66 results about "Succinic acid fermentation" patented technology

A method for sorption extraction of succinic acid in fermentation broth by an anion resin belongs to the biochemical technical field. The method comprises the following steps that succinic acid fermentation broth undergoes decoloring treatment by heated active carbon; fungus residue is eliminated through centrifugal filtration or microfiltration membrane filtration; the obtained fermentation clear solution is adsorbed by an alkaline anion resin column, and impurity is flushed away by water after adsorption saturation and then is eluted by hydrochloric acid solution or sulfuric acid solution, thereby obtaining succinic acid solution; the succinic acid solution undergoes depressurized concentration and crystallization so as to obtain a succinic acid product; moreover, MgCl2 and residual sugar in effluent after anion resin column adsorption of the fermentation broth is reclaimed; the MgCl2 in the effluent generated during anion resin adsorption is passed through CO2 or (Na)2CO3 so as to prepare magnesium carbonate which is reclaimed and used in buffering and adjusting pH during fermentation; and sugar in filtrate is reclaimed and used in fermentation ingredients for further fermentation. The method can realize recovery and reuse of materials during operation, and substantially reduces material consumption during extraction; moreover, the method reduces the treatment cost of waste water for environmental protection, and increases the economic benefit of products.

The invention relates to a method for extracting succinic acid from fermentation liquor, comprising the following steps: 1) degerming and decontaminating succinic acid fermentation liquor to obtain succinate solution; 2) allowing the succinate solution to react with calcium chloride to generate calcium succinate precipitate; 3) carrying out solid-liquid separation on reaction liquid to obtain a calcium succinate solid; 4) allowing the calcium succinate solid to react with hydrochloric acid, and separating out a succinic acid solid at a reduced temperature; and 5) carrying out solid-liquid separation on the reaction liquid to obtain the succinic acid. The method has high yield, good product quality, small original auxiliary material consumption, low energy consumption and applicability to large-scale production.

The invention relates to a bacterial strain for the high yield of succinic acid and application thereof. Escherichia coli is modified in order to remove or decrease the activities of adhE, ackA, pta, focA, pflB, iclR, ldhA, poxB and pepc genes; and the gene knockout bacterial strain then receives ultraviolet mutagenesis, and is screened by culture medium with glucose as the only carbon source, so that an engineering bacterial strain which can produce the succinic acid on basal medium and with the glucose as the only carbon source by anaerobic fermentation can be obtained. The invention adopts the succinic acid-producing escherichia coli as the starting strain, and by means of a rational design, the inveniton obtains the engineering bacterial strain with the glucose as the only carbon source theoretically, which carries out anaerobic fermentation in the basal medium and only produces the succinic acid and no other byproducts. Then by means of irrational metabolic evolution integrating ultraviolet mutagenesis with growth screening, a mutant strain for producing the succinic acid is obtained. The bacterial strain disclosed by the invention nearly produces no other heteroacids in the fermentation of the succinic acid, so the production cost of the succinic acid can be remarkably reduced.

The invention discloses an Escherichia coli engineered strain and application in succinic acid production through the aerobic-microaerobic-anaerobic full-stage fermentation of the Escherichia coli engineered strain. The name of the engineered strain is Escherichia coli YL106. The genotype of the strain is a formula shown in a drawing. The strain is collected by China Center for Type Culture Collection (CCTCC) on April 17th, 2013 and has the collection number of CCTCC NO: M2013149. According to the engineered strain disclosed by the invention, succinic acid is produced under the condition of aerobic-microaerobic-anaerobic full-stage fermentation, a large amount of succinic acid can be accumulated efficiently, and the total productivity (2.13 g / (L.h)) of the engineered strain is the highest among literature reports related to the succinic acid production using Escherichia coli currently, so that the engineered strain disclosed by the invention and an aerobic-microaerobic-anaerobic full-stage succinic acid fermentation process have considerable industrial application values and prospects.

