Clean production process for improving fermentation quality and efficiency of L-lysine

Abstract

The invention relates to the technical field of biological fermentation, and discloses a clean production process for improving the fermentation quality and efficiency of L-lysine, which comprises the steps of strain screening, seed culture, fermentation culture, fermentation liquor preparation and product refining. Vitamin compounds are added into the seed culture medium, nutrition is supplemented, seed culture time is shortened, seed vitality is improved, and a good foundation is laid for fermentation. The whole production process is efficient and clean, the production efficiency is high, the energy consumption is reduced, the production process is simple and convenient, the stability of the production process is ensured, and the product quality is improved.

Description

Technical Field

[0001] The invention relates to the technical field of biological fermentation, and in particular to a clean production process for improving the fermentation quality and efficiency of L-lysine. Background Art

[0002] As one of the essential amino acids for the human body, L-lysine has extensive and important applications in many fields such as food, medicine, feed, etc. With the development of the global economy and the improvement of people's living standards, the market demand for L-lysine continues to grow, and higher requirements are also placed on its fermentation quality and production efficiency.

[0003] The traditional L-lysine fermentation production process faces many challenges. In terms of strain selection, it mostly relies on single gene modification or natural selection, which makes it difficult to achieve comprehensive optimization of the L-lysine anabolic network, resulting in limited improvement in strain production performance. For example, only strengthening the expression of a single key enzyme gene may not fully realize the strain potential due to unbalanced metabolic flow, and the strain has poor adaptability to environmental changes and is easily affected by fluctuations in fermentation conditions, making the fermentation process unstable and the product yield and quality unstable.

[0004] During the fermentation process, the traditional fermentation tank structure and gas supply method have defects, the gas-liquid mixing is uneven, and the oxygen transfer efficiency is low, which affects the growth of bacteria and product synthesis. At the same time, the nutrient composition of the fermentation medium is not reasonably matched, and the nitrogen source utilization efficiency is not high, which increases production costs and easily causes environmental pollution.

[0005] In the product separation and refining stage, traditional processes mostly perform separation operations after the fermentation is completed, and do not achieve in-situ separation, resulting in product accumulation in the late fermentation period, which inhibits bacterial growth and product synthesis. In addition, the separation and refining process is complex, energy-intensive, and the product purity improvement is limited. It also produces a large amount of wastewater, waste gas, and waste residue, which are difficult to handle and put great pressure on the environment.

[0006] For example, in the existing process, wastewater contains high concentrations of organic matter and inorganic salts, which will pollute water bodies if discharged directly; waste gas contains pollutants such as volatile organic compounds, which affect air quality; and waste residues, if not properly handled, will occupy land resources and may cause soil pollution. Therefore, there is an urgent need for a clean production process that can improve the quality and efficiency of L-lysine fermentation to meet market demand, reduce production costs, and achieve sustainable development. Summary of the invention

[0007] In view of the deficiencies of the prior art, the present invention provides a clean production process for improving the quality and efficiency of L-lysine fermentation.

[0008] A clean production process for improving the quality and efficiency of L-lysine fermentation, comprising the following steps: S1: Selection and breeding of multi-gene synergistically modified strains, select suitable host strains, and use gene editing technology to simultaneously carry out targeted modification of multiple genes related to L-lysine synthesis, including enhancing the expression of key enzyme genes, knocking out or inhibiting branch metabolic genes, and constructing multi-gene synergistically optimized L-lysine production strains genetically engineered bacteria; and introduce specific stress response elements during the strain construction process to enhance the strain's adaptability to changes in the fermentation environment.

[0009] S2: Pre-culture and seed expansion culture. The selected strains are first pre-cultured in a pre-culture medium containing special inducers. The pre-culture conditions are temperature 28-32°C, pH 6.5-7.0, and slight shaking culture for 4-6 hours to activate the relevant metabolic pathways of the strains; then they are transferred to the seed culture medium for seed expansion culture. A mixture of complex vitamins and amino acids is added to the seed culture medium. The expansion conditions are temperature 30-34°C, pH 7.0-7.5, stirring speed 180-220r / min, and the culture time is 12-18 hours.

