Method for producing amino acid-containing products from fermentation broth

Abstract

The present application relates to a method for producing amino acid granules from a fermentation broth, and the produced amino acid granules are characterized in that bacterial cells are removed.

Description

[Technical field]

[0001] The present application relates to a method for producing amino acid granules from a fermentation broth in which bacterial cells have been removed. [Background technology]

[0002] One method for producing amino acid granules for feed is a fermentation method using microorganisms, and amino acid granules can be produced by directly drying and solidifying the microbial fermentation liquid.

[0003] In particular, a mixed granulation method for poorly soluble amino acids (US 2021-0094903 A1) is known.

[0004] When producing amino acid granules from the fermentation broth, the strain (bacteria) used in the fermentation broth production process remains in the fermentation broth. If the bacteria are contained in the amino acid granules, the product registration process becomes complicated when commercialized, and it is difficult to sell the product in countries where there are problems with GM strains. In addition, in the case of granules, it is difficult to produce a product with a purity higher than that of the fermentation broth, but by removing the bacteria, it is possible to produce a product with a higher content than existing granules. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent Publication US 2021-0094903 A1 [Patent Document 2] United States Patent Registration Publication US 8465962 B2 [Patent Document 3] United States Patent Publication US 9885093 B2 [Patent Document 4] United States Patent Registration Publication US 10351859 B2 [Patent Document 5] United States Patent Registration Publication US 7863435 B2 [Patent Document 6] United States Patent Registration Publication US 10787692 B2 [Patent Document 7] United States Patent Registration Publication US 9029105 B2 [Patent Document 8] United States Patent Registration Publication US 2021-0094903 A1 Summary of the Invention [Problem to be solved by the invention]

[0006] One objective of the present application is to provide a method for producing a granular product in which bacterial cells have been removed, there are fewer problems with GM strains than with existing granular products, the amino acid content is higher than with existing fermentation liquids, and the content by particle size is uniform.

[0007] Another object of the present application is to provide an amino acid granule from which bacterial cells have been removed, which has fewer problems with GM strains than existing granular products, and which has a higher amino acid content than a basic fermentation liquid. [Means for solving the problem]

[0008] This will be described in detail as follows. Meanwhile, each description and embodiment disclosed in this application can be applied to each other description and embodiment. That is, any combination of various elements disclosed in this application belongs to the scope of the present invention. Also, the specific description described below is not considered to limit the category of this application.

[0009] In addition, many papers and patent documents are referred to and cited throughout this specification, the disclosures of which are incorporated herein by reference in their entirety to more clearly explain the state of the art to which this application pertains and the contents of this application.

[0010] To achieve the above object, one embodiment of the present application includes a first step of removing bacterial cells from a fermentation liquid containing amino acids to prepare a fermentation filtrate; and a second step of forming granules from the fermentation filtrate.

[0011] The manufacturing method of the present application simplifies the product registration process by removing the bacterial cells during the production of amino acid granules, and can be used in advance in countries where there are concerns about genetic modification (GM). In addition, while it is difficult to produce a product with a purity higher than that of the fermentation liquid in the case of granules, removing the bacterial cells has the advantage of being able to produce a product with a higher content than existing granules. Therefore, the manufacturing method of the present application makes it possible to diversify product purity.

[0012] The term "amino acid granules" in the present application means an amino acid-containing mixture in the form of granules. However, if necessary, the dosage form of the amino acid granules may be different within the scope of the present invention. In addition, as described above, in order to realize various dosage forms of the amino acid granules, further subsequent processes may be performed. The amino acid granules described above may also be used as an additive for animal feed, and there is no limitation on their use.

[0013] Each step of the method for producing amino acid granules according to one embodiment of the present application is described in more detail below.

[0014] First, a first step (S100) is performed in which bacterial cells are removed from a fermentation liquid containing amino acids to prepare a fermentation filtrate.

[0015] The term "removed bacteria" in the present application is not limited to the meaning that no bacteria are provided in the solution or product. Specifically, the removal of bacteria from the solution or product means that the strain used to produce the amino acid fermentation liquid is separated from the solution or product to an extent that its mass can be ignored. Therefore, when analyzing the mass of the fermentation filtrate, which is the fermentation liquid from which the bacteria have been removed, or the amino acid granules produced therefrom, and the composition of the product, the mass occupied by the bacteria can be ignored.

[0016] The amino acid contained in the fermentation liquid of the first step may be an L-amino acid, and in particular, the amino acid may be an amino acid with low solubility. For example, the amino acid to which the production method of the present application can be applied may be, but is not limited to, an amino acid with low solubility, that is, a solubility in water of more than 0 g / 100 g and not more than 20 g / 100 g at 25° C., and by applying the method to an amino acid with low solubility as described above, more significant effects can be expected compared to conventional processes.

[0017] Specifically, the amino acid may be, but is not limited to, valine, tryptophan, threonine, isoleucine, leucine, methionine, histidine, or phenylalanine.

