Process for preparing particles comprising guanidinoacetic acid

Abstract

The present application relates to a process for the preparation of granules comprising guanidinoacetic acid comprising the steps of a) providing a fermentation broth comprising guanidinoacetic acid and biomass, b) reducing the content of water in the fermentation broth provided in step a) to obtain a concentrated fermentation broth, and c) wet granulation of the concentrated fermentation broth of step b).

Description

[0001] The present invention relates to a method for preparing granules comprising guanidinoacetic acid, granules comprising specific guanidinoacetic acid and a method for supplementing an animal's diet with said granules comprising guanidinoacetic acid.

[0002] Amidino compounds, i.e. compounds with a guanidine group, are widely used as energy supplements, antidiabetic drugs, anti-inflammatory drugs, antihistamines and hypotensive drugs. Many of these amidino compounds are synthesized by transamidation reactions in which the amidino group of arginine is transferred to various amidino acceptors, such as guanidine acetate, 3-guanidinopropionic acid, 4-guanidinobutyric acid, 2-guanidinoethanol, hydroxy-guanidine and homoarginine. Biocatalytic transamidation reactions using arginine substrates are generally reversible and inhibited by the byproduct ornithine. Due to the inhibition of ornithine and the requirement for the expensive substrate arginine, the biosynthesis of some amidino compounds remains a challenge.

[0003] Guanidinoacetic acid (GAA), which serves as a direct precursor of creatine, has recently attracted new interest as a nutritional additive due to its creatine-recycling effect and its high stability in aqueous solutions. Furthermore, it is also widely used in the pharmaceutical industry and as a feed additive in poultry agriculture. The European Feed Safety Authority (2009) concluded that GAA has no mutagenic or genotoxic properties and does not pose a risk to the environment. Given its widespread use, there is a significant industrial demand for GAA.

[0004] In 1861, GAA was first produced by the chemical reaction of cyanamide with glycine. Currently, GAA is mainly chemically synthesized by reacting glycine or sodium glycinate with a guanidinating agent (e.g., O-alkylisoureas or cyanamide). The purification process of GAA is cumbersome because the final product is contaminated by the initial guanidinating agent or toxic substances such as iminodiacetic acid or methyliminodiacetic acid, and the production process is environmentally unfriendly. Therefore, the production of biotechnological GAA from renewable resources is highly desirable and promising.

[0005] In some vertebrates, GAA can be synthesized from arginine and glycine by arginine:glycine amidinotransferase (AGAT, EC:2.1.4.1). However, only a few prokaryotes, such as cyanobacteria, can produce GAA in specialized metabolite synthesis. AGAT catalyzes the reversible transfer of an amidino group from arginine (donor) to the amino group of glycine (acceptor) to produce GAA and ornithine. To produce one mole of GAA, one mole of arginine is required, and one mole of ornithine is produced.

[0006] The downstream process for chemically produced guanidinoacetic acid comprises the steps of crystallization, mechanical dehydration of the guanidinoacetic acid-containing crystals (e.g., GAA) thus obtained, washing, drying the crystals, granulating the dried crystals with a granulating (gluing) agent, and drying the granules to obtain a free-flowing and low-dust-producing product.

[0007] When guanidinoacetic acid GAA is produced during the fermentation process, this rather complex downstream process can be simplified. In principle, the culture broth from the fermentation process can be fed directly to the pelleting.

[0008] For example, WO2022 / 243116A1 discloses a method for producing guanidinoacetic acid (GAA) by fermentation, comprising the steps of culturing a suitable microorganism in a suitable culture medium under suitable conditions, and accumulating GAA in the culture medium to form a GAA-containing fermentation broth. This document also discloses that the method may further include frying and / or pelleting the GAA-containing fermentation broth.

