Monascus production strain and application thereof
By using conventional solid-state fermentation of Monascus purpureus strain SZHQ089 and optimizing the fermentation medium, the production problem of high-color-value, citrinin-free red yeast rice was solved, achieving efficient improvement in red yeast rice color value and bacterial cellulose yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SHIJIAZHUANG VOCATIONAL TECH INST
- Filing Date
- 2026-03-03
- Publication Date
- 2026-05-29
Smart Images
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of microbial technology, specifically relating to a red yeast rice production strain, Monascus purpureus SZHQ089, and its applications. Background Technology
[0002] Red yeast rice, a traditional Chinese fermented product used in both food and medicine, is widely applied in the food and pharmaceutical industries. *Monascus purpureus* is the core strain for red yeast rice production, and the quality of its fermentation products is typically measured by the content of red yeast pigment (usually expressed as color value, unit u / g) and citrinin content. Red yeast rice can affect the coloring effect and application value of the product. Citrinin is a fungal toxin with nephrotoxicity and hepatotoxicity; its residue directly affects the safety of red yeast rice products for consumption. Therefore, various countries have established strict limits on the amount of citrinin in food.
[0003] However, existing Monascus purpureus strains and fermentation technologies face the challenge of simultaneously achieving high color value and low (or no) citrinin levels. On one hand, some strains, while yielding red yeast rice with high color value, produce citrinin during fermentation. For example, Monascus purpureus FJMR36, disclosed in Chinese patent CN108034591 A, produces red yeast rice with a color value of up to 7600 u / g, but this strain generates citrinin during fermentation, limiting its widespread application in the food industry. On the other hand, a few strains can achieve citrinin-free or extremely low citrinin fermentation, but this requires special fermentation processes and cannot be adapted to conventional production conditions. For example, the purple-red Monascus TY02 disclosed in Chinese patent CN110408545 A can achieve a color value of ≥7000 u / g and a citrinin content of <0.1 mg / kg, but it requires a liquid deep fermentation method. When conventional solid fermentation or ordinary liquid fermentation processes are used, its red yeast color value will drop significantly to around 2000 u / g, and the citrinin content will increase significantly, making it difficult to balance production efficiency, cost and product quality.
[0004] Furthermore, conventional fermentation processes offer advantages such as low equipment requirements, ease of operation, and controllable production costs, making them the mainstream method for industrial production of red yeast rice. Therefore, screening a strain of *Monascus purpureus* that requires no special fermentation process, achieves high color value under conventional fermentation conditions, and does not produce citrinin has significant industrial application value and market prospects. Summary of the Invention
[0005] To address the above problems, the present invention aims to provide a red yeast rice production strain, Monascus purpureus SZHQ089, and its applications.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: This invention first provides a red yeast rice production strain, Monascus purpureus SZHQ089, which was deposited on December 15, 2025, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing; the accession number is CGMCC No. 42476.
[0007] The purple-red Aspergillus SZHQ089 was derived from a vineyard.
[0008] The present invention also provides the application of the above-mentioned *Monascus purpureus* SZHQ089 in the preparation of red yeast rice.
[0009] This invention also provides a method for preparing red yeast rice using *Monascus purpureus* SZHQ089, the method comprising the following steps: (1) Inoculate the purple red Aspergillus strain SZHQ089 onto a plate medium and culture at 26~32℃ for 3~8 days; wash off the spores with sterile water, shake with glass beads and filter to obtain a spore suspension; (2) Inoculate the spore suspension into the seed culture medium and culture at 26-32℃ with shaking at 180-250 rpm for 24-30 h to obtain the seed solution; (3) Inoculate the cultured seed liquid into the solid fermentation medium at an inoculation rate of 2-5% (v / w) and incubate at 26-32℃ for 24-48h. (4) After the static culture is completed, mix thoroughly and add 2-8% (v / w) of sterile water to the solid fermentation medium. Continue to culture, and add an equal amount of sterile water every 24-48 hours and mix thoroughly until the fermentation is completed. The fermentation product is dried at 45-50℃ to obtain red yeast rice.
[0010] Furthermore, the plate culture medium in step (1) is composed of the following raw materials in parts by weight: glucose 55~65g / L, peptone 15~25g / L, soluble starch 25~35g / L, agar 15~20g / L, and the remainder is water.
