Red monascus sf26 and application thereof

Abstract

The application discloses a kind of red monascus SF26 and application thereof, it is related to the technical field of brewing, the preservation number of the strain is CCTCC No: M 20251745, on July 31, 2025, is preserved in China typical culture preservation center, and the preservation address is China.Wuhan.Wuhan University.The application also discloses the application of the above-mentioned red monascus SF26 in preparing esterification red koji.The application also discloses an esterification red koji for improving liquor ester flavor substances and a preparation method thereof.The red monascus SF26 provided by the application has high esterification capacity, and the esterification red koji prepared by the application can significantly improve the quality of liquor, which is conducive to the large-scale promotion and application of esterification red koji.

Description

Technical Field

[0001] This invention relates to the field of brewing technology, specifically to a red Monascus SF26 and its applications. Background Technology

[0002] Monascus purpureus is a filamentous fungus, known as "Millennial Monascus" in my country. During its growth, Monascus purpureus can produce a variety of enzyme systems such as saccharifying enzymes, proteases, and esterifying enzymes, and is widely used in brewing and vinegar making industries. Its history of use can be traced back to the end of the Wei Dynasty.

[0003] Esterified red yeast rice is a general term for a class of Monascus purpureus that produce high levels of esterification enzymes. Their fermentation products can catalyze the esterification of alcohols and acids to synthesize esters such as ethyl hexanoate, ethyl acetate, and ethyl lactate. This process demonstrates a significant advantage in ester production and aroma enhancement, having a crucial impact on the flavor and quality of baijiu (Chinese liquor), resulting in substantial economic benefits. Furthermore, Monascus purpureus can also produce various functional metabolites such as red yeast rice polysaccharides, lovastatin, γ-aminobutyric acid (GABA), and ergosterol, attracting considerable attention in the brewing of emerging baijiu products such as health-enhancing wines and fruit wines.

[0004] Although research institutions and brewing companies have conducted research on esterified red yeast rice, its large-scale production and application in China are still rare. At the same time, the problem of low esterification rate of existing esterified red yeast rice has not been well solved. This invention will promote the large-scale promotion and application of esterified red yeast rice. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a red Monascus SF26 and its applications. The red Monascus SF26 provided by the present invention has high esterification power, and the esterified red yeast rice prepared from it can significantly improve the quality of baijiu (Chinese liquor), which is conducive to the large-scale promotion and application of esterified red yeast rice.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A red Monascus purpureus (… Monascus ruber SF26, with accession number CCTCC No: M 20251745, was deposited at the China Center for Type Culture Collection on July 31, 2025, at Wuhan University, Wuhan, China.

[0007] This invention also provides the application of the aforementioned red Monascus SF26 in brewing.

[0008] This invention also provides the application of the aforementioned red Monascus SF26 in the preparation of esterified red Monascus.

[0009] The present invention also provides an esterified red yeast rice for enhancing the ester flavor of baijiu, which is obtained by solid-state fermentation of the aforementioned red yeast rice SF26.

[0010] This invention also provides a method for preparing the above-mentioned esterified red yeast rice, comprising the following steps:

[0011] Step 1: Preparation of bacterial strains for test tube slant culture

[0012] Pour the sterilized PDA medium into a tilted test tube, inoculate with red Monascus SF26 bacterial suspension by condensation, and incubate at 30℃ for 3-5 days to activate the bacterial strain.

[0013] Step 2: Preparation of microbial culture in liquid Erlenmeyer flasks

[0014] The activated strain was inoculated into a liquid culture medium and cultured at 30°C and 200 rpm for 48 h. The liquid culture medium consisted of 2 g / 100 mL malt extract, 0.1 g / 100 mL peptone, and 2 g / 100 mL glucose.

