Efficient extraction method of biological fermentation product

Abstract

The invention discloses an efficient extraction method of a biological fermentation product, and belongs to the technical field of biology. The invention discloses a high-efficiency extraction method of a biological fermentation product, which comprises the following steps: heating, sterilizing, deactivating enzyme, passing through a ceramic membrane, separating to remove macromolecular protein and thalli, decolorizing by using activated carbon, treating by using a nanofiltration membrane to remove pigment and salt ions, and further purifying and separating by using chromatographic separation resin to obtain the biological fermentation product. And finally, concentrating through a reverse osmosis membrane to obtain a high-concentration fermentation product solution. The high-efficiency extraction method of the biological fermentation product, disclosed by the invention, is relatively high in universality and can be used in most biological fermentation products, and the purity of the finally obtained product can be maintained at 85% or above.

Description

Technical Field

[0001] The invention relates to the field of biotechnology, and more particularly to a method for efficiently extracting biological fermentation products. Background Art

[0002] The downstream technology of microbial fermentation engineering is the technology of separating, extracting, processing and refining biological raw materials obtained from various bio-industrial production processes such as microbial fermentation broth, animal and plant cell tissue culture broth, enzyme reaction broth, etc., and finally making them into products. In microbial fermentation production, separation and purification are important links to finally obtain commercial products. The characteristics of the downstream technology processing process of microbial fermentation engineering are mainly manifested as: complex raw material system, a wide variety of products, low content, variability, and empirical. Generally, the desired product has a low concentration in the fermentation broth, and is often sensitive to heat, acid, alkali, organic solvents, shear force, etc., and is easily inactivated or degraded. However, the content of other substances in the fermentation broth is very high, such as residual fermentation medium and other metabolites, which increases the difficulty of product separation and purification. The extraction method shows superiority in separation due to its characteristics of less product loss and low equipment cost. However, due to the particularity of the fermentation broth, such as high viscosity, large mass transfer resistance, demanding requirements for solvents, and cell-affected fluid dynamics, it is greatly restricted in the separation of fermentation products. At present, there are various methods for separation and purification of products. Patent CN109880770A uses a two-phase aqueous extraction method to extract β-farnesene from the fermentation broth with a separation yield of 88.2% and a purity of more than 95%, which effectively improves the yield and purity; Patent CN112022779A uses ultrafiltration membrane filtration and ceramic membrane contactor to achieve the extraction and purification of various cosmetic water-retaining substances; Patent CN116836098A extracts astaxanthin through ethyl acetate and secondary extraction of astaxanthin with supercritical carbon dioxide, thereby achieving a total extraction rate of more than 82% from yeast wet cells to astaxanthin concentrate. Although the above methods all achieve efficient extraction of products, their versatility is poor.

[0003] Therefore, providing an efficient extraction method for biological fermentation products is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0004] In view of this, the present invention provides a method for efficiently extracting biological fermentation products, which improves the technology for separation and purification of fermentation products. On the basis of ensuring the purity of various fermentation products, the applicability of the method is improved, and a technical reference is provided for subsequent separation and purification of fermentation products.

[0005] The present invention provides a method for separating and purifying fermentation products with strong versatility. Experiments have shown that better separation and purification of glucosamine, inositol, sialic acid and the like can be achieved. Experimental verification shows that after using the method to separate, purify and crystallize the above-mentioned various fermentation products, the purity of the obtained crystals can reach more than 85%. The method has strong versatility and is more suitable for industrial production.