[0018] The amino acids contained in the fermentation broth of the first step may be produced by extraction, synthesis, fermentation, enzymatic methods, etc. In some cases, the amino acids are provided from a fermentation product produced by fermentation using a microorganism. In this case, the term "fermentation product" or "fermentation broth" in this application means the result of enzymatic or metabolic synthesis or decomposition of an organic substance using a microorganism. For example, it may include a culture containing a microorganism obtained by culturing a microorganism in a culture medium, or a concentrate, dried product, or freeze-dried product of the culture obtained by removing the microorganism from the culture medium. In addition, in this case, the amino acid mixture solution may include the entire L-amino acid and the fermentation product, or may be a fermentation product from which impurities have been removed. In the present application, the fermentation liquid containing the amino acid may be a fermentation liquid obtained by a known microbial fermentation method (US 8465962 B2, US 9885093 B2, US 10351859 B2, US 7863435 B2, US 10787692 B2, US 9029105 B2, US 2021-0094903 A1), but is not limited thereto.

[0019] In the present application, the term "fermentation broth containing amino acids" may be used interchangeably with "amino acid-containing fermentation broth" or "amino acid fermentation broth".

[0020] The fermentation liquid produced in the first step to provide amino acids may be a result of culturing an L-amino acid-producing microorganism. In this case, the term "L-amino acid-producing microorganism" in the present application includes all wild-type microorganisms and naturally or artificially genetically modified microorganisms, and may be a microorganism in which a specific mechanism is weakened or enhanced by inserting an exogenous gene or enhancing or inactivating the activity of an endogenous gene, and may be a microorganism that includes a genetic modification for producing a target protein or product.

[0021] The microorganism used in the first step may be at least one selected from microorganisms of the genus Brevibacterium, Corynebacterium, Escherichia, Serratia, Erwinia, Enterobacteria, Streptomyces, or Pseudomonas, or artificial mutants thereof. Therefore, the first step may further include a step of producing an amino acid mixture solution using at least one of the microorganisms.

[0022] Among the aforementioned microorganisms of the present application used in the first step, "microorganisms of the genus Corynebacterium" can include all microorganisms of the genus Corynebacterium. 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 or Corynebacterium flavescens, and more specifically, Corynebacterium glutamicum, but is not limited thereto.

[0023] The genus Corynebacterium, particularly Corynebacterium glutamicum, is a Gram-positive microorganism that is widely used for the production of L-amino acids and other useful substances. In order to produce the L-amino acids and other useful substances, various studies have been conducted to develop highly efficient 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-tryptophan, L-valine, L-isoleucine, L-leucine, L-histidine, or L-threonine, or deleting genes unnecessary for biosynthesis, have been mainly used.

[0024] In the first step, the bacterial cells are removed from the fermentation liquid prepared as described above. As described above, removing the bacterial cells does not necessarily mean completely removing the bacterial cells from the fermentation liquid to sterilize the fermentation liquid. To remove the bacterial cells, centrifugation, filtration, treatment with a crystallized protein precipitant (salting out method), extraction, ultrasonic disruption, ultrafiltration, dialysis, various chromatographies such as molecular sieve chromatography (gel filtration), adsorption chromatography, ion exchange chromatography, and affinity chromatography, HPLC, and combinations of these methods are used. In addition to the above-mentioned methods, the bacterial cells can be separated from the fermentation liquid using any other appropriate method known in the art.

[0025] In the first step, a step of separating amino acid crystals from the fermentation liquid or dissolving the amino acid crystals in the fermentation liquid may be performed before separating the bacteria. When the fermentation liquid contains a high concentration of amino acids with relatively low solubility, some of the amino acids crystallize in the fermentation liquid. When amino acid crystals are contained in the solution, they may be removed during the process of removing the bacteria. The amino acid crystals can be dissolved in the fermentation liquid or separated separately and recycled before removing the bacteria, thereby preventing the amino acids produced in the fermentation process from being wasted.

[0026] When amino acid crystals are separated from the fermentation liquid in the first step, the separated crystals can be recycled in the subsequent second step to increase process efficiency, and the amino acid content (amino acid purity) in the amino acid granules can be adjusted by adjusting the input amount of amino acid crystals.

[0027] When dissolving the amino acid crystals in the fermentation liquid in the first step, a solvent can be added to the fermentation liquid. When adding a solvent, the amount of solvent can be increased up to the solubility of the amino acid. In this case, the solvent is water (H 2 O).

[0028] The first step may also include a step of adding a calcium source. Specifically, the calcium source may be added to the fermentation liquid before or after the bacterial cells are removed from the fermentation liquid in the first step.

[0029] The term "calcium" in this application is an essential mineral for vertebrates, since it functions to strengthen bones and facilitate blood circulation. More than 99% of calcium is present in bones and teeth, and the remainder is present in blood, muscles, etc. A sufficient amount of calcium maintains bone health and prevents osteoporosis. It also plays a role in muscle contraction, preventing muscle cramps, lowering cholesterol levels, and reducing the incidence of cardiovascular disease. However, a lack of calcium leads to abnormal bone formation, muscle and nerve abnormalities, and even minor trauma can lead to injuries such as fractures, increasing the risk of osteoporosis. Such calcium may also be provided to animals in the form of a feed additive to prevent diarrhea and dysentery and to aid digestion and absorption, especially in piglets.

