FIELD OF THE INVENTION
The present disclosure relates to a method of preparing a granular feed additive.
5
DESCRIPTION OF THE RELATED ART
A feed additive is a product intended to be fed as a supplement to the normal diet to
overcome the lack of daily intake of a specific compound. It is common to supplement feed
10 additives for farm animals with amino acids to improve animal performance in animal
husbandry.
Since amino acids for feed additives which are produced by microbial fermentation
exist together with other by-products in a broth, various methods are used to increase the
content of amino acids during the preparation of feed additives. For example, to increase
15 the content of amino acids, an amino acid aqueous solution purified at a high concentration is
mixed with a fermentation broth to prepare granules. However, since a high-content basic
amino acid aqueous solution has hydrophilic and polar characteristics, the final granular
products have high hygroscopicity, which causes agglomeration of the granules. This
agglomeration phenomenon is not suitable for a processing process which is technologically
20 required in a mixed feed factory. In addition, to increase the content of basic amino acids, a
number of purification processes to remove impurities in the fermentation broth and a
crystallization process with hydrochloric acid are also used. However, a number of
purification processes are required, and reagents essentially used are discharged as waste,
which causes economic and environmental problems.
25 Accordingly, it is necessary to develop an economical method of preparing a granular
feed additive composition including basic amino acids with a high content and low
hygroscopicity.
[Prior Art Document]
30 [Patent Document]
(Patent Document 0001) Korean Patent Publication No. 10-2019-0081448
3
SUMMARY OF THE INVENTION
An object of the present disclosure is to provide a method of preparing a granular feed
additive, the method including the steps of preparing a basic amino acid aqueous solution
(step a); and injecting carbon dioxide into the basic amino acid aqueous solution to prepare a
5 neutralized amino acid aqueous solution (step b), wherein the basic amino acid aqueous
solution is prepared from a fermentation broth obtained from microbial culture.
BRIEF DESCRIPTION OF THE DRAWINGS
10 FIG. 1 illustrates the step of preparing a granular feed additive including a high
content of basic amino acids according to an aspect;
FIG. 2 illustrates a method of neutralizing an amino acid aqueous solution using a
bubbling tower;
FIG. 3 illustrates a method of neutralizing an amino acid aqueous solution using a
15 circulating absorption tower; and
FIG. 4 illustrates a method of neutralizing an amino acid aqueous solution using a
continuous absorption tower.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
20
Each description and embodiment disclosed in this disclosure may also be applied to
other descriptions and embodiments. That is, all combinations of various elements
disclosed in this disclosure fall within the scope of the present disclosure. Further, the scope
of the present disclosure is not limited by the specific description described below.
25
An aspect of the present disclosure may provide a method of preparing a granular feed
additive, the method including the steps of preparing a basic amino acid aqueous solution
(step a); and injecting carbon dioxide into the basic amino acid aqueous solution to prepare a
neutralized amino acid aqueous solution (step b), wherein the basic amino acid aqueous
30 solution is prepared from a fermentation broth obtained from microbial culture.
According to the method of preparing a granular feed additive according to an aspect,
the prepared granular feed additive may include a high content of basic amino acids, in which
the basic amino acids may be neutralized by injecting carbon dioxide into relieve polarity of
basic amino acids. Accordingly, it is possible to exhibit the effects of reducing an increase
4
in hygroscopicity and a lumping and caking phenomena which are problems caused by the
polarity of basic amino acids.
As used herein, the term “feed additive” may refer to a substance which is added to a
feed in order to improve productivity or to promote health of a target organism. The feed
5 additive may be prepared in various forms known in the art, and may be used individually or
in combination with the existing known feed additives. The feed additive composition may
be added to a feed at an appropriate compositional ratio, and the compositional ratio may be
easily determined by those skilled in the art in light of common sense and experience in the
field. The feed additive composition may be added to a feed for animals such as a chicken,
10 a pig, a monkey, a dog, a cat, a rabbit, a cow, a sheep, a goat, etc., but is not limited thereto.
