Fermentation products of Feibaiberg lindnella yeast and saccharomycetes sparassis crispa as well as preparation method and application of fermentation products

Abstract

The invention belongs to the field of new materials for daily use, and particularly discloses a strain of Cyberlindnera fibianii, the preservation number of which is GDMCC (China General Microbiological Culture Collection Center) NO.66107, and the preservation number of which is GDMCC NO.66107. The invention also discloses a preparation method of the strain of Cyberlindnera fibianii. The preservation date is April 8, 2025, the preservation unit is Guangdong Microbial Culture Collection Center, and the preservation address is the 5th floor, No. 59 building, No. 100 Courtyard, Xianlie Middle Road, Guangzhou City; the invention also discloses a preparation method of the yeast and sparassis crispa fermentation product, the fermentation efficiency, the product diversity and the system stability are obviously improved by utilizing bidirectional fermentation of the Feibaiberg's yeast and the sparassis crispa through functional complementation and synergy among strains; the viable sparassis crispa can improve the activity of thalli and is more beneficial to transformation and metabolism of the thalli, so that the obtained fermentation product has a better oil control effect; meanwhile, the invention also discloses application of the yeast.

Description

Technical Field

[0001] This invention belongs to the field of new materials for daily chemical products, specifically the fermentation products of *Fibriania cerevisiae*, *Saccharomyces cerevisiae*, and their preparation methods and applications. Background Technology

[0002] *Hydrangea macrophylla*, belonging to the genus *Hydrangea* of the family Hydrangeaceae in the order Polyporaceae of the class Agaricales in the phylum Basidiomycota of the kingdom Fungi, is a relatively rare edible fungus that has gained popularity in recent years. It is rich in nutrients, containing a large amount of glucan, which has excellent anti-inflammatory, antioxidant, anti-aging, and skin-improving effects. Currently, the most common extraction processes for *Hydrangea macrophylla* polysaccharides are hot soaking, ultrasonic extraction, and high-pressure extraction. These processes are relatively complex, have high extraction costs, and generally result in low polysaccharide yields.

[0003] Currently, yeast is mainly used in fermentation processes such as brewing, and there are few methods for using yeast to ferment and extract *Hydrangea macrophylla*. Patent CN107969684A discloses a method for symbiotic fermentation of *Hydrangea macrophylla* using lactic acid bacteria and yeast. This method uses *Hydrangea macrophylla* extract as the main raw material, adds wheat germ, and utilizes the symbiotic relationship between lactic acid bacteria and yeast for bio-fermentation transformation to produce a fermented *Hydrangea macrophylla* stock solution. Further observation reveals that the *Hydrangea macrophylla* extract is prepared from inactivated *Hydrangea macrophylla*. However, the combined two-way fermentation production using yeast and fungi is still a blank area, and there are no reports on the research and development of plant fermentation using yeast to extract live *Hydrangea macrophylla*.

[0004] Therefore, the technical problem to be solved in this case is: how to use yeast to carry out compound two-way fermentation of live *Hydrangea macrophylla* bacteria, so as to improve the conversion of active substances in *Hydrangea macrophylla* bacteria and more comprehensively retain the efficacy of active substances. Summary of the Invention

[0005] The purpose of this invention is to provide a strain of *Fibrian seraberlindnerella* that can be used for bidirectional fermentation with *Hydrangea macrophylla*. Through functional complementarity and synergy between the strains, the fermentation efficiency, product diversity, and system stability are significantly improved. Furthermore, the use of live *Hydrangea macrophylla* can enhance cell activity, which is more conducive to cell transformation and metabolism, resulting in fermentation products with better oil control.

[0006] In addition, the present invention also discloses the fermentation products prepared based on this method.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A strain of *Cyberlindnera fabianii* was deposited at the Guangdong Provincial Center for Microbial Culture Collection on April 15, 2025, with accession number GDMCC NO.66107. The address of the depository is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou. The depository code is GDMCC-Guangdong Provincial Center for Microbial Culture Collection.

