Monascus and its application in mixed bacterial fermentation technology

Abstract

The present invention relates to the field of microbial technology, and in particular to Monascus and its application in mixed bacteria fermentation technology. The present invention separates a strain of Monascus purpurogenus with a preservation number of CGMCC No.41415 and a strain of Monascus fusca with a preservation number of CGMCC No.41287, and compound the two to form a composite bacteria. They are applied to highland barley fermentation to produce pure natural and pollution-free Monascus pigment and can also metabolize to produce lovastatin with blood lipid lowering effect. The fermented highland barley red yeast not only retains the nutritional components of highland barley, but also increases the content of functional active substances in the highland barley red yeast, increases the health care effect of the highland barley red yeast, and is more suitable for the demand of modern consumers for high-quality products.

Description

Technical Field

[0001] The invention relates to the field of microbial technology, in particular to Monascus and application thereof in mixed bacteria fermentation technology. Background Art

[0002] Highland barley (Hordeum vulgare var.coeleste Linnaeus) is an annual herbaceous plant of the Poaceae family and the genus Hordeum, which is suitable for growing in the cool climate of the plateau. Highland barley contains a variety of essential amino acids for the human body, and has the characteristics of "high protein, high fiber, high vitamins, low fat, and low sugar". Processing it into functional food can play the role of anti-inflammatory, anti-cancer, anti-diabetes, antibacterial, anti-aging, and relieve hyperglycemia and hyperlipidemia. The β-glucan rich in highland barley has the functional characteristics of inhibiting and treating some chronic and metabolic diseases such as Alzheimer's disease, type 2 diabetes, cancer, coronary heart disease, etc., and has the effect of reducing postprandial blood sugar and insulin levels, and has a significant effect on preventing cardiovascular diseases and diabetes.

[0003] In my country, highland barley is mainly used as food, and the consumption ratio of processed products is relatively low. The problems of rational development of highland barley resources and high added value utilization are becoming increasingly prominent. If high-density culture and fermentation are carried out in highland barley, the products can retain the nutrients in highland barley while increasing the content of functional active substances in highland barley, increasing the health care effect of highland barley red yeast rice, enhancing the aroma of highland barley red yeast rice, and improving product quality, it will greatly meet the demand of modern people for high-quality products; at the same time, it will realize the improvement of the economic value of the highland barley industry, the high added value transformation, and promote the development of the highland barley industry.

[0004] Monascus spp. is an important production strain of traditional fermented food in my country, and is widely used in the processing of sausages, fermented bean curd, red yeast wine, red yeast vinegar and meat products. Monascus mainly includes M. pilosus, M. purpureus and M. ruber. Monascus can produce a variety of secondary metabolites with antioxidant and lipid-lowering functions, such as Monascus pigments (MPs), Monacolin K (MK), γ-aminobutyric acid, etc., and has broad application prospects in the fields of food colorants, fermentation agents and alternative drugs. However, most of the existing Monascus are screened in plain areas, while highland barley is mainly distributed in plateau areas, where oxygen is thin and air pressure is low. Most Monascus cannot adapt to the plateau environment, resulting in poor fermentation effect of highland barley. Therefore, it is of great significance to screen Monascus that can adapt to the plateau environment and achieve good highland barley fermentation effect. Summary of the invention

[0005] In view of this, the technical problem to be solved by the present invention is to provide Monascus and its application in mixed bacteria fermentation technology.

[0006] The invention provides Monascus purpureus with a deposit number of CGMCC No.41415.

[0007] The present invention selects a purple Monascus strain through strain stability and color value after fermentation, and performs long-term culture and passage on the strain with strong pigment production ability, observes its stability and growth characteristics, and detects the color value according to the color value detection method in GB 4926-2008 "Food Additive Red Yeast Rice (Powder)". The purple Monascus colony has a diameter of 3 to 4 cm, purple-red, flat colonies, dense aerial hyphae that are longer than those of Monascus fusca, velvety; hyphae contain particles; conidia are spherical or inverted pear-shaped; and closed capsules are spherical. The results show that the strain grows faster than other strains and is more suitable for growth in a plateau environment. The colony color is purple-red and has a high pigment content. After repeated cultivation, the strain shows the best stability.

[0008] The invention provides Monascus pilosus with a deposit number of CGMCC No.41287.