[0010] S3: Construction of efficient fermentation system and fermentation culture, using a new type of airlift fermenter, which is equipped with a special flow guide device inside to improve the gas-liquid mixing efficiency, and multiple microporous aeration heads are set at the bottom of the fermenter to achieve precise aeration control; a new type of composite nitrogen source is added to the fermentation medium, including plant protein hydrolysate and microbial protein, as well as an optimized proportion of carbon source, inorganic salt and growth factor; the seed liquid is inoculated into the fermentation medium for fermentation culture, and the fermentation conditions are temperature 33-37℃, pH value 7.2-7.6, stirring speed 200-250r / min, ventilation volume 1.2-1.8vvm. During the fermentation process, an online monitoring system is used to monitor the fermentation parameters in real time, and the fermentation conditions are dynamically adjusted according to the monitoring data through an intelligent control system.

[0011] S4: In-situ product separation and recycling. In the fermentation process, the L-lysine produced is separated by in-situ adsorption using selective adsorption resin. The adsorption resin is filled in a specific adsorption column in the fermentation tank. When the adsorption is saturated, L-lysine is recovered online by elution using a specific eluent. After treatment, part of the eluate is recycled back to the fermentation tank for continued use. At the same time, useful metabolic by-products produced during the adsorption process are recovered. After the fermentation is completed, the remaining fermentation liquid is centrifuged and ultrafiltered to obtain a concentrated liquid containing L-lysine.

[0012] S5: Product refining and environmental protection treatment. The concentrate is refined by ion exchange, and an ion exchange resin with high selectivity and regeneration performance is used to remove impurity ions. Then vacuum freezing crystallization is carried out. During the crystallization process, the cooling rate and vacuum degree are controlled to obtain a high-purity L-lysine crystal product. The wastewater, waste gas and waste residue generated in the entire production process are subjected to comprehensive environmental protection treatment. The wastewater is treated by biological treatment and membrane separation technology and then meets the standards for reuse or discharge. The waste gas is treated by adsorption and catalytic oxidation and then meets the standards for discharge. The waste residue is harmlessly treated and then used as a fertilizer or feed additive for resource utilization.

[0013] Furthermore, the specific operation of the multi-gene coordinated transformation is: in the host strain, the key enzyme genes in the L-lysine synthesis pathway are site-directedly mutated by gene editing technology to improve their enzyme activity; at the same time, genes related to branch metabolism, such as genes that compete for carbon sources and energy, are knocked out to reduce the generation of by-products; and stress response elements, such as heat shock protein gene promoter elements, are introduced to enhance the strain's tolerance to changes in temperature and pH environment.

[0014] Furthermore, the special inducer is a complex containing a short peptide and a small molecule metabolite, and its preparation method is obtained by fermentation of specific microorganisms. The inducer can specifically activate the expression of genes related to L-lysine synthesis.

[0015] Furthermore, the complex vitamins include B vitamins (such as B1, B2, B6, B12), vitamin C and biotin, and the amino acid mixture includes glycine, alanine, glutamic acid and aspartic acid, and the added amounts are 0.01-0.1 g / L of the total amount of vitamins and 0.5-2 g / L of the total amount of amino acids, respectively.

[0016] Furthermore, the mass ratio of plant protein hydrolysate to microbial protein in the novel composite nitrogen source is 2-5:1, the degree of hydrolysis of the plant protein hydrolysate is 30-50%, and the microbial protein comes from a high-efficiency protein production strain.

[0017] Furthermore, the fermentation parameters monitored by the online monitoring system include bacterial concentration, dissolved oxygen, L-lysine concentration, pH value, temperature and redox potential. The intelligent control system automatically adjusts the ventilation volume, stirring speed, feed rate and pH regulator addition amount fermentation conditions based on these parameters according to preset algorithms and models.

