Special monascus culture medium capable of resisting infectious microbe pollution and preparation method of special monascus culture medium

Abstract

The invention provides a special monascus culture medium capable of resisting infectious microbe pollution and a preparation method of the special monascus culture medium, and relates to the technical field. Comprising the following raw materials in parts by weight: 50 to 70 parts of rice flour, 20 to 30 parts of corn flour, 10 to 20 parts of soybean meal, 10 to 15 parts of bran, 5 to 10 parts of glucose, 3 to 5 parts of peptone, 2 to 4 parts of yeast extract, 0.5 to 1 part of monopotassium phosphate, 0.3 to 0.5 part of magnesium sulfate, 0.2 to 0.4 part of sodium chloride, 0.1 to 0.3 part of potassium sorbate and 500 to 800 parts of water. Infectious microbes in the culture medium can be effectively killed, and the sterile state of the culture medium is ensured; other ingredients are added at a proper temperature, so that the damage of high temperature to nutritional ingredients and infectious microbe resistant agents is avoided; the pH value is adjusted to a range suitable for the growth of the monascus, so that the growth and reproduction of the monascus are facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of microbial culture, in particular to a special culture medium for Monascus spp. that is resistant to contamination by miscellaneous bacteria and a preparation method thereof. Background Art

[0002] Monascus is an important industrial microorganism with extensive applications in the food, pharmaceutical, and chemical industries. It produces a variety of economically valuable metabolites, including monascus pigment and monacolin K. During the cultivation process, the culture medium is fundamental to its growth and metabolism, and the quality of the culture medium directly impacts its growth and metabolite production. However, contamination by foreign bacteria is a common and serious problem during the cultivation process. These bacteria compete with Monascus for nutrients and living space, inhibiting its growth, reducing metabolite production, and even producing harmful substances, impacting product quality and safety. Currently, common methods for preventing foreign bacterial contamination include strict aseptic techniques and the use of antibiotics. However, strict aseptic techniques require high equipment and technical requirements, increasing production costs. The use of antibiotics can lead to the development of drug-resistant bacteria and adversely affect the growth and metabolism of Monascus.

[0003] Therefore, it is of great practical significance to develop a special culture medium and a preparation method thereof that can effectively resist contamination by foreign bacteria while not affecting the growth and metabolism of Monascus. Summary of the Invention

[0004] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a special culture medium for Monascus spp. that is resistant to contamination by miscellaneous bacteria and a preparation method thereof.

[0005] To achieve the above object, the present invention adopts the following technical scheme: a special culture medium for Monascus that is resistant to contamination by miscellaneous bacteria, comprising the following raw materials in parts by weight: 50-70 parts of rice flour, 20-30 parts of corn flour, 10-20 parts of soybean meal powder, 10-15 parts of bran, 5-10 parts of glucose, 3-5 parts of peptone, 2-4 parts of yeast extract, 0.5-1 part of potassium dihydrogen phosphate, 0.3-0.5 part of magnesium sulfate, 0.2-0.4 part of sodium chloride, 0.1-0.3 part of potassium sorbate, and 500-800 parts of water.

[0006] Furthermore, the special culture medium for Monascus purpurogenous bacteria that is resistant to contamination by miscellaneous bacteria includes the following raw materials in parts by weight: 60 parts of rice flour, 25 parts of corn flour, 15 parts of soybean meal powder, 12 parts of bran, 8 parts of glucose, 4 parts of peptone, 3 parts of yeast extract, 0.8 parts of potassium dihydrogen phosphate, 0.4 parts of magnesium sulfate, 0.3 parts of sodium chloride, 0.2 parts of potassium sorbate, and 600 parts of water.