[0011] Furthermore, the seed culture medium in step (2) is composed of the following raw materials in parts by weight: glucose 15~25g / L, yeast powder 4~6g / L, K2HPO4 0.5~1.5g / L, MgSO4 0.4~0.6g / L, NaCl 4~6g / L, CaCl 0.4~0.6g / L, glycerol 4~6g / L, corn steep liquor 0.5~1.5g / L, and the balance being water.
[0012] Furthermore, the preparation method of the solid-state fermentation medium in step (3) is as follows: Rice washed with tap water is soaked in a nutrient solution for 4-10 hours, drained, and then frozen at -18 to -22°C for 3-10 days. It is then thawed and sterilized at 120-125°C for 18-25 minutes. The nutrient solution consists of: 1.0 g / L corn steep liquor, 0.1 g / L K₂HPO₄, 0.5 g / L MgSO₄, with the remainder being water.
[0013] The present invention also provides a red yeast rice fermentation culture medium containing red yeast rice components, wherein the red yeast rice is obtained by fermentation of the aforementioned purple red yeast mold SZHQ089.
[0014] The present invention also provides a method for increasing the yield of bacterial cellulose synthesized by microorganisms, wherein the microorganisms synthesize bacterial cellulose using the above-mentioned red yeast rice fermentation medium as a fermentation system.
[0015] The present invention also provides the application of the above-mentioned Monascus purpureus SZHQ089 in the synthesis of Monascus purpureus bacterial cellulose. The Monascus purpureus bacterial cellulose is obtained by microbial fermentation using Monascus purpureus SZHQ089 as one of the components of the fermentation culture medium. The bacterial cellulose not only has a high yield, but also has multiple functions such as the lipid-lowering activity and antioxidant activity of Monascus purpureus.
[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a novel *Monascus purpureus* strain, SZHQ089, isolated from vineyards, unlike other red yeast rice strains. The *Monascus purpureus* strain SZHQ089 can produce red yeast rice products with high color value (above 8000 U / g) using conventional solid-state fermentation methods, without producing citrinin. Furthermore, this invention further enhances the color value of the red yeast rice by adding water replenishment and optimizing the solid-state fermentation medium. In addition, the red yeast rice fermentation medium prepared using the *Monascus purpureus* strain SZHQ089 described in this invention can significantly increase bacterial cellulose yield when used for bacterial cellulose synthesis. Attached Figure Description
[0017] Figure 1 The screening process of Monascus purpureus SZHQ089 is shown in Figure A, which shows the colony morphology of Monascus purpureus SZHQ089 obtained by plate screening; Figure B shows the colony morphology of Monascus purpureus SZHQ089 obtained after purification; Figure C shows the septate hyphae of the strain; and Figure D shows the cleistothecia of the strain.
[0018] Figure 2 A filtration device for the inoculum of Aspergillus violaceus SZHQ089 was developed.
[0019] Figure 3 The red yeast rice prepared in Examples 2 (Figure A), 3 (Figure B), 4 (Figure C), and 5 (Figure D) are respectively.
[0020] Figure 4 The bacterial cellulose synthesized in control group 2 of Example 6 (Figure A) and the red yeast rice bacterial cellulose synthesized in experimental group 4 (Figure B) are respectively. Detailed Implementation
[0021] The following embodiments further illustrate the present invention. It should be noted that the following embodiments are only for explaining the present invention and do not limit its content. Obvious variations or modifications derived from the spirit of the present invention are still within the protection scope of the present invention. Example 1
[0022] Isolation, screening and identification of Monascus purpureus SZHQ089 (1) Strains Isolation Soil samples were collected from a vineyard (March 12, 2025, in an orchard vineyard in Jinzhou City, Hebei Province). The samples were dissolved in sterile water and shaken. 0.5 mL of the solution was added to a 10 mL centrifuge tube containing 4.5 mL of sterile water and mixed thoroughly to prepare 10 mL of the solution. -1 The bacterial suspension was serially diluted using the same procedure to prepare 10... -2 10 -3 10 -4 10 -5 The bacterial suspension was then taken in batches of 10. -3 10 -4 10 -5 Spread 0.1 mL of each concentration gradient dilution onto the isolation medium and incubate at 30°C for 3-5 days, then observe. The isolation medium consists of: 6 g glucose, 2 g peptone, 3 g soluble starch, 1.8 g agar, and 100 mL distilled water. Sterilize at 121°C for 20 min.
[0023] (2) Strain screening and purification After culturing for 3-5 days, select one red colony from the plate. Figure 1 A) The colony is characterized as follows: the colony is round with neat edges, fluffy texture, bright purplish-red on the front and light red on the back, and has no odor.