[0009] The use of *Saccharomyces cerevisiae* fermented with *Saccharomyces cerevisiae* as described above.

[0010] In addition, this invention discloses a method for preparing yeast-derived *Hydrangea macrophylla* fermentation products. The specific steps are as follows: activated *Hydrangea macrophylla* is inoculated into a fermentation medium and cultured until the mycelium is plump and the surface of the mycelium is smooth. After filtration through a 60-mesh filter, yeast is added to the filtrate for continued fermentation. After the fermentation is completed, the cell wall is broken and centrifuged to obtain the fermentation product.

[0011] The yeast strain mentioned is *Cyberlindnera fabianii*, as described above.

[0012] In the research of this invention, it was discovered that yeast and live *Hydrangea hygroscopica* can undergo compound bidirectional fermentation. The possible mechanism is speculated to be as follows: When they are co-cultured and fermented, because yeast has strong fermentation activity, if the fermentation product of inactivated *Hydrangea hygroscopica* is fermented with yeast, the fermentation product of *Hydrangea hygroscopica* will serve as the fermentation nutrient for yeast, and *Hydrangea hygroscopica* will only serve as a carrier for the fermentation product of yeast. The resulting active ingredients will not possess the characteristics of *Hydrangea hygroscopica*. If yeast and live *Hydrangea hygroscopica* are simultaneously subjected to compound bidirectional fermentation, the fermentation product will have a higher sugar content, and after fermentation processing by yeast, the bioconversion rate will be higher, which can significantly improve the conversion of active substances of *Hydrangea hygroscopica*.

[0013] Preferably, in the fermentation medium, the inoculation amount of *Hydrangea macrophylla* seed liquid is 8 wt% to 10 wt% per 1000 ml of medium; and the inoculation amount of yeast seed liquid is 1 wt% to 2 wt% per 1000 ml of medium.

[0014] The fermentation medium has the following composition:

[0015] Each 1000ml of water contains:

[0016] 180–200 g of plant-derived carbon and nitrogen sources;

[0017] Carbon source 20-100g;

[0018] 2-3g of inorganic salts;

[0019] Vitamin 10-20mg;

[0020] The plant-derived carbon and nitrogen sources are one or more combinations of potatoes, wheat bran, soybeans, corn flour, and soybean meal.

[0021] The carbon source is one or more combinations of glucose, sucrose, maltose, and soluble starch.

[0022] The inorganic salt is one or more of magnesium sulfate, potassium dihydrogen phosphate, copper sulfate, and potassium sulfate;

[0023] The vitamin is one or more of vitamin B1, vitamin B2, and B complex vitamins.

[0024] Preferably, the fermentation temperature before adding yeast and the fermentation temperature after adding yeast are both 22℃~25℃;

[0025] The fermentation culture time before adding yeast is 10-12 days; the fermentation culture time after adding yeast is 2-3 days.

[0026] Fermentation is carried out in a shaker at a frequency of 150–180 rpm.

[0027] Preferably, the activation culture method of the *Hydrangea fuciformis* is as follows:

[0028] First, inoculate *Hydrangea macrophylla* onto a solid culture medium plate and culture it at 20℃~25℃ for 15-20 days. After that, transfer it to a culture medium and continue culturing it at 20℃~25℃ in a shaker at 150~180rpm for 10~15 days. After the culture is completed, select *Hydrangea macrophylla* strains with vigor and growth that meet the preset requirements for further fermentation culture.

[0029] Preferably, the cell wall breaking centrifugation operation is a hot extraction at 75°C for 30 minutes, followed by centrifugation at 8000 rpm for 20 minutes in a centrifuge bottle.

[0030] In addition, the present invention discloses a yeast *Hydrangea hydrangea* fermentation product, which is prepared by the preparation method described above.

[0031] Furthermore, this invention discloses the use of the yeast *Hydrangea macrophylla* fermentation product as described above in the preparation of cosmetics.

