阅读说明：本技术 一种低废水产生量生产和提取谷氨酸的方法 (Method for producing and extracting glutamic acid with low wastewater production ) 是由 时夫龙 程士清 孙钦波 徐国莉 杨雪 于 2019-12-21 设计创作，主要内容包括：本发明属于氨基酸生产技术领域,公开了一种低废水产生量生产和提取谷氨酸的方法,其包括：步骤1)生产工艺和步骤2)提取工艺；该生产工艺中使用了豆粕水解产物制备的发酵培养基。该方法发酵成本低廉,提取工艺废水量降低。(The invention belongs to the technical field of amino acid production, and discloses a method for producing and extracting glutamic acid with low wastewater production, which comprises the following steps: step 1) production process and step 2) extraction process; the production process uses a fermentation culture medium prepared from bean pulp hydrolysate. The method has low fermentation cost and reduced extraction process waste water amount.)

1. A method for producing and extracting glutamic acid with low wastewater production, comprising: step 1) production process and step 2) extraction process; the method is characterized in that a fermentation medium prepared from bean pulp hydrolysate is used in the production process.

2. Method according to claim 1, characterized in that it comprises the following steps:

step 1) production process: inoculating the seed liquid of the Brevibacterium flavum producing glutamic acid into a fermentation tank filled with a fermentation medium for fermentation culture, fermenting for 48 hours, and collecting fermentation liquor; in the whole fermentation process, the fermentation temperature is controlled to be 35-37 ℃, the ventilation ratio is 1: 0.6, the stirring speed is 200-;

step 2) extraction process:

taking fermentation liquor, centrifuging for 5min at 4000rpm by adopting a high-speed disc centrifuge, and collecting filtrate and mycoprotein precipitation; adding 1% of flocculating agent into the filtrate, uniformly mixing, standing for 12h, filtering by a plate frame, and collecting liquid; then filtering the mixture by a ceramic membrane, and collecting filtrate; introducing the filtrate into a decolorizing tank for 60min, filtering, and collecting decolorized solution; carrying out secondary decolorization on the decolorized solution through a decolorizing membrane, and collecting decolorized clear liquid; carrying out chromatographic separation on the decolorized clear liquid through a sequential simulated moving bed to obtain an extracting solution; concentrating the extractive solution with four effects, centrifuging, spray drying with fluidized bed, inspecting, and packaging.

3. The method of claim 2, wherein the fermentation medium is prepared by the following process:

taking fermentation medium raw materials, and preparing according to the following concentrations: 50-100g/L of glucose, 300g/L of soybean meal hydrolysate, K₂HPO₄1-3g/L，MgSO₄·7H₂O 30-80mg/L，MnSO₄·H₂O 2-5mg/L，FeSO₄·7H₂O 2-5mg/L，VB₁8-15mg/L, biotin 5-10 mug/L; stirring the above materials, adjusting pH to 6-7, sterilizing, and naturally standingCooling to obtain the fermentation culture medium.

4. A method according to claim 3, characterized in that the method comprises the steps of: taking fermentation medium raw materials, preparing according to the following concentration, glucose 80g/L, soybean meal hydrolysate 200g/L, K₂HPO₄2g/L，MgSO₄·7H₂O50mg/L，MnSO₄·H₂O 3mg/L，FeSO₄·7H₂O 3mg/L，VB₁10mg/L, biotin 7 mu g/L; stirring the raw materials uniformly, adjusting pH to 6.5, sterilizing at 121 deg.C for 15min, and naturally cooling to obtain fermentation culture medium.

5. The method according to claims 1 to 4, wherein the soybean meal hydrolysate is prepared by the following process:

crushing the bean pulp, placing the crushed bean pulp in a reaction kettle, adding corn steep liquor and glutamic acid residue, adding citric acid to prepare suspension with the solid content of 30-40%, and homogenizing by using a high-pressure homogenizer to refine the particle size; heating to 90 deg.C, and hydrolyzing with ultrasound for 5-20 min; continuing to hydrolyze for 5-7h, then performing microwave-assisted hydrolysis for 2-4min, stopping microwave, cooling to 45 ℃, adjusting the pH to 2.5-3.5, then adding acid protease, performing enzymolysis for 6-9h, inactivating enzyme at 95 ℃ for 3min, then filtering, discharging residues, then adding activated carbon for decolorization, and filtering to remove the activated carbon to obtain the bean pulp hydrolysate.

6. The method according to claim 5, wherein the corn steep liquor is added in an amount of 30-50% by weight of the soybean meal, and the glutamic acid residue is added in an amount of 20-40% by weight of the soybean meal.