[0030] In the present application, the term "calcium source" refers to calcium ions (Ca 2+ The calcium source includes, without limitation, calcium hydroxide (Ca(OH) 2), Calcium oxide (CaO), Calcium carbonate (CaCO 3 ), Calcium Sulfate (CaSO 4 ) or calcium chloride (CaCl 2 ) are used, but are not limited to these.

[0031] The term "calcium hydroxide (Ca(OH) 2 Calcium hydroxide is an inorganic compound that has the form of a colorless crystal or a white powder. Calcium hydroxide is used as the source of calcium ions in this application because it dissolves in water, is basic, has low cost and low toxicity.

[0032] The term "calcium oxide (CaO)" in this application refers to a substance that dissolves in water to produce calcium ions, and functions similarly to the calcium hydroxide. Since the heat of dissolution in the process of dissolving in water is relatively large, calcium hydroxide may be supplied to the process in the form of a calcium hydroxide slurry that has been reacted with water in advance. The reaction formula for calcium oxide to calcium hydroxide is as follows: CaO + H2O → Ca(OH) 2 In order to use an equivalent amount of calcium hydroxide, i.e., an equivalent molar ratio based on calcium ions, the amount of calcium hydroxide multiplied by 0.76, which is the value of the molecular weight of calcium oxide relative to the molecular weight of calcium hydroxide, can be added by reacting it with water. As shown in the above reaction formula, calcium oxide and water react in a 1:1 molar ratio, so the amount of additional water added can be equal to or greater than the amount of calcium hydroxide required minus the amount of calcium oxide added, so that all of the calcium oxide used can be reacted.

[0033] In the first step, the calcium source may be added in an amount of 0.02 to 2.0 molar ratio, 0.05 to 2.0 molar ratio, 0.07 to 1.5 molar ratio, 0.1 to 1.0 molar ratio, or 0.2 to 0.6 molar ratio of calcium ions to the amino acids in the fermentation liquid containing amino acids, but is not limited thereto.

[0034] The calcium source may be added in the step of adding a calcium source in the form of, but not limited to, a powder, an aqueous solution, or a slurry.

[0035] As described above, after the first step, the cells are removed from the fermentation liquid containing the amino acids to prepare a fermentation filtrate. Before forming granules from the prepared fermentation filtrate in the second step, a concentration step may be performed to concentrate the fermentation filtrate in order to increase the amino acid concentration in the fermentation filtrate.

[0036] In the concentrating step, the fermentation filtrate is concentrated to prepare a concentrated fermentation filtrate. Concentrating the fermentation filtrate refers to a process for reducing the amount of solvent contained in the fermentation filtrate, thereby increasing the concentration of amino acids.

[0037] The concentrating device used in the concentrating step is not limited. For example, a forced circulation concentrating tube, a paddle dryer, a slurry drying device, etc. can be used in the concentrating step, but is not limited thereto.

[0038] In the concentration step, the concentration can be performed at a concentration level of more than 0% (w / w) and not more than 75% (w / w). The concentration level refers to the degree (weight ratio) of the solvent removed when comparing the fermentation filtrate with the concentrated fermentation filtrate. If the concentration level exceeds the above range, the concentrate may gel and have significantly reduced fluidity, making it difficult to proceed to the subsequent steps. However, the concentration level varies depending on the type and / or driving method of the equipment used in the amino acid granule manufacturing process. For example, the concentration level may be 5% (w / w) to 75% (w / w), 10% (w / w) to 70% (w / w), or 20% (w / w) to 65% (w / w), but is not limited thereto.

[0039] In the concentrating step, a step of adding a calcium source may be further carried out if necessary. When the fermentation filtrate is concentrated in the concentrating step, the concentration of amino acids in the solution increases, which may lead to the precipitation of amino acids in the form of crystals. However, by adding a calcium source to the concentrate, the precipitation of amino acids during the concentrating process can be prevented. In particular, if a calcium source is not added in the first step, a calcium source can be added to the fermentation filtrate or the concentrated fermentation filtrate before or after concentration.

[0040] The method may also include a step of crushing the crystals in the concentrated liquid, which may be performed using a conventional homogenizer, but is not limited thereto. The crushing step can reduce the average particle size of the crystals in the fermentation liquid, and can prevent nozzle clogging that may occur when using a fluidized bed granulator, for example.

[0041] As mentioned above, the concentration process can be carried out at relatively high concentrations through the addition of a calcium source to the concentrate and / or through grinding of crystals, and as the concentration increases, greater amounts of solvent are removed, which can reduce the amount of water that must be removed in the subsequent second step granulation process.

[0042] A second step is then carried out in which granules are produced from the fermentation broth obtained in the first step, or optionally from a concentrated solution of the fermentation broth obtained in the first step.

[0043] The "granules" in the second step refer to macroscopic particles, which are relatively large permanent aggregates formed by the aggregation of smaller particles such as powder, and may be particles with an average particle diameter of 50 μm to 5 mm, 75 μm to 4 mm, or 100 μm to 3 mm.

[0044] In the second step, the powder or fine solid material is used to form granules of particles having a predetermined size, and any granulation method known in the art may be used. For example, a mixed granulation method in which seeds are injected into a mixed granulator from a feeder at a constant speed and the fermentation liquid is supplied by a constant speed liquid pump to obtain granules, or a fluidized bed granulation method in which a predetermined amount of seeds is fed into a fluidized bed granulator and a predetermined amount of fermentation liquid is injected into the fluidized bed granulator at a constant speed to form granules may be applied. At this time, a step of drying the obtained granules may be further included, but is not limited thereto.