[0006] In order to achieve the above object, the present invention adopts the following technical solution:

[0007] A highly efficient extraction method for biological fermentation products (which can be used for the extraction and purification of multiple fermentation products, and can effectively improve the purification efficiency and shorten the extraction and purification time), comprising the following steps:

[0008] (1) Preliminary treatment of fermentation broth: adding antioxidants to the fermentation broth obtained after the fermentation of the fermentation engineering bacteria to obtain a feed liquid; 3 Inert gas is continuously introduced at a rate of 1 / min for 2-5min to drive away oxygen in the fermentation liquid and avoid oxidation;

[0009] (2) Filtration and impurity removal: The liquid treated in step (1) is initially filtered through a ceramic membrane to remove proteins and bacteria in the fermentation liquid;

[0010] (3) Sterilization by heating, enzyme inactivation and impurity removal: The liquid obtained in step (2) is subjected to heating by steam heating to sterilize and enzyme inactivation, thereby further inactivating the bacteria or protein therein; the liquid after the heating treatment is added to diatomaceous earth for heat preservation, stirring and adsorption for 30-60 minutes; the liquid after the treatment is filtered through a ceramic membrane to remove impurities, and a clear liquid is obtained;

[0011] (4) Decolorization and desalination: Add 5-10 kg / m 3 The activated carbon is decolorized by controlling the temperature at 50-70℃ for 30-60min of adsorption reaction, and the activated carbon is removed by filtration. The clear and transparent liquid obtained after the treatment is treated with a nanofiltration membrane to remove small pigment molecules and salt ions therein;

[0012] (5) Purification and concentration: After the treatment in step (4), the target product was purified by 1.5-2 m 3 / h through a chromatographic separation column for purification and separation, and finally through a reverse osmosis membrane for concentration to increase the concentration of the fermentation product, and finally obtain a solution with a fermentation product purity greater than 85%;

[0013] (6) Crystallization: Crystallization is performed according to the properties of the product itself. When the molecular weight of the target product is less than or equal to 250 Da, the slurry obtained in step (5) is subjected to evaporation concentration crystallization. If the molecular weight of the target product is greater than 250 Da, an organic solvent precipitation method is used for crystallization. After crystallization, the target product is obtained by centrifugal drying.

[0014] Furthermore, the antioxidant and dosage in step (1) include but are not limited to ascorbic acid 0.5 g / kg, sodium ascorbate 0.5 g / kg or tocopherol 0.8 g / kg; the inert gas includes but is not limited to nitrogen or argon.

[0015] Furthermore, in step (2), the pore size of the ceramic membrane is 20-200 nm, the operating pressure of the ceramic membrane is 0.2-2.5 bar, and the temperature is 30-45° C.;

[0016] The pore size of the ceramic membrane corresponding to different fermentation engineering bacteria is selected as follows:

[0017] When the fermentation engineering bacteria is Escherichia coli, the pore size of the ceramic membrane is selected to be 20-50nm;

[0018] When the fermentation engineering bacteria is Bacillus subtilis, the pore size of the ceramic membrane is selected to be 40-100nm;

[0019] When the fermentation engineering bacteria is yeast, the pore size of the ceramic membrane is selected to be 80-200nm.

[0020] Furthermore, the sterilization and enzyme inactivation in step (3) is carried out by heating with high temperature steam, maintaining the temperature in the range of 50-80°C for 1-2h; and if the antioxidant added in step (1) is ascorbic acid or sodium ascorbate, the temperature should be controlled not to exceed 65°C.

[0021] Furthermore, the amount of diatomaceous earth added in step (3) is 1-3 kg / m 3 .

[0022] Furthermore, the pore size of the ceramic membrane in step (3) should not be larger than the pore size of the ceramic membrane in step (2).

[0023] Furthermore, in step (4), the pore size of the nanofiltration membrane is 100-200 Da, the operating pressure is 3-6 bar, and the temperature is 30-45°C.

[0024] Furthermore, the chromatographic separation in step (5) uses at least one of a macroporous adsorption resin, a cation exchange resin and an anion resin; the selection of the chromatographic resin needs to be based on the properties of the product itself. If the product is neutral, a macroporous adsorption resin can be selected for selective adsorption; if the product itself contains carboxyl or amino polar groups, the corresponding anionic and cationic lipids should be selected for adsorption.

[0025] Furthermore, in step (5), the pore size of the reverse osmosis membrane is 10-100 Da, the operating pressure is 0.5-5.0 bar, and the temperature is 20-45°C.

