Method for preparing l-valine crystals and / or granules by using ph control

Abstract

The present application relates to a method for preparing valine crystals and / or valine granules by using pH control.

Description

Method for producing L-valine crystals and / or granules using pH control

[0001] The present application relates to a method for producing valine crystals and granules, which can reduce the amount of steam required during the production of valine granules and improve the efficiency of producing valine granules by forming valine crystals and mixed granules with a low moisture content.

[0002]

[0003] In order to obtain high-purity amino acids through fermentation, a separation or purification step of amino acids to remove by-products after the fermentation process step is essential.

[0004] However, in amino acid products for feed use, a product with a high amino acid content (over 98%) is not required, and it may be more appropriate to produce a granular product with a high content (over 70%) that includes other nutritionally valuable components contained in the fermented liquid without generating waste during the purification step.

[0005] In the existing technology (US 7514111 B2), to manufacture amino acid granules for feed additives, a large amount of moisture in the fermentation broth is evaporated and then granules are manufactured using a fluidized bed granulator. In the case of highly soluble amino acids, crystals do not form even when the moisture is evaporated to a solids content of approximately 60-65% (moisture content of 35-40%), so granulation is possible using a fluidized bed granulation method in which the fermentation broth is sprayed through a nozzle. However, valine has low solubility, so crystals form even when the solids content in the fermentation broth is as low as approximately 12-15% (moisture content of 85-88%). Therefore, the moisture content of the fermentation broth cannot be reduced to prevent crystal formation. Therefore, a large amount of water must be evaporated during the drying process, which requires a large amount of energy consumption during drying.

[0006] [Prior Art Literature]

[0007] [Patent Document]

[0008] (Patent Document 1) US 7514111 B2

[0009] (Patent Document 2) US 10072278 B2

[0010]

[0011] The present application aims to provide a method for producing valine crystals, comprising the steps of: preparing a fermentation solution containing valine; adjusting the pH of the fermentation solution; concentrating the fermentation solution to prepare a concentrated fermentation solution; and separating valine crystals containing water from the concentrated fermentation solution.

[0012] In addition, the present application aims to provide a method for producing valine granules, comprising the steps of: preparing a fermentation solution containing valine; adjusting the pH of the fermentation solution; concentrating the fermentation solution to prepare a concentrated fermentation solution; separating valine crystals containing water from the concentrated fermentation solution; mixing the valine crystals with seeds to produce valine mixed granules; and drying the valine mixed granules.

[0013]

[0014] The present application provides a method for producing valine crystals, comprising the steps of: preparing a fermentation solution containing valine; adjusting the pH of the fermentation solution; concentrating the fermentation solution to prepare a concentrated fermentation solution; and separating valine crystals containing water from the concentrated fermentation solution.

[0015] In addition, the present application provides a method for producing valine granules, comprising the steps of: preparing a fermentation solution containing valine; adjusting the pH of the fermentation solution; concentrating the fermentation solution to prepare a concentrated fermentation solution; separating valine crystals containing water from the concentrated fermentation solution; mixing the valine crystals with seeds to produce valine mixed granules; and drying the valine mixed granules.

[0016]

[0017] According to the present application, a fermentation solution containing valine can be concentrated to separate the valine solution, and the separated valine solution can be mixed with seeds to produce large, low-moisture valine granules. These low-moisture valine granules have the advantage of requiring less energy for drying. In particular, according to the present application, the moisture content in the valine granules can be further reduced by adjusting the pH of the fermentation solution and / or controlling the concentration rate.

[0018]

[0019] This is explained in detail as follows. Meanwhile, each description and embodiment disclosed in this application can also be applied to each other description and embodiment. In other words, all combinations of the various elements disclosed in this application fall within the scope of this application. Furthermore, the scope of this application is not limited by the specific descriptions described below.

[0020] Furthermore, those skilled in the art will recognize or be able to ascertain, using only routine experimentation, numerous equivalents to the specific embodiments of the present application described herein. Furthermore, such equivalents are intended to be encompassed by this application.

