阅读说明：本技术 新型谷氨酸发酵与味精生产方法 (Novel glutamic acid fermentation and monosodium glutamate production method ) 是由 孙钦波 刘元涛 李树标 于 2019-12-21 设计创作，主要内容包括：本发明属于味精制备技术领域,公开了新型谷氨酸发酵与味精生产方法,其包括如下步骤：步骤1)制备优化发酵培养基,步骤2)谷氨酸发酵,步骤3)提取谷氨酸,步骤4)制备味精。本发明在味精制备过程中不使用硫酸,杜绝了废液中硫酸铵的产生,极大地降低废液处理难度,制得成品味精质量高,味精雪白透亮,品相好。(The invention belongs to the technical field of monosodium glutamate preparation, and discloses a novel glutamic acid fermentation and monosodium glutamate production method, which comprises the following steps: step 1) preparing an optimized fermentation medium, step 2) fermenting glutamic acid, step 3) extracting glutamic acid, and step 4) preparing monosodium glutamate. The invention does not use sulfuric acid in the process of preparing monosodium glutamate, avoids the generation of ammonium sulfate in waste liquid, greatly reduces the difficulty of waste liquid treatment, and obtains the finished monosodium glutamate with high quality, snow white and transparent monosodium glutamate and good appearance.)

1. The novel glutamic acid fermentation and monosodium glutamate production method comprises the following steps:

step 1) preparing an optimized fermentation medium, step 2) fermenting glutamic acid, step 3) extracting glutamic acid, and step 4) preparing monosodium glutamate.

2. The production method according to claim 1, wherein the optimized fermentation medium comprises a fermentation medium A and a fermentation medium B which are used separately;

the fermentation medium A is prepared by the following method:

taking the following raw materials: glucose, Yeast extract, K₂HPO₄，MgSO₄·7H₂O, 2-hydroxyethylamine, CeCl₃，MnSO₄·H₂O，FeSO₄·7H₂O，VB₁Biotin; stirring the raw materials uniformly, adjusting the pH value, and sterilizing to obtain a fermentation medium A;

the fermentation medium B is prepared by the following method:

taking the following raw materials: succinic acid, urea, chitosan; and (3) uniformly stirring all the raw materials, adjusting the pH value, and sterilizing to obtain a fermentation medium B.

3. The production method according to claims 1-2, wherein the step 2) glutamic acid fermentation specifically comprises: inoculating the seed solution of Brevibacterium flavum for producing glutamic acid into a 100L fermentation tank filled with 60L fermentation medium A according to the inoculation amount of 8-10% for fermentation culture for 24h, then adding 10L fermentation medium B, continuing the fermentation culture for 24h, and collecting the fermentation liquor; in the whole fermentation culture process, the fermentation temperature is controlled to be 30-36 ℃, the ventilation ratio is 1: 0.7-0.9, the stirring speed is 200-.

4. The production method according to claim 3, wherein the step 3) of extracting glutamic acid specifically comprises: taking fermentation liquor, centrifuging by adopting a high-speed disc centrifuge, and collecting filtrate and mycoprotein precipitation; adding 0.5-2% of flocculating agent into the filtrate, standing for 6-12h, filtering with 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 30-120min, filtering, and collecting decolorized solution; and (4) carrying out secondary decolorization on the decolorized solution through a decolorization membrane, and collecting decolorized clear liquid.

5. The production method according to claim 4, wherein the step 4) of preparing monosodium glutamate comprises the following steps:

carrying out chromatographic separation on the decolorized clear liquid through a sequential simulated moving bed to obtain an extracting solution; concentrating the extractive solution to one third of the original volume with a four-effect evaporator, adding 10-20% sodium hydroxide solution dropwise, adjusting pH to 6.9-7.1, spray drying with fluidized bed, and packaging.

6. The production method according to claims 2 to 3, wherein the fermentation medium A is prepared by:

taking the following raw materials according to the following mixture ratio: glucose 50-100g/L, yeast extract 10-30g/L, K₂HPO₄1-5g/L，MgSO₄·7H₂O20-200 mg/L, 2-hydroxyethylamine 10-50mg/L, CeCl₃1-20mg/L，MnSO₄·H₂O 1-10mg/L，FeSO₄·7H₂O 1-10mg/L，VB₁5-50mg/L, biotin 1-10 mug/L; stirring the raw materials uniformly, adjusting pH to 6-7, sterilizing at 121 deg.C, and naturally cooling to obtain fermentation culture medium A.

