xanthan gum, 9% of the modified kaolin and 3% of tyrosine grafted chitosan in 20 parts by mass of ultrapure water, and magnetically stir for 20-30 min, and then react at 40-45 DEG C and 0.1-0.5 MPa for 1-2 h, and then immerse the product in a calcium chloride aqueous solution and crosslink for 1-1.5 h, and then take out and freeze-dry at -20 DEG C for 3-4 h, and then crush and immerse in a mixed buffer solution and crosslink for 20-24 h, with a material-liquid ratio of 1: (8-10) g / mL, to obtain a composite gel.

[0017] Further, step S3 adds the composite gel to the culture solution for culture, to obtain the S. cerevisiae culture, including the following steps:

[0018] After the S. cerevisiae is purified, inoculate in YPD culture medium, add the composite gel to the YPD culture medium, with an addition amount of 30-40 wt%, and place in a constant-temperature incubator at 25-30 DEG C and culture for 12-13 h, and adjust to 2x10 cfu / mL, and inoculate in a solid-state fermentation substrate according to an addition amount of 1-3 wt% for fermentation, seal and shake in an environment at 28-30 DEG C and 200 r / min for 44-48 h, and finally air dry naturally, crush, to obtain the S. cerevisiae culture.

[0019] Further, the cut-off value of the dialysis bag is 3500 Da.

[0020] Further, the concentration of the calcium chloride aqueous solution is 20-25 wt%.

[0021] Further, the concentration of the sulfuric acid solution is 25-30 wt%.

[0022] Further, the mixed buffer solution is prepared by uniformly mixing EDC, NHS and MES in a volume ratio of 1: (1-2): (1-3).

[0023] Compared with the prior art, the present application has at least the following beneficial effects:

[0024] 1. This invention grafts tyrosine onto chitosan. Tyrosine grafting increases the intermolecular cross-linking of chitosan, thereby improving the mechanical strength and stability of the gel scaffold. The phenolic hydroxyl groups of tyrosine react with the amino groups on chitosan, enhancing not only the intermolecular cross-linking of chitosan molecules but also its chemical stability. Simultaneously, the increased cross-linking density of chitosan molecules after tyrosine grafting forms a denser network structure. This structure effectively disperses external forces, improving the mechanical strength of the material. The cross-linked chitosan exhibits enhanced stability in water, making it less prone to dissolution or degradation. This allows the composite gel with tyrosine-grafted chitosan to maintain a stable structure in the culture medium environment, extending its lifespan. Furthermore, tyrosine grafting increases the hydrophobicity and affinity of the chitosan surface, aiding in the adhesion and proliferation of *Saccharomyces cerevisiae*. Tyrosine-grafted chitosan can also mimic certain components of the extracellular matrix, providing a better growth environment for *Saccharomyces cerevisiae*, thereby increasing the content of small-molecule proteins and organic acids in the culture.

[0025] 2. This invention modifies kaolin with sulfuric acid and citric acid. The kaolin modified by the combined acid of sulfuric acid and citric acid exhibits excellent flocculation properties. The combined acid modification of sulfuric acid and citric acid can alter the charge distribution on the surface of kaolin. Sulfuric acid, as a strong acid, can dissolve some metal oxides on the surface of kaolin, releasing metal ions and giving the kaolin surface a charge. Citric acid, as a weak acid, can form complexes with these metal ions, further regulating the surface charge. This allows the prepared composite gel to promote the aggregation and sedimentation of brewing yeast cells. This not only helps improve fermentation efficiency and allows yeast cells to better contact the substrate during fermentation, but also facilitates subsequent separation operations, reducing production costs. Cell aggregation increases local cell concentration, promotes synergistic effects between yeast cells, and improves fermentation efficiency and nutrient content. Furthermore, the improved sedimentation performance also facilitates the recovery and reuse of yeast cells after fermentation.

[0026] 3. This invention prepares a composite gel using xanthan gum, modified kaolin, and tyrosine-grafted chitosan, and adds it to a culture medium for culturing Saccharomyces cerevisiae. Modified kaolin has excellent adsorption properties, capable of adsorbing xanthan gum and tyrosine-grafted chitosan, and providing good flocculation ability. The rheological properties of modified kaolin loaded with xanthan gum and tyrosine-grafted chitosan are also improved by the influence of xanthan gum and tyrosine-grafted chitosan, thereby increasing the viscosity and stability of the culture medium. Furthermore, the presence of modified kaolin also ensures the mechanical strength and stability of the composite gel, enabling it to better maintain its structure during fermentation, improving the adhesion of Saccharomyces cerevisiae to the composite gel, and better forming colonies, thereby increasing the number of Saccharomyces cerevisiae in the culture medium and thus increasing the nutrient content of the culture. Attached Figure Description

[0027] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments of the present disclosure and, together with the description, further serve to explain the principles of the present disclosure and to enable a person skilled in the relevant art to make and use the present disclosure.