[0018] Furthermore, the selective adsorption resin is a macroporous adsorption resin with specific pore size and functional groups, and its adsorption capacity for L-lysine is between 30-50g / L, and the adsorption selectivity coefficient is greater than 10; the eluent is a mixed solution containing a certain concentration of ammonia water and sodium chloride, the ammonia concentration is 1-3mol / L, and the sodium chloride concentration is 0.5-1.5mol / L.

[0019] Furthermore, in the ion exchange refining process, the ion exchange resin used is a combination of a strongly acidic cation exchange resin and a weakly basic anion exchange resin, the volume ratio of the two being 3-5:1, and the ion exchange resin undergoes a special surface modification treatment to improve the selectivity and adsorption rate of L-lysine.

[0020] Furthermore, during the vacuum freezing crystallization process, the cooling rate is controlled at 0.5-1.5°C / h, the vacuum degree is maintained at 0.05-0.1MPa, and the crystallization time is 10-20 hours. The L-lysine crystals obtained in this way have uniform particle size and a purity of more than 99%.

[0021] Furthermore, in the environmental protection treatment link, the biological treatment of wastewater adopts an anaerobic-aerobic combined process, the membrane separation technology adopts an ultrafiltration and reverse osmosis combined process; the waste gas adsorption adopts activated carbon fiber adsorption, and the catalytic oxidation adopts precious metal catalysts; the harmless treatment of waste residue includes high-temperature sterilization and composting and fermentation process to ensure that the treated waste residue meets the relevant environmental protection standards and the quality standards of fertilizers and feed additives.

[0022] In strain selection, multi-gene synergistic transformation combined with the introduction of stress response elements significantly enhances strain performance. By optimizing multiple key genes and balancing metabolic flows, the L-lysine synthesis capacity is greatly improved, while the strain's adaptability to the environment is enhanced, ensuring stable and efficient fermentation, and effectively improving product yield and quality.

[0023] During the pre-culture and seed expansion stages, special inducers and complex nutrients are added to activate the strain metabolic pathway, shorten the seed culture time, improve seed vitality, provide high-quality strains for subsequent fermentation, and further promote fermentation efficiency.

[0024] In terms of the construction of new fermentation systems, the improvement of the airlift fermentation tank structure and precise aeration control greatly improve the efficiency of gas-liquid mixing and oxygen transfer, creating good conditions for bacterial growth and product synthesis. The optimized culture medium formula improves the efficiency of nutrient utilization, reduces costs, and reduces waste emissions.

[0025] In-situ product separation and recycling technology can timely remove the inhibition of fermentation products, increase the concentration of substrates and bacteria in the fermentation tank, accelerate the reaction process, and increase production. At the same time, L-lysine and by-products can be recycled to reduce raw material consumption, improve resource utilization, and reduce wastewater treatment pressure.

[0026] Product refining uses high-efficiency ion exchange resins and vacuum freezing crystallization to improve product purity and crystal quality. Comprehensive environmental protection treatment measures ensure that the three wastes meet discharge standards or are recycled, reduce environmental pollution, achieve clean production, comply with the concept of green development, and have good economic and social benefits. DETAILED DESCRIPTION

[0027] Example 1 Multi-gene collaborative transformation of bacterial strains Using Escherichia coli as the host strain, CRISPR-Cas9 gene editing technology was used to perform site-directed mutations on key enzyme genes in the L-lysine synthesis pathway (such as dapA, lysC, etc.) to improve their enzyme activity; at the same time, branch metabolic genes (such as ilvA, etc.) were knocked out to reduce the generation of by-products. Heat shock protein gene promoter elements were introduced as stress response elements to enhance the strain's tolerance to environmental changes. Genetically engineered bacteria were constructed.

