A kind of fermentation liquid of Saccharomyces cerevisiae, preparation method and application thereof

Abstract

The invention provides a fermentation liquid of spores of spores, a preparation method and an application thereof, and belongs to the technical field of microbial fermentation. The fermentation liquid of spores of spores is prepared by fermentation of spores of spores, the spores of spores is one of spores of spores strains CICC 33377, CICC 1803, CCTCC CB 20081663 and CCTCC DY 20081403, the fermentation medium contains rice bran powder, and the fermentation liquid of spores of spores contains γ-oryzanol. The invention extracts beneficial components in rice bran, especially γ-oryzanol, at a higher level through the metabolic activity of spores of spores, thereby significantly improving the economic value of rice bran.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial fermentation, and particularly relates to a fermentation liquid of Saccharomyces cerevisiae prepared by fermenting rice bran powder with Saccharomyces cerevisiae, a preparation method and application of the fermentation liquid in cosmetics. Background Art

[0002] Rice bran, also known as full-fat rice bran, fine bran, etc., is the peeled off skin layer of brown rice during the whitening process, including pericarp, seed coat, nucellus, endosperm, rice germ and a mixture of small rice crumbs. In the rice processing process, the first process is to remove the rice husk and the outer shell of the rice grain to obtain brown rice; then the second process is whitening to remove the brown skin layer outside the brown rice. In addition to the main product white rice, the main by-product is the peeled brown skin layer. From the perspective of plant morphology, it also includes endosperm, nucellus, seed coat, pericarp layer and several sublayers between them. This is rice bran in the strict sense.

[0003] my country is rich in rice resources, and processed white rice is one of the most commonly consumed staple foods in people's daily lives. However, the process of processing rice into white rice is accompanied by a large loss of nutrients. Rice bran is rich in fat, protein, fiber, minerals and some biologically active substances, such as γ-oryzanol. The antioxidant activity of γ-oryzanol is four times that of vitamin E, and it has multiple physiological functions such as anti-inflammatory, anti-aging, and anti-oxidation.

[0004] Studies have shown that the content of γ-oryzanol in rice bran, paddy, brown rice, and white rice is 3296.50, 454.60, 408.90, and 26.12 mg / kg, respectively, indicating that the content of γ-oryzanol in rice bran is much higher than that in other rice processed products. In 2020, my country's annual production of rice bran was about 16.94 million tons. At present, it is mainly used as a nutritious and cheap feed raw material. The lack of reprocessed products using rice bran as raw material has wasted the nutritional value and economic value of rice bran to a certain extent.

[0005] Saccharomyces cerevisiae Saccharomycopsis fibuligera ), also known as Pseudomonas aeruginosa, is a member of the phylum Ascomycota ( Ascomycota ) Saccharomyces Saccharomycotina ) Saccharomycetes )Saccharomyces cerevisiae ( Saccharomycetales ) Saccharomyces Saccharomycetaceae ) Saccharomycopsis ). Saccharomyces cerevisiae is a type of yeast that has multiple hydrolytic enzyme systems such as amylase and acid protease. As a dominant strain, it is widely present in the koji with high starch content and the mash in the early stage of fermentation, and makes a great contribution to the formation of the aroma and flavor of liquor.

[0006] In the prior art, patent CN118806673A discloses a "fermented rice bran lipid extract with moisturizing effect and its preparation method and application", which provides a method for extracting lipids from rice bran by co-fermentation with Lactobacillus casei and three yeast species, Pichia amiceti, Kluyveromyces marxianus, and Candida ethanolica. Since the metabolic pathways and enzyme production capabilities of different strains vary greatly, this technology is significantly different from the method of extracting γ-oryzanol from rice bran powder by fermentation with Saccharomyces cerevisiae.