As used herein, the term “basic amino acid” may be one or more selected from the
group consisting of lysine, arginine, and histidine. The basic amino acid may be one or
more selected from the group consisting of L-lysine, L-arginine, and L-histidine. The basic
amino acid may be in the form of a salt or a free amino acid of lysine, arginine, or histidine.
15 The salt may be a sulfate, hydrochloride, or carbonate, but is not limited thereto. The basic
amino acid has a property of easily binding with water, and may be polar.
As used herein, the term “basic amino acid aqueous solution” may refer to a product
obtained by purifying a fermentation broth including the basic amino acids. Specifically,
the basic amino acid aqueous solution may be obtained by processes of filtering, purifying,
20 and concentrating a fermentation product which is obtained by culturing a bacterial strain
producing the basic amino acids.
The fermentation product may be achieved by culturing the bacterial strain by
fermentation, and the fermentation may be performed by a fed-batch process (feed process), a
batch process, or a repeated fed-batch process (repeated feed process). A fermentation
25 medium to be used may be optimized according to requirements of the production strain.
A concentration of the basic amino acid aqueous solution may be about 450 g/L to
about 650 g/L, for example, about 500 g/L to about 600 g/L, or about 520 g/L to about
580 g/L. pH of the basic amino acid aqueous solution may be about 10 to about 11. A
specific gravity of the basic amino acid aqueous solution may be about 1.10 to about 1.15.
30 A purity of the basic amino acid aqueous solution may be about 90% by weight to 100% by
weight.
The basic amino acid has a property of easily binding with water and may be polar.
Therefore, when the granular feed additive includes a high content of basic amino acids,
polarity of the granules generally increases to generate problems of increased hygroscopicity
5
and agglomeration. However, the granular feed additive prepared by the above preparation
method may include a high content of basic amino acids without the above problems, and the
feed additive may have transport and storage advantages by including the basic amino acids
in the above-mentioned range. The granular feed additive according to one aspect may
5 include 50% by weight to 90% by weight, for example, about 55% by weight to 89.5% by
weight, about 60% by weight to 89% by weight, about 65% by weight to 88.5% by weight,
about 70% by weight to 88% by weight, about 75% by weight to 87% by weight, about 76%
by weight to 86% by weight, about 77% by weight to 85% by weight, about 78% by weight
to 84% by weight, or about 79% by weight to 80% by weight of the basic amino acids, based
10 on the total weight of the granules. According to the method of preparing the granular feed
additive, the granular feed additive having the high content characteristic may be prepared by
using the amino acid aqueous solution which is obtained by purifying and concentrating the
fermentation broth.
In the preparation method, the bacterial strain producing the basic amino acids is not
15 limited to its type, as long as it is able to produce the basic amino acids without departing
from the scope of the present disclosure. Specific examples thereof may include strains of
the genus Corynebacterium.
In addition, the conditions under which the bacterial strain produces the basic amino
acids may be conditions under which the production amount of the basic amino acids is high,
20 but the accumulation amount thereof in the bacterial strain is small.
The fermentation product may be filtered, and specifically, microorganisms may be
separated therefrom using a membrane. Subsequently, the fermentation broth from which
microorganisms are removed may pass through, for example, an ion exchange resin tower,
and as a result, impurities may be removed to purify the basic amino acids. The process of
25 concentrating the purified basic amino acids may be performed by concentrating the
fermentation broth including basic amino acids through, for example, vacuum and/or drying
process.
The “neutralized amino acid aqueous solution” may refer to a neutralized form of the
basic amino acid aqueous solution. Specifically, the neutralized amino acid aqueous
solution may further include HCO3
−
or CO3
2−
30 in addition to the amino acid aqueous solution.
In other words, the neutralized amino acid aqueous solution may be in the form of an amino
acid aqueous solution neutralized by HCO3
−
or CO3
2−
.