[0009] Through solid culture medium plate culture, the colony color of the Monascus pubescens is observed to be light pink, the edge is white, the colony is flat, and the aerial hyphae are dense and short; under a microscope, the hyphae are smooth, have septa, contain particles and oil droplets; the conidia are spherical or inverted pear-shaped; the cleistothecia are spherical. The strain has a fast growth rate and a high lovastatin yield, and can produce 0.6% to 1.3% lovastatin under fermentation conditions.

[0010] The invention also compounds Monascus rubrum with a preservation number of CGMCC No.41287 and Monascus purpureus with a preservation number of CGMCC No.41415, screens out a strain of Monascus purpureus suitable for matching with the Monascus rubrum, and the formed composite strain includes Monascus rubrum with a preservation number of CGMCC No.41287 and Monascus purpureus with a preservation number of CGMCC No.41415.

[0011] The present invention optimizes the ratio of the number of live bacteria in the composite bacteria by analyzing the effect after fermentation. Preferably, the ratio of the number of Monascus pubescens to Monascus purpureus is (1-2): (1-2). More preferably, the ratio of the number of Monascus pubescens to Monascus purpureus is 1:1. Experiments show that when the ratio of the mixed flora is 1:1, the content of pigment and lovastatin produced by fermentation is the highest, which is significantly different from other groups.

[0012] The present invention also provides the use of the Monascus pubescens, the Monascus purpurogenus and / or the composite strain in the preparation of fermented red yeast rice.

[0013] Furthermore, the present invention also provides a method for preparing fermented red yeast rice, which comprises: inoculating the Monascus rubrum, the Monascus purpurogenum and / or the composite strain into a fermentation substrate containing highland barley, and then fermenting.

[0014] After the fermented highland barley red yeast obtained by the fermentation method of the present invention is detected and compared with the unfermented highland barley, it is found that the fermented highland barley still retains crude polysaccharides, proteins, soluble dietary fiber and antioxidant active ingredients in highland barley. In some embodiments, the Monascus rubrum with a preservation number of CGMCC No.41287 is inoculated on the fermentation matrix alone for fermentation. In other embodiments, the composite strain as described above is inoculated on the fermentation matrix for fermentation. The results show that the scheme of mixed bacteria fermentation is more advantageous. For example, and, after mixed bacteria fermentation, the color value of the fermented product is increased to 253.265U / 100g, which is significantly different from the fermentation of Monascus rubrum provided by the present invention alone. In addition, the speed of mixed bacteria fermentation is faster, and the low-temperature fermentation time is 6d, which is 9d less than the color value of the single strain Monascus rubrum (preservation number is CGMCC No.41287) to meet the requirements.

[0015] In the present invention, the fermentation matrix comprises the following raw materials in parts by weight: 40-100 parts of highland barley, 5-12 parts of bran, 2-5 parts of soybean meal and 20-45 parts of nutrient solution. Preferably, in the fermentation matrix, the parts by weight of each component are: 88 parts of highland barley, 10 parts of bran, 2 parts of soybean meal and 40 parts of nutrient solution.

[0016] As a feasibility case, the nutrient solution is composed of water, a carbon source, a nitrogen source and an inorganic salt, wherein:

[0017] The carbon source is sucrose and / or glucose;

[0018] The nitrogen sources are glutamate and / or histidine;

[0019] The inorganic salt is calcium nitrate, sodium nitrate and / or potassium dihydrogen phosphate.

[0020] In the nutrient solution, the mass ratio of carbon source, nitrogen source, inorganic salt and water is (3-15):(10-50):(1-5):(900-1000). Preferably, the mass ratio of carbon source, nitrogen source and inorganic salt is 4.1:10.2:1.3.

[0021] In the nitrogen source, the mass ratio of glutamic acid to histidine is (7-8): (2-3).

[0022] In the inorganic salt, the mass ratio of calcium nitrate, sodium nitrate and potassium dihydrogen phosphate is (2-3):(0.5-1):(0.1-0.5).

[0023] Specifically, in the nutrient solution, the mass fraction of the carbon source is 0.41%, the mass fraction of the nitrogen source is 10.2%, and the mass fraction of the inorganic salt is 1.3%.

[0024] As a feasibility case, the nutrient solution also includes a lubricant, an antioxidant and a chelating agent.