The invention belongs to a coupling device and a coupling technology for in situ extraction of succinic acid by an expanded bed and fermentation and separation of the succinic acid, in particular relates to a technology for producing the succinic acid by the fermentation method, a technology for separating the succinic acid by the expanded bed and a fermentation and separation coupling process. The device is to couple a chromatography column of the expanded bed and a succinic acid bioreactor, so as to extract the succinic acid in situ. The device utilizes the characteristic of the chromatography column of the expanded bed that microbial zymotic liquid provided with solid materials is allowed to directly enter the chromatography column, avoids the blockage problem of a chromatography column of a fixed bed due to direct coupling of the fixed bed and the bioreactor in the prior art, saves an additional membrane separator between the bioreactor and the chromatography column of the expanded bed, realizes direct coupling of the chromatography column of the expanded bed and the bioreactor, and performs in situ extraction of target substances and does not cause blockage of the chromatography column of the expanded bed. Moreover, a coupling system for in situ extraction of the succinic acid by the expanded bed and the fermentation and the separation of the succinic acid is established to meet the requirements of sterilization and pollution-free operation.

The invention provides a method for extracting succinic acid from succinic acid fermentation liquor. The method includes that succinic acid fermentation liquor produced by anaerobic fermentation is filtered, filtrate directly reacts with ammonia water, ammonium carbonate or ammonium bicarbonate, the obtained filtrate is treated by resin, the obtained solution is subject to decolouration, concentration and centrifugal separation, thus obtaining succinic acid crystal. The method of the invention has the characteristics of low raw material consumption, simpler technology, short operational process, easy control and low cost.

The invention relates to an alcohol and succinic acid production method by fermenting cellulosic raw material. Cellulosic raw material is pulverized, and low-concentration alkali solution is added for pre-treatment; cellulase and xylanase are performed with enzymolysis, and an enzymolysis product is filtered and concentrated to obtain concentrating sugar liquor; in an alcohol fermenting system, the concentrating sugar liquor is used for fermenting and producing alcohol; in a succinic acid fermenting system, the concentrating sugar liquor is used for fermenting and producing succinic acid; gas produced in the alcohol fermenting process is led into a succinic acid fermenting and producing system after degerming, filtering and washing. The invention ensures that a great quantity of cellulosic waste produced in farming and forestry production can be effectively utilized, solves the problem that carbon dioxide auxiliary material is additionally added during succinic acid fermentation, lowers greenhouse gas discharge value during alcohol fermentation and cost for treating tail gas, has the advantages of wide raw material resource, low production cost, high production efficiency and the like, is favourable for energy saving, emission reduction and environment protection, and is favourable for popularizing and applying.

The invention discloses a method for extracting succinic acid from fermentation broth through two aqueous phase extraction and belongs to the technical field of biochemical engineering. The method includes taking succinic acid fermentation broth produced by microbial fermentation, acidizing prior to adding acidic salt high in solubility and a hydrophilic organic solvent, forming a two aqueous phase system, separating an upper phase and performing depressurizing and distilling to recycle the organic solvent, and using activated carbon to decolor, concentrate and crystallize mother liquor to obtain succinic acid crystals; adding hydrophilic alcohol in a lower phase, respectively recycling inorganic salt and the hydrophilic alcohol. By the method, the problems of low efficiency, high cost and difficulty in removing protein and glucose in existing methods for extracting a target product succinic acid from the succinic acid fermentation broth are solved. The method has the advantages of low energy consumption, simplicity in operation and environmental protection.