[0007] Patent CN116218694A discloses "Spore-coated spore yeast, galactosyl yeast-like fermentation product filtrate with firming, rejuvenation, brightening and repairing effects", and provides a method for fermenting hulled sorghum powder, corn starch and wheat starch with separated spore-coated spore yeast. The obtained galactosyl yeast-like fermentation product filtrate has better firming, rejuvenation, brightening and repairing effects. For another example, patent CN111088174A provides "a spore-coated spore yeast with antioxidant and whitening effects and its application", which limits the use of spore-coated spore yeast CCTCC M 2019324 to ferment one or more of the medicinal plants Platycodon grandiflorum, dandelion, mint, ginseng, angelica, ginkgo, daylily or lavender. The above two technologies involve Saccharomyces cerevisiae and its applications in different aspects, but neither of them mentions the technology of fermenting rice bran powder with Saccharomyces cerevisiae. In addition, the content of γ-oryzanol in the raw materials used in these patents is very low or non-existent, and these technologies have not yet conducted in-depth analysis and research on the active ingredients in the fermentation broth. Therefore, the relevant technology of fermenting rice bran powder with Saccharomyces cerevisiae still needs to be developed. Summary of the invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide a fermentation broth of Saccharomyces cerevisiae, through the metabolic activity of Saccharomyces cerevisiae, to extract the beneficial components in rice bran, especially γ-oryzanol, at a higher level, thereby significantly improving the economic value of rice bran.

[0009] On the one hand, the present invention provides a fermentation liquid of Saccharomyces cerevisiae, which is prepared by fermenting Saccharomyces cerevisiae, wherein the Saccharomyces cerevisiae is one of Saccharomyces cerevisiae strains CICC 33377, CICC 1803, CCTCC CB 20081663 and CCTCC DY 20081403, the fermentation medium contains rice bran powder, and the fermentation liquid of Saccharomyces cerevisiae contains γ-oryzanol.

[0010] Optionally, the culture medium contains 1-3% by mass of rice bran powder.

[0011] In another aspect, the present invention provides a method for preparing a fermentation broth of Saccharomyces cerevisiae, comprising:

[0012] The yeast is a strain of Saccharomyces cerevisiae, wherein the yeast is one of the Saccharomyces cerevisiae strains CICC33377, CICC 1803, CCTCC CB 20081663 and CCTCC DY 20081403.

[0013] The fermentation is carried out in a culture medium containing rice bran powder to obtain a fermentation liquid of Saccharomyces cerevisiae.

[0014] The culture medium containing rice bran powder described in the steps of the present invention is prepared by a method known in the art, specifically using rice bran powder as the main fermentation substrate, supplementing a certain proportion of carbon source, nitrogen source and water, and sterilizing by high pressure. Rice bran comes from common indica rice, polished rice, and glutinous rice, and is regionally derived from Northeast my country, South China, Thailand, India and other places. The supplemented nitrogen source can be potato extract, peptone, yeast powder, etc. The supplemented carbon source can be glucose, sucrose, maltose, dextrin, etc. Preferably, potato extract is the nitrogen source, and glucose is the carbon source.

[0015] Optionally, the culture medium comprises, by mass percentage, 1-3% rice bran powder, 0.1-1% nitrogen source, 0.5-2% carbon source, and the remainder is water, the nitrogen source is at least one of potato extract, peptone and yeast powder, the carbon source is at least one of glucose, sucrose, maltose and dextrin, and is sterilized at 120-125° C. for 20-25 min.

[0016] Optionally, the culture medium comprises, by mass percentage, 1-3% rice bran powder, 0.1-1% potato extract, 0.5-2% glucose, and the remainder is water.

[0017] Optionally, the fermentation process parameters include: the inoculation amount of the seed liquid of the Saccharomyces cerevisiae is 1-3%, the fermentation temperature is 25-30°C, the stirring speed is 50-200rpm, and the culture time is 48-96h.

[0018] Optionally, the inoculation amount of the seed liquid of the Saccharomyces cerevisiae is 2%, the fermentation temperature is 28° C., the stirring speed is 150 rpm, and the culture time is 72 h.

