Method for preparing carotenoid from rhodotorula and application of carotenoid

Abstract

The invention relates to the technical field of microorganisms, and discloses a method for preparing carotenoid from rhodotorula and application, the method comprises the following steps: culturing rhodotorula in a fermentation medium, and culturing for 4 days under blue light; the fermentation culture medium comprises glucose, yeast powder, peptone, malt extract, monopotassium phosphate, magnesium sulfate, riboflavin and vitamin B. The mass concentration of the glucose in the fermentation culture medium is 20 g / L, the mass concentration of the yeast powder is 5 g / L, the mass concentration of the peptone is 5 g / L, the mass concentration of the malt extract is 3 g / L, and the mass concentration of the monopotassium phosphate is 3 g / L. The mass concentration of magnesium sulfate is 3g / L, the mass concentration of riboflavin is 3.6 mg / L, and the mass concentration ratio of riboflavin to vitamin B is 7: 3. A liquid culture method is adopted, so that the yield of carotenoid produced by the rhodotorula is increased.

Description

[0001] This application claims priority to Chinese patent application No. 2024114272912 filed on October 14, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present invention relates to the technical field of microorganisms, and in particular to a method and application of red yeast for preparing carotenoids. Background Art

[0003] Carotenoids are a general term for an important class of natural pigments, commonly found in yellow, orange-red, or red pigments found in animals, higher plants, fungi, and algae. Carotenoids are the primary source of vitamin A in the body and also possess antioxidant, immunomodulatory, anti-cancer, and anti-aging properties.

[0004] Currently, some researchers have used blue light to encourage red yeast to produce more carotenoids. Although this has increased carotenoid production, it has also resulted in a decrease in the number of viable red yeast cells. Therefore, using blue light to increase red yeast carotenoid production is not a sustainable process. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a method and application of red yeast for preparing carotenoids. The culture method of the present invention can solve the damage caused by blue light, so that red yeast can sustainably produce more carotenoids.

[0006] The present invention provides a method for preparing carotenoids by using red yeast, the method comprising: culturing red yeast in a fermentation medium under blue light for 4 days; The fermentation medium comprises glucose, yeast powder, peptone, malt extract, potassium dihydrogen phosphate, magnesium sulfate, riboflavin, and vitamin B. The mass concentration of glucose in the fermentation medium is 20 g / L, the mass concentration of yeast powder is 5 g / L, the mass concentration of peptone is 5 g / L, the mass concentration of malt extract is 3 g / L, the mass concentration of potassium dihydrogen phosphate is 3 g / L, the mass concentration of magnesium sulfate is 3 g / L, and the mass concentration of riboflavin is 3.6 mg / L. The mass concentration ratio of riboflavin to vitamin B is 9-5:1-5.

[0007] Furthermore, the red yeast is BNCC119738.

[0008] Furthermore, the mass concentration ratio of riboflavin to vitamin B in the fermentation medium is selected from one of 9:1, 7:3, and 1:1.

[0009] Furthermore, the mass concentration ratio of riboflavin to vitamin B in the fermentation medium is 7:3.

[0010] Furthermore, the vitamin B includes one or more of vitamin B1 and vitamin B6.

[0011] Furthermore, the vitamin B is vitamin B1 and vitamin B6.

[0012] Furthermore, based on mass concentration, the ratio of vitamin B1 to vitamin B6 is (1-7):(1-7).

[0013] Furthermore, based on mass concentration, the ratio of vitamin B1 to vitamin B6 is selected from one of 1:1, 3:7 and 7:3.

[0014] Furthermore, based on mass concentration, the ratio of vitamin B1 to vitamin B6 is 7:3.

[0015] Furthermore, the intensity of the blue light is 1000 lux, and the blue light irradiation time is 4 days.

[0016] Furthermore, the pH value of the fermentation medium is 6-6.4.

[0017] Furthermore, the fermentation culture conditions also include aerobic culture at 30°C.

[0018] Furthermore, before culturing the red yeast in the fermentation medium, the red yeast needs to be activated in the YM medium.

[0019] Furthermore, the components of the YM medium include 3 g / L yeast extract, 3 g / L malt extract, 10 g / L glucose, and 5 g / L peptone.

[0020] Furthermore, the pH value of the YM medium is 6-6.4.