The invention discloses a method for extracting succinic acid from succinic acid fermentation liquor by using an electrodialysis method, and belongs to the technical field of biochemical industry. According to the method, the succinic acid is extracted by using the steps: the ordinary succinic acid fermentation liquor is taken as a raw material, deproteinization and decoloration are carried out through thallus separation and electrodialysis, and then denatrium, concentration, crystal separation, filtration and drying are carried out in a bipolar membrane electrodialysis mode. The light transmittance of the fermentation liquor after passing through an electrodialysis device is improved to be 95% from 15%, the decoloration effect is equivalent to that of active carbon, the extraction rate is about 97-98%, and the yield of decoloration in an absorption mode is only 80-85%. Due to adoption of the method, the decoloration by using the active carbon is changed, the absorption of the active carbon on the succinic acid is avoided, and the loss of the succinic acid after the decoloration is avoided, so that the yield is increased; molecular succinic acid is obtained, and no hydrochloric acid or sulfuric acid is required to be used for adjusting the pH value of a system, so that the purification on the succinic acid can be easily carried out; no organic solvents are used, so that residue of the organic solvents is avoided.

The invention provides actinobacillus and a method for producing succinic acid. The Actinobacillus succinogenes CGMCC2560 for producing the succinic acid by fermenting saccharine materials can produce the succinic acid through fermentation, or joint production is performed through succinic acid fermentation and cellulosic ethanol fermentation. Under the anaerobic condition of introducing CO2 and / or N2 and in the environment that pH is maintained 5.5-7.5, 10-110g / L of succinic acid can be produced from 10-100g / L of saccharine materials by anaerobic fermentation. In the joint production method, CO2 generated in the cellulosic ethanol fermentation process is used for the fermentation production of the succinic acid so as to improve the yield of the succinic acid and the cellulosic ethanol and realize zero emission of the CO2. In the joint production, the yield of the succinic acid can reach 92g / L, and the yield of the cellulosic ethanol reaches 108g / L.

The invention discloses a method for producing butyl alcohol and succinic acid through fermentation. The method which is the method for producing the butyl alcohol and the succinic acid produces the butyl alcohol and the succinic acid simultaneously through fermenting microbe in different systems and gas which is produced in producing the butyl alcohol through the fermentation is inputted in a system for producing the succinic acid through the fermentation. The method connects a butyl alcohol fermentation system and a succinic acid fermentation system in series, CO2 and H2 which are produced through fermenting the butyl alcohol are utilized to promote succinic acid synthesis, which not only realizes the comprehensive use of the CO2, reduces the discharge of greenhouse gas, but also reduces the using amount of carbonate in the succinic acid producing process. The method does not need reforming complex devices and only needs adding a filtrating and removing bacteria device and then connecting with an air intake duct of a succinic acid fermentor. Experiments show that the method of the invention can keep or even increase the synthesis concentration of the succinic acid under the condition that the carbonate is not additionally added and simultaneously butyl alcohol synthesis is not affected.

The invention discloses a method for co-producing butanedioic acid and PHB by utilizing colon bacillus for the first time, which is used for knocking out sdhAB and iclR genes in the colon bacillus, and for constructing aerobic fermentation way of the butanedioic acid, so that butanedioic acid fermentation technology bacterial strains MG1655 delta sdhAB delta iclR::kan; on that basis, a PHB biosynthetic pathway is educed into colon bacillus MG1655 delta sdhAB delta iclR::kan, thereby successfully constructing the butanedioic acid and PHB fermentation way in the same colon bacillus. The fermentation and test results prove that the engineering bacterial strain can effectively transform glucose to generate the butanedioic acid and the PHB. 75g / L of glucose is consumed, and 37.5g / L of butanedioic acid is generated; at the same time, PHB is accumulated by thalli to be weighed as 28% of the dry weight of the thalli. The engineering bacterial strain has important application prospect.

The invention discloses a method for analyzing succinic acid fermentation liquid by utilizing near infrared spectrums on line. The method comprises the following steps: collecting near infrared spectrums of microorganisms at different culture time on line; measuring dry cell weight, glucose and succinic acid by the conventional method after sampling; preprocessing the near infrared spectrograms and establishing dry cell weight, glucose and succinic acid models respectively by a chemometrics method; and substituting the spectrograms of samples to be tested into the models to acquire fermentation liquid component information of the samples to be tested. The method is quick, high in accuracy, high in repeatability and simple and convenient to operate.