[0026] Furthermore, the organic solvent in step (6) includes but is not limited to ethanol, methanol, acetic acid, isopropanol or acetone.

[0027] It can be known from the above technical scheme that compared with the prior art, the present invention discloses a method for efficiently extracting biological fermentation products. Compared with the traditional production method of separation and purification of fermentation products, the present invention improves the level of automation of production, and has an effect on various fermentation products on the basis of ensuring the purity of fermentation products. The fermentation product extraction and purification method with strong versatility involved in the present invention can be used in most biological fermentation products, and the purity of the final product can be maintained at more than 85%. Adding antioxidants and passing inert gases therein can effectively ensure the activity of the product and avoid the loss of activity in the subsequent treatment process. At the same time, the use of the method of the present invention helps to improve the purity and yield of the separated and purified products, ensures the efficiency and convenience of product extraction, and has a certain versatility. It has been verified that a variety of fermentation products can be separated and purified, and it is more suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0029] Figure 1 The accompanying drawing is a liquid phase detection spectrum of glucosamine of the present invention;

[0030] Figure 2 The accompanying drawing is a liquid phase detection spectrum of sialic acid of the present invention;

[0031] Figure 3 The accompanying drawing is a liquid phase detection spectrum of inositol of the present invention;

[0032] Figure 4 The accompanying drawing is a liquid phase detection spectrum of 2'-fucosyllactose of the present invention;

[0033] Figure 5 The accompanying drawing is a liquid phase detection spectrum of astaxanthin of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] Example 1 Separation and purification method of glucosamine

[0036] Reference paper (Chen Xin. Metabolic engineering of Escherichia coli fermentation to produce glucosamine and process optimization and control [D]. Jiangnan University, 2012.) The fermentation method and operation provided in Chapter 3 Optimization of glucosamine fermentation process use Escherichia coli engineered bacteria to ferment and prepare glucosamine fermentation broth.

[0037] (1) Preliminary treatment of fermentation broth: After the fermentation, 0.5 g / kg of ascorbic acid was added to the fermentation broth and 1.5 m 3 Nitrogen was introduced continuously at a rate of 1.34 W / min for 2 min to drive away the dissolved oxygen in the fermentation liquid and avoid oxidation.

[0038] (2) Filtration and impurity removal: The feed liquid treated in step (1) is initially filtered through a 30 nm ceramic membrane at 30° C. and 0.2 bar pressure to remove proteins and bacteria in the fermentation liquid.

[0039] (3) Sterilization, enzyme inactivation and impurity removal by heating: The liquid obtained in step (2) is heated to 50°C by steam heating and kept at this temperature for 1 hour for sterilization and enzyme inactivation, thereby further inactivating the bacteria or proteins therein; the liquid after the heating treatment is added with 1 kg / m 3 The diatomaceous earth was kept warm and stirred for adsorption for 30 minutes. The treated liquid was filtered through a 30nm ceramic membrane at 30℃ and 0.2bar pressure to remove impurities to obtain a clear liquid.

[0040] (4) Decolorization and desalination: Add 5 kg / m 3 The activated carbon was decolorized by controlling the temperature at 50°C for 30 minutes of adsorption reaction, and the activated carbon was removed by filtration. The clear and transparent liquid obtained after the treatment was then passed through a 100Da nanofiltration membrane at 30°C and 3bar to remove small pigment molecules and salt ions.

[0041] (5) Purification and concentration: The liquid treated in step (4) was concentrated to 2 m 3 / h speed through the cation exchange resin, and eluted with clean water, and then concentrated through a 10Da reverse osmosis membrane at 20℃ and 0.5bar pressure to finally obtain glucosamine solution.

[0042] (6) Crystallization: The evaporation concentration crystallization method is used, and the temperature is maintained at 80° C. The glucosamine crystals are obtained by centrifugal drying after crystallization.

[0043] Figure 1 Table 1 is the analysis result table of the liquid phase detection spectrum of the 1% solution prepared according to the mass fraction of the obtained glucosamine crystals; the results show that the purity of the obtained glucosamine crystals can reach 95.66%, wherein peak 1 is the glucosamine peak and peak 2 is the impurity peak.