[0045] In the second step, the mixing ratio of the seeds relative to the slurry solids of the fermentation liquid may be 300-900% (w / w). The mixing ratio of the seeds relative to the slurry solids may be referred to as the "seed input ratio". In some cases, the mixing ratio of the seeds may be 300-850% (w / w), 350-800% (w / w), or 300-800% (w / w). The formation of granules can be promoted by inputting the seeds at the aforementioned ratios and carrying out the process. However, the mixing ratio of the seeds varies depending on the type of amino acid input to the process, the process operation conditions for granule formation in the second step, etc., and is not limited to the aforementioned range.

[0046] The term "seed" in this application is also called seed crystal or seed crystal, and refers to a substance used as a catalyst for crystallization or granulation of a liquid. Specifically, the seed in this application may be, but is not limited to, an amino acid crystal, for example, a crystal of the same type of amino acid as that contained in the fermentation concentrate to be granulated. When the seed comes into contact with the fermentation liquid, the solid components present in the fermentation liquid bind to the seed and agglomerate to form granules.

[0047] For example, the seeds used in this case 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 can be used, but are not limited thereto. The particle size of the seeds used as described above will ultimately affect the productivity of the production of granules according to the present application, and can be appropriately selected by a person skilled in the art in consideration of the desired moisture content, etc.

[0048] In addition, the manufacturing method of the present application may further include a step of adjusting the discharged moisture percentage to 5-50% (w / w) before the second step. In the present application, the term "discharged moisture percentage" is also called "mixed moisture percentage" and means the percentage of moisture in the entire mixture, and is calculated by subtracting the total solids percentage (w / w) from 100% (w / w) of the entire mixture. In the context of the present application, a high discharged moisture percentage reduces the reuse rate when the fermentation liquid is mixed with seeds and fed into a mixer for subsequent granulation, resulting in an effect of increasing the productivity. For example, the discharged moisture percentage is adjusted to 5-50% (w / w), 5-45% (w / w), 6-40% (w / w), 10-30% (w / w), or 15-30% (w / w), but is not limited thereto. However, if the discharged moisture content is less than the above range, the slurry becomes difficult to transport due to the high viscosity of the unit, and if it exceeds the above range, problems of overloading the downstream process and excessive use of steam during granulation may occur. The range of the discharged moisture content varies slightly depending on the type of amino acid contained in the concentrate.

[0049] The drainage moisture percentage is determined according to the feeding speed of the fermentation liquor slurry. Specifically, the moisture content of the granular particles increases as the feeding speed of the slurry increases, and the moisture content of the granular particles decreases as the feeding speed of the slurry decreases. The feeding speed is determined according to the scale of the fermentation liquor slurry, and can be appropriately selected and determined by those skilled in the art.

[0050] In addition, the manufacturing method of the present application may further include one or more steps selected from a step of preparing a fermentation liquid; a step of adjusting pH; a step of concentrating; a step of drying; and a step of screening. Each of the steps may be any method known in the art (US 2021-0094903 A1). Furthermore, the specific conditions may be appropriately changed for process optimization, but are not limited thereto.

[0051] According to the present application, as discussed above, amino acid granules from which the bacterial cells have been removed can be obtained through the first and second steps. Since the amino acid granules do not contain bacterial cells, the amino acid content in the product may be at least 50%, 60%, 70%, 75%, 80%, 85%, or 90% or more. Therefore, the production method of the present application is suitable for providing a product with a high amino acid content. Effect of the Invention

[0052] The manufacturing method of the present application provides amino acid granules from which bacterial cells have been removed. Since the amino acid granules provided by the present application do not contain bacterial cells, they have a higher amino acid content per weight than other amino acid granules that contain bacterial cells. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0053] The present application will be described in more detail with reference to the following examples. However, the following examples are merely illustrative of the present application, and the scope of the present application is not limited thereto.

[0054] Experimental Example 1. Production of amino acid granules containing tryptophan In Experimental Example 1, amino acid granules containing tryptophan were produced. To this end, the following tryptophan-containing fermentation liquid (concentration 90.0 g / L, solid content 13.5% (w / w), specific gravity 1.035, purity 64.4%, bacterial body 15%) was prepared, and amino acid crystals were separated from the tryptophan-containing fermentation liquid using a centrifuge (PTM006, Tomoe Kogyo Co., Ltd., 4000 / 3500 RPM, feeding rate 2.1 LPM, Dam no. 1), and then the bacterial body was separated using a plate-type filtration membrane (Ceramic filtration system / Puretec, temperature 60° C., TMP 1.0, Inverter 40 Hz) to prepare a fermentation filtrate. A calcium source was added to the fermentation filtrate, which was then concentrated using a 20 L concentration tube (N-21NS, EYELA, water bath temperature 70°C, vacuum pressure 120 torr), and the amino acid crystals in the concentrate were crushed using a blender (Hanil Electric, SHMF-3600TG) to prepare a concentrated fermentation filtrate. The concentrated fermentation filtrate and the seeds generated during the process were mixed in a mixing granulator (Ploughshare mixer granulator, Lodige) to obtain a product.