[0025] Preferably, the lubricant is octanoic acid, the antioxidant is ascorbic acid, and the chelating agent is EDTA-disodium. The mass fraction of the lubricant in the nutrient solution is 0.01% to 0.05%, the mass fraction of ascorbic acid is 0.3% to 0.4%, and the mass fraction of EDTA-disodium is 0.00001% to 0.00002%.

[0026] In some specific embodiments, the nutrient solution includes the following components in mass fractions: 0.41% sucrose, 0.76% glutamic acid, 0.26% histidine, 0.09% calcium nitrate, 0.03% sodium nitrate, 0.01% potassium dihydrogen phosphate, 0.01% caprylic acid, 0.34% ascorbic acid, 0.00001% disodium EDTA, and the balance is water.

[0027] In the present invention, the preparation method of the fermentation matrix comprises: removing stones and crushing highland barley, mixing with bran and soybean meal, bottling and mixing with nutrient solution, sterilizing and maturing (121°C, 30min), and cooling to obtain the fermentation matrix.

[0028] In the present invention, the activation of Monascus pilosula and Monascus purpurogenum in the composite strain can be carried out together or separately, and the present invention does not limit this. Preferably, the present invention activates the two strains separately and then inoculates them into the fermentation matrix.

[0029] In a specific embodiment, the activation comprises: inoculating the Monascus pubescens and / or Monascus purpurogenum into a sterilized modified Sabouraud liquid culture medium (glucose 20 g / L, peptone 10 g / L, maltose 5 g / L, yeast extract powder 5 g / L, agar 25-30 g / L), culturing at 30° C., 240 r / min in the dark for 48 h, spreading the diluted culture on a modified Sabouraud agar plate culture medium, picking a single colony for passage, collecting spores after 6-7 days at 28-30° C., culturing in a fermenter for 48-72 h at a seed liquid volume ratio of 0.1%-0.2%, and preparing a secondary seed liquid, wherein the fermenter culture medium (40 L) contains 20 g glucose, 10 g peptone, 5 g maltose, and 5 g yeast extract powder per L.

[0030] In the present invention, the inoculation volume is 40-60 mL, and the fermentation conditions include fermentation at 28-30° C. for 6 days and then fermentation at 20-22° C. for 3-7 days.

[0031] Furthermore, the present invention also provides fermented red yeast rice prepared by the preparation method as described above.

[0032] The present invention separates a strain of Monascus purpureus with a preservation number of CGMCC No.41415 and a strain of Monascus fusca with a preservation number of CGMCC No.41287, and compound the two to form a composite bacteria. The two are applied to highland barley fermentation to produce pure natural and pollution-free red yeast pigment and can also metabolize to produce lovastatin with the effects of lowering blood lipids and blood pressure. The fermented highland barley red yeast not only retains the nutritional components of highland barley, but also increases the content of functional active substances in the highland barley red yeast, increases the health-care effect of the highland barley red yeast, and is more suitable for the demand of modern consumers for high-quality products.

[0033] Biological Deposit Description

[0034] Biomaterial S-19, classification name: Monascus purpureus, was deposited on July 22, 2024 at the General Microbiology Center of China Culture Collection Administration, located at Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with the deposit number CGMCC No.41415.

[0035] The biological material YWG-1, classified and named as Monascus pilosus, was deposited on April 15, 2024 at the General Microbiology Center of China Culture Collection Administration, located at Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, with the deposit number CGMCC No.41287. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The bacterial morphology of the isolated strain of Monascus rubrum with the deposit number of CGMCC No.41287;

[0037] Figure 2 This is a colony picture of Monascus pubescens with a deposit number of CGMCC No.41287, which was cultured on a modified Sabouraud plate medium for 7 days;

[0038] Figure 3 The bacterial morphology of the isolated strain of Monascus purpurogenum with the deposit number of CGMCC No.41415;

[0039] Figure 4 This is a colony picture of Monascus purpurogenus with a deposit number of CGMCC No.41415 cultured on a modified Sabouraud plate medium for 7 days. DETAILED DESCRIPTION

[0040] The present invention provides Monascus and its application in mixed bacteria fermentation technology. Those skilled in the art can refer to the content of this article and appropriately improve the process parameters to achieve it. It is particularly important to point out that all similar replacements and modifications are obvious to those skilled in the art, and they are all considered to be included in the present invention. The method and application of the present invention have been described through preferred embodiments, and relevant personnel can obviously modify or appropriately change and combine the method and application of this article without departing from the content, spirit and scope of the present invention to implement and apply the technology of the present invention.