[0032] Finally, this invention discloses a cosmetic containing the yeast *Hydrangea macrophylla* fermentation product as described above.

[0033] Compared with existing technologies, the beneficial effects of this case are as follows:

[0034] By using two-way fermentation of *Saccharomyces cerevisiae* and *Hydrangea spp.*, the fermentation efficiency, product diversity, and system stability were significantly improved through functional complementarity and synergy between the strains. Furthermore, the use of live *Hydrangea spp.* can enhance cell activity, which is more conducive to cell transformation and metabolism, resulting in fermentation products with better oil control. Attached Figure Description

[0035] Figure 1 Microscopic image of the fermentation product of Example 1;

[0036] Figure 2 Microscopic image of the fermentation product of Comparative Example 1;

[0037] Figure 3 Microscopic image of the fermentation product of Comparative Example 2;

[0038] Figure 4 Microscopic image of the fermentation product of Comparative Example 3;

[0039] Figure 5 Microscopic images of the control group;

[0040] Figure 6 This is a microscopic image of the positive control group. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Product Information

[0043] bacterial strains:

[0044] Sprassis crispa HZB127930 was purchased from Wuhan Gray Algae Biotechnology Co., Ltd.

[0045] Cyberlindnera fabianii, accession number GDMCCNO.66107, accession date April 8, 2025, deposited at Guangdong Provincial Center for Microbial Culture Collection, located at 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

[0046] Hanseniaspora sp. HZB119788 was purchased from Wuhan Gray Algae Biotechnology Co., Ltd.

[0047] Saccharomyces cerevisiae HZB119512 was purchased from Wuhan Gray Algae Biotechnology Co., Ltd.

[0048] Reagents:

[0049] Total sugar assay kit (BC2715) was purchased from Beijing Solarbio Science & Technology Co., Ltd.

[0050] D(+)-anhydrous glucose standard was purchased from Bomei Laboratory Store;

[0051] DMEM culture medium was purchased from Beijing Solarbio Science & Technology Co., Ltd.

[0052] Isotretinoin was purchased from Shanghai Hengyuan Biotechnology Co., Ltd.

[0053] Oil Red O staining solution was purchased from Lianchen flagship store.

[0054] Example 1

[0055] 1. Prepare solid plate culture medium: Prepare 200g potatoes, 20g glucose, 1g magnesium sulfate, 2g potassium dihydrogen phosphate, 3g peptone, 2 vitamin B1 tablets, and 20g agar powder; Peel and slice the potatoes, then boil them in pure water until thoroughly cooked but not mushy. After filtering, add the other ingredients, make up to 1000ml with purified water, shake to dissolve, and then autoclave (121℃ for 20min). Pour the mixture into plates for later use.

[0056] 2. Take the mother culture of *Hydrangea slant* from the refrigerator, pick up a small piece of mycelium (about the size of a millet grain) from the tip of the hyphae on a clean workbench and inoculate it onto a solid culture medium plate. Incubate at 23°C for 17 days for later use.

[0057] 3. Prepare primary culture medium: 200g potato, 20g glucose, 1g magnesium sulfate, 2g potassium dihydrogen phosphate, 2 vitamin B1 tablets, 3g peptone, and 1000ml purified water; put the ingredients into an Erlenmeyer flask, shake to dissolve, then autoclave (121℃ for 20min), and cool for later use.

[0058] 4. From the plates prepared in step 2, select plates with good growth and strong vitality as inoculum. In a clean workbench, transfer the inoculum blocks into a shaker flask and ferment for 12 days at 23°C and 150 rpm for later use.

[0059] 5. Prepare fermentation medium: Prepare 180g potato, 60g glucose, 5g wheat bran, 5g soybean, 1g magnesium sulfate, 2g potassium dihydrogen phosphate, 15mg vitamin B1, and 1000ml purified water. After mixing the ingredients, put them into a 5L shake flask, shake to dissolve, and then autoclave (121℃ for 20min). Cool and set aside. The pH of the fermentation medium is 4.