[0015] Step 3: Preparation of liquid seeds in the seed tank

[0016] Add culture medium to the Erlenmeyer flask and inoculate with the bacterial culture from step two. The culture medium formula is: 3 wt% rice flour, 2 wt% soybean meal, 0.5 wt% corn steep liquor, 0.5 wt% yeast extract, 0.5 wt% wheat bran, 0.4 wt% NaNO3, 0.1 wt% MgSO4, 0.1 wt% K2HPO4, and adjust the pH to 4.5 with lactic acid.

[0017] Then, while ensuring positive pressure in the seed tank, open the mouth of the triangular flask inside the flame ring and pour it into the seed tank. Fermentation time is 40-50 hours.

[0018] Step 4: Solid-state fermentation

[0019] Fermentation ingredients: Mix wheat bran and rice husks evenly after wetting them with water, steam at 120℃ for 30 minutes, and then let them cool.

[0020] Inoculation: Add 0.1 wt% of food-grade glacial acetic acid or lactic acid to the seed liquid after fermentation in step three and mix well. Then add 20 wt% of the fermentation raw material and mix well.

[0021] Pile: Use a cloth cart to pile the inoculated material in the middle of the fermentation tank, form a square pile, insert a temperature probe into the middle of the fermentation pile, and observe the temperature of the pile at intervals;

[0022] Spreading and cultivating flowers: When the temperature of the material in the center of the fermentation tank rises to 40℃-45℃, thoroughly turn over all the material in the tank once, and pile it up again. When the temperature of the material in the center of the tank rises to 40-45℃ again, thoroughly turn over all the material in the tank once more, spread it all over the tank, and make it 9-11 cm high. Set the temperature to 37℃, blow air with a blower, and thoroughly turn over the material every 3-4 hours.

[0023] Add water: When the moisture content of the material is below 35%, spray water to 40-48% and maintain the temperature at 30-33℃; when the moisture content of the material is below 40%, spray water again to 40-48% and maintain the temperature at 30-33℃ for 3 days.

[0024] Drying after fermentation: Spread the fermented bran evenly and dry it at 40-50℃ until the moisture content is ≤12%.

[0025] Furthermore, in step three, the fermentation temperature is 30-32℃, the agitator speed is 240 rpm, the tank pressure is controlled at 0.05-0.07 MPa, and the filtered air flow rate is controlled at 8-10 m³ / h. 3 / h. Detailed Implementation

[0026] The principles and features of this invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0027] Experimental Example 1: Strain Screening and Identification

[0028] First round of screening: Cellar mud samples from Fujian, Hubei, Zhejiang, Shandong and other regions were collected and cultured in 1% lactic acid solution at 30℃ with shaking for 2 h to kill acid-sensitive bacteria and fungi. The suspension was then spread in a gradient onto PDA solid medium (formula: 200 potatoes, 20 g glucose, 18 g agar, 1 L ddH2O) and incubated at 30℃ for 5 days. The size, color, surface morphology and texture of colonies on the plates were observed, and strains with the morphological characteristics of Monascus purpureus were selected.

[0029] Second round of screening: The selected strains were streaked on PDA plates and cultured until single colonies were obtained. A small number of Monascus purpureus single colonies were picked for microscopic examination to observe the hyphal morphology characteristics and further screen for possible Monascus purpureus strains.

[0030] The third round of screening: The isolated strains were initially screened for esterification capacity. The strains were inoculated into emulsified medium (formulation: 3 g / L beef extract, 10 g / L peptone, 0.5 g / L sodium chloride, 2.0 g / L agar, 0.4 g / L glyceryl tartrate) and incubated at 30℃ for 4-7 days. The diameter of colonies and the clear zone were observed and recorded, and the HC value of the strains (diameter of clear zone / colony diameter) was calculated. The strain with the highest HC value was used for subsequent experiments.