[0044] Table 1

[0045]

[0046] Example 2 Isolation and Purification of Sialic Acid

[0047] Referring to the method for preparing the fermentation broth mentioned in Example 1 of the reference patent CN202310771630.8, a method for extracting sialic acid and the extracted sialic acid, sialic acid fermentation broth is prepared by fermentation with Bacillus subtilis engineered bacteria.

[0048] (1) Preliminary treatment of fermentation broth: After the fermentation, 0.5 g / kg of sodium ascorbate was added to the fermentation broth and 1.5 m 3 Argon was introduced continuously at a rate of 1.347 W / min for 5 min to drive away oxygen in the fermentation liquid and avoid oxidation.

[0049] (2) Filtration and impurity removal: The feed liquid treated in step (1) is initially filtered through a 60 nm ceramic membrane at 45°C and 2.5 bar to remove proteins and bacteria in the fermentation liquid.

[0050] (3) Sterilization, enzyme inactivation and impurity removal by heating: The liquid obtained in step (2) is heated to 60°C by steam heating and kept warm for 2 hours to sterilize and inactivate the enzymes, thereby further inactivating the bacteria or proteins therein; the liquid after the heating treatment is added with 3 kg / m 3 The diatomaceous earth was kept warm and stirred for adsorption for 60 minutes. The treated liquid was filtered through a 60nm ceramic membrane at 45°C and 2.5 bar to remove impurities and obtain a clear liquid.

[0051] (4) Decolorization and desalination: Add 10 kg / m 3 The activated carbon was decolorized by controlling the temperature to 70°C for 60 minutes of adsorption reaction, and the activated carbon was removed by filtration. The clear and transparent liquid obtained after treatment was passed through a 200Da nanofiltration membrane at 45°C and 3bar pressure to remove small pigment molecules and salt ions.

[0052] (5) Purification and concentration: The liquid treated in step (4) was concentrated to 1.5 m 3 / h speed through a cation exchange resin and eluted with clean water for purification and separation, and finally concentrated through a reverse osmosis membrane with a pore size of 100Da at a pressure of 45°C and 5.0bar to increase the concentration of the fermentation product and finally obtain a sialic acid solution.

[0053] (6) Crystallization: The feed solution obtained in step (5) is crystallized using an organic solvent precipitation method. One volume of acetic acid is added under stirring at 20 r / min. Crystallization is carried out at 10° C. for 4 h. The crystallized product is centrifuged and dried to obtain sialic acid crystals.

[0054] Figure 2 Table 2 is the liquid phase detection spectrum of a 1% solution prepared according to the mass fraction of the obtained sialic acid crystals; the results show that the purity of the obtained sialic acid can reach 95.65%, wherein peak 1 is a salt peak, peak 2 is a sialic acid peak, and peak 3 is other miscellaneous sugar peaks.

[0055] Table 2

[0056]

[0057] Example 3 Isolation and Purification of Inositol

[0058] Reference patent CN202010652543.7, Example 6 of a method for constructing a high-yield inositol brewer's yeast engineering bacterium, uses brewer's yeast engineering bacteria to ferment and prepare inositol fermentation broth.

[0059] (1) Preliminary treatment of fermentation broth: After the fermentation, 0.8 g / kg tocopherol was added to the fermentation broth and 1.5 m 3 Nitrogen was introduced continuously at a rate of 1.347 W / min for 3 min to drive away oxygen in the fermentation liquid and avoid oxidation.

[0060] (2) Filtration and impurity removal: The feed liquid treated in step (2) is initially filtered through a ceramic membrane with a pore size of 120 nm at 40°C and 1.5 bar to remove proteins and bacteria in the fermentation liquid.