[0060] 6. Select the prepared shake flasks free of contamination from step 4, and add them to the fermentation shake flasks from step 5 at an inoculation rate of 9 wt% per 1000 ml of culture medium in a clean workbench. After fermenting for 11 days in a shaker at 23°C and 150 rpm, the *Hydrangea macrophylla* spores will be visible with beautiful and plump shapes and smooth surfaces. After filtering through a 60-mesh filter, add 2 wt% *Saccharomyces cerevisiae* per 1000 ml of culture medium, adjust the temperature to 22°C, and continue culturing for 2 days to complete the fermentation.

[0061] 7. After the bidirectional fermentation liquid of *Hydrangea macrophylla* and yeast obtained in step 6 is placed in a high-speed blender for cell wall disruption, it is then hot-extracted at 75°C for 30 minutes. The liquid is then transferred to a centrifuge bottle and centrifuged at 8000 rpm for 20 minutes to obtain the supernatant of bidirectional fermentation of *Hydrangea macrophylla* and yeast.

[0062] 8. Take the solution from the previous step, filter it through a 2μm filter in a clean workbench, keep it at 75℃ for 20 minutes, and dispense it into sterilized containers.

[0063] Comparative Example 1

[0064] It is largely the same as Example 1, except that the yeast species is Spore-bearing Hansenula polymorpha.

[0065] Comparative Example 2

[0066] It is largely the same as Example 1, except that the yeast strain is Saccharomyces cerevisiae.

[0067] Comparative Example 3

[0068] 1. Prepare solid plate culture medium: Prepare 200g potatoes, 20g glucose, 1g magnesium sulfate, 2g potassium dihydrogen phosphate, 3g peptone, 2 vitamin B1 tablets, and 20g agar powder; Peel and slice the potatoes, then boil them in pure water until thoroughly cooked but not mushy. After filtering, add the other ingredients, make up to 1000ml with purified water, shake to dissolve, and then autoclave (121℃ for 20min). Pour the mixture into plates for later use.

[0069] 2. Take the mother culture of *Hydrangea slant* from the refrigerator, pick up a small piece of mycelium (about the size of a millet grain) from the tip of the hyphae on a clean workbench and inoculate it onto a solid culture medium plate. Incubate at 23°C for 17 days for later use.

[0070] 3. Prepare primary culture medium: 200g potato, 20g glucose, 1g magnesium sulfate, 2g potassium dihydrogen phosphate, 2 vitamin B1 tablets, 3g peptone, and 1000ml purified water; put the ingredients into an Erlenmeyer flask, shake to dissolve, then autoclave (121℃ for 20min), and cool for later use.

[0071] 4. From the plates prepared in step 2, select plates with good growth and strong vitality as inoculum. In a clean workbench, transfer the inoculum blocks into a shaker flask and ferment for 12 days at 23°C and 150 rpm for later use.

[0072] 5. Prepare fermentation medium: Prepare 180g potato, 60g glucose, 5g wheat bran, 5g soybean, 1g magnesium sulfate, 2g potassium dihydrogen phosphate, 15mg vitamin B1, and 1000ml purified water. After mixing the ingredients, put them into a 5L shake flask, shake to dissolve, and then autoclave (121℃ for 20min). Cool and set aside. The pH of the fermentation medium is 4.

[0073] 6. Select the shake flasks from step 4 that are free of contaminants, and add them to the fermentation shake flasks from step 5 at an inoculation rate of 9wt% per 1000ml of culture medium in a clean workbench. After fermenting for 11 days in a shaker at 23℃ and 150rpm, the *Hydrangea macrophylla* will show that the mycelium balls are basically beautiful and plump with smooth surfaces. Then, sterilize the shake flasks by high-pressure steam (121℃ for 20min) to inactivate them.