In the step of preparing the neutralized amino acid aqueous solution (step b),
neutralization may be performed by injecting carbon dioxide into the basic amino acid
6
aqueous solution. The carbon dioxide may include carbon dioxide generated during the
fermentation process of microorganisms. Specifically, the carbon dioxide may include
carbon dioxide generated in the step of preparing the basic amino acid aqueous solution (step
a). When carbon dioxide is injected into the amino acid aqueous solution, HCO3
−
or CO3
2−
5 is included in the aqueous solution, resulting in the effect of neutralizing basic amino acids.
According to this method, since carbon dioxide generated during fermentation may be used,
carbon dioxide emission may be reduced, and resources may be recycled.
In addition, since a traditional process of using hydrochloric acid for neutralization of
amino acid aqueous solutions may be omitted, the purification process may be simplified.
10 The method of preparing the granular feed additive may further include the step of
preparing a concentrated fermentation broth by concentrating the fermentation broth obtained
by culturing the microorganism (step a-2), after the step of preparing the basic amino acid
aqueous solution (step a).
As used herein, the term “concentrated fermentation broth” may refer to a product
15 obtained by concentrating the fermentation broth including the basic amino acids through
vacuum and/or drying processes. The concentrated fermentation broth may be obtained by
concentrating the fermentation broth, which is obtained by culturing the bacterial strain
producing the basic amino acids, under vacuum and heating without removal of the bacteria
and a purification process such that the total solid content in the fermentation broth is about
20 50% by weight to about 60% by weight, that is, the solid content is about 50% by weight to
about 60% by weight. The “solid content” may refer to the weight of the remainder
resulting from complete removal of liquid.
The method of preparing the granular feed additive may further include the step of
mixing the concentrated fermentation broth and the neutralized amino acid aqueous solution
25 (step b-2), after the step of preparing the neutralized amino acid aqueous solution (step b).
According to one exemplary embodiment, the step of mixing the concentrated
fermentation broth and the neutralized amino acid aqueous solution may be performed such
that a molar ratio of anions to amino acids is more than about 0.19 and 0.62 or less.
After step b, the method of preparing the granular feed additive may further include
30 the step of mixing the concentrated fermentation broth and the neutralized amino acid
aqueous solution (step b-2), thereby more economically improving the purity of amino acids
in granules.
In the method of preparing the granular feed additive, the step of preparing the
neutralized amino acid aqueous solution (step b) may be performed using a bubbling tower, a
7
circulating absorption tower, or a continuous absorption tower. Specifically, in step b, gas
containing carbon dioxide may be injected into the neutralized amino acid aqueous solution
using the above device.
When the step of preparing the neutralized amino acid aqueous solution (step b) may
5 be performed using the bubbling tower, it may be performed for about 1 hour or more, for
example, 1 hour to 15 hours, 1 hour to 12 hours, 2 hours to 15 hours, 2 hours to 12 hours, 3
hours to 15 hours, 3 hours to 12 hours, 3 hours to 11 hours, or 4 hours to 11 hours, but is not
limited thereto, and may be selected within the pH range of the neutralized amino acid
aqueous solution from about 8.5 to about 9.5.
10 When the step of preparing the neutralized amino acid aqueous solution (step b) may
be performed using the circulating absorption tower, gas containing carbon dioxide may be
injected into the absorption tower at a speed of about 700 L/min to about 1500 L/min.
When the step b may be performed using the circulating absorption tower, it may be
performed for about 1 hour or more, for example, 1 hour to 10 hours, 1 hour to 6 hours, 1
15 hour to 4 hours, or 1 hour to 3 hours, but is not limited thereto, and may be selected within
the pH range of the neutralized amino acid aqueous solution from about 8.5 to about 9.5.
In one exemplary embodiment, the circulating absorption tower may be a tray-type
absorption tower.
When the step of preparing the neutralized amino acid aqueous solution (step b) may
20 be performed using the continuous absorption tower, gas containing carbon dioxide may be
injected into the absorption tower at a speed of about 300 L/min to 1500 L/min, or about
400 L/min to 1200 L/min.
When the step b may be performed using the continuous absorption tower, it may be
performed until the neutralized amino acid aqueous solution with predetermined physical
25 properties is discharged in a steady state, and the speed at which the gas containing carbon
dioxide is injected may be controlled such that the pH range of the neutralized amino acid
aqueous solution is from about 8.5 to about 9.5, or the purity range of the neutralized amino
acid aqueous solution is from about 82% by weight to about 89% by weight.
