Production method of arginine with content of 30%

Abstract

The invention discloses a production method of arginine with the content of 30%, and belongs to the technical field of microbial fermentation. Comprising the following steps: adding a filter membrane into arginine fermentation liquor, and filtering to remove thalli and insoluble impurities, so as to obtain arginine supernate; adjusting the pH value of the arginine supernate to 6.8-7.2, and then performing concentration through triple-effect concentration equipment to obtain arginine paste with the content of 50%; and mixing the arginine paste with a carrier and a bulking agent, stirring, granulating and drying to obtain arginine with the content of 30%. According to the method, the arginine fermentation liquor is subjected to primary concentration treatment by virtue of ceramic membrane filtration and evaporation concentration and then is adsorbed by virtue of a carrier, and in order to maintain the stability of the product in a high-humidity environment, silicone oil is selected as a waterproof agent and a bulking agent, so that the arginine product with the content of 30%, of which all properties meet the requirements, is produced. The production method of the low-purity arginine is simple to operate and low in product production cost, greatly reduces the separation and purification cost on the basis of meeting the quality requirement, has economic value and is green and environment-friendly.

Description

Technical Field

[0001] The invention belongs to the technical field of microbial fermentation, and in particular relates to a method for producing arginine with a content of 30%. Background Art

[0002] Arginine, as an important amino acid, plays a key role in living organisms. Its chemical name is 2-amino-5-guanidinopentanoic acid. Structurally, the arginine molecule consists of an amino group (-NH2), a carboxyl group (-COOH), and a guanidino group (-NH-C(=NH)-NH2). This unique structure gives arginine many special properties and functions. In the molecular structure of arginine, the amino and carboxyl groups are located at both ends of the molecule, and their presence gives arginine the properties of an amphoteric electrolyte, capable of reacting with both acids and bases. The guanidino group is the most special part of the arginine molecule. It has a strong alkalinity, making arginine alkaline in aqueous solution. Arginine can synthesize protein and promote muscle deposition and development; its metabolite NO can promote the generation and development of the blood circulation system, relieve stress, and improve embryo survival rate; its metabolite polyamines can promote the growth, development and repair of the small intestinal mucosa, and can also inhibit inflammation; the metabolite agmatine is a neurotransmitter that can promote the proliferation of lymphocytes and thymocytes and resist heat stress; the metabolite citrulline can be used to enhance sperm motility and treat sexual dysfunction, and can also generate guanidine acetic acid under the catalysis of transferase, and further catalyze the formation of creatine, providing a direct energy source for the body.

[0003] Currently, the main methods for producing arginine include chemical synthesis, enzymatic methods, plant extraction methods, protein hydrolysis methods, and fermentation methods. The former methods have multiple problems such as low product purity, large environmental load, and high energy consumption. In comparison, the fermentation method has the advantages of high output, environmental protection, and low energy consumption. However, the separation and purification process of high-purity arginine (98%) also requires the use of a large amount of chemical reagents and equipment, further increasing the cost. In the ion exchange method, the procurement cost of ion exchange resin is high, and the resin gradually loses its activity during use, requiring regular replacement, which increases production costs. In the membrane separation method, the membrane material is expensive, and the membrane has a limited service life and needs to be replaced regularly. At the same time, the energy consumption in the membrane separation process is also high. These factors have led to the high cost of producing high-purity arginine, reducing the market competitiveness of the product.

[0004] By constructing a recombinant strain, Corynebacterium glutamicum, to ferment and produce L-arginine, overexpressing key enzyme genes in the arginine biosynthesis pathway, the yield of industrial arginine production has increased by over 50%. In addition to high concentrations of L-arginine, fermentation broths typically also contain some microbial metabolites and residual fermentation medium. Typically, the fermentation broth is purified to produce a high-concentration, high-purity L-arginine purified solution. However, this method of L-arginine purification is costly. When arginine is used in animal feed, residual culture medium and microbial metabolites are also excellent nutrients for animals. Furthermore, low-concentration arginine products offer a cost advantage, eliminating the need for the addition of high-purity arginine. Therefore, developing a more environmentally friendly, low-cost, and effective 30% L-arginine production process for animal husbandry is of particular interest for the widespread application of fermentation-based L-arginine production. However, since 30% arginine is not crystallized, it easily absorbs moisture and forms lumps during use. Summary of the Invention

[0005] In order to solve the problems of high purification cost of 98% arginine fermentation broth and moisture absorption and agglomeration of 30% arginine in the prior art, the present invention provides a production method of 30% arginine.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for producing arginine with a content of 30%, comprising the following steps:

[0008] Step 1: Add a filter membrane to the arginine fermentation broth, filter and remove the bacteria and insoluble impurities to obtain the arginine supernatant;

[0009] Step 2: adjusting the pH of the arginine supernatant to 6.8-7.2, and then concentrating it through a triple-effect concentrator to obtain an arginine paste with a content of 50%;

[0010] Step 3: mixing the arginine paste with a carrier and a loosening agent, stirring, granulating, and drying to obtain arginine with a content of 30%.