[0021] Furthermore, the activation conditions include culturing at 30° C. for 24-48 hours under aerobic conditions.

[0022] Furthermore, after the red yeast was activated in the YM medium, it was inoculated into the fermentation medium for culture, and the YM medium in which the red yeast was activated was transferred to the fermentation medium, with the volume ratio of the transferred YM medium to the fermentation medium being 4%.

[0023] The present invention also provides the method for preparing carotenoids by using red yeast and the application of the method in producing carotenoids.

[0024] The embodiments of the present invention have the following technical effects: 1. In the present invention, through the design and selection of a liquid culture medium, blue light stimulates the carotenoid synthesis pathway of red yeast in the liquid culture medium, thereby advantageously increasing carotenoid production. Riboflavin and vitamin B are also added to the culture medium of the present invention to stimulate the red yeast metabolic pathway and the growth of red yeast. This not only alleviates the damage caused by blue light to the yeast, promotes the rapid growth of red yeast in the liquid culture medium, and increases the number of viable red yeast cells in the liquid culture medium, but also riboflavin and vitamin B can also increase carotenoid production.

[0025] 2. In the present invention, by further selecting the mass concentration ratio between riboflavin and vitamin B, as well as the blue light irradiation time and intensity, not only the viable bacterial count of red yeast is further increased, but also the yield of carotenoids is further increased. DETAILED DESCRIPTION

[0026] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are also within the scope of protection of the present invention.

[0027] In a first aspect, some embodiments of the present invention provide a method for preparing carotenoids using red yeast, the method comprising: culturing red yeast in a fermentation medium under blue light for 4 days; The fermentation medium includes glucose, yeast powder, peptone, malt extract, potassium dihydrogen phosphate, magnesium sulfate, riboflavin, and vitamin B. The mass concentration of glucose in the fermentation medium is 20 g / L, the mass concentration of yeast powder is 5 g / L, the mass concentration of peptone is 5 g / L, the mass concentration of malt extract is 3 g / L, the mass concentration of potassium dihydrogen phosphate is 3 g / L, the mass concentration of magnesium sulfate is 3 g / L, and the mass concentration of riboflavin is 3.6 mg / L. The mass concentration ratio of riboflavin to vitamin B is (9-5):(1-5).

[0028] In some embodiments, the red yeast is BNCC119738.

[0029] In some embodiments, the mass concentration ratio of riboflavin to vitamin B in the fermentation medium is selected from one of 9:1, 7:3, and 1:1.

[0030] In some embodiments, the mass concentration ratio of riboflavin to vitamin B in the fermentation medium is 7:3.

[0031] In the present invention, when the mass concentration ratio of riboflavin to vitamin B in the fermentation medium is 7:3, the synthesis of carotenoids by red yeast and the growth of living bacteria are promoted.

[0032] In some embodiments, the vitamin B includes one or more of vitamin B1 and vitamin B6.

[0033] In some embodiments, the vitamin B is vitamin B1 and vitamin B6.

[0034] In some embodiments, the ratio of vitamin B1 to vitamin B6 is (1-7):(1-7) based on mass concentration.

[0035] In some embodiments, the ratio of vitamin B1 to vitamin B6 is selected from one of 1:1, 3:7 and 7:3 based on mass concentration.

[0036] In some embodiments, the ratio of vitamin B1 to vitamin B6 is 7:3 based on mass concentration.

[0037] Riboflavin and vitamin B can work synergistically from multiple dimensions to alleviate the damage caused by blue light to yeast cells.

[0038] On the one hand, riboflavin itself possesses antioxidant properties, capable of scavenging ROS and maintaining redox homeostasis. Riboflavin is also a photosensitive molecule that absorbs blue light energy and releases it as heat, reducing the generation of ROS that would otherwise be generated by transferring that energy to other molecules. Riboflavin is a precursor of flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN). FAD / FMN participate in the composition of antioxidant enzymes (such as catalase and glutathione reductase), directly scavenging H₂O₂ and regenerating reduced glutathione (GSH), thereby maintaining intracellular antioxidant capacity. Studies have shown that riboflavin supplementation can increase GSH levels in yeast cells and reduce the levels of blue light-induced lipid peroxidation products (such as malondialdehyde). Furthermore, vitamin B1 is involved in regulating the activity of intracellular antioxidant systems. For example, it may affect the synthesis or activity of certain antioxidant enzymes (such as superoxide dismutase (SOD) and catalase (CAT), enhancing the cell's ability to scavenge ROS. Studies have shown that vitamin B6 deficiency can lead to increased sensitivity of cells to oxidative stress, while vitamin B6 supplementation can enhance the antioxidant capacity of cells and reduce blue light-induced ROS accumulation.