7. The production method according to claim 6, wherein the fermentation medium A is prepared by:

taking the following raw materials according to the following mixture ratio: 80g/L glucose, 20g/L yeast extract, K₂HPO₄2g/L，MgSO₄·7H₂O50mg/L, 2-hydroxyethylamine 40mg/L, CeCl₃10mg/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 A.

8. The production method according to claims 2 to 3, wherein the fermentation medium B is prepared by:

taking the following raw materials according to the following mixture ratio: 1-10g/L of succinic acid, 1-5g/L of urea and 20-100mg/L of chitosan; and (3) uniformly stirring all the raw materials, adjusting the pH value, and sterilizing to obtain a fermentation medium B.

9. The production method according to claim 8, wherein the fermentation medium B is prepared by:

taking the following raw materials according to the following mixture ratio: 5g/L of succinic acid, 2g/L of urea and 80mg/L of chitosan; stirring the raw materials uniformly, adjusting pH to 6.5, sterilizing at 121 deg.C for 15min, and naturally cooling to obtain fermentation medium B.

10. The production method according to claim 4, 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 monosodium glutamate preparation, and particularly provides a novel glutamic acid fermentation and monosodium glutamate production method.

Background

Monosodium glutamate, known as monosodium glutamate and chemical name α -monosodium aminoglutarate, is a salt formed by sodium ions and glutamate ions, wherein glutamic acid is an amino acid, and sodium is a metal element.

Two problems exist in the production process of the existing monosodium glutamate: on one hand, in the fermentation process, the feedback inhibition of the metabolic pathway is intensified along with the gradual increase of the content of the glutamic acid, so that the generation of the glutamic acid can be inhibited; on the other hand, the extraction of monosodium glutamate usually adopts an isoelectric-ion exchange method, glutamic acid is crystallized by adding concentrated sulfuric acid to adjust isoelectric points, and ammonium sulfate waste liquor generated in the production process brings great difficulty to waste liquor treatment and causes direct harm to the environment and water sources.

Disclosure of Invention

On the basis of the prior patent technology 'efficient green manufacturing process of amino acid', the product process is continuously improved and optimized, and glutamic acid is prepared into a monosodium glutamate product, and on the basis, a novel glutamic acid fermentation and monosodium glutamate production method is provided.

The invention is realized by the following technical scheme.

The novel glutamic acid fermentation and monosodium glutamate production method comprises the following steps:

step 1) preparing an optimized fermentation medium, step 2) fermenting glutamic acid, step 3) extracting glutamic acid, and step 4) preparing monosodium glutamate.

Further, the optimized fermentation medium comprises a fermentation medium A and a fermentation medium B which are used separately;

the fermentation medium A is prepared by the following method: taking the following raw materials: glucose, Yeast extract, K₂HPO₄，MgSO₄·7H₂O, 2-hydroxyethylamine, CeCl₃，MnSO₄·H₂O，FeSO₄·7H₂O，VB₁Biotin; stirring the raw materials uniformly, adjusting the pH value, and sterilizing to obtain a fermentation medium A;

the fermentation medium B is prepared by the following method:

taking the following raw materials: succinic acid, urea, chitosan; and (3) uniformly stirring all the raw materials, adjusting the pH value, and sterilizing to obtain a fermentation medium B.

Further, the step 2) of glutamic acid fermentation specifically comprises the following steps: inoculating the seed solution of Brevibacterium flavum for producing glutamic acid into a 100L fermentation tank filled with 60L fermentation medium A according to the inoculation amount of 8-10% for fermentation culture for 24h, then adding 10L fermentation medium B, continuing the fermentation culture for 24h, and collecting the fermentation liquor; in the whole fermentation culture process, the fermentation temperature is controlled to be 30-36 ℃, the ventilation ratio is 1: 0.7-0.9, the stirring speed is 200-.

Further, the step 3) of extracting glutamic acid specifically comprises: taking fermentation liquor, centrifuging by adopting a high-speed disc centrifuge, and collecting filtrate and mycoprotein precipitation; adding 0.5-2% of flocculating agent into the filtrate, standing for 6-12h, filtering with 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 0.5-1% for 30-120min, 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; and (3) carrying out four-effect concentration, centrifugation and fluidized bed spray drying on the extracting solution to obtain the compound.