[0007] A method for preparing a special culture medium for Monascus spp. that is resistant to contamination by miscellaneous bacteria comprises the following steps:

[0008] S1: Weigh the raw materials according to the above weight parts;

[0009] S2: Evenly mixing rice flour, corn flour, soybean meal flour and bran to obtain mixed flour;

[0010] S3: Add water to the mixed powder and stir evenly to obtain a culture medium slurry;

[0011] S4: heating the culture medium slurry to boiling, maintaining boiling and stirring for 30-60 minutes for sterilization and gelatinization;

[0012] S5: When the culture medium slurry is cooled to 50-60°C, glucose, peptone, yeast extract, potassium dihydrogen phosphate, magnesium sulfate, sodium chloride and potassium sorbate are added and stirred evenly;

[0013] S6: adjusting the pH value of the mixed culture medium to 5.0-6.0;

[0014] S7: The culture medium with adjusted pH value is divided into culture containers and sterilized to obtain the special culture medium for Monascus spp. that is resistant to contamination by miscellaneous bacteria.

[0015] Furthermore, in step S4, the mixture is heated to boiling and then kept in a boiling state and stirred for 45 minutes.

[0016] Furthermore, in step S6, hydrochloric acid or sodium hydroxide solution is used to adjust the pH value.

[0017] Furthermore, in step S7, the sterilization treatment conditions are 121° C. and 15-20 minutes.

[0018] Compared with the prior art, the advantages and positive effects of the present invention are:

[0019] The special culture medium for Monascus urticae that is resistant to contamination by miscellaneous bacteria provided by the present invention is characterized by the rational selection of raw materials and their proportions, and the addition of potassium sorbate as an antibacterial agent. Potassium sorbate is a safe and efficient preservative that can inhibit the growth of various miscellaneous bacteria while having no adverse effects on the growth and metabolism of Monascus urticae. In addition, raw materials such as rice flour, corn flour, soybean meal powder and bran in the culture medium provide rich nutrients for Monascus urticae, while glucose, peptone and yeast extract further supplement the carbon source, nitrogen source and growth factors required for the growth of Monascus urticae. Inorganic salts such as potassium dihydrogen phosphate, magnesium sulfate and sodium chloride maintain the osmotic pressure and pH value of the culture medium, which is conducive to the growth of Monascus urticae and the synthesis of metabolites.

[0020] The preparation method of the present invention is simple and easy to implement. Through heating gelatinization and sterilization treatment, miscellaneous bacteria in the culture medium can be effectively killed to ensure the sterility of the culture medium; other components are added at a suitable temperature to avoid the destruction of nutrients and antibacterial agents by high temperature; and the pH value is adjusted to a range suitable for the growth of Monascus, which is conducive to the growth and reproduction of Monascus. DETAILED DESCRIPTION

[0021] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described below in conjunction with the embodiments. It should be noted that, in the absence of conflict, the embodiments of the present application and the features therein can be combined with each other.

[0022] In the description of the present invention, it should be understood that terms such as "length," "width," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," and "outside" indicating positions or locations are intended solely to facilitate description and simplify the present invention. They do not indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, in the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

[0023] Example 1

[0024] A special culture medium for Monascus spp. which is resistant to contamination by miscellaneous bacteria, comprises the following raw materials in parts by weight: 50 parts of rice flour, 20 parts of corn flour, 10 parts of soybean meal powder, 10 parts of bran, 5 parts of glucose, 3 parts of peptone, 2 parts of yeast extract, 0.5 parts of potassium dihydrogen phosphate, 0.3 parts of magnesium sulfate, 0.2 parts of sodium chloride, 0.1 parts of potassium sorbate, and 500 parts of water.

[0025] The preparation method is as follows:

[0026] S1: Weigh the raw materials according to the above weight parts;

[0027] S2: Evenly mixing rice flour, corn flour, soybean meal flour and bran to obtain mixed flour;

[0028] S3: Add water to the mixed powder and stir evenly to obtain a culture medium slurry;

[0029] S4: heating the culture medium slurry to boiling, maintaining boiling and stirring for 30 minutes for sterilization and gelatinization;

[0030] S5: When the culture medium slurry is cooled to 50°C, glucose, peptone, yeast extract, potassium dihydrogen phosphate, magnesium sulfate, sodium chloride and potassium sorbate are added and stirred evenly;

[0031] S6: Adjust the pH of the culture medium to 5.0 using hydrochloric acid solution;

[0032] S7: The culture medium with adjusted pH value is divided into culture containers and sterilized at 121° C. for 15 minutes to obtain the special culture medium for Monascus spp. that is resistant to contamination by other bacteria.