[0021] As used in the specification and appended claims of this application, the singular articles "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Unless the context clearly dictates otherwise, the singular terms include the plural and the plural terms include the singular. In the specification and appended claims of this application, unless the context clearly dictates otherwise, the use of "or" is intended to include "and / or."

[0022] In this application, the term "about" may be used before a specific numerical value. As used herein, the term "about" encompasses not only the exact number described after the term, but also a range that is or is nearly that number. Whether a number is or is nearly the specific number described can be determined based on the context in which it is presented. For example, the term "about" may refer to a range of -10% to +10% of a numerical value. In another example, the term "about" may refer to a range of -5% to +5% of a given numerical value. However, this is not a limitation.

[0023]

[0024] The present application relates to a method and a manufacturing device for valine granules, wherein valine mixed granules are formed by mixing valine moisture and seeds and drying them, thereby reducing the amount of steam consumed in the process of manufacturing valine, an amino acid with low solubility, and increasing the efficiency of manufacturing valine granules.

[0025]

[0026] The method for manufacturing valine crystals according to the present application comprises the steps of preparing a fermentation solution containing valine; adjusting the pH of the fermentation solution; concentrating the fermentation solution to prepare a concentrated fermentation solution; and separating valine crystals containing water from the concentrated fermentation solution. Each step is described in detail below.

[0027] The step of preparing a fermentation solution is a step of preparing a fermentation solution containing valine. Valine contained in the fermentation solution is an amino acid with low solubility in water. In this case, low solubility does not mean that the solubility is below a certain standard. The fermentation solution prepared in the step of preparing a fermentation solution may be a fermentation product prepared by the metabolism of a strain. The term "fermentation product" in the present application may refer to the result of enzymatic or metabolic decomposition of an organic substance using a microorganism, for example, a microorganism that produces valine. For example, the fermentation product may include the culture itself obtained by culturing a microorganism in a culture medium, or a concentrate, dried product, or lyophilized product of the culture obtained by removing the strain therefrom. Furthermore, in this case, the fermentation solution may include the entire fermentation product containing valine, or a fermentation product containing valine from which impurities have been removed.

[0028] The fermentation solution may contain valine as its main component, but may also contain other components. For example, the fermentation solution may further contain amino acids, organic acids, and inorganic substances other than valine, which may be dissolved in water. The concentration of valine in the fermentation solution may range from about 1 g / L to about 200 g / L. However, the above-described valine concentration is merely exemplary, and a fermentation solution having a concentration outside the above-described range may also be used in the method for producing valine crystals according to one embodiment of the present application.

[0029] The "microorganism producing valine" or "microorganism having valine-producing ability" used in the step of preparing the fermentation solution of the present application includes both a wild-type microorganism naturally having valine-producing ability, and a microorganism in which valine-producing ability is conferred on a parent strain without valine-producing ability through natural or artificial genetic modification. It may be a microorganism in which a specific mechanism is weakened or strengthened due to reasons such as the insertion of an external gene or the strengthening or inactivation of an endogenous gene, and may be a microorganism that includes genetic modification for the production of the target amino acid, i.e., valine. Specifically, the microorganism producing valine or the microorganism having valine-producing ability in the present application may be a microorganism in which some of the genes in the biosynthetic pathway of valine, the target product, are strengthened or weakened, or some of the genes in the valine degradation pathway are strengthened or weakened. The "strengthening" or "increasing" of the valine-producing ability of the microorganism of the present application means that the valine-producing ability of the microorganism of the present application is improved compared to other microorganisms other than the microorganism of the present application, the parent strain, or an unmodified microorganism. For example, the microorganism of the present application may have an improved valine productivity of about 1% or more, 10% or more, 100% or more, 200% or more, 500% or more, 1000% or more, 1100% or more, 1200% or more, or 1300% or more, compared to the valine productivity of other microorganisms, and may have an improved productivity of about 1.01 times or more, 2 times or more, 5 times or more, 10 times or more, 11 times or more, 12 times or more, or 13 times or more, but is not limited thereto. The term "about" includes all of ±0.5, ±0.4, ±0.3, ±0.2, ±0.1, etc., and includes all of the values ​​in the range equivalent to or similar to the value following the term "about," but is not limited thereto.