[0011] The carrier used in the present invention, such as talcum powder, has a porous structure with a pore size distribution at the nanometer level. When arginine molecules enter these pores through diffusion, they are captured by the pores, thereby achieving adsorption. In addition, the carrier surface usually has a negative charge, while arginine molecules have a positive charge. When these oppositely charged molecules approach each other, electrostatic attraction is generated, thereby accelerating the adsorption process of the arginine molecules. At the same time, because arginine molecules have strong water absorption, they will absorb water and agglomerate. Loosening agents, such as silicone oil, can be tightly arranged on the surface of an object to form a continuous physical barrier layer. This barrier layer can prevent water molecules from directly contacting the surface of the protected object, thereby reducing the adsorption and penetration of water. Loosening agents can also fill these pores and uneven areas, making the surface smooth and flat, reducing the channels for water to enter, and improving the waterproof effect.

[0012] Furthermore, in step 1, the arginine concentration in the arginine fermentation broth is 97-100 g / L.

[0013] Furthermore, in step 2, the specific operation steps of the concentration include: sequentially passing through a first-effect evaporator, a second-effect evaporator, and a third-effect evaporator;

[0014] The evaporation temperature of the first-effect evaporator is 80-85°C and the vacuum degree is 0.025-0.04MPa;

[0015] The evaporation temperature of the second-effect evaporator is 70-75°C and the vacuum degree is 0.055-0.060MPa;

[0016] The evaporation temperature of the triple-effect evaporator is 60-65° C., and the vacuum degree is 0.08-0.085 MPa.

[0017] Furthermore, in step three, the added amount of the carrier is 40-55% of the mass of the arginine paste.

[0018] Furthermore, in step three, the carrier is selected from talc.

[0019] Furthermore, in step three, the loosening agent is selected from silicone oil.

[0020] Furthermore, in step three, the amount of the loosening agent added is 1-5% of the mass of the arginine paste.

[0021] Furthermore, in step three, the stirring speed is 500 rpm and the time is 2-4 hours.

[0022] Furthermore, in step three, the granulation time is 10-20 minutes.

[0023] Furthermore, in step three, the specific operation steps of drying are: drying at 70-100° C. until the moisture content of the sample is ≤13%.

[0024] Compared with the prior art, the present invention has the following advantages and technical effects:

[0025] The separation and purification method provided by the present invention is simple to operate and can reduce the amount of ion exchange resin used, thereby reducing the generation of resin wastewater. The obtained product has high purity and yield. The present invention not only meets quality standards but also excels in economic value and environmental protection. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0027] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0028] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0029] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments described herein without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the description of the invention. The description and examples are intended to be illustrative only.

[0030] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0031] The present invention utilizes ceramic membrane filtration and evaporative concentration to initially concentrate the arginine fermentation broth. Adsorption is then performed on a selected carrier. To maintain product stability in high-humidity environments, silicone oil is used as a waterproofing agent and bulking agent. This method produces a 30% arginine product that meets all performance requirements. This low-purity arginine production method is simple to operate, has low production costs, and significantly reduces separation and purification costs while meeting quality requirements. It is economically viable and environmentally friendly.

[0032] The "30% arginine content" mentioned in the present invention may have a slight error in the actual preparation process and fluctuate around 30%.

[0033] The embodiment of the present invention provides a method for producing arginine with a content of 30%, comprising the following steps:

[0034] Step 1: Add a filter membrane to the arginine fermentation broth, filter and remove the bacteria and insoluble impurities to obtain the arginine supernatant;

[0035] Step 2: adjusting the pH of the arginine supernatant to 6.8-7.2 (such as 6.9 or 7.0), and then concentrating it through a triple-effect concentrator to obtain an arginine paste with a content of 50%;

[0036] Step 3: mixing the arginine paste with a carrier and a loosening agent, stirring, granulating, and drying to obtain arginine with a content of 30%.

[0037] In some optional embodiments, in step 1, the arginine concentration in the arginine fermentation broth is 97-100 g / L, such as 90 g / L or 100 g / L.