7. The method according to claim 5, wherein the concentration of citric acid is 1-2 mol/L.

8. The method of claim 5, wherein the parameters of the homogenization process are: the pressure is 30MPa, the temperature is 32 ℃, and the time is 10-20 s.

9. The method according to claim 5, wherein the amount of the acidic protease added is 500U/L.

10. The method as claimed in claim 5, wherein the flocculant is prepared by mixing chitosan and sodium alginate according to a mass ratio of 2: 1.

Technical Field

The invention belongs to the technical field of amino acid production, and relates to a method for producing and extracting glutamic acid with low wastewater production.

Background

With the gradual development of the amino acid industry, the microbial fermentation method becomes the most promising production technology for producing amino acid, but the defect of high cost of a fermentation medium exists in the preparation process of microbial fermentation liquid. The extraction process of the glutamic acid mainly has the following disadvantages: 1. the prior domestic amino acid production still adopts the traditional technical means of plate frame, ion exchange, decoloration, drying and the like, and the product has low purity, large acid and alkali dosage, large wastewater yield and serious environmental pollution, thereby becoming a key factor for restricting the green development of the biological fermentation industry. 2. The traditional flocculating agent causes the technical problems of high baume degree and viscosity of waste liquid and high difficulty in waste water treatment. 3. In the drying process, the feed liquid is easy to generate coking phenomenon, the quality of the product is influenced, and bad smell is generated.

Disclosure of Invention

In order to overcome the defects of overlarge wastewater quantity of a glutamic acid fermentation culture medium and an extraction process in the prior art, the invention provides a method for producing and extracting glutamic acid with low wastewater production quantity.

The invention is realized by the following technical scheme:

a method for producing and extracting glutamic acid with low wastewater production, comprising: step 1) production process and step 2) extraction process; the method is characterized in that a fermentation medium prepared from bean pulp hydrolysate is used in the production process.

Further, the method comprises the steps of:

step 1) production process: inoculating the seed liquid of the Brevibacterium flavum producing glutamic acid into a fermentation tank filled with a fermentation medium for fermentation culture, fermenting for 48 hours, and collecting fermentation liquor; in the whole fermentation process, the fermentation temperature is controlled to be 35-37 ℃, the ventilation ratio is 1: 0.6, the stirring speed is 200-;

step 2) extraction process:

taking fermentation liquor, centrifuging for 5min at 4000rpm by adopting a high-speed disc centrifuge, and collecting filtrate and mycoprotein precipitation; adding 1% of flocculating agent into the filtrate, uniformly mixing, standing for 12h, filtering by a plate frame, and collecting liquid; then filtering the mixture by a ceramic membrane, and collecting filtrate; introducing the filtrate into a decolorizing tank with the addition of active carbon of 0.5% for 60min, filtering, and collecting decolorized solution; carrying out secondary decolorization on the decolorized solution through a decolorizing membrane, and collecting decolorized clear liquid; carrying out chromatographic separation on the decolorized clear liquid through a sequential simulated moving bed to obtain an extracting solution; concentrating the extractive solution with four effects, centrifuging, spray drying with fluidized bed, inspecting, and packaging.

Further, the fermentation medium is prepared according to the following process: taking fermentation medium raw materials, and preparing according to the following concentrations: 50-100g/L of glucose, 300g/L of soybean meal hydrolysate, K₂HPO₄1-3g/L，MgSO₄·7H₂O 30-80mg/L，MnSO₄·H₂O 2-5mg/L，FeSO₄·7H₂O 2-5mg/L，VB₁8-15mg/L, biotin 5-10 mug/L; stirring the raw materials uniformly, adjusting pH to 6-7, sterilizing, and naturally cooling to obtain the fermentation culture medium.

Still further, the method comprises the steps of: taking fermentation medium raw materials, preparing according to the following concentration, glucose 80g/L, soybean meal hydrolysate 200g/L, K₂HPO₄2g/L，MgSO₄·7H₂O 50mg/L，MnSO₄·H₂O 3mg/L，FeSO₄·7H₂O 3mg/L，VB₁10mg/L, biotin 7 mu g/L; stirring the raw materials uniformly, adjusting pH to 6.5, sterilizing at 121 deg.C for 15min, and naturally cooling to obtain fermentation culture medium.