The invention relates to a succinic acid separating apparatus and a succinic acid separating method based on a full membrane separation system. According to the invention, the full membrane separation system of the succinic acid separating apparatus comprises a membrane component (5). The apparatus also comprises a fermentation tank (1) and a pump (3). The fermentation tank (1), the pump (3) and the membrane component (5) in the full membrane separation system form a circuit, such that the coupling of succinic acid fermentation and separation is realized. According to the apparatus provided by the invention, the succinic acid fermentation technology and the succinic acid separation technology are coupled, such that high concentration inhibition of succinic acid during a fermentation process is relieved, and high-density succinic acid fermentation broth can be obtained. Therefore, the production intensity can be improved, the succinic acid production period can be shortened, and the production efficiency can be improved.

The invention relates to a method for decoloration of a succinic acid fermentation broth by an ion exchange resin. The method provided by the invention comprises a process of carrying out the decoloration of a succinic acid fermentation broth by an ion exchange resin and the process comprises 1, carrying out centrifugation impurity-removal of the succinic acid fermentation broth to obtain a solid-free succinic acid fermentation broth, 2, connecting a cation exchange resin and an anion exchange resin in series and carrying out pretreatment, 3, at a temperature of 30 to 50 DEG C, adding the solid-free succinic acid fermentation broth obtained by the step 1 into the ion exchange resin treated by the step 2, and carrying out decoloration so that colored matters and impurities are adsorbed by the ion exchange resin and thus a decolored succinic acid fermentation broth is obtained. Compared with the prior art, the method has the advantages that the ion exchange resin has good selective adsorbability of pigments and thus the pigments can be dissociated easily so that only water-washing is needed; and the ion exchange resin can be regenerated by acid-washing and alkali-washing.

The present invention provides a method for rapidly detecting a succinic acid content in fermentation broth, and belongs to the technical field of biochemical engineering. According to the method, the fermentation broth is subjected to a pretreatment, and then is directly added to a supporter (silica gel plates, cellulose acetate membrane or chromatography filter paper and the like can be adopted); after drying and immobilization, a copper sulfate-methanol solution is adopted to carry out a color reaction; after completely drying, a thin layer chromatogram scanner is adopted to analyze an absorbance value of a color spot; the succinic acid content in the fermentation broth is calculated according to a linear relation between the succinic acid content and the absorbance value. The method provided by the present invention has characteristics of is simpleness, easy operation, rapid analysis speed, high accuracy, good reproducibility and low detection cost, is applicable for meeting the requirements of the experimental study of the succinic acid fermenting, and the requirements of the analysis and the detection in the practical production, and is a good analysis and detection method for the succinic acid.

The invention discloses a method for continuously discoloring succinic acid fermentation liquor by using activated carbon. The method comprises the following steps of: performing modification treatment by using granular activated carbon, continuously removing pigments from the succinic acid fermentation liquor, regenerating by using the activated carbon, recycling the activated carbon, and the like. By the method, the modified granular activated carbon is used for filling a chromatographic column to continuously discolor the succinic acid fermentation liquor; compared with the conventional powder activated carbon intermittent discoloring treatment method, the method has the advantages of recycling the activated carbon for multiple times, along with low labor intensity, high treatment capacity, no waste residues and the like; in addition, the succinic acid fermentation liquor is discolored under the condition that pH is approximate to a neutral value of 6.4 to 7, so that an acidic discoloring solution is prevented from corroding equipment, and a large amount of acidic wastewater is prevented from being discharged in the subsequent evaporation concentration process; and by the method, reduction in separation cost of preparing succinic acid by a fermentation method is facilitated. The method is mainly applied in a pigment removing process of preparing the succinic acid by the fermentation method.