[0039] On the other hand, blue light-induced lipid peroxidation can disrupt cell membrane integrity and fluidity. B vitamins can maintain cell integrity. The B vitamin complex may inhibit lipid peroxidation or participate in the synthesis and repair of cell membrane lipids, maintaining normal cell membrane structure and function, thereby mitigating blue light-induced cellular damage. For example, vitamin B1 regulates energy metabolism and maintains ATP supply during cellular stress. Thiamine pyrophosphate (TPP) is a coenzyme of the pyruvate dehydrogenase and α-ketoglutarate dehydrogenase complexes, driving the entry of glycolysis products into the tricarboxylic acid cycle, ensuring cellular energy supply during blue light stress and preventing repair dysfunction caused by ATP deficiency. Studies have shown that vitamin B1 deficiency exacerbates the blue light-induced decrease in yeast mitochondrial membrane potential, while vitamin B1 supplementation can maintain mitochondrial integrity. Vitamin B2 participates in the cell cycle and regulates stress responses. FAD, derived from vitamin B2, acts as a transcription factor cofactor, regulating the expression of stress-related genes such as heat shock proteins (HSPs) and antioxidant enzymes, thereby enhancing cellular tolerance to blue light. Niacin via NAD + Dependent deacetylases (such as Sir2) inhibit the expression of pro-apoptotic genes and reduce blue light-induced programmed cell death. For example, in Saccharomyces cerevisiae, the addition of vitamin B complex can increase cell survival after blue light irradiation.

[0040] Finally, riboflavin, vitamins B1, and B6 act synergistically in cellular metabolism, participating in processes such as cellular metabolism, energy production, antioxidant defense, and cell repair. Riboflavin can work synergistically with glutathione (GSH), vitamins B1, and B6. For example, the ROS generated by riboflavin may promote the redox cycle of GSH (GSH→GSSG→GSH), enhancing the cell's overall free radical scavenging capacity and forming a multi-layered antioxidant defense. Vitamin B1's involvement in glucose metabolism provides energy and intermediates for vitamin B6's involvement in amino acid metabolism and nucleic acid synthesis. In turn, the antioxidant system and protein synthesis regulated by vitamin B6 support the physiological functions of vitamin B1. These interactions effectively mitigate blue light damage to yeast cells.

[0041] In some embodiments, the intensity of the blue light is 1000 lux, and the blue light irradiation time is 4 days.

[0042] In some embodiments, the pH value of the fermentation medium is 6-6.4.

[0043] In some embodiments, the fermentation culture conditions further include aerobic culture at 30°C.

[0044] In some embodiments, before culturing red yeast in a fermentation medium, it is necessary to activate the red yeast in a YM medium.

[0045] In some embodiments, the YM medium comprises 3 g / L yeast extract, 3 g / L malt extract, 10 g / L glucose, and 5 g / L peptone.

[0046] In some embodiments, the pH value of the YM medium is 6-6.4.

[0047] In some embodiments, the activation conditions include culturing at 30° C. for 24-48 hours under aerobic conditions.

[0048] In some embodiments, red yeast is activated in YM medium and then inoculated into fermentation medium for culture. The activated YM medium is transferred to the fermentation medium, and the volume ratio of the transferred YM medium to the fermentation medium is 4%.

[0049] In a second aspect, some embodiments of the present invention further provide the use of the method for preparing carotenoids using red yeast in the production of carotenoids.

[0050] The following is described in conjunction with some specific embodiments: Red yeast activation process: Red yeast (BNCC119738) was inoculated into YM medium (3 g / L yeast extract, 3 g / L malt extract, 10 g / L glucose, 5 g / L peptone, and distilled water) with a pH of 6-6.4. The medium was sterilized at 121°C for 20 minutes and then aerobically incubated at 30°C for 48 hours to activate the red yeast.

