KR850001830B1 - Process of fermentation and recovery of glutamic acid - Google Patents

Abstract

Glutamic acid was prepd. by fermenting Corynebacterium glutamicum in a molasses medium contg. carbon, a nitrogen source and other nutrients. The fermentation broth was treated with a H2SO4 soln. for purification and recovery of Glu. Thus, 16.5kg of conc-H2SO4 was added to 890L of fermn. broth contg. 7.5g of Glu. per dl and adjusted to pH 5.0, followed by the addn. of 20ppm of CaSO4 at pH 4.0. After stirring and centrifuging, the mixture gave 85kg of solids and 779L of broth, which was ppted. by treatment with 32kg of H2SO4 soln. at pH 3.2. After isolation, 73.5kg of Glu. and waste soln. with 1.58g of Glu. per dl were obtd. The latter is used as an organic fertilizer.

Description

Fermentation and Recovery Method of Glutamic Acid

The present invention relates to a method for treating glutamic acid fermentation broth using molasses as a main raw material. Raw materials used in glutamic acid fermentation broth include acetic acid, paraffin, alcohol, glucose, etc., but these are expensive, and thus, low molasses is generally used as fermentation raw material.

Molasses contains a large amount of impurities depending on the composition of the raw sugar or the processing method of the raw sugar, and when used as fermentation raw materials, molasses is used as a fermentation raw material to purify molasses to remove it.

In general, in purifying molasses, the amount of dissolved minerals in diluted molasses is adjusted to pH 3.0-4.0 using H ₂ SO ₄ or more, followed by centrifugation to remove inorganic salts and impurities, and then used as a fermentation raw material. 80-3495, 81-546, etc.).

The fermented broth (hereinafter referred to as fermentation broth) is adjusted to pH 3.2-3.4 by adding sulfuric acid directly to a concentrate or fermentation broth in order to easily recover glutamic acid in the fermentation broth to obtain glutamic acid crystals.

The glutamic acid obtained as described above is neutralized with alkali (caustic soda or soda ash), decolorized with activated carbon and crystallized to obtain glutamic acid soda.

The inventors found that ammonia was consumed more than necessary due to H ₂ SO ₄ used in the refining process of molasses while studying to reduce the consumption of ammonia used in the fermentation process and sulfuric acid used in the recovery of glutamic acid from the fermentation broth. okay.

In the fermentation, Alkali used for pH control when the medium composition is used such as NaOH, Na ₂ CO _3, NH _3, and the NH ₃ is mainly used for simplicity of easy and the raw material on the handle, NH ₃ is the fermentation metabolism There is a dual effect for the formation of amino acids and for the supply of nitrogen sources as microbial nutrients.

However, due to the excess H ₂ SO ₄ introduced during molasses purification, NH ₃ is consumed in excess for pH adjustment of the fermentation broth and neutralization of sulfuric acid. Dissolved ammonia is also an obstacle to recovery of glutamic acid after fermentation. It has been found that a significant proportion of the requirements are used to react with the ammonium salt of glutamic acid or ammonia in its double salt state in fermentation broth.

Therefore, the present inventors have completed the present invention by developing a method of purifying sulfuric acid after the fermentation is completed instead of the method of purifying molasses with sulfuric acid in order to remove the obstacles in the glutamic acid recovery process in advance.

Effects of the present invention include reducing the amount of NH ₃ used during fermentation, reducing the amount of sulfuric acid used by ammonium ion dissolution during neutralization of glutamic acid, improving the separation efficiency during the separation of the glutamine phase, and the sodium glutamate solution without the separate cell separation process. By removing the microbial cells that interfere with decolorization, it is possible to reduce the activated carbon, so that the production cost of glutamic acid is inexpensive and the required amount of raw materials is significantly reduced, thereby economically manufacturing glutamic acid.

In addition, when H ₂ SO _{4 is} added to the fermentation broth, the activity of the cells is significantly reduced due to the exotherm and the pH decrease, so that the sterilization process by a separate heat treatment can be omitted, thereby greatly simplifying the process.