[0074] Take the inactivated *Hydrangea macrophylla*, filter it through a 60-mesh filter, and add 2 wt% *Saccharomyces cerevisiae* per 1000 ml of culture medium. Adjust the temperature to 22°C and continue culturing for 2 days until fermentation ends.

[0075] Performance testing

[0076] Total sugar content test

[0077] Carbohydrates are an important component of plants and a major raw material and storage substance for metabolism. Total sugars mainly refer to reducing sugars such as glucose, fructose, pentose, lactose, and sucrose, maltose, and starch (which can be hydrolyzed into reducing monosaccharides under the test conditions) and may be partially hydrolyzed. Total sugars are hydrolyzed into reducing sugars by acid. These reducing sugars are reduced to amino compounds upon heating with DNS reagent under alkaline conditions, turning reddish-brown in alkaline solution. The amount of reducing sugars is directly proportional to the intensity of the orange-red color, which is used to determine the total sugar content in a sample.

[0078] Main reagents and instruments: visible spectrophotometer, constant temperature water bath, centrifuge, test tubes, pipettes, cuvettes, total sugar assay kit (BC2715).

[0079] Sample group: Fermentation products of *Hydrangea macrophylla* yeast from Example 1 and Comparative Examples 1-3;

[0080] Negative control: 10 mg glucose standard.

[0081] Experimental operation steps:

[0082] Sample group: Take 0.1 mL of the sample to be tested, add 0.1 mL of reagent one and 0.15 mL of distilled water, homogenize, boil in a water bath for 30 min, add 0.1 mL of reagent two after the test, mix well, make up to 1 mL with distilled water, centrifuge at 8000 g at 25℃ for 10 min, and take the supernatant for testing.

[0083] Negative control: Dilute glucose standard with distilled water to 1, 0.8, 0.6, 0.5, 0.4, 0.2, and 0.1 mg / mL.

[0084] Refer to Table 1 for specific test dosages;

[0085] Table 1 Sample Addition Table

[0086]

[0087] Mix the reagents in the test tube thoroughly and measure the absorbance at 540 nm.

[0088] Calculate the total sugar concentration in the sample based on the standard curve equation shown below, and then calculate the total sugar content of the original sample based on the dilution factor.

[0089]

[0090] In the formula:

[0091] C: Sugar concentration (mg / mL) obtained from the standard curve;

[0092] V: Sample volume (mL);

[0093] D: Dilution factor;

[0094] W: Sample mass (g).

[0095] The test data is shown in Table 2.

[0096] Table 2 Total Sugar Content Data

[0097] Sample source Total sugar content / % Example 1 2.58 Comparative Example 1 1.61 Comparative Example 2 1.43 Comparative Example 3 2.26

[0098] Results Analysis

[0099] Analysis of the data in Table 2 shows that:

[0100] The total sugar content of the fermentation product prepared in Example 1 was 2.58%, indicating that the bidirectional fermentation technology of *Saccharomyces cerevisiae* and *Hydrangea spp.* of the present invention can significantly improve the level of total sugar of active substances in the obtained fermentation product.

[0101] As can be seen from the data of Comparative Examples 1-2, using other yeasts instead of the *Saccharomyces ferox* of the present invention resulted in a limited increase in the level of total sugars in the fermentation products, only 1.61% and 1.43%, respectively. This indicates that the bidirectional fermentation of *Saccharomyces ferox* and *Saccharomyces cerevisiae* of the present invention is extremely excellent.

[0102] The data from Comparative Example 3 show that after inactivating the *Hydrangea spp.* before fermentation, the fermentation effect of *Saccharomyces cerevisiae* was slightly reduced, and its total sugar content was 2.26%.