[0055] The weight of the tryptophan-containing amino acid crystals generated in the process was analyzed to be about 4.9 kg, the tryptophan content in the amino acid crystals was about 2.0 kg, the moisture content in the amino acid crystals was about 57.8% (w / w), and the solid content in the amino acid crystals was about 42.2% (w / w).

[0056] In addition, the total weight of the tryptophan-containing fermentation filtrate used in the process was analyzed to be about 31.0 kg, the total volume was about 31.1 L, the tryptophan content in the fermentation filtrate was about 390.1 g (about 1.9 mol), the tryptophan concentration in the fermentation filtrate was about 12.5 g / L, the pH of the fermentation filtrate was about 5.8, the solid content in the fermentation filtrate was about 2.5% (w / w) (0.8 kg), and the amount of tryptophan contained in the fermentation filtrate was about 50.3% of the total solid content.

[0057] The calcium source charged to the process was calcium hydroxide, the amount charged being about 28.3 g (about 0.2 mol).

[0058] A calcium source was added to the fermentation filtrate, and the solid content of the fermentation filtrate to which the calcium source was added was approximately 2.6% (796.6 g), and the amount of tryptophan contained in the fermentation filtrate to which the calcium source was added was analyzed to be approximately 49.0% of the total solid content.

[0059] In addition, the concentrated fermentation filtrate obtained by concentrating the fermentation filtrate containing the calcium source had a calcium concentration of about 240.7 g / L and a solid content of about 48.3 wt%.

[0060] Experimental Example 1-1. Preparation of amino acid granules with tryptophan purity of 84% Using the concentrated fermentation filtrate, amino acid crystals, and seeds prepared in Experimental Example 1, amino acid granules with tryptophan purity of 84% were prepared.

[0061] The tryptophan purity of the amino acid granules was calculated by determining the weight ratio of tryptophan to the total solid content (total weight excluding the weight of water) contained in the amino acid granules.

[0062] The table below summarizes the amounts of concentrated fermentation filtrate, amino acid crystals, seeds, and amino acid granules produced from them that were fed into the process, as well as the solid content, moisture content, and tryptophan content of each component.

[0063] [Table 1]

[0064] As a result of producing amino acid granules, approximately 882.0g of tryptophan granules was produced, and the solid content in the tryptophan granules was analyzed to be 697.7g, the moisture content 184.3g, and the tryptophan content 588.1g. The tryptophan purity, which is the percentage of tryptophan in the solids contained in the tryptophan granules, was analyzed to be approximately 84.3%, and the moisture ratio was approximately 20.9%. The size classification of the tryptophan granules contained in the amino acid granules produced in this process is as follows:

[0065] [Table 2]

[0066] From the above experimental results, it was confirmed that after removing the bacterial cells, amino acid granules with high tryptophan purity can be produced from the concentrated fermentation filtrate, amino acid crystals, and seeds. In addition, size analysis of tryptophan granules confirmed that the amino acid content of each particle size is uniform.

[0067] Experimental Example 1-2. Preparation of amino acid granules with adjusted moisture content Next, in producing amino acid granules with a tryptophan purity of 84% using the concentrated fermentation filtrate, amino acid crystals and seeds prepared in Experimental Example 1, it was confirmed whether it was possible to change the moisture content while maintaining the tryptophan purity in the final product.

[0068] The table below summarizes the amounts of concentrated fermentation filtrate, amino acid crystals, seeds, and amino acid granules produced from them that were fed into the process, as well as the solid content, moisture content, and tryptophan content of each component.

[0069] [Table 3]

[0070] As a result of producing amino acid granules, about 761.0g of tryptophan granules were produced, and the solid content in the tryptophan granules was analyzed to be 614.1g, the moisture content was 146.9g, and the tryptophan content was 515.8g. The tryptophan purity, which is the percentage of tryptophan in the solids contained in the tryptophan granules, was analyzed to be about 84.0%, and the moisture ratio was about 19.3%.

[0071] [Table 4]

[0072] As a result of producing amino acid granules, about 826.0g of tryptophan granules were produced, and the solid content in the tryptophan granules was analyzed to be 642.5g, the moisture content was 183.5g, and the tryptophan content was 539.7g. The tryptophan purity, which is the percentage of tryptophan in the solids contained in the tryptophan granules, was analyzed to be about 84.0%, and the moisture ratio was about 22.2%. However, it was confirmed that granulation did not go well when the moisture ratio was about 25%.

[0073] Experimental Example 1-3. Preparation of amino acid granules with tryptophan purity of about 90% Next, it was confirmed whether amino acid granules with different tryptophan purity could be produced using the concentrated fermentation filtrate, amino acid crystals, and seeds prepared in Experimental Example 1. Specifically, it was confirmed whether amino acid granules with a tryptophan purity of 91% could be produced using the same concentrated fermentation filtrate, amino acid crystals, and seeds.

[0074] The table below summarizes the amounts of concentrated fermentation filtrate, amino acid crystals, seeds, and amino acid granules produced from them that were fed into the process, as well as the solid content, moisture content, and tryptophan content of each component.