[0038] In some optional embodiments, in step 2, the specific operation steps of the concentration include: sequentially passing through a first-effect evaporator, a second-effect evaporator, and a third-effect evaporator;

[0039] The evaporation temperature of the first-effect evaporator is 80-85°C, preferably 85°C, and the vacuum degree is 0.025-0.04MPa, preferably 0.04MPa;

[0040] The evaporation temperature of the second-effect evaporator is 70-75°C, preferably 75°C, and the vacuum degree is 0.055-0.060MPa, preferably 0.060MPa;

[0041] The evaporation temperature of the triple-effect evaporator is 60-65° C., preferably 65° C., and the vacuum degree is 0.08-0.085 MPa, preferably 0.085 MPa.

[0042] In some optional embodiments, in step three, the added amount of the carrier is 40-55% of the mass of the arginine paste, such as 48%, 50% or 55%, preferably 50%.

[0043] In some optional embodiments, in step three, the carrier is selected from one of rice husks, corn cob powder and talcum powder, preferably talcum powder.

[0044] In some optional embodiments, in step 3, the loosening agent can be selected from one of silicon dioxide, silicone oil, diatomaceous earth and calcium carbonate, preferably silicone oil. The loosening agent is sprayed by atomization so that the loosening agent can be evenly distributed on the surface of the arginine particles after the arginine paste and the carrier are mixed.

[0045] In some optional embodiments, in step three, the amount of the loosening agent added is 1-5% of the mass of the arginine paste, such as 1%, 2% or 4%, preferably 2%.

[0046] In some optional embodiments, in step three, the mixing speed is 500 rpm, and the mixing time is 2-4 hours, preferably 3 hours.

[0047] In some optional embodiments, in step three, the granulation time is 10-20 minutes, preferably 10-15 minutes, such as 10 minutes, 12 minutes or 15 minutes. The uniformity of the wet granules prepared under this condition is better. At this time, the moisture content of arginine in the wet granules after carrier adsorption is about 25-30%, and the arginine content is about 24%. Then, excess water in the wet granules is removed by hot air drying or the like to make the granules reach a suitable moisture content. Preferably, it is dried at 70-100°C to a sample moisture content of ≤13%, preferably between 9.4-10.2%; more preferably, it is dried at 80-90°C to a sample moisture content of ≤13%. During the drying process, samples can be taken regularly to detect the moisture content of the material. When the moisture content reaches the expected target, the drying is stopped.

[0048] Unless otherwise specified, the "room temperature" in the present invention refers to 20-30°C.

[0049] The raw materials used in the present invention are all purchased from the market.

[0050] The technical solution of the present invention is further illustrated by the following examples.

[0051] The arginine described in the present invention refers to L-arginine.

[0052] Example 1

[0053] A method for producing arginine with a content of 31.2%, comprising the following steps:

[0054] Step 1: taking an arginine fermentation broth with an initial fermentation broth concentration of 100 g / L, passing it through a ceramic filter membrane to remove bacteria and other large insoluble impurities to obtain an arginine supernatant;

[0055] Step 2: Adjust the pH of the arginine supernatant to 7.0±0.2, and then concentrate it through a triple-effect concentration device. The specific conditions are: the evaporation temperature of the first-effect evaporator is 85°C and the vacuum degree is 0.04MPa; the evaporation temperature of the second-effect evaporator is 75°C and the vacuum degree is 0.060MPa; the evaporation temperature of the third-effect evaporator is 65°C and the vacuum degree is 0.08MPa; after concentration, an arginine paste with a content of 50% is obtained;

[0056] Step 3: Add talcum powder to the obtained arginine paste (the amount of talcum powder added is 50% of the mass of the arginine paste), and at the same time, add silicone oil by atomizing spray (the amount of silicone oil added is 2% of the mass of the arginine paste). At this time, the mixing speed is 500 rpm, so that the silicone oil is evenly distributed on the surface of the mixed arginine particles. Mix for 3 hours and granulate for 15 minutes. At this time, the moisture content of the wet particles is 32% and the arginine content is about 23.8%. Then, the wet particles are dried at 85°C to a moisture content of 10.2%, obtaining an L-arginine content of 31.2% (on a dry basis).

[0057] After testing, the product absorbed 0.34% of water in 30 minutes without agglomeration under constant temperature and humidity conditions (25°C, 60 vol%); and absorbed 0.44% of water in 60 minutes without agglomeration.