[0051] Example 1: Prepare a fermentation medium containing 5g yeast powder, 20g glucose, 5g peptone, 3g malt extract, 3g potassium dihydrogen phosphate, 3g magnesium sulfate, 3.6mg riboflavin, 1.54mg vitamin B (wherein the vitamin B consists of vitamin B1 and vitamin B6, with a mass concentration ratio of 7:3), and 1L distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 minutes. Transfer the activated red yeast YM medium to the sterilized fermentation medium at a volume ratio of 4% to the sterilized fermentation medium. Irradiate and culture the medium under a blue light intensity of 1000 lux at 30°C under aerobic conditions for 4 days.

[0052] Example 2: Prepare a fermentation medium containing 5g yeast powder, 20g glucose, 5g peptone, 3g malt extract, 3g potassium dihydrogen phosphate, 3g magnesium sulfate, 3.6mg riboflavin, 1.54mg vitamin B1, and 1L distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 minutes. Transfer the activated red yeast YM medium to the sterilized fermentation medium at a volume ratio of 4%. Incubate under irradiation at 1000 lux of blue light at 30°C for 4 days under aerobic conditions.

[0053] Example 3: Prepare a fermentation medium containing 5 g yeast powder, 20 g glucose, 5 g peptone, 3 g malt extract, 3 g potassium dihydrogen phosphate, 3 g magnesium sulfate, 3.6 mg riboflavin, 1.54 mg vitamin B6, and 1 L distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 min. Transfer the activated red yeast YM medium to the sterilized fermentation medium at a volume ratio of 4% to the sterilized fermentation medium. Irradiate and culture under a blue light intensity of 1000 lux, 30°C, and aerobic conditions for 4 days.

[0054] Example 4: Prepare a fermentation medium containing 5 g yeast powder, 20 g glucose, 5 g peptone, 3 g malt extract, 3 g potassium dihydrogen phosphate, 3 g magnesium sulfate, 3.6 mg riboflavin, 1.54 mg vitamin B (wherein the vitamin B consists of vitamin B1 and vitamin B6, with a mass concentration ratio of 1:1), and 1 L of distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 min. Transfer the activated red yeast YM medium to the sterilized fermentation medium at a volume ratio of 4% to the sterilized fermentation medium. Irradiate and culture the medium under a blue light intensity of 1000 lux, 30°C, and aerobic conditions for 4 days.

[0055] Example 5: Prepare a fermentation medium containing 5 g yeast powder, 20 g glucose, 5 g peptone, 3 g malt extract, 3 g potassium dihydrogen phosphate, 3 g magnesium sulfate, 3.6 mg riboflavin, 1.54 mg vitamin B (wherein the vitamin B consists of vitamin B1 and vitamin B6, with a mass concentration ratio of 3:7), and 1 L of distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 min. Transfer the activated red yeast YM medium to the sterilized fermentation medium at a volume ratio of 4% to the sterilized fermentation medium. Irradiate and culture the medium under a blue light intensity of 1000 lux at 30°C under aerobic conditions for 4 days.

[0056] Comparative Example 1: Prepare a fermentation medium containing 5 g yeast powder, 20 g glucose, 5 g peptone, 3 g malt extract, 3 g potassium dihydrogen phosphate, 3 g magnesium sulfate, and 1 L distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 minutes. Transfer the activated red yeast YM medium to the sterilized fermentation medium at a volume ratio of 4% to the sterilized fermentation medium. Incubate at 30°C under aerobic conditions for 4 days in the dark.

[0057] Comparative Example 2: Prepare a fermentation medium containing 5 g yeast powder, 20 g glucose, 5 g peptone, 3 g malt extract, 3 g potassium dihydrogen phosphate, 3 g magnesium sulfate, and 1 L distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 min. Transfer the activated red yeast YM medium to the sterilized fermentation medium at a volume ratio of 4%. Incubate under irradiation at 1000 lux of blue light at 30°C under aerobic conditions for 4 days.

[0058] Comparative Example 3: Activation process for Phaffia rhodozyma: Phaffia rhodozyma strain BNCC336673 was inoculated into YM medium (3 g / L yeast extract, 3 g / L malt extract, 10 g / L glucose, 5 g / L peptone, and distilled water). The medium had a pH of 6-6.4 and was sterilized at 121°C for 20 minutes. The yeast was then activated by incubation at 22°C for 48 hours under aerobic conditions.

