Medium and method for the fermentative production of arginine

Abstract

The application discloses a culture medium and a method for fermentative production of arginine, and relates to the technical field of biology. The culture medium comprises the following components: 10g / L of glucose, 15-20g / L of corn syrup dry powder, 20-30g / L of sugarcane molasses, 0.5-1g / L of ornithine, 2g / L of magnesium sulfate, 1g / L of betaine, 6g / L of potassium dihydrogen phosphate, 1g / L of citric acid, 1g / L of sodium glutamate, 0.02g / L of ferrous sulfate, 0.075g / L of manganese sulfate, 0.003g / L of biotin and 0.004g / L of vitamin B2. The application designs a low-cost and high-efficiency culture medium formula, and combines with stage-by-stage fermentation process optimization, so that the yield and production efficiency of arginine are remarkably improved, and the application is especially suitable for industrialized production of arginine.

Description

A culture medium and method for fermenting arginine production Technical Field

[0001] This invention relates to the field of biotechnology, and in particular to a culture medium and method for fermenting and producing arginine. Background Technology

[0002] L-arginine is an important amino acid widely used in the pharmaceutical, food, and feed industries. Currently, it is mainly produced through microbial fermentation, but traditional processes suffer from low yield and high cost.

[0003] Currently, the main methods for producing L-arginine include natural extraction, chemical synthesis, and microbial fermentation. Natural extraction methods primarily isolate arginine from hydrolysates of animal and plant proteins, but these methods suffer from limited raw material sources, low yields, and insufficient purity, making large-scale application difficult. Chemical synthesis can be achieved through the Strecker reaction or guanidinolation pathway, but it faces challenges such as difficulty in chiral control, numerous byproducts, and environmental pollution, and it struggles to meet the optical purity requirements of pharmaceutical-grade products. In contrast, microbial fermentation, due to its mild conditions, environmental friendliness, and ease of achieving chiral specificity, is gradually becoming the mainstream process.

[0004] Existing arginine fermentation technology using *Escherichia coli* suffers from the following problems: 1. Traditional culture media (such as LB medium) rely on expensive organic nitrogen sources, limiting the economic viability of large-scale production; 2. The culture medium composition is not optimized for the arginine metabolic pathway, resulting in low utilization rates of carbon and nitrogen sources and excessive accumulation of byproducts; 3. Improper control of parameters such as dissolved oxygen and pH during fermentation affects strain growth and product synthesis efficiency. Therefore, developing a low-cost, high-efficiency culture medium formulation and optimizing the fermentation process is crucial for promoting the industrialization of arginine. Summary of the Invention

[0005] The purpose of this invention is to provide a culture medium and method for the fermentation production of arginine, thereby solving the problems existing in the prior art. The culture medium provided by this invention, when applied to the fermentation production of arginine, can significantly improve the yield and production efficiency of arginine.

[0006] To achieve the above objectives, the present invention provides the following solution:

[0007] This invention provides a fermentation medium for Escherichia coli that produces arginine, comprising the following components: 10 g / L glucose, 15-25 g / L corn steep liquor powder, 20-30 g / L cane molasses, 0.5-1 g / L ornithine, 2 g / L magnesium sulfate, 1 g / L betaine, 6 g / L potassium dihydrogen phosphate, 1 g / L citric acid, 1 g / L monosodium glutamate, 0.02 g / L ferrous sulfate, 0.075 g / L manganese sulfate, 0.003 g / L biotin, and 0.004 g / L vitamin B2.

[0008] Furthermore, the Escherichia coli was deposited on September 3, 2024, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 31851.

[0009] Preferably, the fermentation medium comprises the following components: glucose 10 g / L, corn steep liquor powder 20 g / L, sugarcane molasses 25 g / L, ornithine 0.75 g / L, magnesium sulfate 2 g / L, betaine 1 g / L, potassium dihydrogen phosphate 6 g / L, citric acid 1 g / L, monosodium glutamate 1 g / L, ferrous sulfate 0.02 g / L, manganese sulfate 0.075 g / L, biotin 0.003 g / L, and vitamin B2 0.004 g / L.

