CN101298422A

CN101298422A - Extraction method of L-isoleucine

Info

Publication number: CN101298422A
Application number: CNA2007100219343A
Authority: CN
Inventors: 缪正兴; 李宝忠
Original assignee: JIANGSU JUHUA MONOSODIUM GLUTAMATE GROUP CO Ltd
Current assignee: JIANGSU JUHUA MONOSODIUM GLUTAMATE GROUP CO Ltd
Priority date: 2007-04-30
Filing date: 2007-04-30
Publication date: 2008-11-05

Abstract

The invention discloses an extraction method of L-isoleucine; the technique process of the invention includes the following steps: obtaining zymotic fluid containing the L-isoleucine by zymotechnics; carrying out filtration on the zymotic fluid after adding a neutral flocculating agent to remove thalli; adding active carbon into filtrate to carry out decoloring; the size of the liquid is condensed to 9 to 11 percent of the original size by heating and vacuum condensing; the condensed liquid is crystallized after being cooled to 24.5 to 25.5 DEG C; then the crude product is obtained by centrifugalizing; the crude product is dissolved into liquor of 3.5 percent and heated up to between 58 to 62 DEG C, then is decolored, filtered, condensed, crystallized and separated to obtain the secondary crude product; the operations are carried out again on the secondary crude product; only a hyperfiltration process is added when filtering and finally the wet finished product is obtained after crystallization. The extraction method has the advantages of greatly reducing the drain amount of waste water as the working procedure of ion exchange is replaced by only adopting the method of condensing crystallization; furthermore, the extraction absorption rate is also remarkably improved.

Description

The extracting method of L-Isoleucine

Technical field

The present invention relates to a kind of extraction process of L-Isoleucine, relate in particular to a kind of improvement of L-Isoleucine extraction process.

Background technology

At present, the L-Isoleucine adopts fermentative Production mostly, extraction for L-Isoleucine in the fermented liquid, all adopt both at home and abroad and remove by filter thalline, filtrate is transferred PH to 2.5-3.0, with 732 cationic exchange resin adsorption L-Isoleucines, then with weak ammonia with L-Isoleucine wash-out, the elutriant activated carbon decolorizing, condensing crystal obtains crude product then; Dissolving crude product is used activated carbon decolorizing, and recrystallization obtains finished product L-Isoleucine.Owing to adopted the ion exchange method extraction, so produce a large amount of waste water in the production process, one ton of finished product of every production produces the water yield and reaches about 800 tons.And owing to L-Isoleucine in the absorption waste liquid is wayward, bring product yield on the low side in the ion-exchange adsorption process, leaching process need consume a large amount of sulfuric acid and ammoniacal liquor simultaneously.Extraction cost is higher.In addition,, in ion exchange process, be difficult for being removed, bring the impurity amino acid that has more content in the product, influence the quality of the finished product because the impurity aminoacids content in the fermented liquid is higher.So at present both at home and abroad to exist sewage quantity big for the L-Isoleucine extraction process that adopts, extract yield is low, yield generally about 55%-60%, cost height, the problem of poor product quality.

Summary of the invention

The object of the present invention is to provide a kind of ion-exchange process that saves, adopt direct condensing crystal, and the extracting method of the L-Isoleucine through repeatedly purifying repeatedly.

For realizing purpose of the present invention, a kind of extracting method of L-Isoleucine, its technological process comprises: the fermented liquid that obtains to contain the L-Isoleucine by fermentation method, after adding neutral flocculation agent fermented liquid is filtered, remove the thalline in the filtered liquid, adding gac in filtrate decolours, liquid after the decolouring is through heating and vacuum concentration, liquid volume is concentrated to about the 9-11% of original volume, then concentrated solution is cooled to 24.5-25.5 ℃ of crystallization, obtain the thick product of crystalline through centrifugation, the mother liquor of separating is got back to down in the filtrate of criticizing and recycle after treatment; It is about 3.5% solution that the thick product that the above-mentioned first time, Crystallization Separation was come out is dissolved in water into weight ratio, solution is heated to 58-62 ℃, adding gac decolours once more, solution after the decolouring after filtration, and with solution concentration to about the 7-9% of original volume, then concentrated solution is cooled to 24.5-25.5 ℃ of crystallization, can obtains the thick product of crystalline for the second time through centrifugation, the mother liquor of separating can postback in the ferment filtrate and reuse; For the second time to be dissolved in water into weight ratio once more be about 3.5% solution to the thick product of crystalline, solution is heated to 58-62 ℃, adding gac decolours once more, solution after the decolouring passes through ultrafiltration after filtration again, once more solution concentration is arrived about the 7-9% of original volume, and then concentrated solution is cooled to 24.5-25.5 ℃ of crystallization, obtain wet finished product through centrifugation, the mother liquor of separating can be used as the batching water of the thick product of crystallization for the first time, and wet finished product becomes finished product after drying; The Tc of described concentrated solution is best 25 ℃ of left and right sides crystallizations all; Described each gac add-on is respectively the 0.17-0.23% of filtrate weight; The mother liquor that separate the described first time is adjusted to 2.5-3.0 through pH value, adopts 732 resin absorption then, adopts the ammoniacal liquor wash-out about 1.0N, and its desorbed solution is got back to down in batch filtrate and recycled.

Advantage of the present invention is: this method has been owing to removed the operation of ion-exchange, and directly adopts the method for condensing crystal, therefore greatly reduces discharged waste water, and extracts specific absorption and also be significantly improved.