[0059] Prepare a fermentation medium containing 5 g of yeast powder, 20 g of glucose, 5 g of peptone, 3 g of malt extract, 3 g of potassium dihydrogen phosphate, 3 g of magnesium sulfate, and 1 L of distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 minutes. Transfer the activated YM medium containing Phaffia rhodozyma to the sterilized fermentation medium at a volume ratio of 4% between the transferred YM medium and the sterilized fermentation medium. Incubate the medium at 30°C under aerobic conditions for 4 days in the dark.

[0060] Comparative Example 4: Activation process for Phaffia rhodozyma: Phaffia rhodozyma strain BNCC336673 was inoculated into YM medium (3 g / L yeast extract, 3 g / L malt extract, 10 g / L glucose, 5 g / L peptone, and distilled water). The medium had a pH of 6-6.4 and was sterilized at 121°C for 20 minutes. The yeast was then activated by incubation at 22°C for 48 hours under aerobic conditions.

[0061] Prepare a fermentation medium containing 5 g of yeast powder, 20 g of glucose, 5 g of peptone, 3 g of malt extract, 3 g of potassium dihydrogen phosphate, 3 g of magnesium sulfate, and 1 L of distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 minutes. Transfer the activated YM medium containing Phaffia rhodozyma to the sterilized fermentation medium at a volume ratio of 4%. Irradiate and culture the medium under a blue light intensity of 1000 lux at 30°C under aerobic conditions for 4 days.

[0062] Comparative Example 5: Activation process for Phaffia rhodozyma: Phaffia rhodozyma strain BNCC336673 was inoculated into YM medium (3 g / L yeast extract, 3 g / L malt extract, 10 g / L glucose, 5 g / L peptone, and distilled water). The medium had a pH of 6-6.4 and was sterilized at 121°C for 20 minutes. The yeast was then activated by incubation at 22°C for 48 hours under aerobic conditions.

[0063] Prepare a fermentation medium containing 5g yeast powder, 20g glucose, 5g peptone, 3g malt extract, 3g potassium dihydrogen phosphate, 3g magnesium sulfate, 3.6mg riboflavin, 1.54mg vitamin B (wherein the vitamin B consists of vitamin B1 and vitamin B6, with a mass concentration ratio of 7:3), and 1L distilled water. Adjust the pH of the fermentation medium to 6.2 and sterilize at 121°C for 20 minutes. Transfer the activated YM medium containing Phaffia rhodozyma to the sterilized fermentation medium at a volume ratio of 4% to the sterilized fermentation medium. Irradiate and culture the medium under a blue light intensity of 1000 lux, 30°C, and aerobic conditions for 4 days.

[0064] The embodiments and comparative examples were tested: Biomass test method: dry weight weighing method, take 5 mL of bacterial solution and centrifuge at 8000 rpm for 10 minutes, then wash twice with deionized water to obtain wet bacteria, and dry them at 60°C.

[0065] Pipette 1mL of fermentation liquid into a 10mL centrifuge tube, dilute it to an appropriate multiple, take 2 / 3 of the bacterial liquid into a cuvette, and measure the OD using a UV spectrophotometer. 600 , the measurement range is between 0.01-0.9, and the biomass of the fermentation broth is calculated.

[0066] Test method for carotenoid production: Take 2mL of fermentation broth in a 10mL centrifuge tube, centrifuge at 8000rpm for 10min, collect the bacteria, wash three times with sterile water, and discard the supernatant. Then add 4mL of freshly prepared 3mol / L hydrochloric acid solution to the washed bacteria, shake and soak for 30min to acidify the yeast cell wall, heat in boiling water for 4min, and when the bacteria appear flocculent, quickly place in ice water to cool. Centrifuge the acid-heat treated and cooled broken cells at 8000rpm for 10min, collect the precipitate, and wash it two or three times with distilled water, pour out the supernatant, add 4mL of acetone and shake and extract for 5min in the dark, centrifuge at 8000rpm for 10min, take a certain amount of supernatant and dilute it a certain number of times, and measure the absorbance A value of the acetone extract at 450nm on a spectrophotometer; if the extraction is incomplete, add acetone again to extract until the bacteria are colorless. Calculate the carotenoid production using the following formula: Carotenoid yield per unit volume of fermentation broth (μg / mL) = ; Total carotenoid production per unit volume of fermentation broth = carotenoid content per unit volume of fermentation broth × W; Where: A—absorbance of carotenoid at maximum wavelength; D—dilution multiple of pigment extract; V—total volume of solvent used for extraction (mL); W—volume of fermentation broth used for extraction (mL); 0.16—Molar extinction coefficient of carotenoids.