[0009] DE1031366A1 discloses that the granulation of a feed additive comprising amino acids and / or vitamins and optionally fermentation broth components is carried out in a circulating fluidized bed. The document also discloses a granular feed additive comprising 40-100 wt.% L-amino acids and up to 20 wt.% fermentation broth components and / or biomass formed during fermentation.

[0010] DE102007034102 A1 discloses wear-resistant and free-flowing guanidinoacetic acid-containing moldings, in particular granules and extrudates, and a process for their preparation. The moldings have a relative humidity of 350 to 850 kg / m², based on the total weight. 3 The invention discloses a novel polyol having a bulk density of 1000 μm, a grain size of 32 to 2750 μm and a guanidinoacetic acid content of 55 to 99.9% by weight, and is particularly suitable as a feed additive.

[0011] However, it was observed that such fermentation broths tend to settle when not stirred, and their pelleting efficiency is low. These effects are believed to be caused by the low amount of dry matter and low viscosity typically contained in the fermentation broth. For example, the dry matter content of GAA fermentation broth is less than 10% by weight, and the particle size distribution of the crystals contained therein is small, for example, the particle size distribution of GAA crystals in the fermentation broth is d10.3: 4.62 μm; d50.3 = 10.50 μm; and d90.3 = 136.6 μm. In detail, it was observed that due to the high water content in the fermentation broth, long operating times of the pelletizer lead to a low increase in dry matter within the pelletizer. To make matters worse, the low increase in dry matter is compounded by attrition between the particles, which results in a particle size reduction from an initial d50.3 of 343 μm to, for example, a d50.3 of 206 μm.

[0012] Therefore, there is still a need for a method for preparing granules comprising guanidinoacetic acid (GAA) which overcomes the above-mentioned problems. Such a method should allow the production of granules comprising guanidinoacetic acid (GAA) without the use of a binder.

[0013] It has been found that the above-mentioned problems are solved in that the water content of the fermentation broth is reduced before being subjected to wet granulation to obtain a concentrated fermentation broth.

[0014] Therefore, an object of the present invention is a process for preparing granules comprising guanidinoacetic acid, comprising the following steps:

[0015] a) providing a fermentation broth comprising guanidinoacetic acid and biomass,

[0016] b) reducing the water content of the fermentation broth provided in step a) to obtain a concentrated fermentation broth, and

[0017] c) wet granulating the concentrated fermentation broth of step b).

[0018] The method according to the present invention is not only simpler and more cost-effective than standard methods, but also more sustainable because it does not produce any waste streams. Instead, all materials from the fermentation process are included in the final product, except for the water recovered in step b) and any water vapor from the wet granulation in step c). Therefore, the product obtained by the method of the present invention contains additional biomass, which is not only useful for animal consumption but also provides additional nutritional value. In contrast, the standard method for preparing granules containing guanidinoacetic acid starts with chemically produced guanidinoacetic acid, which involves further steps in the downstream process, involving crystallization, mechanical dehydration and washing, drying, mechanical granulation with the aid of a granulating agent, and then further drying.

[0019] In one embodiment of the process according to the invention, the fermentation broth is concentrated in step b) to a dry matter content of at least 10% by weight.

[0020] Preferably, the fermentation broth is concentrated in step b) to a dry matter content of at least 15, 20, 25, 30 or 35% by weight.

[0021] In a preferred embodiment of the process according to the invention, the fermentation broth is concentrated in step b) to a dry matter content of 40 to 60% by weight.

[0022] Preferably, the biomass content of the fermentation broth provided in step a) and / or obtained in step b) is from 1 to 10% by weight, or from 1 to 5% by weight, each based on the total weight of the fermentation broth or concentrated fermentation broth.