[0028] Pre-cultivation and seed expansion The pre-culture medium contains: special inducer (short peptide-small molecule metabolite complex prepared by fermentation of Bacillus subtilis, the mass ratio of short peptide to small molecule metabolite is 1:2) 0.5g / L, glucose 10g / L, yeast extract 5g / L, potassium dihydrogen phosphate 1g / L, magnesium sulfate 0.5g / L. The selected strains were inoculated into the pre-culture medium and cultured for 5 hours at a temperature of 30°C, a pH of 6.8, and an oscillation speed of 100r / min.

[0029] The seed culture medium formula is: glucose 20g / L, yeast powder 8g / L, peptone 10g / L, complex vitamins (vitamin B1 0.02g / L, vitamin B2 0.03g / L, vitamin B6 0.01g / L, vitamin B12 0.005g / L, vitamin C 0.1g / L, biotin 0.005g / L), amino acid mixture (glycine 0.8g / L, alanine 0.6g / L, glutamic acid 0.4g / L, aspartic acid 0.2g / L), potassium dihydrogen phosphate 1.5g / L, magnesium sulfate 0.8g / L. The pre-cultured strains were transferred to the seed culture medium and cultured for 15 hours at a temperature of 32°C, a pH value of 7.2, and a stirring speed of 200r / min.

[0030] Construction of efficient fermentation system and fermentation culture A new type of airlift fermentation tank is used, with a spiral guide device inside and 5 microporous aeration heads (aperture 0.5mm) at the bottom. The fermentation medium formula is: 80g / L glucose, 25g / L new composite nitrogen source (the mass ratio of plant protein hydrolysate (hydrolysis degree 40%) to microbial cell protein is 3:1), 2g / L potassium dihydrogen phosphate, 1g / L magnesium sulfate, 0.05g / L ferrous sulfate, 0.02g / L manganese sulfate, and 0.005g / L biotin.

[0031] The seed liquid was inoculated into the fermentation medium at a rate of 10%, and fermented at a temperature of 35°C, a pH value of 7.4, a stirring speed of 220r / min, and a ventilation volume of 1.5vvm. The online monitoring system monitors parameters such as bacterial concentration, dissolved oxygen, L-lysine concentration, pH value, temperature, and redox potential in real time, and the intelligent control system adjusts the fermentation conditions according to the preset algorithm. For example, when the dissolved oxygen is lower than 30%, the ventilation volume is increased; when the pH value deviates from 7.4, the acid-base regulator is automatically added.

[0032] In-situ product separation and recycling The fermenter is filled with a macroporous adsorption resin (functional group is amino group) with high selective adsorption capacity (40g / L) for L-lysine. When the adsorption resin is saturated, an eluent containing 2mol / L ammonia water and 1mol / L sodium chloride is used for online elution. After ultrafiltration and ion exchange treatment, part of the eluate is recycled back to the fermenter.

[0033] Product Refining and Environmental Protection Treatment Ion exchange refining uses strong acid cation exchange resin and weak base anion exchange resin (volume ratio 4:1), and the resin is surface-grafted to improve the selectivity and adsorption rate of L-lysine. Then vacuum freezing crystallization is carried out, the cooling rate is controlled at 1℃ / h, the vacuum degree is maintained at 0.08MPa, and the crystallization time is 15 hours to obtain high-purity L-lysine crystal products.

[0034] The wastewater treatment adopts the anaerobic-aerobic combined process, which first removes most of the organic matter through anaerobic fermentation, and then undergoes aerobic biological treatment; the waste gas uses activated carbon fiber to adsorb volatile organic matter, and then catalytic oxidation is carried out through precious metal catalysts; the waste residue is treated as organic fertilizer after high-temperature sterilization (120℃, 2 hours) and composting and fermentation (30 days). According to the test, the L-lysine yield reaches 65g / L, and the product purity is 99.3%.

[0035] Example 2 Multi-gene collaborative transformation of bacterial strains Bacillus subtilis was selected as the host strain, and gene editing technology was used to enhance the expression of genes related to L-lysine synthesis (such as hom, lysA, etc.), knock out genes that compete for carbon sources and energy (such as pta, etc.), and introduce cold shock protein gene promoter elements as stress response elements to construct genetically engineered bacteria.