The invention relates to a method for extracting a succinic acid by employing a succinic acid fermentation liquor. The method comprises the following steps: (1) preparing a succinic acid fermentation liquor; (2) transforming succinate into succinic acid diammonium and acidizing the succinic acid fermentation liquor; (3) extracting the succinic acid; and (4) introducing a magnesium-salt ammonia production process and an acid and alkali recovery technology based on bipolar membrane electrodialysis, and recycling evaporable water, an ammonia gas, a magnesium carbonate suspension liquid and a hydrochloric acid. Clean production in the process is realized by intermediate products of the succinic acid diammonium; meanwhile, the problem that the succinic acid diammonium is transformed into the succinic acid by virtue of resin exchange in a traditional technological process, so that the discharge amount of wastewater is high is avoided; the process difficulty is lowered; and the method is a closed clean production process.

The invention relates to a method for extracting and separating succinic acid from fermentation liquid by using macroporous adsorption resin. The method includes the following steps that 1, succinic acid fermentation liquid is pretreated to remove solid particles and macromolecule impurities in the fermentation liquid and obtain pretreatment liquid; 2, the pretreatment liquid is regulated to be acidic and then delivered to an adsorption column loaded with the polar macroporous adsorption resin, and the polar macroporous adsorption resin is used for adsorption of succinic acid in the pretreatment liquid; 3, an eluting agent is introduced in the adsorption column for eluting to obtain succinic acid eluent; 4, the succinic acid eluent is regulated to be acidic, then concentration, crystallization, filtration and drying are conducted in sequence, and succinic acid is obtained. Compared with the prior art, the polar macroporous adsorption resin is used for extracting and separating high-impurity succinic acid from the succinic acid fermentation liquid, the process is mild in condition, energy consumption is low, operation is simple and convenient, few solvent is consumed, the process is short, and large-scale commercial production is easy to achieve.

The invention discloses a technique for separating and purifying succinic acid from a microbial fermentation liquid by cocrystallization. The method comprises the following steps: adding a proper amount of urea into a pretreated succinic acid fermentation liquid, and carrying out cocrystallization to obtain a succinic acid-urea adduct; and precipitating a sodium succinate solid by utilizing the acid-base neutralization reaction and the property that the sodium succinate is insoluble in alcohols, converting the sodium succinate into succinic acid by using a strongly-acidic cation exchange resin, carrying out reduced pressure evaporation, and drying to obtain the succinic acid of which the purity is greater than 99%. The technique for separating and purifying succinic acid from a microbial fermentation liquid is simple and green, and has the advantages of low production cost, high quality and environment friendliness.

The invention discloses an extraction method of succinic acid. The method comprises the following steps: performing anaerobic fermentation by adopting actinobacillus succinogenes to obtain succinic acid fermentation liquor; carrying out pretreatment to remove solid particles and macromolecular impurities in the succinic acid fermentation liquor, carrying out adsorption and elution treatment through a one-stage adsorption column to obtain succinic acid eluent and remove pigments, proteins, saccharides, inorganic salt ions and micromolecular acids generated by anaerobic fermentation; and finally, carrying out vacuum concentration, cooling crystallization, filtration, drying and the like to obtain succinic acid. The extracted succinic acid product is high in purity and high in extraction yield.

The invention provides a method for preparing succinimide with succinic acid fermentation liquor.With succinic acid obtained by microorganism fermentation and a product which is obtained by co-crystallizing urea in fermentation liquor being raw materials, succinimide is synthesized through control over the initial proportion of a succinic acid and urea reaction.The succinic acid component in the fermentation liquor can be effectively utilized without matching a succinic acid purification step independently, so that operation procedures are simplified; in addition, with the biological product being the initial raw material, pollution is small, remaining fermentation liquor in the process is free of harm to organisms, and can serve as biological fertilizer because residual urea components exist in the fermentation liquor, and CO2 generated by the synthesized succinimide can be used for microorganism culturing in the fermentation process of succinic acid.In this way, integration of a succinic acid separation technology and the succinimide synthesizing technology is achieved, the valuable intermediate product is obtained, additional value is increased on the basis of improving preparation efficiency, and meanwhile the requirement for environmental friendliness is met.