[0041] The test materials used in the present invention are all common commercial products and can be purchased in the market.

[0042] Table 1 Main reagents

[0043]

[0044]

[0045] Table 2 Main instruments and equipment

[0046] Instruments and reagents model Manufacturer Source Biological Safety Cabinets BHC-1300II A2 Suzhou Antai Air Technology Co., Ltd. Vertical Pressure Steam Sterilizer —— Shanghai Yuntai Instrument Co., Ltd. Biochemical incubator —— Shanghai Yiheng Scientific Instrument Co., Ltd. Electronic balance BSA323S Sartorius Scientific Instruments (Beijing) Co., Ltd. High performance liquid chromatography 1260Infinity Agilent Technologies (China) Co., Ltd. High-speed centrifuge TG-16 Sichuan Shuke Instrument Co., Ltd. Digital Display Gas Bath Constant Temperature Oscillator THZ-82A Changzhou Jintan Kexing Instrument Factory Electric constant temperature blast drying oven DHG-9140A Shanghai Hongdu Electronic Technology Co., Ltd. Ultrasonic Cleaner KH5200E Shanghai Kedao Ultrasonic Instrument Co., Ltd. UV spectrophotometer 759S Manufactured by Shanghai Lingguang Technology Co., Ltd. Water bath constant temperature oscillator SHZ-82 Jiangsu Jinyi Instrument Technology Co., Ltd. microscope Olympus BX53 Olympus (China) Co., Ltd.

[0047] The present invention will be further described below in conjunction with embodiments:

[0048] Example 1 Screening and comparison of highland barley strains fermented with Monascus pubescens

[0049] 1. Screening of Monascus rubrum

[0050] 1. Lhasa is a plateau area, with an oxygen content of 150-170g per cubic meter of air, a normal atmospheric pressure of about 652 hPa (65.2 kPa), and a humidity of 18%-40%. Under such conditions, 5 strains of Monascus were isolated from the soil and identified as Monascus purpurogenus.

[0051] Five strains of Monascus were inoculated into a sterilized modified Sabouraud liquid medium, cultured at 30°C, 240r / min in the dark for 48h, and then spread on a modified Sabouraud agar plate medium after dilution, and a single colony was selected for passage. The activated stable strains and the rejuvenated stable strains were cut into multiple pieces with a scalpel and placed in a preservation tube filled with 50% glycerol, some of which were stored at -80°C and some at 2-8°C. Five strains of Monascus were streaked on a sterile eggplant-shaped bottle medium by the Z-shaped streak method, cultured at 28-30°C for 6-7d, and the spores were washed with sterile water to obtain a spore suspension, and cultured in a fermentation bottle at a ratio of 1.43%-2.86% for 48-72h to obtain a secondary seed solution.

[0052] 2. Determination of colony size and color of strains

[0053] Colony size and color: Use a 0.5 cm cork puncher to take a Monascus colony from the edge of the Monascus culture medium and place it at the midpoint of a new sterile culture medium. Repeat three times for each bacterium. After culturing at 30°C for 7 days, measure the colony size using the cross method, take photos of the Monascus colonies, and record the colony color.

[0054] 3. Molecular identification of strains

[0055] The DNA of the activated strain was extracted and sent to the biotechnology company for identification.

[0056] 4. Stability assessment

[0057] The strains with strong pigment production ability were cultured and subcultured for a long time, and the stability and growth characteristics of the obtained strains under plateau conditions were observed.

[0058] 5. Small test process

[0059] The process of fermenting highland barley red yeast rice is as follows:

[0060] Highland barley - de-stone - crushing - blending - bottling - sterilization and maturation (121°C, 30min), inoculation and fermentation of semi-finished products. The specific steps are as follows:

[0061] (1) Stone removal: Use a stone remover to remove stones. When starting the machine, close the air door first, then slowly open the air door after the fan is running, and start feeding at the same time. Adjust the main air door so that the material covers the second layer and moves in a wave-like boiling state.

[0062] Adjust the back-blowing air door at the stone outlet end and control the back-blowing to form a clear dividing line between the stone and the material (the stone accumulation area is generally about 5 cm).