[0023] In the context of the present invention, the term "wet granulation" is well known to those skilled in the art and means the formation of granules by subjecting a liquid formulation containing suspended or dissolved solids to an agitation system, for example under the influence of an impeller (in a high shear granulator), a screw (in a twin-screw granulator) or air (in a fluidized bed granulator). The agitation generated in the system and the wetting of the components within the formulation cause the primary powder particles to aggregate to produce wet granules. The granulating liquid (fluid) contains a solvent or carrier material, which must be volatile so that it can be removed by drying and, depending on the intended application, non-toxic. Typical liquids used for wet granulation include water, ethanol and isopropanol, alone or in combination, and the liquid solution can be water-based or solvent-based. Aqueous solutions have the advantage of being safer to handle than other solvents. Since a fermentation broth is an aqueous system / formulation, it meets these advantages.

[0024] In principle, the wet granulation according to the method of the invention is not subject to any restrictions with regard to the specific wet granulation technique. Thus, the wet granulation can be high shear granulation, twin-screw granulation or fluidized bed granulation. However, fluidized bed granulation has several advantages over other wet granulation techniques. These advantages are in particular:

[0025] • The fluid bed granulator is a unit system that makes fluid bed granulation a relatively simple process, saving labor costs, transfer losses and time.

[0026] The technology uses a stream of air to evaporate the liquid, thus avoiding a waste stream.

[0027] The heat transfer in a fluid bed granulator is 2 to 6 times greater than that produced by a tray dryer.

[0028] Once the parameters are optimized, the process can be automated.

[0029] Drying occurs evenly and the process prevents staining.

[0030] These aspects contribute to making the method according to the invention simpler and more cost-effective.

[0031] In another embodiment of the process according to the invention the wet granulation in step c) is a fluidized bed granulation.

[0032] The water contained in the fermentation liquid of step a) and the dissolved molecules (or solids) can form bonds between the particles already present in the fermentation liquid, and the bonds are strong enough to stick them together. The combination of particles and liquid is a combination of capillary forces and adhesive forces until a more lasting solid bond is established. However, once the particles obtained in this way are dried, they may separate. Therefore, water may not be strong enough to produce and maintain bonds. The fermentation liquid used in the method according to the present invention contains biomass, which can hold or attract the guanidine acetic acid particles together to form particles. Therefore, the biomass in the fermentation liquid may have served as a granulating agent or adhesive. However, in cases where the biomass does not provide this function at all or does not provide the desired degree of function, it is beneficial to add a granulating agent during the method according to the present invention.

[0033] In one embodiment of the process according to the invention, a granulating agent is added to the concentrated fermentation broth obtained in step b) before step c).

[0034] In principle, any binder or adhesive that holds or draws other materials together to form a cohesive whole, either mechanically, chemically, by adhesion, or by cohesive forces, can be used as a granulating agent. However, the granulating agent used to prepare the granules containing guanidinoacetic acid should not be toxic and should not have its own effects on animals. In addition, any potential incompatibility with guanidinoacetic acid must be excluded. The use of organic binders as granulating agents in the method according to the invention offers the advantage that they are generally non-toxic and compatible with guanidinoacetic acid.

[0035] In a preferred embodiment of the process according to the invention, the granulating agent is an organic binder.

[0036] Organic binders, such as starch, cellulose ethers, cellulose esters, polyvinyl alcohol and / or mixtures thereof, hold or attract solid materials together through adhesion or cohesion to mechanically and chemically form a cohesive whole. In addition, they are also non-toxic and compatible with guanidinoacetic acid.

[0037] In another preferred embodiment of the process according to the invention, the granulating agent is starch, cellulose ether, cellulose ester, polyvinyl alcohol and / or mixtures thereof.

[0038] It is advantageous to keep the amount of granulating agent in the granules to be prepared as low as possible. This prevents the concentration of guanidinoacetic acid and any additional substances having further nutritional value from being unnecessarily reduced. In the process according to the invention, only a maximum of 5% by weight, preferably 1 to 5% by weight or 2 to 4% by weight, of granulating agent is required, based on the mass of dry binder on the dry matter in the fermentation broth.