[0028] Figure 1 Electron microscope image of the composite gel prepared for Example 1 of the present application. DETAILED DESCRIPTION

[0029] A kind of Saccharomyces cerevisiae and Saccharomyces cerevisiae culture production method provided by the present application is described in detail below in combination with the drawings and specific examples. It is explained here that, in order to make the examples more detailed, the following examples are the best, preferred examples, and other alternative ways can also be used by those skilled in the art to implement some known technologies; And the part of the drawings is only to describe the embodiment more specifically, and is not intended to specifically limit the present application.

[0030] Example 1:

[0031] A kind of Saccharomyces cerevisiae and Saccharomyces cerevisiae culture production method, comprising the following steps:

[0032] S1: tyrosine and chitosan grafting

[0033] 1 part by mass of chitosan is added to 45 parts by mass of 2% by volume of glacial acetic acid solution, stirred for 10 min to form a chitosan solution, then 1 part by mass of tyrosine is added to 45 parts by mass of 60wt% ethanol solution, and then added to the chitosan solution, pH adjusted to 4, stirred for 10 min, then placed in a dark environment for 10 h, the product is placed in a dialysis bag, dialyzed in ultrapure water with pH 5.5 for 24 h, the cut-off value of the dialysis bag is 3500 Da, then dialyzed in ultrapure water with pH 7 for 4 h, and finally freeze-dried at -20℃ for 12 h to obtain tyrosine grafted chitosan.

[0034] S2: preparation of composite gel

[0035] Put 10 parts by mass of kaolin into a high-speed universal pulverizer and pulverize for 2 s, and sieve through a 200-mesh screen, and add to 15 parts by mass of a 25wt% sulfuric acid solution, then add 6 parts by mass of a citric acid solution, stir at a speed of 100 r / min for 20 min, seal and stand for reaction for 4 h, then put into a high-temperature oven at 95℃ and dry for 2 h, dry in an oven at 105℃ for 12 h, to obtain modified kaolin; dissolve 2% by mass of xanthan gum, 9% of modified kaolin and 3% of tyrosine grafted chitosan in 20 parts by mass of ultrapure water, magnetically stir for 20 min, then react at 40℃ and 0.1 MPa for 1 h, then immerse the product in a 20wt% calcium chloride aqueous solution for crosslinking for 1 h, then take out and freeze-dry at -20℃ for 3 h, crush and then immerse in a mixed buffer for crosslinking for 20 h, the mixed buffer is prepared by uniformly mixing EDC, NHS and MES in a volume ratio of 1:1:1, the solid-liquid ratio is 1:8 g / mL, then freeze-dry to obtain a composite gel, and the electron microscope image is as shown in Figure 1

[0036] S3: add the composite gel to the culture solution for cultivation to obtain a Saccharomyces cerevisiae culture

[0037] After the Saccharomyces cerevisiae is purified, it is inoculated in a YPD culture medium, the composite gel is added to the YPD culture medium, the amount added is 30wt%, and it is placed in a constant-temperature incubator at 25℃ for cultivation for 12 h, adjusted to 2x10cfu / mL, and inoculated in a solid-state fermentation substrate at an addition amount of 1wt% for fermentation, sealed and fermented in a shaking bed at 28℃ and 200 r / min for 48 h, and finally naturally air-dried, crushed to obtain a Saccharomyces cerevisiae culture.

[0038] Among them, the Saccharomyces cerevisiae is preserved in the China General Microbiological Culture Collection Center on August 27, 2024, the strain number is WJ13, and the registration number is CGMCC No. 31754.