[0010] The present invention also provides the application of the above-mentioned fermentation medium in the production of arginine by fermentation using Escherichia coli.

[0011] This invention also provides a method for producing arginine by fermentation, comprising the following steps:

[0012] After activating the arginine-producing bacteria, seed culture was carried out to obtain seed solution;

[0013] The seed culture was inoculated into a fermentation medium and fermented to obtain arginine fermentation broth;

[0014] The fermentation medium comprises the following components: glucose 10 g / L, corn steep liquor powder 15-20 g / L, sugarcane molasses 20-30 g / L, ornithine 0.5-1 g / L, magnesium sulfate 2 g / L, betaine 1 g / L, potassium dihydrogen phosphate 6 g / L, citric acid 1 g / L, monosodium glutamate 1 g / L, ferrous sulfate 0.02 g / L, manganese sulfate 0.075 g / L, biotin 0.003 g / L, and vitamin B2 0.004 g / L;

[0015] The arginine-producing bacterium is Escherichia coli, which was deposited on September 3, 2024, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 31851.

[0016] Preferably, the fermentation medium comprises the following components: glucose 10 g / L, corn steep liquor powder 20 g / L, sugarcane molasses 25 g / L, ornithine 0.75 g / L, magnesium sulfate 2 g / L, betaine 1 g / L, potassium dihydrogen phosphate 6 g / L, citric acid 1 g / L, monosodium glutamate 1 g / L, ferrous sulfate 0.02 g / L, manganese sulfate 0.075 g / L, biotin 0.003 g / L, and vitamin B2 0.004 g / L.

[0017] Furthermore, the seed culture medium used for the seed culture includes the following components: 25 g / L glucose, 2 g / L magnesium sulfate heptahydrate, 4 g / L potassium dihydrogen phosphate, 4 g / L yeast extract, 5 g / L peptone, 1 g / L sodium glutamate, and 1 g / L citric acid.

[0018] Furthermore, during the fermentation process, the aeration rate is controlled at 10-20 L / min, the rotation speed is controlled at 200-700 rpm, and the tank pressure is controlled at 0.05-0.06 MPa.

[0019] Furthermore, during the fermentation process, the temperature was controlled at 37°C, pH 7.0, and dissolved oxygen at 30-40% during the first 0-24 hours; after 24 hours, the temperature was controlled at 34°C, pH 6.9, and dissolved oxygen at 20-25%.

[0020] Furthermore, during the fermentation process, a mixed solution of glucose and betaine, and a mixed solution of monosodium glutamate and ammonium sulfate are added, controlling the ammonium ion concentration to be 0.5-1 g / L and the residual sugar concentration to be below 0.5 g / L; wherein the mixed solution of glucose and betaine comprises 650 g / L glucose and 1 g / L betaine; and the mixed solution of monosodium glutamate and ammonium sulfate comprises 200 g / L ammonium sulfate and 160 g / L monosodium glutamate.

[0021] The present invention discloses the following technical effects:

[0022] This invention significantly improves the yield and efficiency of arginine production by designing a low-cost, high-efficiency culture medium formulation and optimizing a staged fermentation process. The method for producing arginine by fermentation in this invention achieves high-efficiency arginine production through optimized carbon and nitrogen sources and dynamic control of fermentation parameters. By adding ornithine exogenously, this invention bypasses upstream metabolic steps (such as N-acetylglutamate synthesis), reducing the synthetic burden on the cells and providing more precursors for arginine synthesis. This allows more carbon sources to be used for arginine synthesis rather than growth, thereby increasing arginine yield. This invention offers advantages such as low culture medium cost, high yield, and stable process, making it suitable for the industrial production of arginine in the food, pharmaceutical, and feed industries. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 is a 3D model of the effect of corn steep liquor powder and sugarcane molasses on Escherichia coli yield; where A represents corn steep liquor powder and B represents sugarcane molasses.