[0103] Oil-controlling effect test of yeast and physalis fermentation products

[0104] Test method: Detection of lipid droplet synthesis in SZ95 sebaceous gland cells;

[0105] Main reagents and instruments: SZ95 cells, purchased from Beijing Biowell Biotechnology Co., Ltd.; isotretinoin; Oil Red O staining solution (1 μg / mL); PBS buffer; DMEM medium; CO2 incubator (Thermo, 150I); clean bench (Suzhou Antai, SW-CJ-1F); fluorescence microscope (Leica, DM2500).

[0106] Control and test samples:

[0107] Sample group: DMEM containing fermentation products of *Hydrangea macrophylla* yeast from Examples 1 and Comparative Examples 1-3;

[0108] Positive control group: DMEM containing 50 μM isotretinoin;

[0109] Blank group: DMEM.

[0110] Experimental procedure:

[0111] SZ95 cell density was adjusted to 1×10⁵ cells / mL using DMEM medium. 3 mL of the solution was seeded into each well of a 6-well cell culture plate and incubated overnight at 37°C with 5% CO₂. When cell seeding reached 60%–70% confluence, cells were divided into groups and treated with 1 mL of the solution per well, with three replicates per group. After treatment, the 6-well plates were incubated at 37°C with 5% CO₂ for 72 hours, with daily medium changes and treatment. After 72 hours, the old medium was discarded, and the cells were washed once with PBS. 500 μL of Oil Red O staining solution (1 μg / mL) was added to each well, and the cells were stained in the dark for 15 minutes (incubated at 37°C). The cells were then washed twice with PBS. Microscopic observation was performed; specific results are shown in Table 3.

[0112] Table 3. Statistics of Microscopic Images

[0113] Sample source Corresponding to the attached diagram Example 1 Figure 1 Comparative Example 1 Figure 2 Comparative Example 2 Figure 3 Comparative Example 3 Figure 4 Blank group Figure 5 Positive control group Figure 6

[0114] Statistical analysis of results:

[0115] 1. Oil Red O staining can specifically bind to lipids and glycolipids in cells, forming visible staining substances. The larger the stained area and the more chromophores, the higher the lipid content in the cells.

[0116] 2. As shown in the figure, compared with the blank group, the positive control group showed a significant reduction in oil droplet staining, indicating that the positive control was effective.

[0117] 3. By comparing the results of Example 1 and the blank group, it can be seen that the yeast *Hydrangea hydrangea* fermentation product prepared in Example 1 has a good inhibitory effect on lipid droplet synthesis, and the staining area and aggregation size of the lipid droplets are significantly smaller than those of the blank group; indicating that the bidirectional fermentation technology of *Fibrian seraphim* and *Hydrangea hydrangea* of the present invention can significantly improve the inhibitory effect of the obtained fermentation product on lipid droplet synthesis and has an excellent oil control effect.

[0118] 4. By comparing the results of Example 1, Comparative Example 1, and Comparative Example 2, it can be seen that the effects of products obtained by different fermentation strains are different. The fermentation product prepared by Hansenula polysaccharide fermentation does not have a strong inhibitory effect on lipid droplet synthesis. On the one hand, Hansenula polysaccharide may produce some aromatic hydrocarbons during fermentation, which will directly affect lipid droplet synthesis and aggregation. On the other hand, it may be that Saccharomyces cerevisiae produced acidic components during fermentation, which can effectively dissolve lipid droplets. The fermentation product of Saccharomyces cerevisiae and Saccharomyces cerevisiae has an excellent oil control effect.

[0119] In addition, fermenting *Saccharomyces cerevisiae* with *Saccharomyces cerevisiae* can have a certain effect, and can decompose lipid droplets and inhibit lipid droplet synthesis. However, due to the different fermentation mechanisms of different fermenting bacteria, their fermentation products have certain differences. The oil control effect of the fermentation product of *Saccharomyces cerevisiae* by *Saccharomyces cerevisiae* in Example 1 is relatively more significant.