[0061] (3) Sterilization, enzyme inactivation and impurity removal by heating: The liquid obtained in step (3) is heated to 80°C by steam heating and kept at this temperature for 1.5 hours to sterilize and inactivate the bacteria or protein therein. The liquid after heating treatment is added with 2 kg / m 3 The diatomaceous earth was kept warm and stirred for adsorption for 40 minutes. The treated liquid was further filtered and impurities were removed through a ceramic membrane with a pore size of 120 nm at 40°C and 1.5 bar to obtain a clear liquid.

[0062] (4) Decolorization and desalination: Add 7 kg / m 3The activated carbon was decolorized by controlling the temperature at 60°C for 40 minutes of adsorption reaction, and the activated carbon was removed by filtration. The clear and transparent liquid obtained after the treatment was passed through a 150Da nanofiltration membrane at 40°C and 4 bar to remove small pigment molecules and salt ions.

[0063] (5) Purification and concentration: The liquid obtained in step (4) is passed through an adsorption resin and then eluted with clean water to obtain an inositol solution, which is then concentrated through a 50Da reverse osmosis membrane at 30°C and 2.5 bar pressure to obtain an inositol solution.

[0064] (6) Crystallization: Using the evaporation concentration crystallization method, the temperature is maintained at 90°C for evaporation concentration crystallization, and after crystallization, centrifugal drying is performed to obtain inositol crystals.

[0065] Figure 3 Table 3 is the phase detection spectrum of a 1% solution prepared according to the mass fraction of the obtained inositol crystals. The results show that the purity of the obtained inositol can reach 87.89%, wherein peak 1 is a salt peak, peak 2 is a miscellaneous sugar peak, and peak 3 is an inositol peak.

[0066] Table 3

[0067]

[0068] Example 42'-Separation and Purification of Fucosyllactose

[0069] Reference paper (Peng Zetao. Design, construction and fermentation optimization of 2'-fucosyllactose-producing Escherichia coli [D]. Tianjin University of Science and Technology, 2023.) 2.4.3 The fermentation method provided in high-density fermentation uses Escherichia coli engineered bacteria to ferment and prepare 2'-fucosyllactose fermentation broth.

[0070] (1) Preliminary treatment of fermentation broth: After the fermentation, 0.5 g / kg of ascorbic acid was added to the fermentation broth and 1.5 m 3 Nitrogen was introduced continuously at a rate of 1.34 °C / min for 3 min to drive away the dissolved oxygen in the fermentation liquid and avoid oxidation.

[0071] (2) Filtration and impurity removal: The feed liquid treated in step (1) is initially filtered through a 30 nm ceramic membrane at 30° C. and 0.2 bar pressure to remove proteins and bacteria in the fermentation liquid.

[0072] (3) Sterilization, enzyme inactivation and impurity removal by heating: The liquid obtained in step (2) is heated to 55°C by steam heating and kept at this temperature for 1.5 hours for sterilization and enzyme inactivation, thereby further inactivating the bacteria or proteins therein; the liquid after the heating treatment is added with 1.5 kg / m 3The diatomaceous earth was kept warm and stirred for adsorption for 45 minutes. The treated liquid was filtered through a 40nm ceramic membrane at 30℃ and 0.2bar pressure to remove impurities to obtain a clear liquid.

[0073] (4) Decolorization and desalination: Add 5 kg / m 3 The activated carbon was decolorized by controlling the temperature at 50°C for 45 minutes of adsorption reaction, and the activated carbon was removed by filtration. The clear and transparent liquid obtained after the treatment was then passed through a 150Da nanofiltration membrane at 30°C and 3bar to remove small pigment molecules and salt ions.

[0074] (5) Purification and concentration: The liquid treated in step (4) was concentrated to 2 m 3 / h speed through anion exchange resin, and eluted with clean water, and then concentrated through a 10Da reverse osmosis membrane at 20°C and 0.5bar pressure to finally obtain a 2'-fucosyllactose solution.

[0075] (6) Crystallization: Crystallization was performed using an organic solvent precipitation method. 1.5 times the volume of ethanol was added under stirring at 15 r / min, and crystallization was performed at 15° C. for 3 h. 2'-fucosyllactose crystals were obtained by centrifugal drying.