[0025] Figure 2 is a 3D model diagram showing the effect of corn steep liquor powder and ornithine on Escherichia coli yield; where A represents corn steep liquor powder and C represents ornithine.

[0026] Figure 3 is a 3D model of the effect of sugarcane molasses and ornithine on Escherichia coli yield; where B represents sugarcane molasses and C represents ornithine.

[0027] Figure 4 is a comparison chart of arginine yield and OD value between Example 1 and Comparative Example 1. Detailed Implementation

[0028] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0029] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0030] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0031] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0032] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0033] The arginine-producing bacteria used in this invention is Escherichia coli JA-6, which was deposited on September 3, 2024, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 31851.

[0034] Example 1

[0035] The seed culture medium formula is as follows: glucose 25g / L, magnesium sulfate heptahydrate 2g / L, potassium dihydrogen phosphate 4g / L, yeast extract 4g / L, peptone 5g / L, monosodium glutamate 1g / L and citric acid 1g / L.

[0036] The fermentation medium formula is as follows: glucose 10g / L, corn steep liquor powder 20g / L, sugarcane molasses 25g / L, ornithine 0.75g / L, magnesium sulfate 2g / L, betaine 1g / L, potassium dihydrogen phosphate 6g / L, citric acid 1g / L, monosodium glutamate 1g / L, ferrous sulfate 0.02g / L, manganese sulfate 0.075g / L, biotin 0.003g / L, and vitamin B2 0.004g / L.

[0037] Arginine is produced by fermentation using the above-mentioned seed culture medium and fermentation culture medium, as follows:

[0038] 1. Transfer Escherichia coli JA-6 from the glycerol tube to the slant of a flask and incubate for 16 hours;

[0039] 2. After the culture in the eggplant-shaped flasks is complete, the inoculum is washed with 20 mL of physiological saline and then transferred to a seed tank containing seed culture medium. After culturing for 7 hours, the seed solution is obtained.

[0040] 3. Inoculate the seed culture at 15% by volume into a 50L fermenter containing 20L of fermentation medium and incubate for 48 hours to obtain arginine fermentation broth. The specific fermentation conditions and feeding procedures are as follows:

[0041] During the fermentation cycle of 0-24h, the temperature is controlled at 37℃, pH at 7.0, and dissolved oxygen at 30-40%; after 24h, the temperature is controlled at 34℃, pH at 6.9, and dissolved oxygen at 20-25%.

[0042] The initial ventilation rate is 10 L / min, the rotation speed is 200 rpm, and the tank pressure is 0.05 MPa. The rotation speed, ventilation rate, and tank pressure are alternately increased according to the dissolved oxygen demand. The ventilation rate is controlled at 10-20 L / min, the rotation speed is controlled at 200-700 rpm, and the tank pressure is controlled at 0.05-0.06 MPa.

[0043] During fermentation, a mixed solution of glucose and betaine, and a mixed solution of monosodium glutamate and ammonium sulfate are fed in, controlling the ammonium ion concentration at 0.5-1 g / L and the residual sugar at 0-0.5 g / L. The mixed solution of glucose and betaine consists of 650 g / L glucose and 1 g / L betaine; the mixed solution of monosodium glutamate and ammonium sulfate consists of 200 g / L ammonium sulfate and 160 g / L monosodium glutamate. The feeding process in this embodiment is shown in Tables 1 and 2.