[0019] Optionally, the seed liquid of the Saccharomyces cerevisiae is prepared by the following method: using PDB culture medium to activate the Saccharomyces cerevisiae, the PDB culture medium containing 0.1-1% potato extract powder, 0.5-2% glucose, and the remainder water in mass percentage, and high-pressure sterilization at 120-125°C for 20-25min, and the activation culture conditions are temperature 25-30°C, rotation speed 50-200rpm, and fermentation 24-48h.

[0020] Optionally, the method for preparing the fermentation broth of Saccharomyces cerevisiae further includes: sterilizing the fermentation broth of Saccharomyces cerevisiae and removing alcohol at the same time; centrifuging and filtering the sterilized fermentation product to obtain clarified Saccharomyces cerevisiae fermentation broth.

[0021] The present invention sterilizes the fermentation liquid of the spores ...

[0022] On the other hand, the present invention also provides the use of the fermentation liquid of Saccharomyces cerevisiae in cosmetics.

[0023] The present invention efficiently extracts the bioactive components rich in rice bran; the fermentation liquid is rich in active components such as gamma-oryzanol, has excellent anti-oxidation and moisturizing effects, and can be applied to cosmetic products.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The invention extracts beneficial components in rice bran, especially gamma-oryzanol, at a higher level through the metabolic activity of specific Saccharomyces cerevisiae, thereby improving the economic value of rice bran. The obtained Saccharomyces cerevisiae fermentation liquid has excellent antioxidant, moisturizing and other effects, and has good application prospects in cosmetics. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 : DPPH free radical scavenging rate results;

[0028] Figure 2 : Relative gene expression results of filaggrin gene (FLG);

[0029] Figure 3 : Relative gene expression results of hyaluronan synthase genes (HAS1, HAS2, HAS3);

[0030] Among them, A1: Example 1, A2: Example 2, A3: Example 3, A4: Example 4, B1: Comparative Example 1, B2: Comparative Example 2, B3: Comparative Example 3, C1: Comparative Example 4, C2: Comparative Example 5. DETAILED DESCRIPTION

[0031] In order to better understand the present invention, the content of the present invention is further clearly set forth in conjunction with the embodiments below, but the protection content of the present invention is not limited to the following embodiments. In the following description, a large number of specific details are provided in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details.

[0032] The present invention relates to the yeast of the present invention Saccharomycopsis fibuligera )CICC 33377, CICC1803 and Saccharomyces cerevisiae ( Saccharomyces cerevisiae ) CICC 1445, the depository is China Industrial Microbiological Culture Collection Center; the Saccharomyces cerevisiae ( Saccharomycopsis fibuligera )CCTCCC CB20081663 and CCTCC DY 20081403, the depository is China Center for Type Culture Collection; Malanga spore yeast ( Saccharomycopsis malanga ) ATCC 36237 and Saccharomyces cerevisiae fermentans ( Saccharomycopsis fermentans ) CBS 7830 were purchased from Wuhan Huizao Biotechnology Co., Ltd. The above strains were purchased in the form of freeze-dried powder.

[0033] Example 1: A method for preparing a fermentation broth of Saccharomyces cerevisiae, comprising the following steps:

[0034] The strains shown in Table 1 were activated in PDB medium and cultured at 30°C and 150rpm for 36 hours to serve as seed solution; wherein the PDB medium contained 0.4% potato extract powder, 2% glucose, and the balance water by mass percentage, and was sterilized by high pressure at 121°C for 20 minutes;

[0035] The seed liquid is inoculated into the fermentation medium at an inoculation rate of 2%, and the fermentation is carried out at 28° C. and 150 rpm for 72 hours, and the fermentation is terminated to obtain the fermentation liquid of the Solanum cingulatum complex. The fermentation medium comprises, by mass percentage, 2% rice bran powder, 0.1% potato extract, 0.5% glucose, and the balance is water, and the medium is sterilized at high temperature at 121° C. for 20 minutes.