[0031] The selected strain was streaked in PDA medium, and the spore suspension was washed with sterile water. The strain was then autoclaved, centrifuged, and the cell lysate was obtained. The ITS sequence of the strain was amplified by PCR. Sequence alignment and phylogenetic analysis revealed that the strain belongs to *Monascus rubrum*, and it was named *Monascus rubrum* SF26, with the strain accession number CCTCC M 20251745. The strain originated from a cellar mud sample from Shaoxing, Zhejiang Province.

[0032] Experimental Example 2: Solid-state fermentation

[0033] Step 1: Preparation of bacterial strains for test tube slant culture

[0034] Pour the sterilized PDA medium into a tilted test tube, inoculate with red Monascus SF26 bacterial suspension by condensation, and incubate at 30℃ for 4 days to activate the bacterial strain.

[0035] Step 2: Preparation of microbial culture in liquid Erlenmeyer flasks

[0036] The activated bacterial strain was inoculated into a liquid culture medium and cultured at 30°C and 200 rpm for about 48 h. The liquid culture medium consisted of 2 g / 100 mL malt extract, 0.1 g / 100 mL peptone, and 2 g / 100 mL glucose.

[0037] Step 3: Preparation of liquid seeds in the seed tank

[0038] Add culture medium to the Erlenmeyer flask and inoculate with the bacterial culture from step two. The culture medium formula is: 3 wt% rice flour, 2 wt% soybean meal, 0.5 wt% corn steep liquor, 0.5 wt% yeast extract, 0.5 wt% wheat bran, 0.4 wt% NaNO3, 0.1 wt% MgSO4, 0.1 wt% K2HPO4, and adjust the pH to 4.5 with lactic acid.

[0039] Then, while maintaining positive pressure in the seed tank, open the mouth of the triangular flask within the flame ring and pour the contents into the seed tank. Fermentation time is 48 hours; fermentation temperature is 30-32℃, stirrer speed is 240 rpm, tank pressure is controlled at 0.06 MPa, and filtered air flow rate is controlled at 9 m³ / s. 3 / h.

[0040] Step 4: Solid-state fermentation

[0041] Fermentation ingredients: Mix wheat bran and rice husks evenly after wetting them with water, steam at 120℃ for 30 minutes, and then let them cool.

[0042] Inoculation: Add 0.1 wt% of food-grade glacial acetic acid or lactic acid to the seed liquid after fermentation in step three and mix well. Then add 20 wt% of the fermentation raw material and mix well.

[0043] Pile: Use a cloth cart to pile the inoculated material in the middle of the fermentation tank, form a square pile, insert a temperature probe into the middle of the fermentation pile, and observe the temperature of the pile at intervals;

[0044] Spreading and cultivating flowers: When the temperature of the material in the center of the fermentation tank rises to 40℃-45℃, thoroughly turn over all the material in the tank once, and pile it up again. When the temperature of the material in the center of the tank rises to 40-45℃ again, thoroughly turn over all the material in the tank once more, spread it to cover the entire tank, and make it about 10 cm high. Set the temperature to 37℃ and blow air with a blower. Thoroughly turn over the material every 3-4 hours.

[0045] Add water: When the moisture content of the material is below 35%, spray water to 40-48% and maintain the temperature at 30-33℃; when the moisture content of the material is below 40%, spray water again to 40-48% and maintain the temperature at 30-33℃ for 3 days.

[0046] Drying after fermentation: Spread the fermented bran evenly and dry it at 40-50℃ until the moisture content is ≤12%.

[0047] Experimental Example 3

[0048] (1) According to the industry standard method test (QB / T 5188-2017), the esterification power of Monascus purpureus SF26 reached 54 mg / g∙100 h.

[0049] (2) The esterification enzyme produced by Monascus purpureus strain SF26 can catalyze the reaction of organic acids and alcohols to form ester flavor substances. When the esterified red yeast prepared in Experiment 2 was added to the aroma-enhancing yeast of baijiu at a ratio of 2 wt%, the total ester content in baijiu increased by 17.8%, of which the content of ethyl hexanoate increased by 8.2% and the content of ethyl lactate increased by 3.7%. In addition, the contents of short-chain alcohols such as n-propanol, isobutanol, and n-butanol all decreased to a certain extent. After tasting by national-level wine tasters, it was found that the baijiu with added esterified red yeast showed more outstanding performance in terms of aroma coordination and taste balance.