[0063] (2) Grinding: Use a grinder with a screen of 8 to 20 meshes to grind the highland barley and the soybean meal being prepared.

[0064] (3) Preparation: 40-100 parts of highland barley, 5-12 parts of bran, 2-5 parts of soybean meal and 20-45 parts of nutrient solution. Preferably, the mass parts of each component in the fermentation matrix are: 88 parts of highland barley, 10 parts of bran, 2 parts of soybean meal and 40 parts of nutrient solution.

[0065] In terms of mass percentage, the nutrient solution consists of 0.41% sucrose, 0.76% glutamic acid, 0.26% histidine, 0.09% calcium nitrate, 0.03% sodium nitrate, 0.01% potassium dihydrogen phosphate, 0.01% n-octanoic acid, 0.34% ascorbic acid, 0.00001% EDTA-disodium, and the balance is water.

[0066] (4) Bottling: After mixing, fill each fermentation bottle with 360g of material. Seal the bottle with cotton cloth and thread, and wrap the thread around the bottle mouth 3 to 4 times to tighten it.

[0067] (5) Sterilization and aging: Autoclave at 121°C for 30 min. Shake well immediately after aging.

[0068] (6) Inoculation: The cooled fermentation matrix is ​​inoculated with 40-50 ml of Monascus secondary seed liquid on a clean bench, sealed and shaken for fermentation.

[0069] (7) Fermentation culture: shake flask culture at high temperature of 30°C every 24 h for 6 days; shake flask culture at low temperature of 22°C every 24 h for 6 days.

[0070] (8) Drying and collecting the koji: Place the uncontaminated fermentation substrate in a drying oven at 60°C and dry it for 24 hours before taking it out.

[0071] 6. Determination of color value in red yeast rice

[0072] Refer to the color value detection method in GB 4926-2008 "Food Additive Red Yeast Rice (Powder)" for detection.

[0073] 7. Determination of Lovastatin in Red Yeast Rice

[0074] The determination is based on the method specified in the existing saffron yeast implementation standard XZ-BC-2016-2020.

[0075] 2. Experimental Results

[0076] 2.1 Colony size and color of strains

[0077] The colony is light pink with white edges. The colony is flat and the aerial hyphae are dense and short. Microscopic observation shows that the hyphae are smooth, septate, and contain particles and oil droplets. The conidia are spherical or inverted pear-shaped; the cleistothecia are spherical.

[0078] 2.2 Results of molecular identification of strains

[0079] Based on the determination of the rDNA-ITS sequence of Monascus CGMCC No.41287, it was determined that CGMCC No.41287 was Monascus purpurogenum.

[0080] 2.3 Differences in growth rate and stability of different Monascus rubrum strains on plate culture medium

[0081] According to the method described above, the colony size was measured every day and the changes in colony diameter were recorded. The results are shown in Table 1:

[0082] Table 1

[0083]

[0084] It can be seen that under plateau conditions, different strains have different growth rates on the same culture medium. The growth rate of Monascus purpurogenus CGMCC No.41287 is significantly higher than that of G-4, G-5, G-10, and G-11, and it is more adaptable to growth in plateau environments.

[0085] Through repeated cultivation, Monascus purpureus CGMCC No.41287 and G-5 were discovered, among which Monascus purpureus CGMCC No.41287 had better performance and could maintain the fastest growth rate in multiple generations, so it was preserved.

[0086] 2.4 Differences in color value and lovastatin content among different Monascus pubescens strains

[0087] Table 2

[0088]

[0089] It can be seen from Table 2 that the color value and lovastatin of Monascus rubrum CGMCC No.41287 are significantly higher than those of G-4, G-5, G-10, and G-11. After statistical analysis, there is a significant difference, p<0.05.

[0090] Example 2 Screening and comparison of Monascus purpurogenum fermented highland barley strains

[0091] 1. Screening of Monascus purpurogenus

[0092] 1. Although the Monascus rubrum obtained by screening in Example 1 can produce high levels of lovastatin, the pigment content produced by it is slightly inferior. Considering the color adjustment during fermentation, Monascus with high pigment production was further screened. Four strains of Monascus were isolated from the soil and identified as Monascus purpurogenum. The screening steps were the same as in Example 1.

[0093] 2. Experimental Results

[0094] 2.1 Colony size and color of strains

[0095] The colony diameter is 3 to 4 cm, purple-red, flat, with dense aerial hyphae that are longer and velvety than those of Monascus rubrum; the hyphae contain granules; the conidia are spherical or inverted pear-shaped; and the cleistothecia are spherical.