[0036] The fermentation liquid of Saccharomyces cerevisiae was sterilized at 115°C for 20 minutes, and the alcohol produced during the fermentation process was removed;

[0037] Use a disc centrifuge to remove insoluble residual fermentation substrates and the yeast cells of the cysticercus complex multiplied during the fermentation process;

[0038] The insoluble matter was further removed by filtering through a plate and frame filter using a 0.22 μm filter membrane to obtain a clarified Saccharomyces cerevisiae fermentation broth.

[0039] Embodiment 2: A method for preparing a fermentation broth of Saccharomyces cerevisiae, comprising the following steps:

[0040] The strains shown in Table 1 were activated in PDB medium and cultured at 25°C and 200 rpm for 32 hours to serve as seed solution; wherein the PDB medium contained 0.5% potato extract powder, 1.8% glucose, and the remainder water by mass percentage, and was sterilized by high pressure at 121°C for 20 minutes;

[0041] The seed liquid is inoculated into a fermentation medium at an inoculation rate of 2%, and the fermentation is carried out at 25° C. and 200 rpm for 84 hours, and the fermentation is terminated to obtain a fermentation liquid of Saccharomyces cerevisiae; wherein the fermentation medium comprises, by mass percentage, 2% rice bran powder, 0.3% potato extract, 1% glucose, and the balance is water, and the medium is sterilized at high temperature at 121° C. for 20 minutes;

[0042] The fermentation liquid of Saccharomyces cerevisiae was sterilized at 115°C for 20 minutes, and the alcohol produced during the fermentation process was removed;

[0043] Use a disc centrifuge to remove insoluble residual fermentation substrates and the yeast cells of the cysticercus complex multiplied during the fermentation process;

[0044] The insoluble matter was further removed by filtering through a plate and frame filter using a 0.22 μm filter membrane to obtain a clarified fermentation broth of Saccharomyces cerevisiae.

[0045] Embodiment 3: A method for preparing a fermentation broth of Saccharomyces cerevisiae, comprising the following steps:

[0046] The strains shown in Table 1 were activated in PDB medium, and cultured at 28°C and 120 rpm for 48 hours to serve as seed solution; wherein the PDB medium contained 0.7% potato extract powder, 1.5% glucose, and the remainder water by mass percentage, and was sterilized by high pressure at 121°C for 20 minutes;

[0047] The seed liquid is inoculated into the fermentation medium at an inoculation rate of 2%, and the fermentation is carried out at 30° C. and 120 rpm for 90 hours, and the fermentation is terminated to obtain the fermentation liquid of the Solanum cingulatum complex; wherein the fermentation medium comprises, by mass percentage, 2% rice bran powder, 0.5% potato extract, 1.5% glucose, and the balance is water, and the medium is sterilized at high temperature at 121° C. for 20 minutes;

[0048] The fermentation liquid of Saccharomyces cerevisiae was sterilized at 115°C for 20 minutes, and the alcohol produced during the fermentation process was removed;

[0049] Use a disc centrifuge to remove insoluble residual fermentation substrates and the yeast cells of the cysticercus complex multiplied during the fermentation process;

[0050] The insoluble matter was further removed by filtering through a plate and frame filter using a 0.22 μm filter membrane to obtain a clarified fermentation broth of Saccharomyces cerevisiae.

[0051] Example 4: A method for preparing a fermentation broth of Saccharomyces cerevisiae, comprising the following steps:

[0052] The strains shown in Table 1 were activated in PDB medium and cultured at 26°C and 180 rpm for 40 h to serve as seed solution; wherein the PDB medium contained 1.0% potato extract powder, 2% glucose, and the balance water by mass percentage, and was sterilized by high pressure at 121°C for 20 min;

[0053] The seed liquid is inoculated into the fermentation medium at an inoculation rate of 2%, and the fermentation is carried out under the conditions of 26°C and 180rpm for 60 hours, and the fermentation is terminated to obtain the fermentation liquid of the Solanum cingulatum complex; wherein the fermentation medium comprises, by mass percentage, 2% rice bran powder, 1% potato extract, 2% glucose, and the balance is water, and the medium is sterilized at high temperature at 121°C for 20 minutes;

[0054] The fermentation liquid of Saccharomyces cerevisiae was sterilized at 115°C for 20 minutes, and the alcohol produced during the fermentation process was removed;

[0055] Use a disc centrifuge to remove insoluble residual fermentation substrates and the yeast cells of the cysticercus complex multiplied during the fermentation process;

[0056] The insoluble matter was further removed by filtering through a plate and frame filter using a 0.22 μm filter membrane to obtain a clarified Saccharomyces cerevisiae fermentation broth.