In more detail, the culture medium consisting of a carbon source, a nitrogen source and other nutrients, 3.0% glucose, KH ₂ PO ₄ 0.05%, K ₂ HPO ₄ 0.05%, MgSO ₄ . 7H ₂ O 0.03%, FeSO ₄ . 7H ₂ O 0.001%, MnSO ₄ . Glutamic acid-producing bacteria of Corynebacterium glutamicum cultured at 0.001% of 4H ₂ O, 0.3% of urea, 0.2% of soybean meal, 200 μg / l of hydrochloric acid amine, 100 μg of biotin, and pH 7.0 Fermented at 30-35 ℃ for 30-40 hours by adding NH ₃ feed, Aeration, and other nutrients while culturing in molasses sterilized by diluting with water. Was added to concentrated sulfuric acid in the fermentation broth was then stirred and pH 4.0-5.0 with the addition of CaSO ₄ in order to facilitate the reaction of the dissolved inorganic and H ₂ SO ₄ and stirred for about 1 hour at 50-60 ℃ by high-speed centrifugal separator (5,000rpm ) Separate solids (inorganic salts such as CaSO ₄ , MgSO ₄ , cells, etc.) and fermentation broth.

Sulfuric acid was added to the fermentation broth to pH 3.2-3.4, and then separated by cooling crystallization for about 5-8 hours. Coarse crystals of glutamic acid were obtained to prepare glutamic acid soda. use.

Compared to the method for recovering glutamic acid in the fermentation broth obtained by purifying the present invention and the conventional molasses with sulfuric acid (hereinafter, referred to as a conventional method) is as follows.

Table 1 Comparison of Acid Alkali Consumption between the Present Invention and Conventional Methods

The results are the same) and the results of several experiments under the conditions did not affect the concentration of glutamic acid in the fermentation broth.

[Table 2] Quality Comparison of Sodium Glutamate Solution of the Present Invention and Conventional Methods

Briefly, the present invention is as follows.

Example 1

245 L of molasses (sugar 50w / w%) was diluted with water to 40g / dl and sterilized, and then inoculated with Corynebacterium glutamitum cultured in a cultivation medium to fermentation medium glucose 8.0%, K ₂ HPO ₄ 0.1%, MgSO ₄ . Fermented by a conventional method at 0.05% of 7H ₂ O, 100 μg / l of chiamine HCl, 0.2% of soybean meal digestion, pH 7.5 and incubated for 36 hours, NH ₃ consumed by nitrogen source was 21.5 kg.

1890 kg of concentrated sulfuric acid was added to 890 l of glutamic acid (concentration 9.5 g / dl yield per 50%) of the fermentation broth to pH 5.0, 20 ppm CaSO ₄ crystals were added, stirred for 30 minutes, adjusted to pH 4.0, stirred for 30 minutes, and then a high speed centrifuge. (4,000 rpm) was used to obtain 85 kg of solid content and 770 l of fermentation broth.

The fermentation broth was neutralized with pH 3.2 using glutamic acid-containing sulfuric acid solution (32 kg of sulfuric acid), followed by separation.

The glutamic acid crystals obtained as described above were dissolved in caustic soda and dissolved in Ca. It was 0.025% and 0.05 ((lambda: 400 nm).

Example 2

As a result of diluting with molasses (51 w / w% of sugar) 1,225 l of water to 40 g / dl of sugar and fermenting it as in Example 1, NH ₃ was consumed by 110 kg as a nitrogen source. To 5,000 liters of fermented glutamic acid (concentration 9.8% 對 糖 收 率 50%) using 72 kg of concentrated sulfuric acid at pH 5.0, 40 ppm CaSO _{4 was} added and stirred for 30 minutes, followed by pH 4.0 again. As addition, 375 kg (87% yield) of glutamic acid were obtained.

In the same manner as in Example 1, sodium glutamate solution Ca ⁺⁺ 0.028% and an OD (absorbance) 4.8 (λ: 400 nm) were obtained.

Claims (2)

Sulfuric acid (H ₂ SO ₄ ) was added to the fermented glutamic acid fermentation broth without purifying the spent molasses to pH 4.0-5.0 to separate the cells and inorganic salts, and then the glutamic acid was recovered using an isoelectric point, a known method. Treatment method. The method of claim 1, wherein when adding H ₂ SO ₄ to the fermentation broth, CaSO ₄ is added to remove solids.