[0039] In a further embodiment of the process according to the invention the amount of granulating agent is at most 5% by weight, based on the mass of dry binder relative to the dry matter in the fermentation broth.

[0040] Preferably, the amount of granulating agent is 1 to 5 wt% or 2 to 4 wt% based on the mass of dry binder relative to the dry matter in the fermentation broth.

[0041] Fluidized bed spray granulation can be defined as a particle formation method by which a solid-containing liquid is converted into a dust-free granular solid in a single step by drying. Essentially, hot air is used to fluidize an already formed bed of particles (seed particles), which may be the same or different from the dissolved components. In the context of the present invention, the liquid to be treated is a solution or suspension and is continuously sprayed onto or into the bed from a space above the upper bed surface using an atomizing nozzle. The solvent evaporates through the thermal fluidization, leaving the dissolved material on the surface of the seed particles. If the dissolved solids in the spray liquid and the particles in the fluidized bed are composed of the same material, the process is called layered granulation. If different solids are sprayed, the particles are coated, forming different layers on the seed particles. If the spray droplets hit the fluidized particles (seed particles) and do not rebound, they will diffuse on the particle surface and eventually dry, leaving solids that form layers around the particles. Thus, a layer-by-layer growth of particles is achieved. The resulting particles are called granules or granules. Preferably, the method according to the present invention is layered granulation. Therefore, the seed granules provided in the fluid-feed granulator also comprise or consist of guanidinoacetic acid.

[0042] In another embodiment of the process according to the invention the wet granulation in step c) is an agglomeration granulation.

[0043] In the context of the present invention, guanidinoacetic acid containing seed particles having a d50.3 of 300 to 400 μm has been successfully used to prepare guanidinoacetic acid containing particles having a particle size distribution of d10.3 of 220 to 720 μm, d50.3 of 300 to 1100 μm, and d90.3 of 420 to 1700 μm. Specifically, the seed particles had a particle size distribution of d10.3 of 150 to 250 μm, d50.3 of 300 to 400 μm, and d90.3 of 475 to 575 μm.

[0044] Preferably, seed particles having a d50.3 of 300 to 400 μm are used in step c) of the process according to the invention.

[0045] The examples of the present invention show that particles comprising guanidinoacetic acid and biomass and having a particle size distribution of d10.3 from 220 to 720 μm, d50.3 from 300 to 1100 μm and d90.3 from 420 to 1700 μm have improved or at least beneficial particle properties, such as good flowability, and / or improved particle quality, such as high bulk density.

[0046] Therefore, another object of the present invention is a particle comprising guanidinoacetic acid and biomass, wherein the particle size distribution of the particle is d10.3 from 220 to 720 μm, d50.3 from 300 to 1100 μm, and d90.3 from 420 to 1700 μm.

[0047] In principle, the granules according to the present invention are not subject to any restrictions regarding their preparation method, provided that the method in question allows for obtaining granules with the desired particle size distribution. However, it is preferred that the guanidinoacetic acid-containing granules be obtained by the method according to the present invention. This is because the method according to the present invention, including the wet granulation step c), further improves product quality aspects, such as particle size or transient properties, by binding together existing solids to form larger granules. In addition to being simpler, more cost-effective, and more sustainable, the method according to the present invention involving a specific granulation step also leads to improved product quality aspects of the guanidinoacetic acid-containing granules, such as an increased particle size distribution with a d10.3 of 220 to 720 μm, a d50.3 of 300 to 1100 μm, and a d90.3 of 420 to 1700 μm, as well as a high bulk density, and improved granule properties, such as good flowability.

[0048] The examples of the present invention show that the use of a granulating agent, such as a binder, is not mandatory for providing granules containing guanidinoacetic acid. However, there may be situations in which the additional presence of a granulating agent, such as a binder, is beneficial in holding the granules together, particularly under difficult or extreme conditions, such as under the influence of pressure, such as mixing.