[0096] 2.2 Results of molecular identification of strains

[0097] By comparing and identifying the rDNA-ITS sequence of S-19 Monascus, it was determined that S-19 was Monascus purpurogenus.

[0098] 2.3 Differences in growth rate and stability of different Monascus strains on plate culture medium

[0099] According to the method described above, the colony size was measured every day and the changes in colony diameter were recorded. The results are shown in Table 3:

[0100] Table 3

[0101] strains S-14 S-19 S-3 S-4 Growth rate (cm / d) 0.63±0.00 0.58±0.01 0.56±0.01 0.55±0.01

[0102] It can be seen that under plateau conditions, different strains have different growth rates on the same culture medium. The growth rate of Monascus purpurogenus S-19 is significantly higher than that of S-3 and S-4, and the growth rate of S-4 is significantly higher than that of S-19, which is more adaptable to growth in plateau environments.

[0103] Through repeated cultivation, it was found that Monascus purpurogenus S-14 and S-19 had the best stability and could maintain the fastest growth rate in multiple generations. Among them, the pigment content of S-19 had the smallest difference in multiple cultures.

[0104] Table 4

[0105] strains S-14 S-19 S-3 S-4 Color Price 564.91±17.52 734.72±21.96 306.24±37.75 307.99±30.18 Lovastatin 0 0 0 0

[0106] The color value of Monascus purpureus S-19 was significantly higher than that of S-14, S-3, and S-4, and there was a significant difference with the other strains. After statistical analysis, p < 0.05. S-19 was preserved and the strain preservation number obtained was CGMCC No. 41415.

[0107] Example 3 Research on mixed bacterial flora fermentation process of highland barley

[0108] 2.1 Test methods

[0109] In order to explore the effect of composite flora on the pigment production of highland barley substrate fermentation, a composite method was first designed. In the first treatment, the first-level seed liquid of a single strain was inoculated into a sterile modified sand liquid medium at 240r / min. After 48h of cultivation, it was inoculated into highland barley medium in proportion. In the second treatment, a single strain was inoculated into a sterile modified sand liquid medium at 240r / min for 48h and then inoculated into highland barley medium. The composite inoculation ratios of Monascus fusca with a preservation number of CGMCC No.41287 and S-14, and Monascus fusca with a preservation number of CGMCC No.41287 and Monascus purpureus with a preservation number of CGMCC No.41415 were compounded at 1:1, 1:2, and 2:1 and inoculated into highland barley medium.

[0110] 2.1.1 Main reagents

[0111] Megazyme mixed β-glucan test kit, copper sulfate, potassium sulfate, sulfuric acid, sodium hydroxide, p-nitrophenol, sodium acetate, anhydrous sodium acetate, acetic acid, 37% formaldehyde, acetylacetone, anhydrous ethanol, phenol.

[0112] 2.1.2 Main instruments and equipment See Table 2

[0113] 2.1.3 Determination of protein content in fermented highland barley

[0114] It is measured according to the method specified in the existing national standard GB5009.5-2016.

[0115] 2.1.4 Determination of crude polysaccharide content in fermented highland barley

[0116] It is determined according to the method specified in the existing implementation standard SN / T 4260-2015.

[0117] 2.1.5 Determination of β-glucan content in fermented highland barley

[0118] The determination is based on the method specified in the existing saffron yeast implementation standard XZ-BC-2016-2020.

[0119] 2.2 Experimental Results

[0120] 2.2.1 Effects of mixed bacterial flora on highland barley fermentation

[0121] Table 5

[0122]

[0123] As shown in Table 5, after the highland barley substrate was fermented by mixed bacterial communities, it metabolized and generated components that did not exist in the highland barley substrate, pigments and lovastatin. After the strains were cultured alone and mixed and inoculated into the highland barley culture medium, the color and lovastatin were higher. After the strains were mixed and cultured, the color and lovastatin were lower when inoculated into the highland barley culture medium.