[0036] Pre-cultivation and seed expansion The preculture medium contained 0.8 g / L of special inducer (a short peptide-small molecule metabolite complex obtained by fermentation of Bacillus licheniformis, with a mass ratio of short peptide to small molecule metabolite of 2:3), 8 g / L of sucrose, 6 g / L of beef extract, 1.2 g / L of diammonium hydrogen phosphate, and 0.6 g / L of magnesium sulfate, and was cultured at 29°C, pH 6.6, and an oscillation speed of 120 r / min for 4 hours.

[0037] The seed culture medium consisted of sucrose 22 g / L, tryptone 9 g / L, complex vitamins (vitamin B1 0.03 g / L, vitamin B2 0.02 g / L, vitamin B6 0.008 g / L, vitamin B12 0.003 g / L, vitamin C 0.08 g / L, biotin 0.003 g / L), amino acid mixture (glycine 0.6 g / L, alanine 0.7 g / L, glutamic acid 0.3 g / L, aspartic acid 0.3 g / L), diammonium phosphate 1.8 g / L, and magnesium sulfate 0.7 g / L. The culture was carried out at 31 °C, pH 7.3, and stirring speed 190 r / min for 16 hours.

[0038] Construction of efficient fermentation system and fermentation culture The new airlift fermenter has a baffle guide device and 6 microporous aeration heads (aperture 0.4mm) at the bottom. The fermentation medium is sucrose 75g / L, new composite nitrogen source (plant protein hydrolysate (hydrolysis degree 35%) and microbial cell protein mass ratio of 4:1) 22g / L, diammonium hydrogen phosphate 2.5g / L, magnesium sulfate 1.2g / L, zinc sulfate 0.03g / L, copper sulfate 0.01g / L, and calcium pantothenate 0.005g / L.

[0039] The seed liquid was inoculated at an inoculum rate of 12%, and fermented at a temperature of 34° C., a pH value of 7.5, a stirring speed of 230 r / min, and a ventilation volume of 1.6 vvm. The online monitoring and intelligent control were as in Example 1.

[0040] In-situ product separation and recycling Fill with macroporous adsorption resin (functional group is carboxyl, adsorption capacity 35g / L), after saturation, elute with eluent containing 1.5mol / L ammonia water and 1.2mol / L sodium chloride, and partially circulate the eluate after treatment.

[0041] Product Refining and Environmental Protection Treatment The ion exchange resin and treatment were the same as in Example 1, the vacuum freezing crystallization cooling rate was 0.8°C / h, the vacuum degree was 0.06MPa, and the crystallization took 18 hours. The waste water, waste gas, and waste residue treatment were the same as in Example 1. The final L-lysine yield reached 62g / L, and the product purity was 99.1%.

[0042] Comparative Example Bacteria selection Use a wild-type E. coli strain that has not been genetically modified.

[0043] Seed cultivation The seed culture medium was 20 g / L glucose, 8 g / L yeast powder, 10 g / L peptone, 1.5 g / L potassium dihydrogen phosphate, and 0.8 g / L magnesium sulfate. The culture was carried out at a temperature of 32°C, a pH value of 7.2, and a stirring speed of 200 r / min for 20 hours.

[0044] Fermentation culture A traditional mechanical stirring fermenter was used. The fermentation medium was 80 g / L glucose, 15 g / L ammonium sulfate, 2 g / L potassium dihydrogen phosphate, 1 g / L magnesium sulfate, 0.05 g / L ferrous sulfate, 0.02 g / L manganese sulfate, and 0.005 g / L biotin. The inoculation amount was 10%. The fermentation was carried out at a temperature of 35°C, a pH value of 7.4, a stirring speed of 220 r / min, and a ventilation volume of 1.5 vvm. No online monitoring or intelligent control was performed, and only the pH value was manually tested and adjusted at regular intervals.