Preferably, the bean pulp hydrolysate is prepared by the following process:

crushing the bean pulp, placing the crushed bean pulp in a reaction kettle, adding corn steep liquor and glutamic acid residue, adding citric acid to prepare suspension with the solid content of 30-40%, and homogenizing by using a high-pressure homogenizer to refine the particle size; heating to 90 deg.C, and hydrolyzing with ultrasound for 5-20 min; continuing to hydrolyze for 5-7h, then performing microwave-assisted hydrolysis for 2-4min, stopping microwave, cooling to 45 ℃, adding ammonia water, adjusting pH to 2.5-3.5, then adding acid protease, performing enzymolysis for 6-9h, inactivating enzyme at 95 ℃ for 3min, then filtering, discharging residue, then adding activated carbon for decolorization, and filtering to remove activated carbon to obtain a soybean meal hydrolysate.

More preferably, the adding amount of the corn steep liquor accounts for 30-50% of the weight of the soybean meal, and the adding amount of the glutamic acid residue accounts for 20-40% of the weight of the soybean meal.

More preferably, the concentration of the citric acid is 1-2 mol/L.

More preferably, the parameters of the homogenization process are: the pressure is 30MPa, the temperature is 32 ℃, and the time is 10-20 s.

More preferably, the amount of the acidic protease added is 500U/L.

More preferably, the flocculant is prepared by mixing chitosan and sodium alginate according to the mass ratio of 2: 1.

Compared with the prior art, the invention has the advantages that the following aspects are mainly included but not limited:

the method for hydrolyzing the protein by acid and enzyme by using the physical method has the characteristics of quick and thorough hydrolysis, low cost, small investment, wide application and the like;

according to the invention, the glutamic acid residue and the corn steep liquor are added into the soybean meal, and the three proteins can be jointly hydrolyzed by an optimized process, so that the nutrition in the hydrolysate is more balanced and comprehensive, and the fermentation effect is better compared with that of a single hydrolysate;

according to the invention, by means of a soybean meal hydrolysis technology, the corn steep liquor and the glutamic acid residues are matched with the soybean meal, and the macromolecular protein which is difficult to utilize by microorganisms in the corn steep liquor and the glutamic acid residues is hydrolyzed to free amino nitrogen and micromolecular substances which are easy to utilize by thalli, so that the advantages of the raw materials are effectively utilized and used as specific nutrient components of a fermentation medium, the phenomenon that more foams are generated in the fermentation process is reduced, the effective utilization rate of the fermentation tank capacity is increased, and the fermentation contamination rate is reduced;

the method adopts a mode of hydrolyzing various proteins by weak acid and protease simultaneously and adopts various auxiliary modes of high-pressure homogenization, ultrasound and microwave, so that the leaching rate of the proteins is improved, the hydrolysis degree is greatly improved, the hydrolysis condition is mild, and amino acid components cannot be damaged; homogenizing with a high-pressure homogenizer to refine the particle size, so that the protein particles reach 1-10 μm level, and the hydrolysis contact area is increased; the ultrasonic treatment with proper frequency can not only improve the protein extraction rate, but also destroy protein chains, improve the protein solubility and the hydrophilicity, and is beneficial to overcoming the defect of incomplete weak acid hydrolysis; the microwave with certain power enables peptide molecules to vibrate in an electromagnetic field, so that the structure of partial polypeptide which cannot be hydrolyzed by citric acid is loosened, sulfydryl is destroyed, and the internal structure is changed, thereby being beneficial to further enzymolysis.

The method takes the final aims of obtaining the high-purity and high-cost-performance amino acid product, reducing the environmental pollution and improving the greening level, adopts a comprehensive green separation and extraction technology taking a chromatography and a multistage membrane coupling separation and purification technology as the core, greatly reduces the acid-base usage amount and the water consumption in the extraction process, reduces the energy consumption in the extraction process, and reduces the generation amount of high ammonia-nitrogen wastewater in the extraction process; the fine filtration of the amino acid fermentation liquor is realized by a ceramic membrane and decolorizing membrane filtration technology, so that the precision requirement of the simulated moving bed chromatography is met; the novel chitosan and sodium alginate flocculant replaces the traditional polyacrylamide, obviously improves the protein yield, reduces the baume degree and viscosity of waste liquid, and realizes the breakthrough of greening of industrial flocculant.

Drawings

FIG. 1: the effect of different acid types on the hydrolysis rate;

FIG. 2: the influence of different hydrolysis temperatures on the hydrolysis rate;

FIG. 3: the influence of microwave time on the hydrolysis rate;

FIG. 4: the influence of different enzyme types and enzyme activities on the hydrolysis rate.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the present application will be clearly and completely described below with reference to specific embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.