As used herein, the “steady state” is also referred to as a “stationary state”, and refers
30 to a constant state in which the state of the material system does not change over time.
The step of preparing the neutralized amino acid aqueous solution (step b) may be
performed at about 35°C to about 65°C, about 40°C to about 60°C, or about 45°C to about
55°C.
8
pH of the neutralized amino acid aqueous solution may be about 8.5 to about 9.5. A
specific gravity of the neutralized amino acid aqueous solution may be about 1.18 to about
1.22. A purify of the neutralized amino acid aqueous solution may be about 78% by weight
or more, for example, about 78% by weight to about 91% by weight, about 78% by weight to
5 about 89% by weight, or about 80% by weight to about 89% by weight.
The method of preparing the granular feed additive may further include the step of
granulating the neutralized amino acid aqueous solution (step c), after the step of preparing
the neutralized amino acid aqueous solution (step b).
Further, when the method of preparing the granular feed additive may further include
10 the step of mixing the concentrated fermentation broth and the neutralized amino acid
aqueous solution (step b-2) after the step b, the method may further include the step of
granulating the mixture of the concentrated fermentation broth and the neutralized amino acid
aqueous solution (step c-2), after the step b-2.
The step of granulating (step c or c-2) may be performed by, for example,
15 continuously spraying the neutralized amino acid aqueous solution or the mixed solution into
a granulator and continuously supplying hot air so that particles with a predetermined range
of size formed by spraying form a fluidized bed. For this process, a general fluidized bed
circulating granulator, etc. may be used. Granulation conditions may include, for example,
an injection rate of about 5 mL/min to about 10 mL/min, a nozzle pressure of about
1.2 kg/cm2
20 , and a temperature of about 75°C to about 80°C, but are not limited thereto.
In the method of preparing the granular feed additive, the granular feed additive may
include the basic amino acid and an anion represented by the following Formula 1, wherein a
molar ratio of the anion to the basic amino acid may be more than 0.1 and 0.52 or less:
25 [Formula 1]
HnCO3
(2−n)−
(in Formula 1, n is 0 or 1).
The anion represented by Formula 1 may specifically include a bicarbonate ion
(HCO3
−
) or a carbonate ion (CO3
2−
).
30 The anion may be produced by adding carbon dioxide to the aqueous solution
including basic amino acids. Carbon dioxide reacts with hydrogen ions in the aqueous
solution to produce carbonate ions, which may be converted into bicarbonate ions. During
this process, pH of the granular feed additive composition may be reduced or neutralized.
9
Therefore, according to one exemplary embodiment, the granular feed additive may include
the carbonate ion, the bicarbonate ion, or a mixture thereof.
As used herein, the term “molar ratio of the anion to the basic amino acid” may also
be expressed as a molar ratio of the bicarbonate ion or carbonate ion to the basic amino acid,
HCO3
−
/basic amino acid, or CO3
2−
5 /basic amino acid.
When the molar ratio is 0.1 or less, the content of bicarbonate ion or carbonate ion in
the granules is lowered, and the neutralizing effect of the basic amino acids is lowered to
cause a hygroscopicity or solidification problem of the granules. When the molar ratio is
more than about 0.52, there is a problem in that the content of granules is lowered, and the
10 product value is not significantly reduced. In other words, the granular feed additive may
have improved hygroscopicity, as compared to granular feed additives without bicarbonate
ion or carbonate ion.
As used herein, the term “hygroscopicity” refers to the tendency to absorb or retain
water. Since a common granular feed additive, particularly, granular feed additive
15 composition including basic amino acids, has high hygroscopicity, agglomeration increases,
and thus the product value decreases. According to the present disclosure, the product value
of the feed additive may be improved.
The molar ratio may be specifically about 0.15 to about 0.5, or about 0.2 to about 0.45.