[0030] The above-described microorganism used in the step of preparing the fermentation solution of the present application may be at least one selected from the group consisting of the yeast Candida famata, the ascomycetes Eremothecium ashbyii and Ashbyagossypii, the bacteria Bacillus subtilis, and the microorganism of the genus Corynebacterium sp.

[0031] For example, if the microorganism used in the step of preparing the fermentation solution of the present application is a microorganism of the genus Corynebacterium, the microorganism is specifically Corynebacterium glutamicum, Corynebacterium crudilactis, Corynebacterium deserti, Corynebacterium efficiens, Corynebacterium callunae, Corynebacterium stationis, Corynebacterium singulare, Corynebacterium halotolerans, Corynebacterium striatum, Corynebacterium ammoniagenes ammoniagenes), Corynebacterium pollutisoli, Corynebacterium imitans, Corynebacterium testudinoris, Corynebacterium crenatum, or Corynebacterium flavescens, and more specifically, Corynebacterium glutamicum, but is not limited thereto.

[0032] Microorganisms of the genus Corynebacterium, particularly Corynebacterium glutamicum, are Gram-positive microorganisms widely used for the production of L-amino acids and other useful substances. To produce the aforementioned L-amino acids and other useful substances, various studies are being conducted to develop high-efficiency production microorganisms and fermentation process technologies. For example, target substance-specific approaches, such as increasing the expression of genes encoding enzymes involved in the biosynthesis of L-valine or deleting genes unnecessary for biosynthesis, are mainly used. In the present application, a fermentation solution containing amino acids can be prepared using a strain of the genus Corynebacterium.

[0033] According to one specific example of the present application, the Corynebacterium glutamicum used to prepare a fermentation solution containing valine may be an L-valine biosynthesis overexpression strain in which the L-valine biosynthesis control region is inactivated by transforming Corynebacterium glutamicum ATCC13032, but is not limited thereto. Alternatively, the above Corynebacterium glutamicum may be a strain transformed with the pDZDvalL, pDZDvalP, or pDZDvalS vector using the chromosome of Corynebacterium glutamicum KCCM11201P, Corynebacterium glutamicum KCCM11336P, Corynebacterium glutamicum KCCM11337P, Corynebacterium glutamicum KCCM11338P, or Corynebacterium glutamicum KCCM11201P_DvalA as a template. According to another example, the Corynebacterium glutamicum may be, but is not limited to, a strain of Corynebacterium glutamicum ATCC13032_DvalL, Corynebacterium glutamicum ATCC13032_DvalP, or Corynebacterium glutamicum ATCC13032_DvalS, and includes, without limitation, a microorganism capable of producing a fermentation broth containing valine (US 10072278 B2).

[0034] The step of preparing the fermentation solution may further include culturing a "valine-producing microorganism." Culturing the microorganism can be performed using any suitable medium and culture conditions known in the art. This culture process can be easily adjusted and used by those skilled in the art depending on the selected strain. Specifically, the culture may be batch, continuous, or fed-batch, but is not limited thereto.

[0035] In this application, the term "medium" refers to a material containing nutrients necessary for culturing the microorganism as a main component, and supplies nutrients and growth factors, including water, which is essential for survival and growth. Specifically, the medium and other culture conditions used for culturing the microorganism of this application may be any medium used for culturing general microorganisms without particular limitation, but the microorganism of this application may be cultured under aerobic conditions while controlling temperature, pH, etc. in a general medium containing an appropriate carbon source, nitrogen source, phosphorus source, inorganic compound, amino acid, and / or vitamin.