[0050] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A type of red Monascus ( Monascus ruber SF26, characterized in that, Its accession number is CCTCC No: M20251745, and it was deposited at the China Center for Type Culture Collection on July 31, 2025, at Wuhan University, Wuhan, China.

2. The application of the red Monascus SF26 as described in claim 1 in brewing.

3. The application of the red Monascus SF26 according to claim 1 in the preparation of esterified red Monascus.

4. An esterified red yeast rice for enhancing the ester flavor compounds in baijiu (Chinese liquor), characterized in that, It is prepared by solid-state fermentation of Monascus purpureus SF26 as described in claim 1.

5. The method for preparing esterified red yeast rice according to claim 4, characterized in that, Includes the following steps: Step 1: Preparation of bacterial strains for test tube slant culture Pour the sterilized PDA medium into a tilted test tube, inoculate with red Monascus SF26 bacterial suspension by condensation, and incubate at 30℃ for 3-5 days to activate the bacterial strain. Step 2: Preparation of microbial culture in liquid Erlenmeyer flasks The activated strain was inoculated into a liquid culture medium and cultured at 30°C and 200 rpm for 48 h. The liquid culture medium consisted of 2 g / 100 mL malt extract, 0.1 g / 100 mL peptone, and 2 g / 100 mL glucose. Step 3: Preparation of liquid seeds in the seed tank Add culture medium to the Erlenmeyer flask and inoculate with the bacterial culture from step two. The culture medium formula is: 3 wt% rice flour, 2 wt% soybean meal, 0.5 wt% corn steep liquor powder, 0.5 wt% yeast extract, 0.5 wt% wheat bran, 0.4 wt% NaNO3, 0.1 wt% MgSO4, 0.1 wt% K2HPO4, and adjust the pH to 4.5 with lactic acid. Then, while ensuring positive pressure in the seed tank, open the mouth of the triangular flask inside the flame ring and pour it into the seed tank. Fermentation time is 40-50 hours. Step 4: Solid-state fermentation Fermentation ingredients: Mix wheat bran and rice husks evenly after wetting them with water, steam at 120℃ for 30 minutes, and then let them cool. Inoculation: Add 0.1 wt% of food-grade glacial acetic acid or lactic acid to the seed liquid after fermentation in step three and mix well. Then add 20 wt% of the fermentation raw material and mix well. Pile: Use a cloth cart to pile the inoculated material in the middle of the fermentation tank, form a square pile, insert a temperature probe into the middle of the fermentation pile, and observe the temperature of the pile at intervals; Spreading and cultivating flowers: When the temperature of the material in the center of the fermentation tank rises to 40℃-45℃, thoroughly turn over all the material in the tank once, and pile it up again. When the temperature of the material in the center of the tank rises to 40-45℃ again, thoroughly turn over all the material in the tank once more, spread it all over the tank, and make it 9-11 cm high. Set the temperature to 37℃, blow air with a blower, and thoroughly turn over the material every 3-4 hours. Add water: When the moisture content of the material is below 35%, spray water to 40-48% and maintain the temperature at 30-33℃; when the moisture content of the material is below 40%, spray water again to 40-48% and maintain the temperature at 30-33℃ for 3 days. Drying after fermentation: Spread the fermented bran evenly and dry it at 40-50℃ until the moisture content is ≤12%.

6. The preparation method according to claim 5, characterized in that, In step three, the fermentation temperature is 30-32℃, the agitator speed is 240 rpm, the tank pressure is controlled at 0.05-0.07 MPa, and the filtered air flow rate is controlled at 8-10 m³ / h. 3 / h.