[0039] Example 2:

[0040] A Saccharomyces cerevisiae and a Saccharomyces cerevisiae culture production method, as shown in Figure 1 , comprising the following steps:

[0041] S1: grafting of tyrosine and chitosan

[0042] ​2 parts by mass of chitosan was added to 50 parts by mass of a 2% by volume acetic acid solution, stirred for 10 min to form a chitosan solution, 2 parts by mass of tyrosine was added to 50 parts by mass of a 60 wt% ethanol solution, and then added to the chitosan solution, the pH was adjusted to 4, stirred for 10 min, then placed in the dark for 10 h, the product was placed in a dialysis bag, dialyzed in ultrapure water with a pH of 5.5 for 24 h, the cut-off value of the dialysis bag was 3500 Da, then dialyzed in ultrapure water with a pH of 7 for 4 h, and finally freeze-dried at -20℃ for 12 h to obtain tyrosine grafted chitosan.

[0043] S2: Preparation of composite gel

[0044] 15 parts by mass of kaolin was put into a high-speed universal crusher and crushed for 2 s, sieved through a 200-mesh sieve, and then added to 20 parts by mass of a 25 wt% sulfuric acid solution, then 10 parts by mass of a citric acid solution was added, stirred at a speed of 100 r / min for 20 min, sealed and left to react for 4 h, then placed in a high-temperature oven at 95℃ for drying for 2 h, and dried in an oven at 105℃ for 12 h to obtain modified kaolin; 2% by mass of xanthan gum, 9% of modified kaolin and 3% of tyrosine grafted chitosan were dissolved in 20 parts by mass of ultrapure water, magnetically stirred for 20 min, then reacted at 40℃ and 0.1 MPa for 1 h, then the product was immersed in a 20 wt% calcium chloride aqueous solution for crosslinking for 1 h, then taken out and freeze-dried at -20℃ for 3 h, crushed and then immersed in a mixed buffer solution for crosslinking for 20 h, the mixed buffer solution was prepared by uniformly mixing EDC, NHS and MES in a volume ratio of 1:1:1, the solid-liquid ratio was 1:10 g / mL, and then freeze-dried to obtain a composite gel.

[0045] S3: The composite gel was added to the culture solution for cultivation to obtain a Saccharomyces cerevisiae culture

[0046] After the Saccharomyces cerevisiae was purified, it was inoculated in a YPD culture medium, the composite gel was added to the YPD culture medium, the addition amount was 40 wt%, and it was placed in a constant temperature incubator at 25℃ for cultivation for 12 h, adjusted to 2×10 cfu / mL, and inoculated in a solid-state fermentation substrate according to an addition amount of 1 wt% for fermentation, sealed and fermented in a shaking bed at 28℃ and 200 r / min for 48 h, and finally naturally air-dried, crushed to obtain a Saccharomyces cerevisiae culture.

[0047] The Saccharomyces cerevisiae is Saccharomyces cerevisiae, which was preserved in the China General Microbiological Culture Collection Center on August 27, 2024, with a strain number of WJ13 and a registration number of CGMCC No. 31754.

[0048] Example 3:

[0049] A Saccharomyces cerevisiae and a production method of a Saccharomyces cerevisiae culture, as shown in the specification, comprising the following steps: Figure 1

[0050] S1: grafting tyrosine with chitosan

[0051] 1 part by mass of chitosan was added to 45 parts by mass of a 2% by volume acetic acid solution, stirred for 15 min to form a chitosan solution, 1 part by mass of tyrosine was added to 45 parts by mass of a 60 wt% ethanol solution, and the solution was added to the chitosan solution, the pH was adjusted to 5, stirred for 15 min, and then left to react in the dark for 11 h, the product was placed in a dialysis bag, dialyzed in ultrapure water with a pH of 6 for 25 h, the cut-off value of the dialysis bag was 3500 Da, dialyzed in ultrapure water with a pH of 7.5 for 4.5 h, and finally freeze-dried at -20°C for 13 h to obtain tyrosine grafted chitosan.

[0052] S2: preparation of a composite gel

[0053] 10 parts by mass of kaolin were put into a high-speed universal crusher and crushed for 2 s, sieved through a 200-mesh sieve, and added to 15 parts by mass of a 25 wt% sulfuric acid solution, then 6 parts by mass of a citric acid solution was added, stirred at a speed of 120 r / min for 25 min, left to react after sealing for 5 h, then put into a high-temperature oven at 100°C and dried for 2.5 h, and dried in an oven at 110°C for 13 h to obtain modified kaolin; 2% by mass of xanthan gum, 9% of modified kaolin, and 3% of tyrosine grafted chitosan were dissolved in 20 parts by mass of ultrapure water, magnetically stirred for 20 min, then reacted at 45°C and 0.5 MPa for 2 h, then the product was immersed in a 20 wt% calcium chloride aqueous solution to crosslink for 1.5 h, then taken out and freeze-dried at -20°C for 4 h, crushed, then immersed in a mixed buffer solution to crosslink for 24 h, the mixed buffer solution was prepared by uniformly mixing EDC, NHS, and MES in a volume ratio of 1:1:1, the solid-liquid ratio was 1:8 g / mL, then freeze-dried to obtain a composite gel.