[0075] [Table 5]

[0076] As a result of producing amino acid granules, approximately 1099.1g of tryptophan granules was produced, and the solid content in the tryptophan granules was analyzed to be 846.3g, the moisture content was 252.8g, and the tryptophan content was 773.5g. The tryptophan purity, which is the percentage of tryptophan in the solids contained in the tryptophan granules, was analyzed to be approximately 91.4%, and the moisture ratio was approximately 23.0%. The tryptophan granules contained in the amino acid granules produced in this process were classified by size as follows:

[0077] [Table 6]

[0078] From the above experimental results, it was confirmed that after removing the bacterial cells, amino acid granules with higher tryptophan purity could be produced from the concentrated fermentation filtrate, amino acid crystals and seeds. In addition, size analysis of tryptophan granules confirmed that the amino acid content of each particle size was uniform.

[0079] Experimental Example 1-4. Preparation of amino acid granules with tryptophan purity of about 70% Next, it was confirmed whether amino acid granules with reduced tryptophan purity could be produced using the concentrated fermentation filtrate, amino acid crystals, and seeds prepared in Experimental Example 1. Specifically, it was confirmed whether amino acid granules with a tryptophan purity of 70% could be produced using the same concentrated fermentation filtrate, amino acid crystals, and seeds.

[0080] The table below summarizes the amounts of concentrated fermentation filtrate, amino acid crystals, seeds, and amino acid granules produced from them that were fed into the process, as well as the solid content, moisture content, and tryptophan content of each component.

[0081] [Table 7]

[0082] As a result of producing amino acid granules, about 830.0g of tryptophan granules were produced, and the solid content in the tryptophan granules was analyzed to be 678.5g, the moisture content was 151.5g, and the tryptophan content was 469.6g. The tryptophan purity, which is the percentage of tryptophan in the solids contained in the tryptophan granules, was analyzed to be about 69.2%, and the moisture ratio was about 18.2%. We checked whether it was possible to change the moisture content while maintaining the tryptophan purity of the amino acid granules mentioned above, which have a tryptophan purity of about 70%.

[0083] [Table 8]

[0084] As a result of producing amino acid granules, approximately 900.0g of tryptophan granules was produced, and the solid content in the tryptophan granules was analyzed to be 710.5g, the moisture content 189.5g, and the tryptophan content 491.5g. The tryptophan purity, which is the percentage of tryptophan in the solids contained in the tryptophan granules, was analyzed to be approximately 69.2%, and the moisture ratio was approximately 21.2%. The tryptophan granules contained in the amino acid granules produced in this process were classified by size as follows:

[0085] [Table 9]

[0086] From the above experimental results, it was confirmed that after removing the bacterial cells, amino acid granules with reduced tryptophan purity can be produced from the concentrated fermentation filtrate, amino acid crystals, and seeds. It was also confirmed that it is possible to produce amino acid granules with various water contents while reducing the purity. Furthermore, through size analysis of tryptophan granules, it was confirmed that the amino acid content of each particle size was similar.

[0087] However, it was found that when the moisture content was about 15%, granules were not successfully formed.

[0088] Experimental Example 2. Preparation of amino acid granules containing threonine In Experimental Example 2, amino acid granules containing threonine were produced. To this end, a fermentation liquid containing threonine (concentration 221.0 g / L, solid content 23.3% (w / w), specific gravity 1.028, purity 92.4%, bacterial cells 16.7%) was prepared, and amino acid crystals were separated from the threonine-containing fermentation liquid using a centrifuge (PTM006, Tomoe Kogyo Co., Ltd., 4000 / 3500 RPM, Feeding rate 2.1 LPM, Dam no. 1), and then the bacterial cells were separated using a plate-type filtration membrane (Ceramic filtration system / Puretec, temperature 60°C, TMP 1.0, Inverter 40 Hz) to prepare a fermentation filtrate. The fermentation filtrate was added with Ca(OH) 2 After adding at a molar ratio of 0.3, it was concentrated using a 20L concentration tube (N-21NS, EYELA, water bath temperature 70℃, vacuum pressure 120 torr), and after concentration, the amino acid crystals in the concentrate were crushed using a blender (Hanil Electric, SHMF-3600TG) to prepare a concentrated fermentation filtrate. In the case of seeds, they were produced using a double drum dryer (DS-21, Taisei Machinery, steam pressure 0.4 bar, feeding rate 0.5 LPM, 10 RPM).

[0089] In producing the threonine-containing amino acid granules, a mixer granulator (Ploughshare mixer granulator, Lodige) (Experimental Example 2-1) and a fluidized bed granulator (FBG-3, S-One Korea Co., Ltd.) (Experimental Example 2-2) were used in the granulation process.

[0090] Experimental Example 2-1. Production of threonine-containing amino acid granules using a mixing type granulator In producing the amino acid granules containing threonine, a mixer granulator (Ploughshare mixer granulator, Lodige) was used. The composition of the feed (concentrated fermentation filtrate) used in the experiment is as follows:

[0091] [Table 10]

[0092] Next, the composition of the seeds used in the experiment is as follows:

[0093] [Table 11]

[0094] The composition analysis results of the amino acid granules in the form of threonine granules prepared by adding the concentrated fermentation filtrate feed and seeds are as follows.

[0095] [Table 12]

[0096] As a result of the above experiment, amino acid granules with a threonine purity of 79.2% were obtained.