[0036] Next, a step of adjusting the pH of the fermentation solution is performed. Here, the pH of the fermentation solution can be adjusted to a range of about 3.0 or more and less than 6.0. In some cases, the pH of the fermentation solution can be adjusted to about 3.5 to less than 6.0, about 4.0 to less than 6.0, about 4.5 to less than 6.0, about 5.0 to less than 6.0, about 5.5 to less than 6.0, about 3.0 to 5.5, about 3.5 to 5.5, about 4.0 to 5.5, about 4.5 to 5.5, about 5.0 to 5.5, about 3.0 to 5.0, about 3.5 to 5.0, about 4.0 to 5.0, about 4.5 to 5.0, about 3.0 to 4.5, about 3.5 to 4.5, about 4.0 to 4.5, about 3.0 to 4.0, about 3.5 to 4.0, or about 3.0 to 3.5.

[0037] By adjusting the pH of the fermentation solution, the size and hardness of the valine crystals formed in the subsequent concentration step can be controlled. Specifically, when the pH of the fermentation solution is adjusted to the above-described range and then concentration is performed, large and hard valine crystals can be formed, thereby reducing the moisture content of the separated valine crystals. If the pH of the fermentation solution is outside the above-described range, the crystal size of the valine crystals precipitated after concentration may be small, making it difficult to separate the valine crystals from the fermentation solution mother liquor. Furthermore, since a relatively large amount of moisture is separated along with the valine crystals, a lot of energy is required for subsequent drying.

[0038] In the pH adjustment step of the fermentation solution, pH adjustment can be performed using conventional acidic or alkaline substances. However, the substance added to the fermentation solution for pH adjustment can be determined as long as it does not affect the physical properties or chemical structure of the valine contained in the solution. Furthermore, considering that the valine product will be used for food or feed purposes, edible acidic or alkaline substances may be added.

[0039] After the pH adjustment described above, procedures such as heating the fermentation broth may be performed to completely dissolve any valine that may have precipitated within the fermentation broth, if necessary. For example, the fermentation broth may be heated to about 60°C to about 90°C.

[0040] After performing the step of adjusting the pH of the fermentation liquid, a step of concentrating the prepared fermentation liquid to prepare a concentrated fermentation liquid is performed.

[0041] In the concentration step, moisture in the fermentation solution is removed to precipitate valine in the form of crystals. Concentration can be performed in various ways. Concentration can be performed in a conventional concentrator (e.g., a paddle dryer, a slurry dryer, a vacuum concentrator, a forced circulation concentrator, a thin-film concentrator, or a rotary concentrator) according to the selection of a person skilled in the art.

[0042] In the concentration step, concentration can be performed by removing moisture in the fermentation broth at a rate of 60 g / L / hr to 150 g / L / hr (meaning that 60 g to 150 g of moisture per liter of fermentation broth is removed for 1 hour). In some cases, concentration can be performed by removing moisture in the fermentation broth at a rate of 90 g / L / hr to 150 g / L / hr, 120 g / L / hr to 150 g / L / hr, 60 g / L / hr to 120 g / L / hr, 90 g / L / hr to 120 g / L / hr, or 60 g / L / hr to 90 g / L / hr. In the present application, the concentration rate is a factor affecting the size of valine crystals. When concentrated at the above-mentioned rate, relatively large-sized valine crystals are formed, and the valine crystals can be easily separated from the fermentation broth mother liquor. In addition, the moisture in the valine crystals is reduced accordingly.

[0043] Next, a separation step is performed to separate the valine crystals precipitated by the concentration step from the mother liquor.

[0044] In the separation step, water-containing valine crystals are separated from the concentrated fermentation liquid. At this time, a solid-liquid separator such as a pressure-reducing membrane filtration device, a pressure-reducing membrane filtration device, or a centrifugal separator can be used. However, the above-described means are exemplary, and the means for performing the separation step are not limited to the above-described examples.

[0045] The mother liquor remaining after the separation of valine crystals in the separation step can be reused for concentration. Accordingly, valine that fails to form wet crystals during the concentration step or that precipitates as crystals smaller than a certain size and remains in the mother liquor without being separated during the valine crystal separation step can be recycled. Furthermore, after the mother liquor circulation, additional processes, such as heating the fermentation liquor, can be performed, if necessary, to re-dissolve valine precipitated in the form of fine crystals within the fermentation liquor.