[0057] Comparative Example 1: Compared with Example 1, only the strains were replaced, and the specific selections are shown in Table 1.

[0058] Comparative Example 2: Compared with Example 1, only the strains were replaced, and the specific selections are shown in Table 1.

[0059] Comparative Example 3: Compared with Example 1, only the strains were replaced, and the specific selections are shown in Table 1.

[0060] Comparative Example 4: Compared with Example 1, only the rice bran powder in the fermentation medium was replaced, and the specific selection is shown in Table 1.

[0061] Comparative Example 5: Compared with Example 1, only the rice bran powder in the fermentation medium was replaced, and the specific selection is shown in Table 1.

[0062] The γ-oryzanol content of the Saccharomyces cerevisiae fermentation broth obtained in the above Examples 1-4 and Comparative Examples 1-5 was respectively detected.

[0063] The detection method of γ-oryzanol was carried out according to the HPLC method described in the literature (Gong Yuansheng, Yao Huiyuan. Research on the determination method of γ-oryzanol in rice bran [J]. Journal of Henan University of Technology (Natural Science Edition), 2001, 22(001):28-31.).

[0064] The fermentation strains, main fermentation substrates, and the content of γ-oryzanol in the fermentation broth used in Examples 1-4 and Comparative Examples 1-5 are shown in Table 1.

[0065] Table 1 Fermentation strains, main fermentation substrates and γ-oryzanol content in fermentation broth

[0066]

[0067] The above results show that the content of γ-oryzanol in the fermentation liquid obtained by combining the selected Saccharomyces cerevisiae strains CICC 33377, CICC 1803, CCTCCCB 20081663 or CCTCC DY 20081403 of the present invention with rice bran powder as the main fermentation substrate after fermentation is much higher than that of the combination of rice bran powder fermented by other yeast strains and non-rice bran powder fermented by Saccharomyces cerevisiae, which indicates that the selected Saccharomyces cerevisiae strains of the present invention can more efficiently extract γ-oryzanol from rice bran powder by fermentation, and the effect is remarkable.

[0068] Efficacy evaluation

[0069] 1. Antioxidant test

[0070] Take 5.0 mg of DPPH, add an appropriate amount of anhydrous ethanol to dissolve, and then use anhydrous ethanol to make it fully dissolved. Then use anhydrous ethanol to make the volume to 100 ml to prepare a 50.0 μg / ml DPPH solution. Take anhydrous ethanol as a blank control, take 2 ml of the blank control liquid and the sample solution to be tested, add 2 ml of DPPH solution, mix well, let stand at room temperature for 30 minutes, and measure the absorbance at 517 nm.

[0071] DPPH free radical scavenging rate calculation formula: scavenging rate (%) = [1-(A1-A2)] / A3×100%

[0072] Where:

[0073] A1: absorbance value of the sample solution added to the DPPH solution;

[0074] A2: absorbance value of the sample solution added to anhydrous ethanol;

[0075] A3: The absorbance value of adding anhydrous ethanol to DPPH solution.

[0076] For the results of the antioxidant experiments, please refer to Figure 1 .