[0058] Example 2

[0059] A method for producing arginine with a content of 30.5%, comprising the following steps:

[0060] Step 1: taking an arginine fermentation broth with an initial fermentation broth concentration of 100 g / L, passing it through a ceramic filter membrane to remove bacteria and other large insoluble impurities to obtain an arginine supernatant;

[0061] Step 2: Adjust the pH of the arginine supernatant to 6.9, and then concentrate it through a triple-effect concentration device. The specific conditions are: the evaporation temperature of the first-effect evaporator is 85°C and the vacuum degree is 0.04MPa; the evaporation temperature of the second-effect evaporator is 75°C and the vacuum degree is 0.060MPa; the evaporation temperature of the triple-effect evaporator is 65°C and the vacuum degree is 0.08MPa; after concentration, an arginine paste with a content of 50% is obtained;

[0062] Step 3: Add talcum powder to the obtained arginine paste (the amount of talcum powder added is 48% of the mass of the arginine paste), and at the same time, add silicone oil by atomizing spray (the amount of silicone oil added is 4% of the mass of the arginine paste). At this time, the mixing speed is 500 rpm, so that the silicone oil is evenly distributed on the surface of the mixed arginine particles. Mix for 3 hours and granulate for 10 minutes. At this time, the moisture content of the wet particles is 30.5% and the arginine content is 24.3%. Then, the wet particles are dried at 80°C to a moisture content of 9.8%, obtaining an L-arginine content of 30.5% (on a dry basis).

[0063] After testing, the product absorbed 0.52% of water in 30 minutes under constant temperature and humidity conditions (25°C, 60 vol%), did not agglomerate, and had oil leaching when left standing; it absorbed 1.06% of water in 60 minutes, had pseudo-agglomeration, and had oil leaching when left standing.

[0064] Example 3

[0065] A method for producing arginine with a content of 30%, comprising the following steps:

[0066] Step 1: taking an arginine fermentation broth with an initial fermentation broth concentration of 97 g / L, passing it through a ceramic filter membrane to remove bacteria and other large insoluble impurities to obtain an arginine supernatant;

[0067] Step 2: Adjust the pH of the arginine supernatant to 7.0, and then concentrate it through a triple-effect concentration device. The specific conditions are: the evaporation temperature of the first-effect evaporator is 85°C and the vacuum degree is 0.04MPa; the evaporation temperature of the second-effect evaporator is 75°C and the vacuum degree is 0.060MPa; the evaporation temperature of the third-effect evaporator is 65°C and the vacuum degree is 0.08MPa; after concentration, an arginine paste with a content of 50% is obtained;

[0068] Step 3: Add talcum powder to the obtained arginine paste (the amount of talcum powder added is 55% of the mass of the arginine paste), and at the same time, add silicone oil by atomizing spray (the amount of silicone oil added is 1% of the mass of the arginine paste). At this time, the mixing speed is 500 rpm, so that the silicone oil is evenly distributed on the surface of the mixed arginine particles. Mix for 3 hours and granulate for 12 minutes. At this time, the moisture content of the wet particles is 25.8% and the arginine content is 24.4%. Then, the wet particles are dried at 85° C. to a moisture content of 9.4%, obtaining an L-arginine content of 30.2% (on a dry basis).

[0069] After testing, the product absorbed 0.87% of water in 30 minutes under constant temperature and humidity conditions (25°C, 60 vol%), without any caking; and absorbed 1.16% of water in 60 minutes, with slight caking.

[0070] Comparative Example 1

[0071] Same as Example 1, except that silicone oil is not added.

[0072] Comparative Example 2

[0073] Same as Comparative Example 1, except that talcum powder and other substances are replaced with corn cob powder.

[0074] Comparative Example 3

[0075] Same as comparative example 1, except that talcum powder and other materials are replaced with rice husk.

[0076] The samples prepared in Comparative Examples 1-3 were subjected to a water absorption test under constant temperature and humidity conditions (25° C., 60 vol %). The results are shown in Table 1.

[0077] Table 1 Water absorption of different samples under constant temperature and humidity (%)

[0078]

[0079]

[0080] As can be seen in Table 1, arginine absorbed the least water when using talc as a carrier, while it absorbed the most water when using corncob powder as a carrier. This is likely due to the larger pore size of corncob powder, which allows arginine molecules to adsorb without interfering with water molecules. Furthermore, its increased surface area allows for more thorough contact with water molecules, resulting in higher water absorption. Furthermore, talc typically has a negative surface charge, while arginine molecules have a positive charge. When oppositely charged molecules approach, electrostatic attraction occurs, hindering arginine adsorption. In summary, talc is the most effective carrier.