[0033] Example 2

[0034] A special culture medium for Monascus spp. which is resistant to contamination by miscellaneous bacteria, comprises the following raw materials in parts by weight: 60 parts of rice flour, 25 parts of corn flour, 15 parts of soybean meal powder, 12 parts of bran, 8 parts of glucose, 4 parts of peptone, 3 parts of yeast extract, 0.8 parts of potassium dihydrogen phosphate, 0.4 parts of magnesium sulfate, 0.3 parts of sodium chloride, 0.2 parts of potassium sorbate, and 600 parts of water.

[0035] The preparation method is as follows:

[0036] S1: Weigh the raw materials according to the above weight parts;

[0037] S2: Evenly mixing rice flour, corn flour, soybean meal flour and bran to obtain mixed flour;

[0038] S3: Add water to the mixed powder and stir evenly to obtain a culture medium slurry;

[0039] S4: heating the culture medium slurry to boiling, maintaining boiling and stirring for 45 minutes for sterilization and gelatinization;

[0040] S5: When the culture medium slurry is cooled to 55°C, glucose, peptone, yeast extract, potassium dihydrogen phosphate, magnesium sulfate, sodium chloride and potassium sorbate are added and stirred evenly;

[0041] S6: Use hydrochloric acid solution to adjust the pH value of the culture medium to 5.5;

[0042] S7: The culture medium with adjusted pH value is divided into culture containers and sterilized at 121° C. for 18 minutes to obtain the special culture medium for Monascus spp. that is resistant to contamination by other bacteria.

[0043] Example 3

[0044] A special culture medium for Monascus spp. which is resistant to contamination by miscellaneous bacteria, comprises the following raw materials in parts by weight: 70 parts of rice flour, 30 parts of corn flour, 20 parts of soybean meal powder, 15 parts of bran, 10 parts of glucose, 5 parts of peptone, 4 parts of yeast extract, 1 part of potassium dihydrogen phosphate, 0.5 parts of magnesium sulfate, 0.4 parts of sodium chloride, 0.3 parts of potassium sorbate, and 800 parts of water.

[0045] The preparation method is as follows:

[0046] S1: Weigh the raw materials according to the above weight parts;

[0047] S2: Evenly mixing rice flour, corn flour, soybean meal flour and bran to obtain mixed flour;

[0048] S3: Add water to the mixed powder and stir evenly to obtain a culture medium slurry;

[0049] S4: heating the culture medium slurry to boiling, maintaining boiling and stirring for 60 minutes for sterilization and gelatinization;

[0050] S5: When the culture medium slurry is cooled to 60°C, glucose, peptone, yeast extract, potassium dihydrogen phosphate, magnesium sulfate, sodium chloride and potassium sorbate are added and stirred evenly;

[0051] S6: Use hydrochloric acid solution to adjust the pH value of the culture medium to 6.0;

[0052] S7: The culture medium with adjusted pH value is divided into culture containers and sterilized at 121° C. for 20 minutes to obtain the special culture medium for Monascus spp. that is resistant to contamination by other bacteria.

[0053] Comparative Example 1

[0054] Compared with Example 2, potassium sorbate was not added, and other raw materials and preparation methods were the same.

[0055] Comparative Example 2

[0056] Compared with Example 2, potassium sorbate was replaced by sodium benzoate in equal parts by weight, and other raw materials and preparation methods were the same.