[0054] S3: adding the composite gel to the culture solution for cultivation to obtain a Saccharomyces cerevisiae culture

[0055] After the Saccharomyces cerevisiae was purified, it was inoculated in a YPD culture medium, the composite gel was added to the YPD culture medium, the amount added was 30 wt%, and it was placed in a constant-temperature incubator at 28°C for cultivation for 13 h, adjusted to 2×10 cfu / mL, and inoculated in a solid-state fermentation substrate according to an addition amount of 1 wt% for fermentation, sealed, and fermented in a shaking bed at 28°C and a speed of 200 r / min for 44 h, and finally naturally air-dried and crushed to obtain a Saccharomyces cerevisiae culture.

[0056] ​Saccharomyces cerevisiae, which was preserved in China General Microbiological Culture Collection Center on August 27, 2024, with a strain number of WJ13 and a registration number of CGMCC No. 31754.

[0057] Comparative Example 1

[0058] Comparative Example 1 is different from Example 1 in that step S1 is not performed, and chitosan is used instead of tyrosine grafted chitosan in step S2, specifically “S2: preparing a composite gel

[0059] The 10 parts by mass of kaolin were put into a high-speed universal crusher and crushed for 2 s, sieved through a 200-mesh screen, and then added to 15 parts by mass of a 25wt% sulfuric acid solution, 6 parts by mass of a citric acid solution was added, stirred at a speed of 100 r / min for 20 min, sealed and left to stand for 4 h of reaction, then put into a high-temperature oven at 95 ℃ for drying for 2 h, and dried in an oven at 105 ℃ for 12 h to obtain modified kaolin; 2% by mass of xanthan gum, 9% of modified kaolin and 3% of chitosan were dissolved in 20 parts by mass of ultrapure water, magnetically stirred for 20 min, then reacted at 40 ℃ and 0.1 MPa for 1 h, then the product was immersed in a 20wt% calcium chloride aqueous solution for crosslinking for 1 h, then taken out and freeze-dried at-20 ℃ for 3 h, crushed and then immersed in a mixed buffer solution for crosslinking for 20 h, the mixed buffer solution was prepared by uniformly mixing EDC, NHS and MES in a volume ratio of 1:1:1, the solid-liquid ratio was 1:8 g / mL, and then freeze-dried to obtain a composite gel, and the remaining steps were unchanged. The prepared Saccharomyces cerevisiae culture was recorded as Comparative Example 1.

[0060] Comparative Example 2

[0061] Comparative Example 2 is different from Example 1 in that the kaolin is not treated in step S2, but is directly reacted with xanthan gum and tyrosine grafted chitosan, specifically “S2: preparing a composite gel

[0062] 2% by mass of xanthan gum, 9% of kaolin and 3% of tyrosine grafted chitosan were dissolved in 20 parts by mass of ultrapure water, magnetically stirred for 20 min, then reacted at 40 ℃ and 0.1 MPa for 1 h, then the product was immersed in a 20wt% calcium chloride aqueous solution for crosslinking for 1 h, then taken out and freeze-dried at-20 ℃ for 3 h, crushed and then immersed in a mixed buffer solution for crosslinking for 20 h, the mixed buffer solution was prepared by uniformly mixing EDC, NHS and MES in a volume ratio of 1:1:1, the solid-liquid ratio was 1:8 g / mL, and then freeze-dried to obtain a composite gel”, and the remaining steps were unchanged. The prepared Saccharomyces cerevisiae culture was recorded as Comparative Example 2.