[0046] According to the method for producing valine crystals according to one embodiment of the present application described above, valine crystals having a low moisture content and being easy to separate can be obtained by controlling the pH of a fermentation liquid containing valine and concentrating the fermentation liquid at an appropriate rate.

[0047] The valine crystals manufactured according to one aspect of the present application may have a viscosity of more than 0 cp and less than 80 cp. In some cases, the viscosity of the valine crystal is greater than 10 cp and less than 80 cp, greater than 15 cp and less than 80 cp, greater than 20 cp and less than 80 cp, greater than 30 cp and less than 80 cp, greater than 40 cp and less than 80 cp, greater than 50 cp and less than 80 cp, greater than 60 cp and less than 80 cp, greater than 0 cp and less than 70 cp, greater than 10 cp and less than 70 cp, greater than 15 cp and less than 70 cp, greater than 20 cp and less than 70 cp, greater than 30 cp and less than 70 cp, greater than 40 cp and less than 70 cp, greater than 50 cp and less than 70 cp, greater than 60 cp and less than 70 cp, greater than 0 cp and less than 50 cp, greater than 10 cp and less than 50 cp, More than 15 cp but less than 50 cp, More than 20 cp but less than 50 cp, More than 30 cp but less than 50 cp, More than 40 cp but less than 50 cp, More than 0 cp but less than 30 cp, More than 10 cp but less than 30 cp, More than 15 cp but less than 30 cp, More than 20 cp but less than 30 cp, More than 0 cp but less than 25 cp, More than 10 cp but less than 25 cp, More than 15 cp but less than 25 cp, More than 20 cp but less than 25 cp, More than 0 cp but less than 20 cp, More than 10 cp but less than 20 cp, More than 10 cp but less than 20 cp, More than 0 cp but less than 15 cp, More than 10 cp but less than 15 cp, Or More than 0 cp but 10 cp It may be less than. Valine crystals having a viscosity in the above-mentioned range can be easily separated from the mother liquor because they have a low moisture content and an appropriate size.

[0048] The valine crystals manufactured according to one embodiment of the present application may comprise 10 wt% to 55 wt% of moisture. In some cases, the valine crystals may comprise 20 wt% to 55 wt%, 30 wt% to 55 wt%, 40 wt% to 55 wt%, 50 wt% to 55 wt%, 10 wt% to 50 wt%, 20 wt% to 50 wt%, 30 wt% to 50 wt%, 40 wt% to 50 wt%, 10 wt% to 40 wt%, 20 wt% to 40 wt%, 30 wt% to 40 wt%, 10 wt% to 30 wt%, 20 wt% to 30 wt%, or 10 wt% to 20 wt% of moisture. Since the valine crystals having the moisture content described above have a relatively low moisture content, they can be used directly without a separate drying step or after only a slight drying step, thereby reducing the energy required for the process.

[0049]

[0050] A method for manufacturing valine granules comprises the steps of preparing a fermentation solution containing valine; adjusting the pH of the fermentation solution; concentrating the fermentation solution to prepare a concentrated fermentation solution; separating valine crystals containing water from the concentrated fermentation solution; mixing the valine crystals with seeds to prepare valine mixed granules; and drying the valine mixed granules.

[0051] Here, the steps of preparing the fermentation solution, adjusting the pH of the fermentation solution, concentrating the fermentation solution, and separating the valine crystals can be performed in the same manner as in the method for manufacturing valine crystals described above. To avoid duplication of explanation, the following description focuses on the steps of manufacturing mixed granules by mixing valine crystals with seeds; and the steps of drying the mixed granules.

[0052] In the mixed granule manufacturing step, the valine crystals obtained in the valine crystal separation step are mixed with seeds for manufacturing valine granules.