[0045] Product separation and purification After fermentation, centrifugal separation (speed 8000r / min) and common ion exchange resin are used for separation and purification, and in-situ product separation is not performed. Natural cooling crystallization is used for crystallization.

[0046] Environmental protection treatment Wastewater is discharged after simple acid-base neutralization treatment; waste gas is discharged directly; waste residue is landfilled. According to the test, the L-lysine yield is 35g / L and the product purity is 90%.

[0047]

[0048] The process of the present invention has significant advantages in improving the quality and efficiency of L-lysine fermentation. Compared with the comparative example, Examples 1 and 2 significantly improved the yield (respectively 65g / L and 62g / L, while the comparative example was only 35g / L) by means of multi-gene modified strains, optimized seed culture, the use of new fermentation tanks and intelligent control, and the product purity was also greatly improved (99.3%, 99.1% vs. 90%). At the same time, the fermentation cycle was shortened, and the environmental protection treatment was fully up to standard, reducing pollution. It can be seen that the present invention effectively optimizes the production process and shows good application prospects in terms of economic and environmental benefits.

[0049] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A clean production process for improving the quality and efficiency of L-lysine fermentation, characterized in that: The following steps are involved: S1: Multi-gene collaborative transformation strain selection, select suitable host strains, use gene editing technology to simultaneously perform targeted transformation of multiple genes related to L-lysine synthesis, including strengthening the expression of key enzyme genes, knocking out or inhibiting branch metabolism genes, and constructing multi-gene collaboratively optimized L-lysine production strain genetic engineering bacteria; And specific stress response elements were introduced during strain construction; S2: Pre-culture and seed expansion culture. The selected strains are first pre-cultured in a pre-culture medium containing special inducers. The pre-culture conditions are 28-32°C, pH 6.5-7.0, and slight shaking culture for 4-6 hours to activate the relevant metabolic pathways of the strains. Then they are transferred to the seed culture medium for seed expansion culture. A mixture of vitamins and amino acids is added to the seed culture medium. The expansion culture conditions are 30-34°C, pH 7.0-7.5, stirring speed 180-220r / min, and the culture time is 12-18 hours. S3: Construction of efficient fermentation system and fermentation culture, using a new type of airlift fermenter with a special flow guide device inside, multiple microporous aeration heads at the bottom of the fermenter, adding a new type of composite nitrogen source to the fermentation medium, including plant protein hydrolysate and microbial protein, as well as an optimized proportion of carbon source, inorganic salt and growth factor; inoculating the seed liquid into the fermentation medium for fermentation culture, the fermentation conditions are temperature 33-37℃, pH value 7.2-7.6, stirring speed 200-250r / min, ventilation volume 1.2-1.8vvm, and an online monitoring system is used to monitor the fermentation parameters in real time during the fermentation process, and the fermentation conditions are dynamically adjusted according to the monitoring data through an intelligent control system; S4: In-situ product separation and recycling. In the fermentation process, the L-lysine produced is separated by in-situ adsorption using a selective adsorption resin. The adsorption resin is filled in a specific adsorption column in the fermentation tank. When the adsorption is saturated, the L-lysine is recovered online by eluting with a specific eluent. After the eluate is treated, part of it is recycled back to the fermentation tank for continued use. At the same time, the useful metabolic by-products produced during the adsorption process are recovered. After the fermentation is completed, the remaining fermentation liquid is centrifuged and ultrafiltered to obtain a concentrated liquid containing L-lysine. S5: Product refining and environmental protection treatment. The concentrate is refined by ion exchange, and an ion exchange resin with high selectivity and regeneration performance is used to remove impurity ions. Then vacuum freezing crystallization is carried out. During the crystallization process, the cooling rate and vacuum degree are controlled to obtain a high-purity L-lysine crystal product. The wastewater, waste gas and waste residue generated in the entire production process are subjected to comprehensive environmental protection treatment. The wastewater is treated by biological treatment and membrane separation technology and then meets the standards for reuse or discharge. The waste gas is treated by adsorption and catalytic oxidation and then meets the standards for discharge. The waste residue is harmlessly treated and then used as a fertilizer or feed additive for resource utilization.