[0049] In one embodiment, the granules according to the invention further comprise a granulating agent.

[0050] Preferably, the granulating agent is an organic binder, in particular starch, cellulose ether, cellulose ester, polyvinyl alcohol and / or mixtures thereof.

[0051] In one embodiment, the particles according to the invention have the following particle size distribution: d10.3 from 300 to 720 μm, d50.3 from 450 to 1100 μm, and d90.3 from 700 to 1700 μm, preferably a particle size distribution: d10.3 from 300 to 720 μm, d50.3 from 600 to 1100 μm, and d90.3 from 800 to 1700 μm.

[0052] Guanidine acetic acid is widely used as an energy supplement, antidiabetic, anti-inflammatory, antihistamine, and hypotensive drug.

[0053] Another object of the present invention is a method for supplementing an animal's diet, wherein the diet is supplemented with the guanidinoacetic acid-containing particles according to the invention and / or with the guanidinoacetic acid-containing particles obtained by the method according to the invention. Example:

[0054] I. According to the embodiment 1 of the present invention

[0055] A fermentation broth with a biomass content of 45 g / kg was provided. The used fluidized bed granulator consisted of an electric heater to heat a gas (air, nitrogen, CO2 or a combination thereof) to an elevated temperature (180°C) before flowing it through a distribution tray to fluidize the seed particles (d50.3: 343 μm). A nozzle fed by a pump was used to atomize the fermentation broth into fine droplets, which dried on the seed particles and formed a solid layer on the surface of the seed particles, or used as a binder to combine the seed particles into larger agglomerates or a combination thereof. The fluidizing gas was passed through a filter before being released into the environment.

[0056] Broths with less than 10% dry matter by weight, containing biomass and crystals with a particle size distribution of d10.3 = 4.62 μm; d50.3 = 10.50 μm; and d90.3 = 136.6 μm, tend to settle when not stirred. This settling of particles and the resulting inefficient pelleting due to the low dry matter content can lead to problems in broth handling and pelleting. Specifically, high water content results in a low increase in dry matter within the pellet mill, which results in long pellet mill run times. Due to the long run times, abrasion between the particles increases, resulting in a particle size reduction from an initial d50.3 value of 343 μm to, for example, 206 μm.

[0057] Therefore, the culture liquid is evaporated to a dry matter content of up to 50% by weight in a vacuum evaporation at 50 to 100 mbara. In addition to the advantage of less water in the culture liquid, the increased viscosity also leads to a more homogeneous liquid due to the reduced sedimentation rate and thus the reduced tendency of suspended particles to settle.

[0058] The following fluidized bed granulation was carried out with different granulating agents such as corn starch, CMC (carboxymethyl cellulose) and PVA (polyvinyl alcohol) in the range of 2-4 wt.%-% (dry binder mass on dry matter in liquid medium). An increase in particle size distribution (PSD) can be achieved with each additive used and at each concentration.

[0059] Since the granulation experiments with the granulating agent resulted in an increase in the particle size distribution, additional granulation experiments were performed without the granulating agent. Surprisingly, a significant increase in the particle size distribution was also observed when the evaporated fermentation broth was granulated with an additional granulating agent.

[0060] Experiment number Granulating agent [wt%] d10.3[μm] d50.3[μm] d90.3[μm] Seed material - 204 343 525 1 Corn starch, 3.03 426 650 1112 2 CMC, 2.87 712 1067 1634 3 PVA K90,3.96 411 712 1097 4 - 327 508 751

[0061] Table 1: Overview of the first round of granulation experiments with and without granulating agents

[0062] II. Example 2 according to the present invention

[0063] To confirm these results and investigate the influence of the initial biomass concentration, a second round of experiments was conducted without any additional granulating agents or the like. Here, a fermentation broth containing 15 g of biomass / kg of broth was used, which was evaporated to a dry matter content of approximately 50% by weight. In this round, the results of the previous experiments were replicated, and in particular, a significant increase in the particle size distribution was again observed. Significantly smaller starting materials were used to highlight the influence of the particle size distribution growth without reaching the limits of the experimental equipment used to fluidize the material.