[0057] The culture media prepared in Examples 1-3 and Comparative Examples 1-2 were used to culture Monascus, respectively. The inoculation amount was 5%, the culture temperature was 30°C, and the culture time was 7 days. The growth of miscellaneous bacteria on the culture media was observed, and the biomass of Monascus and the yield of Monascus pigment were measured. The results are shown in the following table:

[0058]

[0059] From the experimental results, it can be seen that no foreign bacteria grew in the culture media of Examples 1-3, and the biomass and red koji pigment production of Monascus were high; in the culture medium of Comparative Example 1, since potassium sorbate was not added, a large amount of foreign bacteria grew, and the biomass and red koji pigment production of Monascus were significantly reduced; in the culture medium of Comparative Example 2, sodium benzoate was added as an anti-fungal agent. Although the growth of foreign bacteria was improved, a small amount of foreign bacteria still grew, and the biomass and red koji pigment production of Monascus were also lower than those of Example 2.

[0060] In summary, the special culture medium for Monascus resistant to contamination by foreign bacteria and the preparation method thereof provided by the present invention can effectively inhibit the growth of foreign bacteria, improve the culture efficiency of Monascus and the yield of metabolites, and have good application prospects.

[0061] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any other form. Any person skilled in the art may use the technical contents disclosed above to change or modify them into equivalent embodiments with equivalent changes for application in other fields. However, any simple modification, equivalent change and modification of the above embodiments made in accordance with the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A special culture medium for Monascus spp. that is resistant to contamination by miscellaneous bacteria, characterized in that: The invention comprises the following raw materials in parts by weight: 50-70 parts of rice flour, 20-30 parts of corn flour, 10-20 parts of soybean meal powder, 10-15 parts of bran, 5-10 parts of glucose, 3-5 parts of peptone, 2-4 parts of yeast extract, 0.5-1 part of potassium dihydrogen phosphate, 0.3-0.5 part of magnesium sulfate, 0.2-0.4 part of sodium chloride, 0.1-0.3 part of potassium sorbate and 500-800 parts of water.

2. The Monascus spp. special culture medium for resisting contamination by miscellaneous bacteria according to claim 1, wherein: The special culture medium for Monascus spp. that is resistant to contamination by miscellaneous bacteria comprises the following raw materials in parts by weight: 60 parts of rice flour, 25 parts of corn flour, 15 parts of soybean meal powder, 12 parts of bran, 8 parts of glucose, 4 parts of peptone, 3 parts of yeast extract, 0.8 parts of potassium dihydrogen phosphate, 0.4 parts of magnesium sulfate, 0.3 parts of sodium chloride, 0.2 parts of potassium sorbate, and 600 parts of water.

3. The method for preparing the special culture medium for Monascus spp. resistant to contamination by miscellaneous bacteria according to claim 1, wherein The following steps are involved: S1: Weigh the raw materials according to the above weight parts; S2: Evenly mixing rice flour, corn flour, soybean meal flour and bran to obtain mixed flour; S3: Add water to the mixed powder and stir evenly to obtain a culture medium slurry; S4: heating the culture medium slurry to boiling, maintaining boiling and stirring for 30-60 minutes for sterilization and gelatinization; S5: When the culture medium slurry is cooled to 50-60°C, glucose, peptone, yeast extract, potassium dihydrogen phosphate, magnesium sulfate, sodium chloride and potassium sorbate are added and stirred evenly; S6: adjusting the pH value of the mixed culture medium to 5.0-6.0; S7: The culture medium with adjusted pH value is divided into culture containers and sterilized to obtain the special culture medium for Monascus spp. that is resistant to contamination by miscellaneous bacteria.

4. The method for preparing the special culture medium for Monascus spp. resistant to contamination by miscellaneous bacteria according to claim 1, wherein: In step S4, the mixture is heated to boiling and then kept in a boiling state and stirred for 45 minutes.

5. The method for preparing the special culture medium for Monascus spp. resistant to contamination by miscellaneous bacteria according to claim 1, wherein: In step S6, hydrochloric acid or sodium hydroxide solution is used to adjust the pH value.

6. The method for preparing the special culture medium for Monascus purpurogenous bacteria according to claim 1, wherein: In step S7, the sterilization treatment conditions are 121° C. and 15-20 minutes.

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