[0077] Figure 1 The results show that the DPPH free radical scavenging rates of Examples 1-4 using the Saccharomyces cerevisiae strain CICC 33377, CICC 1803, CCTCCCB 20081663 or CCTCC DY 20081403 of the present invention as fermentation strains and rice bran powder as the main fermentation substrate are all as high as 60% or more, showing excellent antioxidant effects. In these four groups of Examples, the content of γ-oryzanol in the fermentation broth is far greater than that of Comparative Examples 1-5, indicating that the increase in the content of γ-oryzanol is likely to greatly improve the antioxidant capacity of the fermentation broth. In contrast, in Comparative Examples 1-3, which use Saccharomyces cerevisiae, Saccharomyces cerevisiae and Saccharomyces cerevisiae as fermentation strains, and also use rice bran powder as the main fermentation substrate, and Comparative Examples 4-5, which use Saccharomyces cerevisiae strains as fermentation strains, do not use rice bran powder as the main fermentation substrate, but add brown rice flour and white rice flour respectively, the γ-oryzanol in the fermentation broth is significantly lower than that in the embodiments, and the antioxidant capacity is also significantly weaker.

[0078] 2. Expression of FLG gene

[0079] Filaggrin (FLG) in the epidermis can decompose to form a small molecule complex natural moisturizing factor (NMF) with water-absorbing properties, which can effectively absorb and lock in moisture, cooperate with the protection of keratin cell structure, and strengthen the water-locking barrier.

[0080] Human keratinocytes (Hacat) were cultured at 4.0 × 10 5 / well were inoculated on a 6-well cell culture plate and cultured in a CO2 incubator at 37°C for 24 hours. The cells were divided into a blank control group and a sample treatment group. The blank control group was added with 1% saline, and the sample treatment groups were added with 1% of the fermentation solution to be tested and incubated for another 24 hours. RNA was extracted according to the instructions of the RNA extraction kit and its purity and concentration were tested. RNA was used as a template for reverse transcription into cDNA. RT-PCR was then used to detect the expression of the target gene, with GAPDH as the housekeeping gene. For the expression level of the target gene filaggrin gene (FLG), please refer to Figure 2 .

[0081] Figure 2The results show that the examples 1-4 using the spore yeast strain CICC 33377, CICC 1803, CCTCCCB 20081663 or CCTCC DY 20081403 of the present invention as fermentation strains and rice bran powder as the main fermentation substrate can promote the expression of the filaggrin gene FLG to a large extent, thereby helping to moisturize the skin and improve the barrier function. In contrast, the expression level of the filaggrin gene FLG in the comparative examples 1-3 using the spore yeast of Malanga, the fermentation spore yeast and the saccharomyces cerevisiae as fermentation strains and rice bran powder as the main fermentation substrate is significantly lower than that in the examples; the expression level of the filaggrin gene FLG in the comparative examples 4-5 using the spore yeast strain of spore yeast as fermentation strains and not using rice bran powder as the main fermentation substrate, but adding brown rice flour and white rice flour respectively, is also not significantly improved. These indicate that the specific Saccharomyces cerevisiae strain selected in the present invention can better extract the active ingredients in rice bran powder through its own metabolic activity, thereby obtaining a fermentation liquid with excellent moisturizing and skin barrier enhancement effects.

[0082] 3. Expression of hyaluronan synthase 1 (HAS1), hyaluronan synthase 2 (HAS2), and hyaluronan synthase 3 (HAS3) genes

[0083] Hyaluronic acid has a regulatory effect on epidermal proliferation and water retention. Hyaluronic acid is produced on the plasma membrane by hyaluronic acid synthase using UDP-glucuronic acid and UDP-N-acetylglucosamine in the cytoplasm as substrates. There are three types of hyaluronic acid synthase in the skin, namely HAS1, HAS2 and HAS3.

[0084] Human keratinocytes (Hacat) were cultured at 4.0 × 10 5 / well were inoculated on a 6-well cell culture plate and cultured in a CO2 incubator at 37°C for 24 hours. The cells were divided into a blank control group and a sample treatment group. The blank control group was added with 1% normal saline, and the sample treatment groups were added with 1% of the fermentation solution to be tested, and the cells were incubated for another 24 hours. RNA was extracted according to the instructions of the RNA extraction kit and its purity and concentration were tested. RNA was used as a template for reverse transcription into cDNA. Subsequently, the expression of the target gene was detected by RT-PCR, with GAPDH as the housekeeping gene. For the expression levels of the target gene hyaluronan synthase HAS1, HAS2, and HSA3, please refer to Figure 3 .