[0120] 5. Comparing the results of Example 1 and Comparative Example 1, it can be seen that, since Comparative Example 1 sterilized the *Hydrangea macrophylla* before fermentation and then fermented it with yeast, although it had a certain effect on inhibiting lipid droplet synthesis, the overall staining area of ​​the lipid droplets was still relatively large. In contrast, Example 1 did not undergo sterilization. The difference in fermentation process suggests that the activity of *Hydrangea macrophylla* has an effect on improving the oil control effect of the fermentation product. The main reason is that *Hydrangea macrophylla* is rich in amino acids and polysaccharides, which are abundant nutrients for yeast fermentation. These components can provide the nutrients needed for the growth of fermentation strains, enhance the activity of the cells, and are more conducive to cell transformation and metabolism, thereby improving the oil control effect.

[0121] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A strain of *Cyberlindnera fabianii*, characterized in that, The accession number is GDMCC NO.66107; the accession date is April 8, 2025; the depositary institution is Guangdong Provincial Center for Microbial Culture Collection; the depositary address is 5th Floor, Building 59, No. 100 Xianlie Middle Road, Guangzhou.

2. Use of the *Fibriania cerevisiae* fermentation method as described in claim 1.

3. A method for preparing a yeast fermentation product of *Hydrangea macrophylla*, characterized in that, The specific steps are as follows: the activated *Hydrangea macrophylla* is inoculated into a fermentation medium and cultured until the mycelium is plump and the surface of the mycelium is smooth. After filtration, yeast is added to the filtrate and fermentation continues. After the fermentation is completed, the cell wall is broken and centrifuged to obtain the fermentation product. The yeast strain is *Cyberlindnera fabianii* as described in claim 1.

4. The preparation method according to claim 3, characterized in that, In the fermentation medium, the inoculation amount of *Hydrangea macrophylla* seed liquid is 8 wt% to 10 wt% per 1000 ml of medium; the inoculation amount of yeast seed liquid is 1 wt% to 2 wt% per 1000 ml of medium. The fermentation medium has the following composition: Each 1000ml of water contains: 180–200 g of plant-derived carbon and nitrogen sources; Carbon source 20-100g; 2-3g of inorganic salts; Vitamin 10-20mg; The plant-derived carbon and nitrogen sources are one or more combinations of potatoes, wheat bran, soybeans, corn flour, and soybean meal. The carbon source is one or more combinations of glucose, sucrose, maltose, and soluble starch. The inorganic salt is one or more of magnesium sulfate, potassium dihydrogen phosphate, copper sulfate, and potassium sulfate; The vitamin is one or more of vitamin B1, vitamin B2, and B complex vitamins.

5. The preparation method according to claim 3, characterized in that, The fermentation temperature before adding yeast and the fermentation temperature after adding yeast were both 22℃~25℃. The fermentation culture time before adding yeast is 10-12 days; the fermentation culture time after adding yeast is 2-3 days. Fermentation is carried out in a shaker at a frequency of 150–180 rpm.

6. The preparation method according to claim 3, characterized in that, The activation culture method for the *Hydrangea macrophylla* is as follows: First, inoculate *Hydrangea macrophylla* onto a solid culture medium plate and culture it at 20℃~25℃ for 15-20 days. After that, transfer it to a culture medium and continue culturing it at 20℃~25℃ on a shaker at 150~180rpm for 10~15 days. After the culture is completed, select *Hydrangea macrophylla* strains with vigor and growth that meet the preset requirements for fermentation culture.

7. The preparation method according to claim 3, characterized in that, The aforementioned cell wall breaking centrifugation operation involves hot extraction at 75°C for 30 minutes, followed by centrifugation at 8000 rpm for 20 minutes in a centrifuge bottle.

8. A yeast fermentation product of *Hydrangea macrophylla*, characterized in that, It is prepared by the preparation method described in claims 3 to 7.

9. Use of the yeast *Hydrangea macrophylla* fermentation product as described in claim 8 for the preparation of cosmetics.

10. A cosmetic product, characterized in that, It contains the yeast *Hydrangea macrophylla* fermentation product as described in claim 8.

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