[0044] Table 1. Flow rate of the mixed solution of glucose and betaine in Example 1

[0045]

[0046]

[0047] Table 2. Flow rate of the mixed solution of sodium glutamate and ammonium sulfate in Example 1

[0048] Cycle / h Flow Acceleration Rate (mL / h) 8-10h 50 11-14h 100 15-16h 150 17-18h 180 19-48h 160 surface

[0049] Example 2

[0050] The seed culture medium formula is as follows: glucose 25g / L, magnesium sulfate heptahydrate 2g / L, potassium dihydrogen phosphate 4g / L, yeast extract 4g / L, peptone 5g / L, monosodium glutamate 1g / L and citric acid 1g / L.

[0051] The fermentation medium formula is as follows: glucose 10g / L, corn steep liquor powder 20g / L, sugarcane molasses 25g / L, ornithine 0.75g / L, magnesium sulfate 2g / L, betaine 1g / L, potassium dihydrogen phosphate 6g / L, citric acid 1g / L, monosodium glutamate 1g / L, ferrous sulfate 0.02g / L, manganese sulfate 0.075g / L, biotin 0.003g / L, and vitamin B2 0.004g / L.

[0052] Arginine is produced by fermentation using the above-mentioned seed culture medium and fermentation culture medium, as follows:

[0053] 1. Transfer Escherichia coli JA-6 from the glycerol tube to the slant of a flask and incubate for 15 hours;

[0054] 2. After the culture in the eggplant-shaped flasks is complete, the inoculum is washed with 20 mL of physiological saline and then transferred to a seed tank containing seed culture medium. After culturing for 8 hours, the seed solution is obtained.

[0055] 3. Inoculate the seed culture at 15% by volume into a 50L fermenter containing 20L of fermentation medium and incubate for 46 hours to obtain arginine fermentation broth. The specific fermentation conditions and feeding procedures are as follows:

[0056] During the fermentation cycle of 0-24h, the temperature is controlled at 37℃, pH at 7.0, and dissolved oxygen at 30-40%; after 24h, the temperature is controlled at 34℃, pH at 6.9, and dissolved oxygen at 20-25%.

[0057] The initial ventilation rate is 10 L / min, the rotation speed is 200 rpm, and the tank pressure is 0.05 MPa. The rotation speed, ventilation rate, and tank pressure are alternately increased according to the dissolved oxygen demand. The ventilation rate is controlled at 10-20 L / min, the rotation speed is controlled at 200-700 rpm, and the tank pressure is controlled at 0.05-0.06 MPa.

[0058] During fermentation, a mixed solution of glucose and betaine, and a mixed solution of monosodium glutamate and ammonium sulfate are fed in, controlling the ammonium ion concentration at 0.5-1 g / L and the residual sugar at 0-0.5 g / L. The mixed solution of glucose and betaine consists of 650 g / L glucose and 1 g / L betaine; the mixed solution of monosodium glutamate and ammonium sulfate consists of 200 g / L ammonium sulfate and 160 g / L monosodium glutamate. The feeding process in this embodiment is shown in Tables 3 and 4.

[0059] Table 3. Flow rate of the mixed solution of glucose and betaine in Example 2

[0060]

[0061]

[0062] Table 4. Flow rate of the mixed solution of sodium glutamate and ammonium sulfate in Example 2

[0063] Cycle / h Flow Acceleration Rate (mL / h) 8-10h 55 11-14h 95 15-16h 155 17-18h 175 19-48h 165 surface

[0064] Example 3

[0065] The seed culture medium formula is as follows: glucose 25g / L, magnesium sulfate heptahydrate 2g / L, potassium dihydrogen phosphate 4g / L, yeast extract 4g / L, peptone 5g / L, monosodium glutamate 1g / L and citric acid 1g / L.

[0066] The fermentation medium formula is as follows: glucose 10g / L, corn steep liquor powder 20g / L, sugarcane molasses 25g / L, ornithine 0.75g / L, magnesium sulfate 2g / L, betaine 1g / L, potassium dihydrogen phosphate 6g / L, citric acid 1g / L, monosodium glutamate 1g / L, ferrous sulfate 0.02g / L, manganese sulfate 0.075g / L, biotin 0.003g / L, and vitamin B2 0.004g / L.