[0024] A multi-step purification process using the streak plate method was employed to obtain pure strains with completely identical morphology and free from contamination. Figure 1 (B) The colony characteristics of this pure strain are stable, with no other colonies of different colors or shapes mixed in.
[0025] (3) Strain identification Morphological identification: Fresh hyphae and spores of the pure strain were picked and placed in a sterile droplet of water on a glass slide, gently spread evenly, and covered with a coverslip to prepare a temporary slide. Under an optical microscope, septate hyphae of the strain were observed. Figure 1 C), capable of producing spherical conidia and cleistothecia ( Figure 1 D), which conforms to the typical morphological characteristics of Monascus purpureus.
[0026] Molecular biological identification: Genomic DNA was extracted from the purified strain using the CTAB method. PCR amplification of the ribosomal DNA transcription spacer (ITS) was performed using universal fungal primers ITS1 (5'-TCCGTAGGTGAACCTGCGG-3') and ITS4 (5'-TCCTCCGCTTATTGATATGC-3'). The amplified products were detected by agarose gel electrophoresis and then sent to a sequencing company for sequencing. The obtained ITS sequence (as shown in SEQ ID No. 1) was compared with known strain sequences in the GenBank database for homology. The results showed that this strain shared ≥99% homology with the *Monascus purpureus* standard strain.
[0027] Based on morphological characteristics and molecular biological identification results, the pure strain was finally identified as *Monascus purpureus*. This strain has been deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 42476 and deposit date of December 15, 2025. Example 2
[0028] This embodiment utilizes *Monascus purpureus* SZHQ089 to prepare red yeast rice, including the following steps: (1) Inoculate the purple red Aspergillus strain SZHQ089 into a plate culture medium and culture it at 30℃ for 5 days for plate culture; (2) After the spores mature in the plate culture, wash them off with sterile water, transfer them to a sterile conical flask containing glass beads, shake thoroughly, and then filter with sterile cotton or gauze. Figure 2 ), to prepare spore suspension; (3) Inoculate the spore suspension into the seed culture medium, and culture at 30℃ and 220 rpm for 24 h with shaking. Then culture in seed bottles to obtain seed liquid. (4) Inoculate the cultured seed liquid into the solid fermentation medium at an inoculation rate of 5% (v / w), stir evenly, and incubate at 30℃ for 24h; add 2% (v / w) water, stir evenly, and continue to incubate for 24h; repeat the water addition, stirring, and incubation 4 times until the fermentation is completed, and red yeast rice is obtained.
[0029] The composition of the plate culture medium is as follows: 6g glucose, 2g peptone, 3g soluble starch, 1.8g agar, 100mL purified water, and natural pH.
[0030] The seed culture medium consists of: 2g glucose, 0.5g yeast extract, 0.1g K₂HPO₄, 0.05g MgSO₄, 0.5g NaCl, 0.05g CaCl₂, 0.5g glycerol, 0.1g corn steep liquor, 100mL purified water, and natural pH. The seed culture apparatus is a 100mL beaker with a volume of 30mL.
[0031] The method for preparing the solid-state fermentation medium is as follows: Take 50g of rice (it can be indica rice, japonica rice or glutinous rice, and japonica rice is preferred in this embodiment), wash it with tap water and soak it for 8 hours; drain the soaked rice and freeze it at -20℃ for 7 days; thaw the frozen rice, put it into a 500mL Erlenmeyer flask, and sterilize it at 121℃ for 20 minutes.
[0032] The fermented red yeast rice was transferred to a sterile drying oven and dried at 45℃. The color value (unit: μ / g) and citrinin (unit: μg / kg) were determined according to the methods in GB 1886.19-2015 National Food Safety Standard for Food Additives Red Yeast Rice and GB 5009.222-2016 National Food Safety Standard for Determination of Citrinin in Food.
[0033] The red yeast rice obtained in this embodiment is as follows: Figure 3 As shown in Figure A, its color value was measured to be 8512 μ / g, and no citrusin was detected. Example 3
[0034] This embodiment uses Monascus purpureus SZHQ089 to prepare red yeast rice. The specific preparation method is the same as in Example 2. The difference is that when preparing the solid fermentation culture medium in this embodiment, the tap water used to soak the rice is replaced with nutrient solution. The composition of the nutrient solution is: corn steep liquor 0.1%, K2HPO4 0.1g / L, MgSO4 0.5g / L, and the remainder is water.