The molar ratio may be calculated according to results obtained through high20 performance liquid chromatography (HPLC) after dissolving the granules in water, but is not
limited thereto.
The size of the granules included in the granular feed additive may be selected
according to animal husbandry use.
According to one exemplary embodiment, the average diameter of the granules may
25 be 0.1 mm to 3.0 mm, and according to another exemplary embodiment, it may be 0.5 mm to
3.0 mm, but variations are possible without departing from the object of the present
disclosure. When the average diameter of the granules is less than about 0.1 mm, the degree
of solidification may become severe or dust may be generated. When the average diameter
of the granules is more than about 3.0 mm, a problem of non-uniform mixing may occur
30 during the preparation of feeds.
The granules may have an irregular shape, for example, a spherical shape.
According to one exemplary embodiment, the content of the basic amino acid may be
50% by weight to 90% by weight, based on the total weight of granules.
10
The granular feed additive may be suitable for use in the preparation of animal feeds.
For example, the feed additive as it is may be mixed, as a part of an animal feed premix or as
a precursor of an animal feed, with feed materials.
The granular feed additive may be administered to animals alone or in combination
5 with other feed additives in an edible carrier. In addition, the feed additive may be easily
administered to animals as a top dressing, or by directly mixing with an animal feed, or as an
oral formulation separately from the feed.
Another aspect may provide a granular feed additive prepared by the method of
10 preparing the granular feed additive.
The granular feed additive is the same as described above.
Hereinafter, the present disclosure will be described in more detail with reference to
exemplary embodiments. However, these exemplary embodiments are for illustrative
15 purposes only, and the scope of the present disclosure is not intended to be limited by
exemplary embodiments.
Examples 1 to 6 and Comparative Examples 1 to 6. Preparation of Granular
Feed Additive Using Bubbling Tower and Characterization (1)
20 FIG. 1 illustrates the step of preparing a granular feed additive including a high
content of basic amino acids according to an aspect. Hereinafter, each step will be
described in detail with reference to FIG. 1.
1. Preparation of granular feed additive
25 1.1. Preparation of amino acid mixed solution
According to compositions in Tables 1 to 2, amino acid aqueous solutions and
concentrated fermentation broths were prepared, and they were mixed to prepare mixed
solutions, respectively. In this Example, L-lysine was used as an example of a basic amino
acid. First, each amino acid aqueous solution was prepared by purifying a fermentation
30 broth containing L-lysine. For the production of the fermentation broth, a bacterial strain of
the genus Corynebacterium capable of producing L-lysine was subjected to seed-culture in
25 mL of a seed medium at pH 7.0 at 30°C at 200 rpm for 20 hours. The seed medium
consisted of, based on 1 L of distilled water, 20 g of glucose, 10 g of peptone, 5 g of yeast
extract, 1.5 g of urea, 4 g of KH2PO4, 8 g of K2HPO4, 0.5 g of MgSO4 7H2O, 100 μg of biotin,
11
1 mg of thiamine HCl, 2 mg of calcium pantothenate, and 2 mg of nicotinamide. The
bacterial seed obtained through the seed culture was inoculated at 4% (v/v) in a production
medium at pH 7.0, and cultured with sufficient aeration and agitation at 30°C until the input
glucose was completely consumed to thereby obtain the final fermentation broth. The
5 production medium consisted of, based on 1 L of distilled water, 100 g of glucose, 40 g of
(NH4)2SO4, 2.5 g of soybean protein, 5 g of corn steep solids, 3 g of urea, 1 g of KH2PO4,
0.5 g of MgSO4 7H2O, 100 μg of biotin, 1 mg of thiamine hydrochloride, 2 mg of calcium
pantothenate, 3 mg of nicotinamide, and 30 g of CaCO3. After the culture was completed,
the concentration of L-lysine in the fermentation broth was analyzed using HPLC (Waters,
10 2478). Microorganisms in the fermentation broth were removed using a membrane having a
size of 0.1 μm. In the separation process using the membrane, the pH of the fermentation
broth was adjusted to 4.0 and then heated to 50°C. The fermentation broth from which
microorganisms were removed was passed through a cation exchange resin tower, and Llysine in the fermentation broth was adsorbed onto the resin tower to separate L-lysine from
15 other impurities. The adsorbed L-lysine was desorbed from the resin tower using about 2 N
ammonia water, recovered, heated in a vacuum, and concentrated to prepare an L-lysine
aqueous solution, and when concentrated, the solid material in the aqueous solution was
allowed to be 50% by weight to 60% by weight. After concentration, the concentration of
the L-lysine aqueous solution was 560 g/L, pH thereof was 10.2, a specific gravity thereof
20 was 1.13, and a purity thereof was 99% by weight.