[0067] Arginine is produced by fermentation using the above-mentioned seed culture medium and fermentation culture medium, as follows:

[0068] 1. Transfer Escherichia coli JA-6 from the glycerol tube to the slant of a flask and incubate for 18 hours;

[0069] 2. After the culture in the eggplant-shaped flasks is complete, the inoculum is washed with 20 mL of physiological saline and then transferred to a seed tank containing seed culture medium. After culturing for 6 hours, the seed solution is obtained.

[0070] 3. Inoculate the seed culture at 15% by volume into a 50L fermenter containing 20L of fermentation medium and incubate for 52 hours to obtain arginine fermentation broth. The specific fermentation conditions and feeding procedures are as follows:

[0071] During the fermentation cycle of 0-24h, the temperature is controlled at 37℃, pH at 7.0, and dissolved oxygen at 30-40%; after 24h, the temperature is controlled at 34℃, pH at 6.9, and dissolved oxygen at 20-25%.

[0072] The initial ventilation rate is 10 L / min, the rotation speed is 200 rpm, and the tank pressure is 0.05 MPa. The rotation speed, ventilation rate, and tank pressure are alternately increased according to the dissolved oxygen demand. The ventilation rate is controlled at 10-20 L / min, the rotation speed is controlled at 200-700 rpm, and the tank pressure is controlled at 0.05-0.06 MPa.

[0073] During fermentation, a mixed solution of glucose and betaine, and a mixed solution of monosodium glutamate and ammonium sulfate are fed in, controlling the ammonium ion concentration at 0.5-1 g / L and the residual sugar at 0-0.5 g / L. The mixed solution of glucose and betaine consists of 650 g / L glucose and 1 g / L betaine; the mixed solution of monosodium glutamate and ammonium sulfate consists of 200 g / L ammonium sulfate and 160 g / L monosodium glutamate. The feeding process in this embodiment is shown in Tables 5 and 6.

[0074] Table 5. Flow rate of the mixed solution of glucose and betaine in Example 3

[0075] Cycle / h Flow rate (mL / h) Base sugar depletion (5h) 120 6-7h 155 8h 165 9-12h 205 13-14h 225 15-16h 255 17-30h 305 31-36h 285 37-42h 245 43-48h 235 surface

[0076] Table 6. Flow rate of the mixed solution of sodium glutamate and ammonium sulfate in Example 3.

[0077] Cycle / h Flow Acceleration Rate (mL / h) 8-10h 45 11-14h 105 15-16h 145 17-18h 185 19-48h 155 surface

[0078] Experimental Example 1

[0079] Based on the initial fermentation medium formulation range, it was optimized, and the method for producing arginine by fermentation with Escherichia coli was the same as in Example 1.

[0080] Initial fermentation medium range: glucose 10 g / L, corn steep liquor powder 15-25 g / L, sugarcane molasses 20-30 g / L, ornithine 0.5-1 g / L, magnesium sulfate 2 g / L, betaine 1 g / L, potassium dihydrogen phosphate 6 g / L, citric acid 1 g / L, monosodium glutamate 1 g / L, ferrous sulfate 0.02 g / L, manganese sulfate 0.075 g / L, biotin 0.003 g / L, and vitamin B2 0.004 g / L.

[0081] The Box-Behnken experiment was used to investigate three factors that significantly affect arginine yield: corn steep liquor powder, sugarcane molasses, and ornithine. The effects of these three factors on yield were examined using arginine yield as the indicator. Each group was set up in triplicate. The experimental design and results for each factor and level are shown in Tables 7-8.