[0085] Figure 3The results show that Examples 1-4 using the Saccharomyces cerevisiae strain CICC 33377, CICC 1803, CCTCCCB 20081663 or CCTCC DY 20081403 of the present invention as the fermentation strain and rice bran powder as the main fermentation substrate can also significantly promote the expression of hyaluronic acid synthase genes (HAS1, HAS2, HAS3), especially the expression of HAS1, thereby significantly improving the skin's water retention capacity. In contrast, in Comparative Examples 1-3, which use Saccharomyces cerevisiae, Saccharomyces cerevisiae and Saccharomyces cerevisiae as fermentation strains and also use rice bran powder as the main fermentation substrate, the expression levels of hyaluronan synthase genes (HAS1, HAS2, HAS3) are significantly lower than those in the embodiment; in Comparative Examples 4-5, which use Saccharomyces cerevisiae as fermentation strains and do not use rice bran powder as the main fermentation substrate, but add brown rice powder and white rice powder respectively, the expression levels of hyaluronan synthase genes (HAS1, HAS2, HAS3) do not show a significant improvement. The above results show that the Saccharomyces cerevisiae strains CICC 33377, CICC 1803, CCTCC CB 20081663 or CCTCC DY20081403 selected by the present invention can better extract the active ingredients in rice bran powder through their own metabolic activities, thereby obtaining a fermentation liquid with excellent skin moisture retention effect.

[0086] In summary, the present invention extracts beneficial ingredients in rice bran, especially γ-oryzanol, at a higher level through the metabolic activity of specific Saccharomyces cerevisiae, thereby improving the economic value of rice bran. The obtained Saccharomyces cerevisiae fermentation liquid has excellent antioxidant and moisturizing effects, and has good application prospects in cosmetics.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in the field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for preparing a fermentation broth of Saccharomyces cerevisiae, characterized in that: include: The yeast is a strain of Saccharomyces cerevisiae, wherein the yeast is one of the Saccharomyces cerevisiae strains CICC 33377, CICC 1803, CCTCC CB 20081663 and CCTCC DY 20081403. Fermentation is performed in a culture medium containing rice bran powder to obtain a fermentation liquid of Saccharomyces cerevisiae, wherein the culture medium comprises, by mass percentage, 2% rice bran powder, 0.1-1% potato extract, 0.5-2% glucose, and the balance is water, and sterilized at 121° C. for 20 minutes; The fermentation process parameters include: the inoculation amount of the seed liquid of the spore-forming yeast is 2%, the fermentation temperature is 25-30° C., the stirring speed is 120-200 rpm, and the culture time is 72-90 hours; The seed liquid of the spore yeast is prepared by the following method: using PDB culture medium to activate the spore yeast, the PDB culture medium contains 0.4-1% potato extract powder, 1.5-2% glucose, and the balance is water, and sterilizing by high pressure at 121° C. for 20 minutes. The activation culture conditions are temperature 25-30° C., rotation speed 120-200 rpm, and fermentation for 32-48 hours. The method also includes: sterilizing the fermentation liquid of Saccharomyces cerevisiae at a high temperature of 115° C. for 20 minutes, and removing alcohol at the same time; centrifuging the sterilized fermentation product and filtering it with a 0.22 μm filter membrane to obtain a clarified fermentation liquid of Saccharomyces cerevisiae.

2. The method for preparing a fermentation broth of Saccharomyces cerevisiae as claimed in claim 1, characterized in that: The inoculation amount of the seed liquid of the Saccharomyces cerevisiae is 2%, the fermentation temperature is 28° C., the stirring speed is 150 rpm, and the culture time is 72 hours.

3. Use of the fermented broth of Saccharomyces cerevisiae obtained by the method for preparing the fermented broth of Saccharomyces cerevisiae as claimed in claim 1 or 2 in cosmetics, wherein the cosmetics have antioxidant and moisturizing effects.

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