[0076] Figure 4 Table 4 is the liquid phase detection spectrum of a 1% solution of the obtained 2'-fucosyllactose crystals prepared according to the mass fraction, and the analysis results are shown in Table 4; the results show that the purity of the obtained 2'-fucosyllactose crystals can reach 89.72%, wherein peak 4 is the 2'-fucosyllactose peak, and peaks 1, 2, 3, 5, and 6 are impurity peaks.

[0077] Table 4

[0078]

[0079] Example 5 Isolation and Purification of Astaxanthin

[0080] Reference paper (Gong Zhongkuo. Construction of astaxanthin cell factory and optimization of fermentation process [D]. Changchun University of Technology, 2021.) The fermentation method provided in Chapter 4 High-density fermentation optimization of astaxanthin engineering strains uses Escherichia coli engineered bacteria to ferment and prepare astaxanthin fermentation broth.

[0081] (1) Preliminary treatment of fermentation broth: After the fermentation, 0.5 g / kg of sodium ascorbate was added to the fermentation broth and 1.5 m 3 Argon was introduced continuously at a rate of 1.34 ℃ / min for 4 min to drive away the dissolved oxygen in the fermentation liquid and avoid oxidation.

[0082] (2) Filtration and impurity removal: The feed liquid treated in step (1) is initially filtered through a 20 nm ceramic membrane at 30° C. and 0.2 bar pressure to remove proteins and bacteria in the fermentation liquid.

[0083] (3) Sterilization, enzyme inactivation and impurity removal by heating: The liquid obtained in step (2) is heated to 50°C by steam heating and kept at this temperature for 1 hour for sterilization and enzyme inactivation, thereby further inactivating the bacteria or protein therein; the liquid after the heating treatment is added with 1.5 kg / m 3 The diatomaceous earth was kept warm and stirred for adsorption for 35 minutes. The treated liquid was filtered through a 30nm ceramic membrane at 35℃ and 1.5bar pressure to remove impurities to obtain a clear liquid.

[0084] (4) Decolorization and desalination: Add 5 kg / m 3 The activated carbon was decolorized by controlling the temperature at 60°C for 45 minutes of adsorption reaction, and the activated carbon was removed by filtration. The clear and transparent liquid obtained after the treatment was then passed through a 100Da nanofiltration membrane at 30°C and 3bar to remove small pigment molecules and salt ions.

[0085] (5) Purification and concentration: The liquid treated in step (4) was concentrated to 2 m 3 / h speed through anion exchange resin and eluted with clean water, and then concentrated through a 10Da reverse osmosis membrane at 20℃ and 0.5bar pressure to finally obtain an astaxanthin solution.

[0086] (6) Crystallization: Crystallization was performed using an organic solvent precipitation method. 1.5 times the volume of ethanol was added under stirring at 15 r / min, and crystallization was performed at 15° C. for 3 h. Astaxanthin crystals were obtained by centrifugal drying.

[0087] Figure 5 Table 5 is the liquid phase detection spectrum of the 1% solution prepared according to the mass fraction of the obtained astaxanthin crystals, and the analysis results are shown in Table 5; the results show that the purity of the obtained astaxanthin crystals can reach 97.02%, wherein peak 4 is astaxanthin, and peaks 1, 2, and 3 are impurity peaks.

[0088] Table 5

[0089]