[0082] Table 7 Experimental Design for Each Factor and Level

[0083]

[0084]

[0085] Table 8. Analysis of Experimental Variance

[0086] Factors, sum of squares, degrees of freedom, mean square, F-value, P-value, model: 437.11948.5727.030.0010A-Corn steep liquor powder 0.32011 0.3201 0.1782 0.6905B-Sugarcane molasses 3.401 3.401 1.89 0.2276C-Ornithine 0.01971 0.0197 0.0109 0.9208AB 0.06621 0.0662 0.0369 0.8553AC 0.17511 0.1751 0.0975 0.7675BC 2.361 2.36 1.31 0.3036A 2 373.191373.19207.73 < 0.0001B 2 80.40180.4044.750.0011C 2 9.9019.905.510.0658 Residual 8.9851.80 / / Misfit 1.9730.65760.18760.8971 Pure Error 7.0123.50 / / Total Corrected Sum of Squares 446.0914 / / / surface

[0087] The results were fitted using multiple quadratic regression using Design Expert software, yielding the regression equation: Arginine production = 144.68 + 0.20*A - 0.6515*B ​​+ 0.0496*C + 0.1287*AB - 0.2092*AC - 0.7681*BC - 10.05A 2 -4.67B 2 -1.64C 2 Where A is the concentration of corn steep liquor powder, B is the concentration of sugarcane molasses, and C is the concentration of ornithine; the coefficients preceding A, B, and C are linear correlation coefficients. 2 B 2 C 2 The preceding coefficients are square coefficients, while the preceding coefficients for AB, AC, and BC are interaction coefficients.

[0088] An analysis graph was generated based on the regression equation to examine the shape of the response surface. The contour plots of the response surfaces for each factor are shown in Figures 1-3. The centers of the contour lines for the three response surfaces are all within the set range, indicating the existence of optimal conditions at the factor levels designed in this invention.

[0089] Optimal analysis of the three factors revealed that the optimal concentration of corn steep liquor powder was 20 g / L, the optimal concentration of sugarcane molasses was 25 g / L, and the optimal concentration of ornithine was 0.75 g / L.

[0090] Comparative Example 1

[0091] Same as Example 1, except that the fermentation medium formula is as follows: glucose 10g / L, corn steep liquor powder 20g / L, sugarcane molasses 25g / L, magnesium sulfate 2g / L, betaine 1g / L, potassium dihydrogen phosphate 6g / L, citric acid 1g / L, monosodium glutamate 1g / L, ferrous sulfate 0.02g / L, manganese sulfate 0.075g / L, biotin 0.003g / L and vitamin B2 0.004g / L.

[0092] In Example 1, the arginine yield after 48 hours of fermentation was 146.72 g / L, with a conversion rate of 53.3%. The concentrations of byproducts acetic acid and lactic acid were below 0.3 g / L and 0.2 g / L, respectively. In Comparative Example 1, the arginine yield after 48 hours of fermentation was 121.6 g / L, with a conversion rate of 48.6%, representing a 17% decrease in arginine yield compared to Example 1. This invention bypasses upstream metabolic steps (such as N-acetylglutamate synthesis) by exogenously adding ornithine, reducing the metabolic burden on the cells and providing more precursors for arginine synthesis. This allows more carbon sources to be used for arginine synthesis rather than growth, thereby increasing arginine yield. The arginine yield and cell mass of Example 1 and Comparative Example 1 are compared, as shown in Figure 4. The results show that in the early stage of fermentation, the cell mass accumulation in Example 1 was significantly faster than in Comparative Example 1. However, in the later stage of fermentation, the cell mass in Example 1 was significantly lower than in Comparative Example 1, but the arginine yield continued to increase. This indicates that this invention compensates for insufficient endogenous synthesis by exogenously adding ornithine, maintaining a smooth metabolic pathway.