[0053] The seed used in the mixed granulation manufacturing step, also called a seed crystal or seed crystal, can refer to a substance used as a catalyst for the crystallization or granulation of a liquid. The seed in the present application may be a valine crystal. When the seed comes into contact with the fermentation liquid, the solid components present in the fermentation liquid bind to the seed, causing coagulation, thereby forming granules.

[0054] The seeds used in the mixed granule manufacturing step may have an average particle size of 150 to 300 μm. Specifically, seeds having an average particle size of 150 to 250 μm, 200 to 300 μm, or 200 to 250 μm may be used, but are not limited thereto. The particle size of the seeds used may ultimately affect the productivity of the granule manufacturing according to the present application, and thus, those skilled in the art may appropriately select the seeds by considering the desired moisture content, etc.

[0055] A mixed granulator may be used in the mixed granule manufacturing step. The mixed granulator may obtain granules by feeding seeds into the mixed granulator through a feeder at a constant rate while simultaneously supplying valine crystals obtained in the previous separation step. The mixed granulator may each include a feeder for supplying seeds therein and a member for supplying valine crystals. In addition, the mixed granulator may be provided with a gas nozzle for generating air flow within a chamber, a paddle for mixing the seeds and valine crystals provided within the chamber, and the like. The seeds and valine crystals introduced into the chamber may clump together to form amino acid mixed granules.

[0056]

[0057] According to one embodiment of the present application, amino acid mixed granules having a low moisture content and large crystal size can be produced by mixing seeds and amino acid wet granules. As previously discussed, according to the present application, large valine crystals are precipitated, and the large valine crystals can be easily separated from the fermentation liquid, so the moisture content within the valine crystals is relatively low. Furthermore, in the mixed granule production step, valine crystals with a low moisture content and seeds are granulated in a mixed granulator, so the produced valine mixed granules also have a low moisture content and large size.

[0058] Here, "granules" are macroscopic particles which are permanent aggregates of larger particles such as powders, and may be particles having an average particle diameter of 50 μm to 5 mm, 75 μm to 4 mm or 100 μm to 3 mm.

[0059] The valine mixed granules obtained in the mixed granule manufacturing step may contain 10 wt% to 50 wt% of moisture. In some cases, the valine mixed granules may contain 20 wt% to 50 wt%, 30 wt% to 50 wt%, 40 wt% to 50 wt%, 10 wt% to 40 wt%, 20 wt% to 40 wt%, 30 wt% to 40 wt%, 10 wt% to 30 wt%, 20 wt% to 30 wt%, or 10 wt% to 20 wt% of moisture. This is a lower moisture content compared to amino acid granules obtained according to the prior art. Therefore, the amount of energy required to dry the valine mixed granules obtained according to the present application can be reduced.

[0060] Next, a drying step is performed to dry the valerian mixed granules to obtain an amino acid product.

[0061] In the drying step, the previously obtained valine mixed granules are dried, and there are no restrictions on the drying method. After drying, a valine product can be obtained. The term "valine product" in the present application refers to a product in which valine contained in a fermentation solution is commercialized in various formulations. For example, the valine product may refer to a valine-containing mixture in granule form. However, if necessary, the formulation of the valine product may vary as long as it does not change the spirit of the invention of the present application. In addition, as described above, further subsequent processes may be performed to implement various valine product formulations. The valine product described above can be used as an additive to animal feed, etc., and there are no restrictions on its use.

[0062] According to the present application, a fermentation solution containing amino acids can be concentrated to separate the amino acid wet residue, and the separated amino acid wet residue can be mixed with seeds to produce large, low-moisture amino acid mixed granules. Amino acid mixed granules with low moisture content have the advantage of requiring less energy for drying. In particular, according to the present application, the moisture content in the amino acid mixed granules can be further reduced by adjusting the pH of the fermentation solution or controlling the concentration rate.

[0063]

[0064] The present application will be described in more detail below through examples. However, the following examples are merely preferred embodiments intended to illustrate the present application and are therefore not intended to limit the scope of the present application. Furthermore, technical details not described herein can be readily understood and implemented by those skilled in the technical field of the present application or similar fields.