[0081] Comparative Example 4

[0082] Same as Example 1, except that the silicone oil is replaced by silicon dioxide.

[0083] Comparative Example 5

[0084] Same as Example 1, except that the silicone oil is replaced with diatomaceous earth.

[0085] Comparative Example 6

[0086] Same as Example 1, except that the silicone oil is replaced with calcium carbonate.

[0087] The samples prepared in Example 1 and Comparative Examples 4-6 were subjected to a water absorption test under constant temperature and humidity conditions (25° C., 60 vol %). The results are shown in Table 2.

[0088] Table 2 Water absorption of different samples under constant temperature and humidity (%)

[0089]

[0090] As can be seen in Table 2, the addition of silicone oil to 30% arginine reduces water absorption and improves bulkiness. This is primarily due to the presence of silicon-oxygen bonds and organic groups in the silicone oil molecular structure, which imparts excellent hydrophobicity. This creates a protective barrier on the talc surface, preventing moisture from coming into contact with the arginine.

[0091] Silica has strong water absorption properties and is often used as a desiccant, absorbing large amounts of water. While its use in this context does not significantly improve moisture absorption, it does help prevent caking. Compared to 30% arginine without a bulking agent, 30% arginine with silica added exhibits greater bulk and more dispersed particles when absorbing less water. However, silica can also clump when absorbing too much water.

[0092] Calcium carbonate has good fluidity. When mixed with other substances, it can improve the fluidity of the entire system. It also acts as a steric barrier, separating particles that tend to aggregate, preventing them from approaching and forming aggregates, thereby maintaining a loose system. However, its moisture absorption resistance is poor, and using it as a carrier for arginine does not significantly improve its water absorption.

[0093] Diatomaceous earth can absorb moisture on the surface of material particles and help increase the looseness between particles, but the effect is not as obvious as silicone oil.

[0094] To sum up, silicone oil is the best loosening agent.

[0095] By comparing the above comparative examples with the embodiments, it can be seen that the 30% arginine produced by the technical solution of the present invention can obtain an arginine product with good content and moisture content; from an environmental perspective, it avoids pollution from various chemical reagents used in the arginine separation process and a large amount of wastewater generated by resin purification; the 30% arginine produced by the present invention is simpler to operate, greatly reducing production costs.

[0096] The above are merely preferred embodiments of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for producing arginine with a content of 30%, characterized in that: The following steps are involved: Step 1: Add a filter membrane to the arginine fermentation broth, filter and remove the bacteria and insoluble impurities to obtain the arginine supernatant; Step 2: adjusting the pH of the arginine supernatant to 6.8-7.2, and then concentrating it through a triple-effect concentrator to obtain an arginine paste with a content of 50%; Step 3: mixing the arginine paste with a carrier and a loosening agent, stirring, granulating, and drying to obtain arginine with a content of 30%.

2. The method for producing arginine with a content of 30% according to claim 1, characterized in that: In step 1, the arginine concentration in the arginine fermentation broth is 97-100 g / L.

3. The method for producing arginine with a content of 30% according to claim 1, characterized in that: In step 2, the specific operation steps of the concentration include: passing through a first-effect evaporator, a second-effect evaporator and a third-effect evaporator in sequence; The evaporation temperature of the first-effect evaporator is 80-85°C and the vacuum degree is 0.025-0.04MPa; The evaporation temperature of the second-effect evaporator is 70-75°C and the vacuum degree is 0.055-0.060MPa; The evaporation temperature of the triple-effect evaporator is 60-65° C., and the vacuum degree is 0.08-0.085 MPa.

4. The method for producing arginine with a content of 30% according to claim 1, characterized in that: In step 3, the added amount of the carrier is 40-55% of the mass of the arginine paste.

5. The method for producing arginine with a content of 30% according to claim 4, characterized in that: The carrier is selected from talc.

6. The method for producing arginine with a content of 30% according to claim 1, characterized in that: In step 3, the amount of the loosening agent added is 1-5% of the mass of the arginine paste.

7. The method for producing arginine with a content of 30% according to claim 6, characterized in that: The loosening agent is selected from silicone oil.

8. The method for producing arginine with a content of 30% according to claim 1, characterized in that: In step 3, the stirring speed is 500 rpm and the time is 2-4 hours.

9. The method for producing arginine with a content of 30% according to claim 1, characterized in that: In step 3, the granulation time is 10-20 minutes.

10. The method for producing arginine with a content of 30% according to claim 1, characterized in that: In step 3, the specific operation steps of drying are: drying at 70-100° C. until the moisture content of the sample is ≤13%.

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