[0035] The red yeast rice obtained in this embodiment is as follows: Figure 3 As shown in Figure B, its color is deeper than that of the red yeast rice obtained in Example 2. Its color value was measured to be 9926 μ / g, and no citrusin was detected. Example 4
[0036] In this embodiment, red yeast rice is prepared using Monascus purpureus SZHQ089. The specific preparation method is the same as in embodiment 2. The difference is that in this embodiment, the amount of water added each time in step (4) is 4%.
[0037] The red yeast rice obtained in this embodiment is as follows: Figure 3 As shown in Figure C, its color value was determined to be 9105 μ / g, and no citrusin was detected.
[0038] Compared with Example 2, Example 4 increased the amount of water added each time during solid-state fermentation. The color value of the resulting red yeast rice was not as significantly improved as in Example 3. However, the resulting red yeast rice was fully fermented (with higher levels of other active ingredients), had a plump appearance, and the cross-section of the red yeast rice did not show any white core. It was more effective than the red yeast rice of Example 3 (Example 6) in the production of bacterial cellulose. Example 5
[0039] This embodiment uses *Monascus purpureus* SZHQ089 to prepare red yeast rice. The specific preparation method is the same as in Example 2, except that in the preparation of the solid-state fermentation culture medium described in this embodiment, the tap water used for soaking rice is replaced with nutrient solution. The composition of the nutrient solution is: 0.1% corn steep liquor, 0.1 g / L K2HPO4, 0.5 g / L MgSO4, and the remainder is water. Furthermore, in step (4), the amount of water added each time is adjusted to 4%.
[0040] The red yeast rice obtained in this embodiment is as follows: Figure 3 As shown in D, its color value was measured to be 10760 μ / g, and no citrusin was detected.
[0041] Compared with Example 2, this embodiment increases the amount of water added each time during solid-state fermentation, and uses nutrient solution for soaking during the preparation of solid-state fermentation culture medium. As a result, the prepared red yeast rice has a deeper color, the color value is increased by 26.4%, and the prepared red yeast rice is fully fermented (with higher levels of other active ingredients), with a full appearance and no white core visible on the cross-section of the red yeast rice. Example 6
[0042] This embodiment provides the application of red yeast rice in increasing bacterial cellulose production.
[0043] (1) Preparation of culture medium Take 100g of red yeast rice prepared in Examples 2, 3, 4, and 5 respectively, add 500mL of purified water, soak for 8 hours, filter to obtain red yeast rice filtrate; prepare red yeast rice fermentation medium by sterilizing at 121℃ for 20 minutes with 4g of glucose, 0.5g of yeast powder, 0.1g of K2HPO4, 0.15g of MgSO4, 0.1g of citric acid, and 100mL of red yeast rice filtrate, at natural pH. (The fermentation medium prepared by red yeast rice in Examples 2, 3, 4, and 5 correspond to experimental groups 1, 2, 3, and 4 respectively.)
[0044] Control culture medium 1: Take 100g of commercially available red yeast rice (Gutian Pinghu red yeast rice, origin: Fujian Province; specification: 500g / bag), add 500mL of purified water, soak for 8h, filter to obtain red yeast rice filtrate; 4g of glucose, 0.5g of yeast powder, 0.1g of K2HPO4, 0.15g of MgSO4, 0.1g of citric acid, 100mL of red yeast rice filtrate, pH natural, sterilize at 121℃ for 20min to prepare control fermentation culture medium 1.
[0045] Control culture medium 2: Take 4g of glucose, 0.5g of yeast powder, 0.1g of K2HPO4, 0.15g of MgSO4, 0.1g of citric acid, 100mL of pure water, natural pH, sterilize at 121℃ for 20min to prepare control fermentation culture medium 2.
[0046] (2) Bacterial cellulose production In this embodiment, the standard strain of Acetobacter xylinum ATCC 23767 was used as the bacterial cellulose production strain.
[0047] Acetobacter xylophilus ATCC 23767 was inoculated into slant culture medium (slant culture medium components: glucose 6g, peptone 2g, soluble starch 3g, agar 1.8g, distilled water 100mL) and cultured at 28℃ for 5 days; after the slant culture matured, it was inoculated into seed culture Erlenmeyer flasks and cultured at 28℃ and 180rpm for 24 hours; after the seed culture matured, it was thoroughly vortexed and then filtered. The filtrate was inoculated into different fermentation media described in step (1) at an inoculation rate of 2.5% and cultured statically at 28℃ for 5 days.