[0065]

[0066] Experimental Example 1. Production of valine fermentation solution through Corynebacterium microbial culture.

[0067] In order to manufacture granules containing L-valine in this experimental example, Corynebacterium glutamicum KCCM11338P (US 10072278 B2), one of the strains producing L-valine, was cultured in a medium containing 5% glucose, 2% ammonium sulfate, 0.1% monobasic potassium phosphate, 0.05% magnesium sulfate (7a), 2.0% CSL (corn steep liquor), 200 μg / L biotin, and pH 7.2 at approximately 30°C for 72 hours to obtain a fermented solution having the following composition. The fermented solution contained the cultured medium and microorganisms, and the moisture content and composition were analyzed. Table 2 shows the results of the analysis of the composition of the valine fermented solution.

[0068] Composition (g / L) Valine 80.0 Other amino acids 8.8 Organic acids 0.7 Inorganic substances 11.0 Moisture (%) 89.0

[0069]

[0070] Experimental Example 2. Comparative Analysis of Moisture Content in Amino Acid Wetlands According to the pH of the Fermentation Solution

[0071] The fermentation solution with an L-valine concentration of 80 g / L prepared in Experimental Example 1 was divided into 2 L portions, and sulfuric acid was added to prepare process solutions at different pH levels (7.5 to 3.0). In order to precipitate valine crystals from the prepared process solution, a vacuum evaporator was used to concentrate the solution at a rate of 60 g / L / hr under a vacuum of 120 torr until the valine concentration of the process solution became 200 g / L. The concentrated crystal slurry containing valine crystals was subjected to solid-liquid separation using a basket separator to obtain L-valine crystals and a mother liquor.

[0072] The moisture content in valine crystals according to the pH of the fermentation solution was compared through LOD analysis.

[0073] pH of fermentation solution 7.06.05.04.03.0 Slurry viscosity (cp) 898020.516.090 Moisture content in crystals (wt%) 4540323039

[0074] The LOD moisture measurement results confirmed that the moisture content in the valine crystals was low when the pH of the fermentation broth was over 3.0 and less than 6.0. In addition, when the viscosity of the concentrated slurry was analyzed, it was confirmed that the viscosity of the concentrated slurry was low when the pH of the fermentation broth was over 3.0 and less than 6.0. The low viscosity of the concentrated slurry means that the size of the valine crystals contained in the concentrated slurry is large, and not many fine crystals were formed. In contrast, in the case of the fermentation broth with a pH of 7.0, where the viscosity of the concentrated slurry was high, it was analyzed that many fine valine crystals were formed, resulting in a high slurry viscosity. Therefore, it was confirmed that the pH of the fermentation broth affects the formation of valine crystals. Specifically, it was confirmed that large valine crystals were formed in a specific pH range, resulting in a low viscosity of the concentrated slurry and low moisture in the separated crystals.

[0075]

[0076] Experimental Example 3. Comparative Analysis of Moisture Content in Valine Crystals According to the Concentration Rate (g / L / hr) of the Fermentation Solution

[0077] In Experimental Example 1, the fermentation broth with an L-valine concentration of 80 g / L was divided into 5 L portions, and sulfuric acid was added to adjust the pH of the fermentation broth to 3.8. To precipitate valine crystals, a vacuum evaporator was used to concentrate the mixture at a vacuum of 120 torr until the concentration reached 200 g / L. The concentration rate was varied from 18 g / L / hr to 120 g / L / hr for each batch, and the properties of the concentrated crystal slurries obtained at different concentration rates were compared. The concentration rate was calculated by expressing the concentration of concentrated valine per hour (g / L) based on the time it took for moisture to be removed from the initial valine concentration of 80 g / L in the fermentation broth until the valine concentration reached 200 g / L. The volume of condensate and the time required for this were measured to calculate the concentration rate.