[0124] 2.2.2 Effect of mixed bacterial fermentation ratio on highland barley fermentation

[0125] Table 6

[0126]

[0127]

[0128] As shown in Table 6, the color value is significantly higher when the mixed flora ratio is 1:2 than 1:1, and the color value is significantly higher when the mixed flora ratio is 1:1 than 2:1. Lovastatin is significantly higher when the mixed flora ratio is 2:1 than 1:1, and the color value is significantly higher when the mixed flora ratio is 1:1 than 1:2. Therefore, when the mixed flora ratio is 1:1, the color and lovastatin content produced by fermentation are both moderate.

[0129] Table 7

[0130]

[0131] As shown in Table 7, the content of metabolites produced by mixed bacterial fermentation is higher than that of a single strain, Monascus rubrum with a preservation number of CGMCC No.41287. Through comprehensive indicators, it was found that the fermentation effect of Monascus rubrum with a preservation number of CGMCC No.41287 + Monascus purpurogenum with a preservation number of CGMCC No.41415 was better.

[0132] Example 4 Effect of composite bacterial fermentation time on the quality of highland barley red yeast rice

[0133] 3.1 Test methods

[0134] The high-temperature fermentation temperature is set at 28-30°C, the low-temperature fermentation temperature is 20-22°C, the high-temperature fermentation time is uniformly 6 days, and the low-temperature fermentation temperature is set to 3d, 4d, 5d, 6d, and 7d.

[0135] 3.2 Experimental Results

[0136] Table 8

[0137]

[0138] As shown in Table 8, the color value and lovastatin of the Monascus rubrum with a preservation number of CGMCC No. 41287 + Monascus rubrum with a preservation number of CGMCC No. 41415 fermentation at low temperature on the 6th day were significantly higher than those on the 3rd, 4th and 5th days, and there was no significant difference on the 6th and 7th days. Therefore, the Monascus rubrum with a preservation number of CGMCC No. 41287 + Monascus rubrum with a preservation number of CGMCC No. 41415 can be fermented at low temperature until the 6th day.

[0139] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Monascus purpureus with a deposit number of CGMCC No. 41415 or Monascus pilosus with a deposit number of CGMCC No. 41287.

2. A composite strain comprising the Monascus purpurogenum described in claim 1 and the Monascus pubescens described in claim 1.

3. The composite strain according to claim 2, characterized in that: The number ratio of Monascus pubescens to Monascus purpurogenum is (1-2):(1-2).

4. The composite bacterial strain according to claim 3, characterized in that: The quantity ratio of Monascus pubescens to Monascus purpurogenum is 1:

1.

5. Use of the Monascus purpurogenum according to claim 1, the Monascus pubescens according to claim 1 and / or the composite strain according to any one of claims 2 to 4 in the preparation of fermented red yeast rice.

6. A method for preparing fermented red yeast rice, comprising: The Monascus pubescens described in claim 1, the Monascus purpurogenum described in claim 1 or the composite strain described in any one of claims 2 to 4 is inoculated into a fermentation substrate containing highland barley, and then fermented.

7. The preparation method according to claim 6, characterized in that: The fermentation matrix comprises the following raw materials in parts by weight: 40 to 100 parts of highland barley, 5 to 12 parts of bran, 2 to 5 parts of soybean meal and 20 to 45 parts of nutrient solution; The nutrient solution consists of water, a carbon source, a nitrogen source and inorganic salts, wherein: The carbon source is sucrose and / or glucose; The nitrogen sources are glutamate and / or histidine; The inorganic salt is calcium nitrate, sodium nitrate and / or potassium dihydrogen phosphate.

8. The preparation method according to claim 6, characterized in that: The Monascus pubescens and Monascus purpurogenus in the composite bacteria were activated and inoculated into the fermentation matrix. The activation comprises: inoculating the Monascus pubescens and / or Monascus purpurogenus into a sterilized modified Sabouraud liquid culture medium, culturing at 30°C and 240 r / min in the dark for 48 hours, spreading the diluted liquid on a modified Sabouraud agar plate culture medium, picking a single colony for passage, collecting spores after 6 to 7 days at 28 to 30°C, and culturing the spores in a fermenter at a ratio of 0.1% to 0.2% for 48 to 72 hours to obtain a secondary seed liquid.

9. The preparation method according to claim 6, characterized in that: The inoculation volume is 40-60 mL, and the fermentation conditions include fermentation at 28-30° C. for 6 days and then fermentation at 20-22° C. for 3-7 days.

10. Fermented red yeast rice obtained by the preparation method according to any one of claims 6 to 9.

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