2. A clean production process for improving the quality and efficiency of L-lysine fermentation according to claim 1, characterized in that: The specific operation of the multi-gene collaborative transformation is: in the host strain, the key enzyme genes in the L-lysine synthesis pathway are subjected to site-directed mutation by gene editing technology; and genes related to branch metabolism, including genes that compete for carbon sources and energy, are knocked out at the same time; In addition, stress response elements, including heat shock protein gene promoter elements, are introduced to enhance the strain's tolerance to environmental changes in temperature and pH.

3. A clean production process for improving the quality and efficiency of L-lysine fermentation according to claim 1, characterized in that: The special inducer is a complex containing a short peptide and a small molecule metabolite, and its preparation method is obtained through microbial fermentation, and is used to specifically activate the expression of genes related to L-lysine synthesis.

4. A clean production process for improving the quality and efficiency of L-lysine fermentation according to claim 1, characterized in that: The complex vitamins include vitamin B1, B2, B6, B12, vitamin C and biotin, and the amino acid mixture includes glycine, alanine, glutamic acid and aspartic acid, and the added amounts thereof are respectively 0.01-0.1 g / L of the total amount of vitamins and 0.5-2 g / L of the total amount of amino acids.

5. A clean production process for improving the quality and efficiency of L-lysine fermentation according to claim 1, characterized in that: The mass ratio of plant protein hydrolysate to microbial protein in the novel composite nitrogen source is 2-5:1, the hydrolysis degree of the plant protein hydrolysate is 30-50%, and the microbial protein comes from a high-efficiency protein production strain.

6. A clean production process for improving the quality and efficiency of L-lysine fermentation according to claim 1, characterized in that: The fermentation parameters monitored by the online monitoring system include bacterial concentration, dissolved oxygen, L-lysine concentration, pH value, temperature and redox potential. The intelligent control system automatically adjusts the fermentation conditions such as ventilation volume, stirring speed, feed rate and pH regulator addition amount based on these parameters according to preset algorithms and models.

7. A clean production process for improving the quality and efficiency of L-lysine fermentation according to claim 1, characterized in that: The selective adsorption resin is a macroporous adsorption resin with specific pore size and functional groups, and its adsorption capacity for L-lysine is between 30-50g / L, and the adsorption selectivity coefficient is greater than 10; the eluent is a mixed solution containing ammonia water and sodium chloride with a set concentration, the ammonia concentration is 1-3mol / L, and the sodium chloride concentration is 0.5-1.5mol / L.

8. A clean production process for improving the quality and efficiency of L-lysine fermentation according to claim 1, characterized in that: In the ion exchange refining process, the ion exchange resin used is a combination of a strongly acidic cation exchange resin and a weakly basic anion exchange resin, the volume ratio of the two is 3-5:1, and the ion exchange resin is subjected to a special surface modification treatment.

9. A clean production process for improving the quality and efficiency of L-lysine fermentation according to claim 1, characterized in that: During the vacuum freezing crystallization process, the cooling rate is controlled at 0.5-1.5°C / h, the vacuum degree is maintained at 0.05-0.1MPa, and the crystallization time is 10-20 hours. The L-lysine crystals obtained in this way have uniform particle size and a purity of more than 99%.

10. A clean production process for improving the quality and efficiency of L-lysine fermentation according to claim 1, characterized in that: In the environmental protection treatment link, wastewater biological treatment adopts an anaerobic-aerobic combined process, and membrane separation technology adopts an ultrafiltration and reverse osmosis combined process; waste gas adsorption adopts activated carbon fiber adsorption, and catalytic oxidation adopts precious metal catalysts; waste residue harmless treatment includes high-temperature sterilization and composting and fermentation processes to ensure that the treated waste residue meets relevant environmental protection standards and fertilizer and feed additive quality standards.

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