FIG. 2 illustrates a method of neutralizing the amino acid aqueous solution using a
bubbling tower. Hereinafter, each step will be described in detail with reference to FIG. 2.
After 35 kg of the L-lysine aqueous solution was put into a neutralization tank, a gas
containing 5% by volume of carbon dioxide was injected at a temperature of 50°C at
25 1000 L/min under stirring conditions of 500 rpm for 10 hours. The L-lysine concentration
and the bicarbonate ion (HCO3
−
) or carbonate ion (CO3
2−
) concentration in the L-lysine
aqueous solution neutralized by carbon dioxide injection were analyzed using HPLC (Waters,
2478). pH of the neutralized L-lysine aqueous solution was 8.9, a specific gravity thereof
was 1.20, and a purity thereof was 81.6% by weight.
30 The concentrated fermentation broth was prepared by heating and concentrating the
fermentation broth obtained by culturing the bacterial strain of the genus Corynebacterium as
described above without removal of the microorganisms and a purification process. After
concentration, the total solid content in the fermentation broth was allowed to be 50% by
weight to 60% by weight.
12
The L-lysine aqueous solution or the neutralized L-lysine aqueous solution was mixed
with the concentrated fermentation broth according to ratios specified in Tables 1 and 2 to
prepare a mixture. The concentrations of L-lysine and HCO3
−
or CO3
2−
in the mixture were
analyzed using HPLC (Waters, 2478). The results of calculating a molar ratio of HCO3
−
to
5 L-lysine in the mixed solutions of Examples 1 to 6 and Comparative Examples 1 to 6 using
the concentration analysis results are shown in Tables 1 and 2, respectively.
[Table 1]
Example 1 Example 2 Example 3 Example 4 Example 5 Example 6
Neutralize
d L-lysine
aqueous
solution
Concentra
ted
fermentati
on broth
Neutralize
d L-lysine
aqueous
solution
Concentra
ted
fermentati
on broth
Neutralize
d L-lysine
aqueous
solution
Concentra
ted
fermentati
on broth
Neutralize
d L-lysine
aqueous
solution
Concentra
ted
fermentati
on broth
Neutralize
d L-lysine
aqueous
solution
Concentra
ted
fermentati
on broth
Neutralize
d L-lysine
aqueous
solution
Concentra
ted
fermentati
on broth
Lysine ratio in mixed
solution
(%)
100 0 90 10 80 20 70 30 60 40 55 45
Molar ratio of HCO3
−
/Llysine in mixed solution
0.62 0.54 0.43 0.32 0.27 0.19
10 [Table 2]
Comparative
Example 1
Comparative
Example 2
Comparative
Example 3
Comparative
Example 4
Comparative
Example 5
Comparative
Example 6
L-Lysine
aqueous
solution
Concentra
ted
fermentati
on broth
L-Lysine
aqueous
solution
Concentra
ted
fermentati
on broth
L-Lysine
aqueous
solution
Concentra
ted
fermentati
on broth
L-Lysine
aqueous
solution
Concentra
ted
fermentati
on broth
L-Lysine
aqueous
solution
Concentra
ted
fermentati
on broth
L-Lysine
aqueous
solution
Concentrat
ed
fermentatio
n broth
Lysine ratio in mixed
solution
(%)
100 0 90 10 80 20 70 30 60 40 55 45
Molar ratio of HCO3
−
/Llysine in mixed solution
0.04 0.02 0.02 0.05 0.03 0.02
As shown in Table 1, Examples 1 to 6 showed that as the ratio of the L-lysine aqueous
solution decreased and the ratio of the concentrated fermentation broth increased, the molar
ratio of HCO3
−
/L-lysine in the mixed solution decreased.