[0063] Comparative Example 3:

[0064] Comparative Example 3 differs from Example 1 in that no tyrosine chitosan is added in step S2, specifically “S2: Preparation of composite gel

[0065] Put 10 parts by mass of kaolin into a high-speed universal crusher and crush for 2 s, and sieve through a 200-mesh screen, and add to 15 parts by mass of a 25wt% sulfuric acid solution, then add 6 parts by mass of a citric acid solution, stir at a speed of 100 r / min for 20 min, seal and stand for reaction for 4 h, then put into a high-temperature oven at 95°C and dry for 2 h, dry in an oven at 105°C for 12 h, to obtain modified kaolin; dissolve 2% by mass of xanthan gum and 9% of modified kaolin in 20 parts by mass of ultrapure water, magnetically stir for 20 min, then react at 40°C and 0.1 MPa for 1 h, then immerse the product in a 20wt% calcium chloride aqueous solution to crosslink for 1 h, then take out and freeze-dry at -20°C for 3 h, crush and then immerse in a mixed buffer solution to crosslink for 20 h, the mixed buffer solution is prepared by uniformly mixing EDC, NHS and MES in a volume ratio of 1:1:1, the solid-liquid ratio is 1:8 g / mL, then freeze-dry to obtain a composite gel”, and the remaining steps are unchanged, and the prepared Saccharomyces cerevisiae culture is recorded as Comparative Example 3.

[0066] Comparative Example 4:

[0067] Comparative Example 4 differs from Example 1 in that no xanthan gum is added in step S2, specifically “S2: Preparation of composite gel

[0068] Put 10 parts by mass of kaolin into a high-speed universal crusher and crush for 2 s, and sieve through a 200-mesh screen, and add to 15 parts by mass of a 25wt% sulfuric acid solution, then add 6 parts by mass of a citric acid solution, stir at a speed of 100 r / min for 20 min, seal and stand for reaction for 4 h, then put into a high-temperature oven at 95°C and dry for 2 h, dry in an oven at 105°C for 12 h, to obtain modified kaolin; dissolve 2% by mass of xanthan gum and 9% of modified kaolin in 20 parts by mass of ultrapure water, magnetically stir for 20 min, then react at 40°C and 0.1 MPa for 1 h, then immerse the product in a 20wt% calcium chloride aqueous solution to crosslink for 1 h, then take out and freeze-dry at -20°C for 3 h, crush and then immerse in a mixed buffer solution to crosslink for 20 h, the mixed buffer solution is prepared by uniformly mixing EDC, NHS and MES in a volume ratio of 1:1:1, the solid-liquid ratio is 1:8 g / mL, then freeze-dry to obtain a composite gel”, and the remaining steps are unchanged, and the prepared Saccharomyces cerevisiae culture is recorded as Comparative Example 3.

[0069] The Saccharomyces cerevisiae used in the comparative examples is Saccharomyces cerevisiae, which was preserved in the China General Microbiological Culture Collection Center on August 27, 2024, with a strain number of WJ13 and a registration number of CGMCC No. 31754.

[0070] The nutritional components of Examples 1-4 and Comparative Examples 1-4 were detected, and part of the nutritional components accounted for, for example, as shown in Table 1.

[0071] The content of small molecule proteins in the crude protein of Examples 1-4 and Comparative Examples 1-4 was detected and calculated, as shown in Table 2.

[0072] Table 1

[0073]

[0074] Table 2

[0075]

[0076] As can be seen from Table 1, the contents of crude protein, ash and organic acid of Examples 1-4 are higher than those of Comparative Examples. Crude protein refers to the total of all nitrogen-containing compounds in the sample, including true protein and non-protein nitrogen-containing compounds; ash refers to the total amount of inorganic substances remaining after complete combustion of organic matter in the sample at a certain temperature, and the ash content can reflect the content of minerals and inorganic salts in the Saccharomyces cerevisiae culture, and a higher ash content usually means that the culture contains more minerals such as calcium, phosphorus, potassium, etc.; the organic acid content refers to various organic acids produced by Saccharomyces cerevisiae during fermentation, such as lactic acid, acetic acid, succinic acid and citric acid, etc. Through these content indicators, it can be seen that the amount of nutrients in the Saccharomyces cerevisiae culture, and it can be seen that the composite gel prepared by the raw material combination of the present application has higher nutrient content and higher nutritional value after being added to the culture medium.

[0077] As can be seen from Table 2, the proportion of small molecule proteins in crude protein is higher in Examples than in Comparative Examples. Small molecule proteins refer to complete proteins with relatively small molecular weights, which are usually composed of more than 20 amino acids, but have relatively small molecular weights. They are still complete proteins with specific three-dimensional structures and functions, and small molecule proteins have high biological activity and rapid absorption and utilization capacity, and a higher proportion thereof represents that the Saccharomyces cerevisiae culture is easier to absorb and has better nutritional supplement effect.