[0078] Additionally, a concentrated crystal slurry containing valine crystals was subjected to solid-liquid separation using a basket separator to obtain L-valine crystals and a mother liquor. The moisture content in the valine crystals was compared according to the concentration rate. The moisture content in the valine crystals according to the fermentation broth concentration rate was compared using LOD analysis.

[0079] Concentration rate (g / L / hr) 18306090120 Slurry viscosity (cp) Not measurable 99.716.08.36.7 Moisture content in crystals (weight%) Not separated 58352928

[0080] LOD moisture measurement results showed that as the concentration rate increased, the moisture content within the crystals decreased, confirming that the concentration rate affected the formation of valine crystals. In contrast, when the concentration rate was 18 g / L / hr, the crystals were formed in a gel-like form, making flow and separation difficult.

[0081]

[0082] Experimental Example 4. Preparation of valine crystals from valine fermentation solution.

[0083] Sulfuric acid was added to 10 L of fermentation broth containing 80 g / L of L-valine to adjust the pH of the broth to 3.8. To precipitate valine crystals, a vacuum evaporator was used to concentrate the broth at a rate of 60 g / L / hr under a vacuum of 120 torr until the concentration of the fermentation broth reached 200 g / L.

[0084] The concentrated crystal slurry was separated into solid and liquid using a decanter to obtain 840 g of L-valine solids and 2850 mL of supernatant. At this time, the moisture content of the valine crystals was confirmed to be 37 wt%, and the valine crystal yield was 80.0% based on the fermentation broth.

[0085]

[0086] Experimental Example 5. Preparation of Valine Granules from Separated Crystals

[0087] Valine crystals were manufactured in the same manner as in Experimental Example 4, and separated valine crystals and pre-dried valine seeds (valine content 75 w / w%) were mixed to manufacture crystals having a moisture content of 15% to 47%, and then valine mixed granule crystals were manufactured using a mixing granulator.

[0088] It was confirmed that mixed granules could be manufactured using a mixed granulator for crystals with a moisture content of 15% to 47%.

[0089] Mixed moisture (%) 15.0 24.0 30.0 35.0 47.0 Equipment Type CVG Mixer rpm 2000 Presence of mixed granules OOOOO

[0090]

[0091] From the above description, those skilled in the art will understand that the present application can be implemented in other specific forms without altering its technical concept or essential characteristics. In this regard, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of this application should be interpreted to include all changes or modifications derived from the meaning and scope of the following claims and their equivalents, rather than the detailed description above.

Claims

1. Step of preparing a fermentation solution containing valine; A step of adjusting the pH of the above fermentation solution; A step of concentrating the above fermentation liquid to prepare a concentrated fermentation liquid; and A method for producing valine crystals, comprising a step of separating valine crystals containing moisture from the concentrated fermentation liquid.

2. In paragraph 1, A method for producing valine crystals, wherein in the step of adjusting the pH of the fermentation solution, the pH of the fermentation solution is adjusted to be greater than 3.0 and less than 6.

0.

3. In paragraph 1, A method for producing valine crystals, wherein the step of concentrating the fermentation liquid to prepare a concentrated fermentation liquid is performed by removing moisture in the fermentation liquid at a rate of 60 g / L / hr to 150 g / L / hr.

4. In paragraph 1, A method for producing a valine crystal, wherein the above valine crystal has a viscosity of more than 0 and less than 80 cp.

5. In paragraph 1, A method for producing a valine crystal, wherein the valine crystal contains 10 to 55 wt% of moisture.

6. Step of preparing a fermentation solution containing valine; A step of adjusting the pH of the above fermentation solution; A step of concentrating the above fermentation liquid to prepare a concentrated fermentation liquid; A step of separating valine crystals containing moisture from the above concentrated fermentation liquid; A step of preparing a valine mixed granule by mixing the above valine crystals with seeds; and A method for producing valine granules, comprising the step of drying the above valine mixed granules.

7. In paragraph 6, A method for producing valine granules, wherein the mixed granules contain 10 to 50 wt% of moisture.