[0064] d10.3[μm] d50.3[μm] d90.3[μm] Starting materials 6.21 17.14 76.88 End material 232.7 313.8 432.9

[0065] Table 2: Summary of the second round of granulation experiments without granulating agent

[0066] III. Determination of fluidity

[0067] The flowability of the granules was determined using five different funnels, each with a different hole diameter: the first funnel had a hole diameter of 2.5 mm, the smallest hole diameter. The product that passed through this hole was graded as a flowability value of 1. This was followed by the second to fourth funnels, each with a hole diameter of 5 mm, 8 mm, and 12 mm. The product that passed through the hole of the second funnel was graded as a flowability value of 2, the product that passed through the hole of the third funnel was graded as a flowability value of 3, and the product that passed through the hole of the fourth funnel was graded as a flowability value of 4. The hole diameter of the fifth and final funnel was 18 mm, and the flowability value of the product that passed through this hole was 5. Any product that did not pass through the hole of the fifth funnel was graded as a flowability value of 6. A flowability value of 5 or greater indicates that the product in question may not be suitable for an automated high-output feed plant. Table 3 below summarizes the results of the flowability determinations.

[0068] IV. Determination of the angle of repose

[0069] The flow characteristics of powdered substances are determined by measuring the height of the cone formed. For this test, a sieve with a mesh size that the particles should pass through without obstruction is fixed at a distance of 60 mm above the top of a metal cylinder. The substance to be evaluated is gently rubbed through the sieve until a geometrically constant cone is formed on the top of the metal cylinder. The angle of repose is calculated using the following formula:

[0070]

[0071] in

[0072] H = cone height, in mm

[0073] r = radius of the metal cylinder, in mm

[0074] V. Bulk density (ρ b ) and compacted apparent density (ρ t )

[0075] For bulk density, the mass of a powdered or granular substance of a defined volume is determined. The tapped apparent density indicates the volume that changes after tapping the mass obtained in the bulk density measurement. Here, a standardized test apparatus consisting of a metal tripod, a funnel with a defined tulip-shaped outlet, and a rotating slide is used. The test apparatus is placed on top of a 250 mL glass cylinder. The test substance is filled into the metal funnel, and then the rotating slide is opened to allow the test substance to flow out evenly until 20 mL of the test substance is filled into the cylinder. The bulk density is then calculated by the following formula:

[0076]

[0077] V 初始 =250mL.

[0078] The tamping apparent density is determined using a tamping device, such as JEL ST 2 (Fa Engelsmann AG, Ludwigshafen), according to DIN 53194. The tamping apparent density is calculated by the following formula:

[0079]

[0080] VI. Determination of the Carr Index

[0081] The Carr Index is an indicator of the compressibility of a powder and is calculated by the following formula:

[0082]

[0083] in

[0084] ρ b =Bulk density

[0085] ρ t = compacted apparent density

[0086] The results of the determination of flowability, angle of repose, bulk density, tamped apparent density and Carr's index are summarized in Table 3.

[0087]

[0088] Table 3: Granules from Examples 1 and 2 and commercial products (from Evonik) or (from Alzchem Group) for handling properties.

[0089] Comparison of the data in Table 3 shows that the products obtained by the process according to the invention (Examples 1 and 2) have the same or at least comparable quality to the comparative material, i.e. the commercially available product (from Evonik) or (from the Alzchem Group). However, the comparative material was prepared chemically, and the resulting material was further processed in a highly complex process. By comparison, the products of Examples 1 and 2 were obtained using a significantly less complex process according to the present invention. The higher water absorption effect may be due to the hygroscopic biomass in the product, but this can be managed.