Embodiment

When adopting fermentative Production L-Isoleucine, contain required L-Isoleucine in the fermented liquid that obtains through the fermentation of bacterial classification and secondary bacterial classification, analyze the various major ingredient in the fermented liquid, wherein: the L-Isoleucine is about 2%, Methionin is below 0.3%, (NH ₄) ₂SO ₄Inorganic salt, pigment and protein are a small amount of.Because the solubleness of L-Isoleucine in water is less, solubleness in the time of 25 ℃ is about 4%, and the solubleness of other impurity is all than L-Isoleucine height, therefore, can adopt the fermented liquid direct filtration, decolouring, concentrate, centrifugation then obtains L-Isoleucine crude product then, and crude product dissolves once more then, through the concentrated L-Isoleucine that obtains that decolours, repeat aforesaid operations, the product yield of L-Isoleucine is reached by original 53-55% bring up to more than 60, the sewage consumption of ton product is below 50 tons, quality product obviously improves, reach 29 editions requirements of American Pharmacopeia, promptly total heteroacid is less than 2.0%, and single heteroacid is less than 0.5%.The extracting method of L-Isoleucine is as follows:

1, obtain to contain the fermented liquid of L-Isoleucine by fermentation method, content is generally about 2%, after adding neutral flocculation agent fermented liquid is filtered, by removing by filter the thalline in the fermented liquid, adding the gac that accounts for filtrate weight 2% in filtrate decolours, liquid after the decolouring is through heating and concentrated, liquid volume is concentrated to about the 9-11% of original volume, then concentrated solution is cooled to 24.5-25.5 ℃ of crystallization, best Tc is about 25%, and obtain the thick product of crystalline through centrifugation, the mother liquor of separating is adjusted to 2.5-3.0 through pH value, adopt 732 resin absorption then, adopt the ammoniacal liquor wash-out about 1.0N, its desorbed solution is got back to down in batch filtrate and is recycled.

2, the thick product that the above-mentioned first time, Crystallization Separation was come out being dissolved in water into weight ratio is about 3.5% solution, solution is heated to 58-62 ℃, adding gac decolours once more, the gac add-on is the 0.17-0.23% of filtrate weight, solution after the decolouring after filtration, and with solution concentration to about the 7-9% of original volume, then concentrated solution is cooled to 24.5-25.5 ℃ of crystallization, best Tc is about 25%, can obtain the thick product of crystalline for the second time through centrifugation, the mother liquor of separating can postback in the ferment filtrate and reuse;

3, for the second time to be dissolved in water into weight ratio once more be about 3.5% solution to the thick product of crystalline, solution is heated to 58-62 ℃, adding gac decolours once more, the gac add-on is the 0.17-0.23% of filtrate weight, solution after the decolouring after filtration, pass through ultrafiltration again, once more solution concentration is arrived about the 7-9% of original volume, and then concentrated solution is cooled to 24.5-25.5 ℃ of crystallization, best Tc is about 25%, obtain wet finished product through centrifugation, the mother liquor of separating can be used as the batching water of the thick product of crystallization for the first time, and wet finished product becomes finished product after drying.

Claims

1, a kind of extracting method of L-Isoleucine, its technological process comprises: the fermented liquid that obtains to contain the L-Isoleucine by fermentation method, after adding neutral flocculation agent fermented liquid is filtered, remove the thalline in the filtered liquid, adding gac in filtrate decolours, liquid after the decolouring is through heating and vacuum concentration, liquid volume is concentrated to about the 9-11% of original volume, then concentrated solution is cooled to 24.5-25.5 ℃ of crystallization, obtain the thick product of crystalline through centrifugation, the mother liquor of separating is got back to down in the filtrate of criticizing and recycle after treatment; It is about 3.5% solution that the thick product that the above-mentioned first time, Crystallization Separation was come out is dissolved in water into weight ratio, solution is heated to 58-62 ℃, adding gac decolours once more, solution after the decolouring after filtration, and with solution concentration to about the 7-9% of original volume, then concentrated solution is cooled to 24.5-25.5 ℃ of crystallization, can obtains the thick product of crystalline for the second time through centrifugation, the mother liquor of separating can postback in the ferment filtrate and reuse; For the second time to be dissolved in water into weight ratio once more be about 3.5% solution to the thick product of crystalline, solution is heated to 58-62 ℃, adding gac decolours once more, solution after the decolouring passes through ultrafiltration after filtration again, once more solution concentration is arrived about the 7-9% of original volume, and then concentrated solution is cooled to 24.5-25.5 ℃ of crystallization, obtain wet finished product through centrifugation, the mother liquor of separating can be used as the batching water of the thick product of crystallization for the first time, and wet finished product becomes finished product after drying.

2, the extracting method of a kind of L-Isoleucine according to claim 1 is characterized in that: the Tc of described concentrated solution all is the best 25 ℃ of left and right sides crystallizations.

3, the extracting method of a kind of L-Isoleucine according to claim 1 is characterized in that: the add-on of described each gac is respectively the 0.17-0.23% of filtrate weight.

4, the extracting method of a kind of L-Isoleucine according to claim 1, it is characterized in that: the mother liquor that separate the described first time is adjusted to 2.5-3.0 through pH value, adopt 732 resin absorption then, adopt the ammoniacal liquor wash-out about 1.0N, its desorbed solution is got back to down in batch filtrate and is recycled.