[0048] After fermentation, the bacterial cellulose membrane was removed and soaked in a 0.1 mol / L NaOH solution at 80°C for 2 hours, with the NaOH solution being replaced every 0.5 hours until the membrane turned milky white and translucent. Then, it was soaked in a 0.5% acetic acid solution and rinsed with distilled water until the surface of the membrane was neutral as measured by pH paper. The surface water was then drained and the membrane was weighed.
[0049] The bacterial cellulose yield obtained using the fermentation medium of control group 1 was 2.97 g / L, while the bacterial cellulose yield obtained using the fermentation medium of control group 2 was 2.06 g / L. Figure 4 As shown in A), the bacterial cellulose yields obtained using the fermentation media described in experimental groups 1, 2, 3, and 4 were 4.93 g / L, 5.36 g / L, 5.92 g / L, and 6.67 g / L, respectively (as shown in A). Figure 4 (As shown in B). The bacterial cellulose yield produced using the fermentation medium described in experimental group 4 was 223.79% higher than that in control group 2.
[0050] The above embodiments are only some embodiments of the present invention, and not all embodiments. The detailed description of the embodiments is merely for the purpose of clearly illustrating the present invention, and is not intended to limit the implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.
Claims
1. Aspergillus violaceus ( Monascus purpureus SZHQ089, characterized in that, It is deposited at the China General Microbiological Culture Collection Center (CGMCC) with accession number CGMCC No. 42476.
2. The application of the purple-red Monascus SZHQ089 as described in claim 1 in the preparation of red yeast rice.
3. A method for preparing red yeast rice using *Monascus purpureus* SZHQ089 as described in claim 1, characterized in that, The method includes the following steps: (1) Inoculate the purple red Aspergillus strain SZHQ089 onto a plate medium and culture at 26~32℃ for 3~8 days; wash off the spores with sterile water, shake with glass beads and filter to obtain a spore suspension; (2) Inoculate the spore suspension into the seed culture medium and culture at 26-32℃ with shaking at 180-250 rpm for 24-30 h to obtain the seed solution; (3) Inoculate the cultured seed liquid into the solid fermentation medium at an inoculation rate of 2-5% (v / w) and incubate at 26-32℃ for 24-48h. (4) After the static culture is completed, mix thoroughly and add 2-8% (v / w) of sterile water to the solid fermentation medium. Continue to culture, and add an equal amount of sterile water every 24-48 hours and mix thoroughly until the fermentation is completed. The fermentation product is dried at 45-50℃ to obtain red yeast rice.
4. The method according to claim 3, characterized in that, The plate culture medium in step (1) consists of the following raw materials in parts by weight: glucose 55~65g / L, peptone 15~25g / L, soluble starch 25~35g / L, agar 15~20g / L, and the remainder is water.
5. The method of claim 3, characterized in that, The seed culture medium in step (2) consists of the following raw materials in parts by weight: glucose 15~25g / L, yeast powder 4~6g / L, K2HPO4 0.5~1.5g / L, MgSO4 0.4~0.6g / L, NaCl 4~6g / L, CaCl 0.4~0.6g / L, glycerol 4~6g / L, corn steep liquor 0.5~1.5g / L, and the balance being water.
6. The method of claim 3, characterized in that, The preparation method of the solid fermentation culture medium in step (3) is as follows: After rinsing the rice with tap water, soak it in a nutrient solution for 4-10 hours, drain the water, and freeze it at -18 to -22℃ for 3-10 days. Then thaw it and sterilize it at 120 to 125℃ for 18 to 25 minutes.
7. The method according to claim 6, characterized in that, The nutrient solution consists of: 1.0 g / L corn steep liquor, 0.1 g / L K2HPO4, 0.5 g / L MgSO4, with the remainder being water.
8. A red yeast rice fermentation culture medium, characterized in that, The red yeast rice fermentation medium contains red yeast rice components, and the red yeast rice is obtained by fermentation of Monascus purpureus SZHQ089 as described in claim 1.
9. A method for increasing the yield of microbial synthetic bacterial cellulose, characterized in that, The microorganisms synthesize bacterial cellulose using the red yeast rice fermentation medium as described in claim 8 as the fermentation system.
10. The application of Monascus purpureus SZHQ089 as described in claim 1 in the synthesis of Monascus purpureus cellulose.