[0090] VII. Determination of Particle Size Distribution

[0091] Particle size distribution (PSD) is measured using a laser diffraction method. This method uses the effect that particles scatter light at certain angles depending on their size. Smaller particles scatter light at larger angles, while larger particles scatter light at smaller angles. Therefore, a certain light pattern can be detected based on the overall PSD of the measured sample.

[0092] Here, PSD was measured using a laser diffraction particle size analyzer LA950 (Horiba). The samples to be measured were suspended in isopropyl alcohol. Prior to measurement, the samples were ultrasonically treated for 60 or 120 seconds. Alternatively, the samples were measured without ultrasound. The results showed that the measured values ​​for the samples without ultrasound treatment were higher, while the results for the samples with 60 and 120 seconds were comparable within the measurement accuracy. Therefore, only the values ​​measured after 60 seconds of ultrasound treatment are mentioned here.

[0093] VIII. Summary

[0094] In comprehensive experimental studies, it was shown that granules containing guanidinoacetic acid (GAA) can be produced from a fermentation broth containing guanidinoacetic acid by evaporation and granulation, particularly by fluidized bed granulation. Standard methods start with a chemically produced product that undergoes complex downstream processes, including crystallization, mechanical dehydration and washing, drying, mechanical granulation with the aid of a granulating agent, and further drying. In contrast, the method according to the present invention is much simpler. In detail, the method according to the present invention is simpler, more cost-effective, and more sustainable than standard methods. Another benefit of the method according to the present invention is that, apart from the water from evaporation and the water vapor from wet granulation (e.g., fluidized bed granulation), it produces no waste streams, as all materials from the fermentation process are included in the final product. In addition, all residues from the fermentation have potential nutritional value and can be consumed by animals. Finally, the granules obtained by the method according to the present invention have the same or at least similar quality as products from standard methods.

Claims

1. A method for preparing granules containing guanidinoacetic acid, comprising the following steps: a) providing a fermentation broth comprising guanidinoacetic acid and biomass, b) reducing the water content of the fermentation broth provided in step a) to obtain a concentrated fermentation broth, and c) wet granulating the concentrated fermentation broth of step b).

2. The process according to claim 1, wherein in step b) the fermentation broth is concentrated to a dry matter content of at least 10% by weight.

3. The process according to claim 1 or 2, wherein in step b) the fermentation broth is concentrated to a dry matter content of 40% to 60% by weight.

4. The method according to any one of claims 1 to 3, wherein the wet granulation in step c) is fluidized bed granulation.

5. The process according to any one of claims 1 to 4, wherein a granulating agent is added to the concentrated fermentation broth obtained in step b) before step c).

6. The method of claim 5, wherein the granulating agent is an organic binder.

7. The process according to claim 5 or 6, wherein the granulating agent is starch, cellulose ether, cellulose ester, polyvinyl alcohol and / or a mixture thereof.

8. The process according to any one of claims 5 to 7, wherein the amount of granulating agent is at most 5% by weight, based on the mass of the dry binder relative to the dry matter in the fermentation broth.

9. The process according to any one of claims 1 to 8, wherein the wet granulation in step c) is agglomeration granulation.

10. Particles comprising guanidinoacetic acid and biomass, wherein the particles have a particle size distribution of d10.3 from 220 to 720 μm, d50.3 from 300 to 1100 μm, and d90.3 from 420 to 1700 μm.

11. The granule of claim 10, wherein the granule further comprises a granulating agent.

12. The particle according to claim 10 or 11, wherein the particle has the following particle size distribution: d10.3 is 300-720 μm, d50.3 is 450-1100 μm, and d90.3 is 700-1700 μm.

13. Method for supplementing an animal's diet, wherein the diet is supplemented with particles comprising guanidinoacetic acid according to any one of claims 10 to 12 and / or particles comprising guanidinoacetic acid obtained by a method according to any one of claims 1 to 9.

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