[0067] Results and Analysis: Table 1 Biomass test results of Examples and Comparative Examples Table 2 Carotenoid yield test results of Examples and Comparative Examples In Table 2, a comparison of Comparative Examples 1-4 reveals that while blue light irradiation can increase carotenoid production in red yeast and Phaffia rhodozyma, it also inhibits their growth. This is due to blue light damage to yeast cells, which in turn hinders yeast growth, as demonstrated in Table 1. In Table 1, within 10 days of fermentation, the yeast biomass of Comparative Example 1 was significantly higher than that of Comparative Example 2. However, the addition of vitamin B can reduce blue light damage to yeast, thereby increasing yeast biomass. Within 10 days of fermentation, the biomass of Examples 1-3 was significantly higher than that of Comparative Examples 1-2.

[0068] It can be seen from Table 1 that the growth of yeast slows down with the increase of fermentation time. Therefore, the present invention studies the yield of carotenoids within 4 days of fermentation, as shown in Table 2.

[0069] Based on this, further research into the synergistic effects between other B vitamins and riboflavin revealed that, while all belong to the B vitamin family, the different structures and mechanisms of action of vitamin B contribute to the differences in their effects. A comparison of Examples 1 to 5 revealed that Example 1 exhibited superior effects. This may be due to the synergistic effect of vitamin B1, riboflavin, and vitamin B6, which can better mitigate the damage caused by blue light to yeast, thereby promoting yeast biomass growth and further increasing carotenoid production. Therefore, it is further preferred that the B vitamins be vitamin B1 and vitamin B6, with a mass concentration ratio of 7:3.

[0070] Finally, a comparison of Examples 1-5 with Comparative Examples 3-4 revealed that, although all yeasts were damaged by blue light, the effects were different due to the different yeasts. This suggests that the method of the present invention is more suitable for red yeast.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing carotenoids using red yeast rice, characterized in that: The method comprises: culturing red yeast in a fermentation medium under blue light for 4 days; The fermentation medium comprises glucose, yeast powder, peptone, malt extract, potassium dihydrogen phosphate, magnesium sulfate, riboflavin, and vitamin B, wherein the mass concentration of glucose in the fermentation medium is 20 g / L, the mass concentration of yeast powder is 5 g / L, the mass concentration of peptone is 5 g / L, the mass concentration of malt extract is 3 g / L, the mass concentration of potassium dihydrogen phosphate is 3 g / L, the mass concentration of magnesium sulfate is 3 g / L, the mass concentration of riboflavin is 3.6 mg / L, and the mass concentration ratio of riboflavin to vitamin B is 7:3; The vitamin B is vitamin B1 and vitamin B6; In terms of mass concentration, the ratio of vitamin B1 to vitamin B6 is (1-7):(1-7).

2. The method according to claim 1, characterized in that The red yeast is BNCC119738 from Beina Biotechnology.

3. The method according to claim 1, characterized in that The intensity of the blue light is 1000 lux, and the blue light irradiation time is 4 days.

4. The method according to claim 1, wherein The pH value of the fermentation medium is 6-6.4; the fermentation culture conditions also include being at 30° C. and requiring oxygen.

5. The method according to claim 1, wherein Before culturing red yeast in fermentation medium, it is necessary to activate red yeast in YM medium.

6. The method according to claim 1, characterized in that After being activated in YM medium, red yeast was inoculated into fermentation medium for cultivation. The YM medium for the activated red yeast was transferred to the fermentation medium. The volume ratio of the transferred YM medium to the fermentation medium was 4%.

7. Use of the method for preparing carotenoids using red yeast rice according to any one of claims 1 to 6 in the production of carotenoids.

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