[0097] Experimental Example 2-2. Production of threonine-containing amino acid granules using a fluidized bed granulator A fluidized bed granulator (FBG-3, S-One Korea Co., Ltd.) was used to produce amino acid granules containing threonine. The composition of the feed (concentrated fermentation filtrate) used in the experiment is as follows:

[0098] [Table 13]

[0099] The composition of the seeds used in the experiment was as follows: The seeds were produced using a pilot drum dryer.

[0100] [Table 14]

[0101] The composition analysis results of the amino acid granules in the form of threonine granules prepared by adding the concentrated fermentation filtrate feed and seeds are as follows.

[0102] [Table 15]

[0103] As a result of the above experiment, amino acid granules with a threonine purity of 80.9% were obtained. As mentioned above, it was confirmed that both a fluidized bed granulator and a mixed type granulator can be used to produce amino acid granules containing threonine. The purity of threonine in the produced amino acid granules was substantially the same in both cases.

[0104] Experimental Example 3: Production of amino acid granules containing isoleucine In Experimental Example 3, amino acid granules containing isoleucine were produced by preparing the following fermentation liquid containing isoleucine (concentration 86.9 g / L, solid content 10.5% (w / w), specific gravity 1.030, purity 81.0%, bacterial cell content 11%), and concentrating the fermentation filtrate in the same manner as in Experimental Example 2.

[0105] In producing amino acid granules containing isoleucine, a mixer granulator (Ploughshare mixer granulator, Lodige) (Experimental Example 3-1) and a fluidized bed granulator (FBG-3, S-One Korea Co., Ltd.) (Experimental Example 3-2) were used.

[0106] Experimental Example 3-1. Production of isoleucine-containing amino acid granules using a mixing type granulator A mixing type granulator was used to produce amino acid granules containing isoleucine. The composition of the feed (concentrated fermentation filtrate) used in the experiment is as follows:

[0107] [Table 16]

[0108] The composition of the seeds used in the experiment was as follows: The seeds were produced using a pilot drum dryer.

[0109] [Table 17]

[0110] The composition analysis results of the amino acid granules in the form of isoleucine granules prepared by adding the concentrated fermentation filtrate feed and seeds are as follows.

[0111] [Table 18]

[0112] As a result of the above experiment, amino acid granules with an isoleucine purity of 69.4% were obtained.

[0113] Experimental Example 3-2. Production of isoleucine-containing amino acid granules using a fluidized bed granulator A fluidized bed granulator was used to produce amino acid granules containing isoleucine. The composition of the feed (concentrated fermentation filtrate) used in the experiment was as follows:

[0114] [Table 19]

[0115] The composition of the seeds used in the experiment was as follows: The seeds were produced using a pilot drum dryer.

[0116] [Table 20]

[0117] The composition analysis results of the amino acid granules in the form of isoleucine granules prepared by adding the concentrated fermentation filtrate feed and seeds are as follows.

[0118] [Table 21]

[0119] As a result of the above experiment, amino acid granules with an isoleucine purity of 67.9% were obtained. As mentioned above, it was confirmed that both a fluidized bed granulator and a mixed type granulator can be used to produce amino acid granules containing isoleucine. The purity of isoleucine in the produced amino acid granules was uniform in both cases.

[0120] Experimental Example 4. Preparation of amino acid granules containing valine In Experimental Example 4, amino acid granules containing valine were produced. To this end, a fermentation liquid containing valine (concentration 68.4 g / L, solid content 10.1% (w / w), specific gravity 1.020, purity 66.8%, bacterial cell 5%) was prepared, and a fermentation filtrate was concentrated in the same manner as in Experimental Example 2.

[0121] In producing the valine-containing amino acid granules, a mixer granulator (Ploughshare mixer granulator, Lodige) (Example 4-1) and a fluidized bed granulator (FBG-3, S-One Korea Co., Ltd.) (Example 4-2) were used.

[0122] Experimental Example 4-1. Production of valine-containing amino acid granules using a mixing type granulator A mixing type granulator was used to produce amino acid granules containing valine. The composition of the feed (concentrated fermentation filtrate) used in the experiment is as follows:

[0123] [Table 22]

[0124] The composition of the seeds used in the experiment was as follows: The seeds were produced using a pilot drum dryer.

[0125] [Table 23]

[0126] The composition analysis results of the amino acid granules in the form of valine granules prepared by adding the concentrated fermentation filtrate feed and seeds are as follows.

[0127] [Table 24]

[0128] As a result of the above experiment, amino acid granules with a valine purity of 74.3% were obtained.

[0129] Experimental Example 4-2. Production of valine-containing amino acid granules using a fluidized bed granulator A fluidized bed granulator was used to produce amino acid granules containing valine. The composition of the feed (concentrated fermentation filtrate) used in the experiment was as follows:

[0130] [Table 25]

[0131] The composition of the seeds used in the experiment was as follows: The seeds were produced using a pilot drum dryer.

[0132] [Table 26]

[0133] The composition analysis results of the amino acid granules in the form of valine granules prepared by adding the concentrated fermentation filtrate feed and seeds are as follows.