A butanol expression cassette includes a butanol production related genes and a fermentation regulatory element. The fermentation regulatory element controls the expression of the butanol production related gene and locates upstream of the butanol production related gene. The fermentation regulatory element includes a promoter, a ribosome binding site and a transcription factor binding site of a fermentation gene. A fermentation in which the fermentation regulatory element involves includes an acetic acid fermentation, an alcohol fermentation, a succinic acid fermentation or a lactic acid fermentation, the butanol production related gene is not the fermentation gene or a gene of an upstream product of the fermentation in which the fermentation gene involves. The present invention provides a recombinant plasmid formed by cloning the butanol expression cassettes in the expression vector. The present invention also provides a butanol production related gene expression method to express butanol production related gene by using recombinant plasmid.

The invention discloses a method for preparing tetrahydrofuran by using succinic acid fermentation broth, belonging to the technical field of biochemical engineering. According to the method, tetrahydrofuran is prepared by directly esterifying, hydrogenating and refining fermentation liquid containing butanedioic acid, so as to avoid the technological process of performing the consequent reaction after the butanedioic acid solid is obtained at high cost; bipolar membrane electrodialysis is used for removing sodium ions from butanedioic acid fermentation liquid which is subjected to filtering treatment, so as to reduce the influence on the service life of an esterified catalyst in the follow-up working section; the pigment in the fermentation liquid can be removed through rectification so as to prevent the activated carbon from decoloring. The method has the beneficial effects of avoiding the obtainment of the butanedioic acid solid, reducing a great amount of steam consumed in the process, and greatly lowering the cost; a sodium removal technology can be simplified, and the introduction of impurity negative ions can be avoided; the pigment can be removed through adopting a rectification and separation method while the refinement of tetrahydrofuran is realized.

The invention relates to an alcohol and succinic acid production method by fermenting cellulosic raw material. Cellulosic raw material is pulverized, and low-concentration alkali solution is added for pre-treatment; cellulase and xylanase are performed with enzymolysis, and an enzymolysis product is filtered and concentrated to obtain concentrating sugar liquor; in an alcohol fermenting system, the concentrating sugar liquor is used for fermenting and producing alcohol; in a succinic acid fermenting system, the concentrating sugar liquor is used for fermenting and producing succinic acid; gasproduced in the alcohol fermenting process is led into a succinic acid fermenting and producing system after degerming, filtering and washing. The invention ensures that a great quantity of cellulosic waste produced in farming and forestry production can be effectively utilized, solves the problem that carbon dioxide auxiliary material is additionally added during succinic acid fermentation, lowers greenhouse gas discharge value during alcohol fermentation and cost for treating tail gas, has the advantages of wide raw material resource, low production cost, high production efficiency and the like, is favourable for energy saving, emission reduction and environment protection, and is favourable for popularizing and applying.

The invention discloses a method for utilizing dextran fermentation waste liquor for succinic acid fermentation production, and belongs to the technical field of biological engineering. According to the method, the dextran fermentation waste liquor serves as mother liquor to prepare a succinic acid fermentation culture medium, and 30-40 g / L of succinic acid can be produced through batch fermentation; or the mode of taking 10-40 g / L glucose as a carbon source of an initial fermentation culture medium, and concentrated dextran fermentation waste liquor which is subsequently added is adopted for material supplementary to produce succinic acid through batch fermentation, the concentration of succinic acid can reach 40-55.0 g / L after 40-60 hours, the production intensity ranges from 0.8 g / L / h to 1.0 g / L / h, and the sugar acid conversion ratio ranges from 0.70 g / g to 0.83 g / g. According to the method for utilizing the dextran fermentation waste liquor for succinic acid fermentation production, reducing sugar in the dextran fermentation waste liquor can be fully utilized to serve as the carbon source for producing the succinic acid through fermentation, the wastewater discharge amount in the dextran production process is effectively reduced, the use amount of glucose for preparing the succinic acid fermentation culture medium is decreased, and waste utilization of the dextran fermentation waste liquor is achieved.