[0090] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for efficiently extracting a biological fermentation product, characterized in that: The following steps are involved: (1) Preliminary treatment of fermentation broth: adding antioxidants to the fermentation broth obtained after the fermentation of the fermentation engineering bacteria to obtain a feed liquid; 3 Inert gas is continuously introduced at a rate of / min for 2-5min; (2) Filtration and impurity removal: The liquid treated in step (1) is initially filtered through a ceramic membrane; (3) Sterilization by heating, enzyme inactivation and impurity removal: The liquid obtained in step (2) is heated by steam heating to sterilize and enzyme inactivation; the liquid after the heating treatment is added to diatomaceous earth for heat preservation, stirring and adsorption for 30-60 minutes; the liquid after the treatment is filtered through a ceramic membrane to remove impurities and obtain a clear liquid; (4) Decolorization and desalination: Add 5-10 kg / m 3 The activated carbon is decolorized by controlling the temperature at 50-70℃ for 30-60min of adsorption reaction, and the activated carbon is removed by filtration. The clear and transparent liquid obtained after the treatment is treated with a nanofiltration membrane to remove small pigment molecules and salt ions therein; (5) Purification and concentration: After step (4), the target product is purified according to the properties of the target product at 1.5-2 m 3 / h through a chromatographic separation column for purification and separation, and finally through a reverse osmosis membrane for concentration to increase the concentration of the fermentation product, and finally obtain a solution with a fermentation product purity greater than 85%; (6) Crystallization: Crystallization is performed according to the properties of the product itself. When the molecular weight of the target product is less than or equal to 250 Da, the feed solution obtained in step (5) is subjected to evaporation concentration crystallization; If the molecular weight of the target product is greater than 250Da, an organic solvent precipitation method is used for crystallization; after crystallization, the target product is obtained by centrifugal drying.

2. The method for efficiently extracting a biological fermentation product according to claim 1, characterized in that: The antioxidant and dosage of step (1) are ascorbic acid 0.5 g / kg, sodium ascorbate 0.5 g / kg or tocopherol 0.8 g / kg; the inert gas is nitrogen or argon.

3. The method for efficiently extracting a biological fermentation product according to claim 2, characterized in that: The pore size of the ceramic membrane in step (2) is 20-200 nm, the operating pressure of the ceramic membrane is 0.2-2.5 bar, and the temperature is 30-45° C.; The pore size of the ceramic membrane corresponding to different fermentation engineering bacteria is selected as follows: When the fermentation engineering bacteria is Escherichia coli, the pore size of the ceramic membrane is selected to be 20-50nm; When the fermentation engineering bacteria is Bacillus subtilis, the pore size of the ceramic membrane is selected to be 40-100nm; When the fermentation engineering bacteria is yeast, the pore size of the ceramic membrane is selected to be 80-200nm.

4. The method for efficiently extracting a biological fermentation product according to claim 3, characterized in that: The sterilization and enzyme inactivation in step (3) is carried out by heating with high temperature steam, maintaining the temperature in the range of 50-80°C for 1-2h; if the antioxidant added in step (1) is ascorbic acid or sodium ascorbate, the temperature should be controlled not to exceed 65°C.

5. The method for efficiently extracting a biological fermentation product according to claim 4, characterized in that: The amount of diatomaceous earth added in step (3) is 1-3 kg / m 3 .

6. The method for efficiently extracting a biological fermentation product according to claim 5, characterized in that: The pore size of the ceramic membrane in step (3) should not be larger than the pore size of the ceramic membrane in step (2).

7. The method for efficiently extracting a biological fermentation product according to claim 6, characterized in that: The nanofiltration membrane pore size in step (4) is 100-200Da, the operating pressure is 3-6bar, and the temperature is 30-45°C.

8. The method for efficiently extracting a biological fermentation product according to claim 7, characterized in that: The resin used for the chromatographic separation in step (5) is at least one of a macroporous adsorption resin, a cation exchange resin, and an anion resin; the selection of the chromatographic resin needs to be based on the properties of the product itself. If the product is neutral, a macroporous adsorption resin can be selected for selective adsorption; if the product itself contains carboxyl or amino polar groups, the corresponding anionic and cationic lipids should be selected for adsorption.

9. The method for efficiently extracting a biological fermentation product according to claim 8, characterized in that: The reverse osmosis membrane of step (5) has a pore size of 10-100 Da, an operating pressure of 0.5-5.0 bar, and a temperature of 20-45°C.

10. The method for efficiently extracting a biological fermentation product according to claim 9, characterized in that: The organic solvent in step (6) is ethanol, methanol, acetic acid, isopropanol or acetone.

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