[0134] [Table 27]

[0135] As a result of the above experiment, amino acid granules with a valine purity of 75.5% were obtained. As mentioned above, it was confirmed that both a fluidized bed granulator and a mixed type granulator can be used to produce amino acid granules containing valine. The purity of valine in the produced amino acid granules was uniform in both cases.

[0136] Experimental Example 5. Preparation of amino acid granules containing histidine In Experimental Example 5, histidine-containing amino acid granules were produced. To this end, a fermentation liquid containing histidine (concentration 97.0 g / kg, solid content 15.4% (w / w), purity 63.0%, bacterial cell content 13%) was prepared, and a fermentation filtrate was concentrated in the same manner as in Experimental Example 2.

[0137] In producing the histidine-containing amino acid granules, a mixer granulator (Ploughshare mixer granulator, Lodige) (Experimental Example 5-1) and a fluidized bed granulator (FBG-3, S-One Korea Co., Ltd.) (Experimental Example 5-2) were used.

[0138] Experimental Example 5-1. Production of histidine-containing amino acid granules using a mixing type granulator A mixed granulator was used to produce histidine-containing amino acid granules. The composition of the feed (concentrated fermentation filtrate) used in the experiment was as follows:

[0139] [Table 28]

[0140] The composition of the seeds used in the experiment was as follows: The seeds were prepared by drying them at about 100° C. for 2 hours using a vacuum dryer.

[0141] [Table 29]

[0142] The composition analysis results of the amino acid granules in the form of histidine granules prepared by adding the concentrated fermentation filtrate feed and seeds are as follows.

[0143] [Table 30]

[0144] As a result of the above experiment, amino acid granules with a histidine purity of 66.6% were obtained.

[0145] Experimental Example 5-2. Production of histidine-containing amino acid granules using a fluidized bed granulator A fluidized bed granulator was used to produce amino acid granules containing histidine. The composition of the feed (concentrated fermentation filtrate) used in the experiment was as follows:

[0146] [Table 31]

[0147] The composition of the seeds used in the experiment was as follows: The seeds were prepared by drying them at about 100° C. for 2 hours using a vacuum dryer.

[0148] [Table 32]

[0149] The composition analysis results of the amino acid granules in the form of histidine granules prepared by adding the concentrated fermentation filtrate feed and seeds are as follows.

[0150] [Table 33]

[0151] As a result of the above experiment, amino acid granules with a histidine purity of 66.0% were obtained. As mentioned above, it was confirmed that both a fluidized bed granulator and a mixed type granulator can be used to produce amino acid granules containing histidine. The histidine purity in the produced amino acid granules was similar in both cases.

[0152] Through the above experimental examples, it was confirmed that it is possible to produce amino acid granules from which bacterial strains have been removed using various devices for various amino acids. As can be seen from the above experimental examples, when producing amino acid granules by removing bacterial strains, it was confirmed that it is advantageous to produce products with high amino acid content as the amino acid content in the final product increases.

[0153] It was also confirmed that amino acid granules can be produced using both a fluidized bed granulator and a mixed type granulator by adjusting the amounts of seeds, concentrated fermentation filtrate, and, if necessary, amino acid crystals used in the process.

[0154] From the above description, a person skilled in the art to which the present application pertains will understand that the present application may be implemented in other specific forms without changing its technical ideas or essential features. In this regard, it should be understood that the above described embodiments are merely illustrative and not limiting. The scope of the present application should be interpreted as including any modified or altered forms derived from the meaning and scope of the claims below, and their equivalent concepts, rather than the above detailed description.

Claims

1. A first step of removing bacterial cells from a fermentation broth containing amino acids to prepare a fermentation filtrate; A method for producing amino acid granules, comprising a second step of forming granules from the fermentation filtrate.

2. 2. The method for producing amino acid granules according to claim 1, wherein the amino acid has a solubility in water at 25°C of more than 0 g / 100 g and not more than 20 g / 100 g.

3. 2. The method for producing amino acid granules according to claim 1, wherein the amino acid is at least one selected from the group consisting of valine, tryptophan, threonine, isoleucine, leucine, methionine, histidine, and phenylalanine.

4. The method for producing amino acid granules according to claim 1 , wherein the first step comprises concentrating the fermentation filtrate.

5. The first step further comprises separating amino acid crystals from the fermentation liquid; The method for producing amino acid granules according to claim 1 , wherein the separated amino acid crystals are provided to the second step.

6. 2. The method for producing amino acid granules according to claim 1, wherein the first step further comprises a step of dissolving amino acid crystals present in the fermentation liquid and / or fermentation filtrate.

7. 2. The method for producing amino acid granules according to claim 1, wherein the first step further comprises adding a calcium source to the fermentation liquid and / or fermentation filtrate.

8. The method for producing amino acid granules according to claim 7, wherein the calcium source is provided so that calcium ions are added in a molar ratio of 0.02 to 2.0 relative to the amino acid.

9. 2. The method for producing amino acid granules according to claim 1, further comprising a step of re-supplying at least a portion of the amino acid seeds obtained in the second step to a granule formation step.

10. Amino acid granules containing 50% or more amino acids and not containing bacterial cells.

11. 8. The amino acid granules according to claim 7, wherein the amino acid granules contain calcium in a molar ratio of 0.02 to 2.0 relative to the amino acids in the product.

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