As shown in Table 2, Comparative Examples 1 to 6 showed no significant change in
the molar ratio of HCO3
−
15 /L-lysine in the mixed solution according to the change in the ratio
of L-lysine aqueous solution.
1.2. Preparation of granular feed additive
Each of the mixed solutions prepared in 1.1. above was granulated. Specifically, the
20 prepared mixed solution was granulated by injecting it into a fluidized bed circulation
13
granulator at 5 mL/min, and spraying it into the granulator at 80°C at a nozzle pressure of
1.2 kg/cm2
. The prepared granules were screened with a size of about 0.5 mm to 3.0 mm
through sieving.
5 2. Characterization of granular feed additive
2.1. Analysis of molar ratio of HCO3
−
to L-lysine and L-lysine content in
granules
To analyze the molar ratio of HCO3
−
to L-lysine and the L-lysine content in the
granules of Examples 1 to 6 and Comparative Examples 1 to 6, a trace amount of granules
10 was dissolved in 1 L of deionized water, followed by HPLC (Waters, 2478), and from the
results, the molar ratio was calculated. The calculation results are shown in Tables 3 and 4
below.
WE CLAIM:
1. A method of preparing a granular feed additive, the method comprising steps of:
preparing a basic amino acid aqueous solution (step a); and
injecting carbon dioxide into the basic amino acid aqueous solution to prepare a
5 neutralized amino acid aqueous solution (step b),
wherein the basic amino acid aqueous solution is prepared from a fermentation
broth obtained from microbial culture.
2. The method of claim 1, wherein the carbon dioxide includes carbon dioxide generated
10 in the step a.
3. The method of claim 1, further comprising a step of preparing a concentrated
fermentation broth by concentrating the fermentation broth (step a-2), after the step a.
15 4. The method of claim 3, further comprising a step of mixing the concentrated
fermentation broth and the neutralized amino acid aqueous solution (step b-2), after the
step b.
5. The method of claim 1, further comprising a step of granulating the neutralized amino
20 acid aqueous solution (step c), after the step b.
6. The method of claim 4, further comprising a step of granulating the mixed solution of
the concentrated fermentation broth and the neutralized amino acid aqueous solution
(step c-2), after the step b-2.
25
7. The method of claim 1, wherein the bacterial strain is a bacterial strain of the genus
Corynebacterium.
8. The method of claim 1, wherein pH of the basic amino acid aqueous solution is 10.0 to
30 11.0.
9. The method of claim 1, wherein a purity of the basic amino acid aqueous solution is 90%
by weight to 100% by weight.
22
10. The method of claim 1, wherein a specific gravity of the basic amino acid aqueous
solution is 1.10 to 1.15.
11. The method of claim 1, wherein the basic amino acid is one or more selected from the
5 group consisting of lysine, arginine, and histidine.
12. The method of claim 1, wherein, in the step b, a bubbling tower, circulating absorption
tower, or continuous absorption tower device is used.
10 13. The method of claim 1, wherein the step b is performed at 35°C to 65°C.
14. The method of claim 1, wherein pH of the neutralized amino acid aqueous solution is
8.5 to 9.5.
15 15. The method of claim 1, wherein a specific gravity of the neutralized amino acid
aqueous solution is 1.18 to 1.22.
16. The method of claim 1, wherein the granular feed additive includes a basic amino acid
and an anion represented by the following Formula 1, and
20 a molar ratio of the anion to the basic amino acid is more than 0.1 and 0.52 or less:
[Formula 1]
HnCO3
(2−n)−
(in Formula 1, n is 0 or 1).
25 17. The method of claim 1, wherein an average diameter of the granules is 0.1 mm to
3.0 mm.
18. The method of claim 1, wherein the content of the basic amino acid is 50% by weight
to 90% by weight, based on the total weight of the granules