[0078] The above embodiments are only illustrative of the principles of the present application and its efficacy, and are not intended to limit the present application. Any modification or change made by any person skilled in the art without departing from the spirit and scope of the present application shall be covered by the claims of the present application.

Claims

1. A method of production of a Saccharomyces cerevisiae culture, characterized in that, Comprising the following steps: S1: grafting tyrosine with chitosan Chitosan is added to an ice acetic acid solution, stirred to form a chitosan solution, tyrosine is added to an ethanol solution, which is added to the chitosan solution, stirred, allowed to react, dialyzed, and tyrosine grafted chitosan is obtained; S2: preparing a composite gel Put 10-15 parts by mass of kaolin into a high-speed universal pulverizer and crush for 1-2 s, sieve through a 200-mesh screen, and add to 15-20 parts by mass of a sulfuric acid solution, then add 6-10 parts by mass of a citric acid solution, stir at a speed of 100-120 r / min for 20-25 min, seal and allow to react for 4-5 h, then put into a high-temperature oven at 95-100℃ and dry for 2-2.5 h, dry in an oven at 105-110℃ for 12-13 h, and obtain modified kaolin; Dissolve 2% by mass of xanthan gum, 9% of modified kaolin, and 3% of tyrosine grafted chitosan in 20 parts by mass of ultrapure water, magnetically stir for 20-30 min, then react at 40-45℃ and 0.1-0.5 MPa for 1-2 h, then immerse the product in a calcium chloride aqueous solution for crosslinking for 1-1.5 h, then take out and freeze-dry at -20℃ for 3-4 h, crush, then immerse in a mixed buffer solution for crosslinking for 20-24 h, with a material-liquid ratio of 1: (8-10) g / mL, and take out to obtain a composite gel, wherein the mixed buffer solution is prepared by uniformly mixing EDC, NHS, and MES in a volume ratio of 1: (1-2): (1-3); S3: adding the composite gel to a culture solution for culture to obtain a Saccharomyces cerevisiae culture After purification, the Saccharomyces cerevisiae is inoculated in a YPD culture medium, the composite gel is added to the YPD culture medium, and the YPD culture medium is cultured in a constant-temperature incubator, inoculated in a solid-state fermentation substrate for fermentation, and finally naturally air-dried and crushed to obtain a Saccharomyces cerevisiae culture, Among them, brewer's yeast ( Saccharomyces cerevisiae It is deposited at the China General Microbiological Culture Collection Center, strain number WJ13, and registration number CGMCC No.31754.

2. A method for the production of a Saccharomyces cerevisiae culture according to claim 1, characterized in that, Step S1: grafting tyrosine with chitosan, comprising the following steps: Add 1-2 parts by mass of chitosan to 45-50 parts by mass of a 2% by volume ice acetic acid solution, stir for 10-15 min to form a chitosan solution, then add 1-2 parts by mass of tyrosine to 45-50 parts by mass of a 60 wt% ethanol solution, and add it to the chitosan solution, adjust the pH to 4-5, stir for 10-15 min, then allow to react in the dark for 10-11 h, put the product in a dialysis bag, dialyze in ultrapure water with a pH of 5.5-6 for 24-25 h, dialyze in ultrapure water with a pH of 7-7.5 for 4-4.5 h, and finally freeze-dry at -20℃ for 12-13 h to obtain tyrosine grafted chitosan.

3. The method for producing a brewing yeast culture according to claim 1, characterized in that, Step S3: adding the composite gel to a culture solution for culture to obtain a Saccharomyces cerevisiae culture, comprising the following steps: After the purification of Saccharomyces cerevisiae, it is inoculated in YPD culture medium, and a composite gel is added in the YPD culture medium in an amount of 30-40wt%, and it is placed in a constant temperature incubator at 25-30℃ for 12-13h, and adjusted to 2x10cfu / mL, and inoculated in a solid-state fermentation substrate in an amount of 1-3wt%, and sealed in a 28-30℃, 200r / min environment for 44-48h, and finally naturally air-dried, crushed, and Saccharomyces cerevisiae culture is obtained.

4. The method for producing a brewing yeast culture according to claim 2, characterized in that, The cut-off value of the dialysis bag is 3500Da.

5. The method for producing a brewing yeast culture according to claim 1, characterized in that, The concentration of the calcium chloride aqueous solution is 20-25wt%.

6. The method for producing a brewing yeast culture according to claim 1, characterized in that, The concentration of the sulfuric acid solution is 25-30wt%.

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