The invention provides a method for lowering generation of a succinic acid fermentation byproduct, i.e., acetic acid. In the method, in a process that Actinobacillus succinogenes utilizes different carbon sources (glucose, starch hydrolysate and cellulose hydrolysate) to ferment succinic acid, a certain quantity of sodium hydrogen sulfite is added, and the generation of the byproduct, i.e., the acetic acid, can be obviously lowered. When the glucose is taken as a raw material to ferment the succinic acid, after the sodium hydrogen sulfite is added, the yield of the acetic acid can be lowered to 8.18 g / L from 17.85 g / L, and decreasing amplitude is as high as 54.17%. According to the method, the problem that the content of the byproduct, i.e., the acetic acid, is slightly high in a processthat microorganism fermentation is carried out for generating the succinic acid is solved, the separation and purification cost of the succinic acid is lowered, and therefore, the method disclosed bythe invention is favorable for accelerating the development of the industry that the succinic acid is produced by a microorganism fermentation method.

The invention provides a method for preparing butanedioic acid and belongs to the field of microbes. The method comprises the following specific steps: (1) carrying out culture by a microbial fermentation method, so as to obtain sodium succinate fermentation liquor; and (2) adjusting the pH value of the butanedioic acid containing fermentation liquor, carrying out solid-liquid separation on the butanedioic acid containing fermentation liquor, removing part of proteins and pigments so as to obtain clarified fermentation liquor, subjecting the fermentation liquor to concentrating and crystallizing, then, dissolving crystals, carrying out activated-carbon decoloring on the dissolved liquid so as to obtain decolored fermentation liquor, and subjecting the obtained decolored fermentation liquor to acidifying, crystallizing and baking, thereby obtaining the butanedioic acid. The traditional calcium salt method, liquid-liquid extraction method and electrodialysis method all have some disadvantages. According to the method, a novel butanedioic acid extraction process is developed on the basis of a membrane separation technology; and compared with the prior art, the method has the advantages that the decoloring cost is reduced relatively substantially, and the purity of the obtained butanedioic acid product can reach 99.8% to the maximum.

The invention provides a method for separating high-purity succinic acid from a fermentation broth, comprising the following steps of: removing thalline from a succinic acid fermentation broth, condensing, centrifuging, adding active carbon to remove impurities, crystallizing under an acidic condition, filtering, and drying to obtain high-purity succinic acid. The invention is superior to the prior art in the following aspects: the combination of protein denaturation and dehydration is realized through distillation, the denatured protein can be removed from a concentrate in a simple way, microfiltration and ultrafiltration units are saved, the technological flow is simplified, the equipment investment cost is reduced, and there exist no discharge of microfilt membrane-washing wastewater after washing of microfiltration and ultrafilter membranes.

The invention discloses a method for reducing the proportion of succinic acid fermentation by-products of actinobacillus succinogenes, comprising the following steps: carrying out fermentation cultureon strains subjected to strain activation and propagation, with the inoculum size of 5-15% by volume; and adding 1-20 g / L of hydrosulphite or metabisulfite into the fermentation medium. According tothe invention, hydrosulphite or metabisulfite is added in the process of producing succinic acid by fermentation of actinobacillus succinogenes, and is subjected to addition reaction with an intermediate product acetyl phosphate generated in cells to hinder further conversion into acetic acid, so that the content of acetic acid by-products can be greatly reduced under the condition of not influencing the yield of succinic acid. The process is simple in operation process and low in cost, and has industrial application value.