[0093] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A fermentation medium for Escherichia coli that produces arginine, characterized in that, The contents include the following components: glucose 10 g / L, corn steep liquor powder 15-25 g / L, sugarcane molasses 20-30 g / L, ornithine 0.5-1 g / L, magnesium sulfate 2 g / L, betaine 1 g / L, potassium dihydrogen phosphate 6 g / L, citric acid 1 g / L, monosodium glutamate 1 g / L, ferrous sulfate 0.02 g / L, manganese sulfate 0.075 g / L, biotin 0.003 g / L, and vitamin B2 0.004 g / L; the *Escherichia coli* was deposited on September 3, 2024, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 31851.

2. The fermentation medium according to claim 1, characterized in that, The fermentation medium comprises the following components: glucose 10 g / L, corn steep liquor powder 20 g / L, sugarcane molasses 25 g / L, ornithine 0.75 g / L, magnesium sulfate 2 g / L, betaine 1 g / L, potassium dihydrogen phosphate 6 g / L, citric acid 1 g / L, monosodium glutamate 1 g / L, ferrous sulfate 0.02 g / L, manganese sulfate 0.075 g / L, biotin 0.003 g / L, and vitamin B2 0.004 g / L.

3. The use of a fermentation medium as described in any one of claims 1-2 in the fermentation production of arginine using Escherichia coli.

4. A method for producing arginine by fermentation, characterized in that, Includes the following steps: Arginine-producing bacteria were activated and then cultured in seed culture to obtain seed solution; The seed culture was inoculated into a fermentation medium and fermented to obtain arginine fermentation broth. The fermentation medium included the following components: glucose 10 g / L, corn steep liquor powder 15-20 g / L, sugarcane molasses 20-30 g / L, ornithine 0.5-1 g / L, magnesium sulfate 2 g / L, betaine 1 g / L, potassium dihydrogen phosphate 6 g / L, citric acid 1 g / L, monosodium glutamate 1 g / L, ferrous sulfate 0.02 g / L, manganese sulfate 0.075 g / L, biotin 0.003 g / L, and vitamin B2 0.004 g / L. The arginine-producing bacterium was Escherichia coli, which was deposited on September 3, 2024, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 31851.

5. The method according to claim 4, characterized in that, The fermentation medium comprises the following components: glucose 10 g / L, corn steep liquor powder 20 g / L, sugarcane molasses 25 g / L, ornithine 0.75 g / L, magnesium sulfate 2 g / L, betaine 1 g / L, potassium dihydrogen phosphate 6 g / L, citric acid 1 g / L, monosodium glutamate 1 g / L, ferrous sulfate 0.02 g / L, manganese sulfate 0.075 g / L, biotin 0.003 g / L, and vitamin B2 0.004 g / L.

6. The method according to claim 4, characterized in that, The seed culture medium used for the seed culture includes the following components: glucose 25 g / L, magnesium sulfate heptahydrate 2 g / L, potassium dihydrogen phosphate 4 g / L, yeast extract 4 g / L, peptone 5 g / L, monosodium glutamate 1 g / L and citric acid 1 g / L.

7. The method according to claim 4, characterized in that, During the fermentation process, the aeration rate is controlled at 10-20 L / min, the rotation speed is controlled at 200-700 rpm, and the tank pressure is controlled at 0.05-0.06 MPa.

8. The method according to claim 4, characterized in that, During the fermentation process, the temperature was controlled at 37°C, pH at 7.0, and dissolved oxygen at 30-40% during the first 0-24 hours; after 24 hours, the temperature was controlled at 34°C, pH at 6.9, and dissolved oxygen at 20-25%.

9. The method according to claim 4, characterized in that, During the fermentation process, a mixed solution of glucose and betaine, and a mixed solution of monosodium glutamate and ammonium sulfate are added, with the ammonium ion concentration controlled at 0.5-1 g / L and the residual sugar concentration below 0.5 g / L. The mixed solution of glucose and betaine consists of 650 g / L glucose and 1 g / L betaine; the mixed solution of monosodium glutamate and ammonium sulfate consists of 200 g / L ammonium sulfate and 160 g / L monosodium glutamate.

Images