Further, the step 4) of preparing monosodium glutamate comprises the following steps:

carrying out chromatographic separation on the decolorized clear liquid through a sequential simulated moving bed to obtain an extracting solution; concentrating the extractive solution to one third of the original volume with a four-effect evaporator, adding 10-20% sodium hydroxide solution dropwise, adjusting pH to 6.9-7.1, spray drying with fluidized bed, and packaging.

Preferably, the preparation method of the fermentation medium A comprises the following steps: taking the following raw materials: glucose 50-100g/L, yeast extract 10-30g/L, K₂HPO₄1-5g/L，MgSO₄·7H₂O20-200 mg/L, 2-hydroxyethylamine 10-50mg/L, CeCl₃1-20mg/L，MnSO₄·H₂O 1-10mg/L，FeSO₄·7H₂O 1-10mg/L，VB₁5-50mg/L, biotin 1-10 mug/L; stirring the raw materials uniformly, adjusting pH to 6-7, sterilizing at 121 deg.C, and naturally cooling to obtain fermentation culture medium A.

Preferably, the preparation method of the fermentation medium A comprises the following steps:

taking the following raw materials: 80g/L glucose, 20g/L yeast extract, K₂HPO₄2g/L，MgSO₄·7H₂O50mg/L, 2-hydroxyethylamine 40mg/L, CeCl₃10mg/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 A.

Preferably, the preparation method of the fermentation medium B comprises the following steps:

taking the following raw materials: 1-10g/L of succinic acid, 1-5g/L of urea and 20-100mg/L of chitosan; stirring the raw materials uniformly, adjusting the pH value, and sterilizing to obtain a fermentation medium B;

preferably, the preparation method of the fermentation medium B comprises the following steps:

taking the following raw materials: 5g/L of succinic acid, 2g/L of urea and 80mg/L of chitosan; stirring the raw materials uniformly, adjusting pH to 6.5, sterilizing at 121 deg.C for 15min, and naturally cooling to obtain fermentation medium B.

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 fermentation medium of the invention is composed of two parts, wherein the fermentation medium A emphasizes on the improvement of the proliferation of strains, and the fermentation medium B emphasizes on the synthesis and the secretion of glutamic acid.

During early cell proliferation, 2-hydroxyethylamine can promote synthesis of phosphatidylethanolamine cell wall components, so that the proliferation rate of strains is increased, later-stage strain proliferation is slowed down, acid production is mainly achieved, and 2-hydroxyethylamine can also be used as a cationic surfactant, so that cell walls are loosened, cell permeability is improved, and release of glutamic acid to the outside of cells is promoted.

CeCl₃The rare earth salt can promote the proliferation of strains, improve the activity of the related synthetase of the glutamic acid and improve the yield of the glutamic acid; however, excessive concentration of glutamic acid causes slow proliferation and death of the strainThe amount decreases accordingly.

In the middle and later period of fermentation, the proliferation speed of the strain is slowed down, acid production is taken as the main part, amino on chitosan is combined with teichoic acid or lipopolysaccharide with negative charges in the bacterial cell wall, and metal cations are chelated, so that the permeability of the cell wall is changed, and the glutamic acid is promoted to be secreted out of cells.

Succinic acid is added into a fermentation medium, so that the tricarboxylic acid cycle has a certain promotion effect, and the glyoxylate cycle pathway is inhibited, so that the intermediate metabolite flows to the tricarboxylic acid cycle pathway more, and the increase of the glutamic acid yield is promoted.

The invention greatly reduces the usage amount of acid and alkali and water 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 by a comprehensive green separation and extraction technology taking a chromatography and a multistage membrane coupling separation and purification technology as a core.

The invention does not use sulfuric acid in the process of preparing monosodium glutamate, and the whole process improves the income by about 20 percent; meanwhile, the production process avoids the generation of ammonium sulfate in the waste liquid, greatly reduces the difficulty of waste liquid treatment, and thoroughly solves the problem of environmental protection; the finished product of the monosodium glutamate prepared by the production method has high quality, snow white and transparent monosodium glutamate and good appearance.

Drawings

FIG. 1: CeCl₃Influence of rare earth salts on the concentration of the bacteria;

FIG. 2: CeCl₃Influence of rare earth salts on glutamic acid content;

FIG. 3: influence of 2-hydroxyethylamine on the concentration of the bacteria;

FIG. 4: the effect of 2-hydroxyethylamine on glutamic acid content;

FIG. 5: influence of 2-hydroxyethylamine on the conversion of sugar acids.

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.