JP2001072701A - Manufacture of tapioca starch and production of amino acid by fermentation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for separating and collecting tapioca starch efficiently from cassava roots and an industrially advantageous method for producing amino acids by fermenting the tapioca starch as the starting material. SOLUTION: A tapioca starch manufacturing method is presented, in which cassava roots are crushed in a conventional starch collecting process into 1-10 mm diameter grains, and then ground mechanically into 50 mesh passable granules or subjected to a cellulase-aided enzymatic process after being ground mechanically. Trash is removed from the starch suspension, and starch is finally collected from the starch suspension. An amino acid producing method by fermentation is also presented, in which the thus collected tapioca starch is treated with a starch liquefying enzyme and with saccharogenic amylase for development into a high-concentration saccharide solution usable as the material for an amino acid producing fermentation process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for separating and obtaining tapioca starch with good yield by subjecting cassava potatoes to mechanical grinding or enzymatic treatment, and enzymatic saccharification of the tapioca starch thus obtained and obtained. The present invention relates to a method for producing amino acids by fermentation using a sugar solution as a fermentation raw material.

[0002]

2. Description of the Related Art Tapioca is a starch produced from cassava potato, which is converted into glucose by enzymatic saccharification.
It is used as a main raw material for amino acid fermentation products such as L-glutamic acid monosodium salt and L-lysine.

[0003] Conventionally, tapioca crushes cassava potatoes,
It is manufactured by separating and collecting starch fine particles stored in potatoes from scum such as fibrous material and drying. Generally, the cassava potato (raw potato) as a raw material is 20 to
Tapioca is obtained at a yield of 25%, and at present, almost the same amount of scum is discharged.

[0004] Cassava potatoes are usually crushed by a raspar or the like, but the crushed potato tissue is several hundred to several thousand times larger than starch particles and cannot be said to be sufficient for separating starch particles. No significant improvement in starch yield is observed.

[0005] In order to reproduce the same state as crushing of cassava potato in a laboratory, cassava potatoes were grated with a grater according to a flow sheet shown in FIG. 7, and a starch production experiment was carried out. Each weight of starch and scum was measured to determine the starch yield (extraction rate). Table 1 shows the results of three experiments performed under the same conditions.

[0006]

[Table 1]

[0007] As shown in Table 1, the weight of the starch and the weight of the scum obtained each time are almost the same, and almost the same amount of scum as the product tapioca is discharged from the actual tapioca starch factory. Well matched with the situation.

However, when the starch content of cassava potato was analyzed, 40-45% of the raw potato (water content: about 50%) was starch. Etc. will remain in the residue.
In fact, the scum obtained in the above experiment was used for scanning electron microscopy (SE
M), as shown in FIGS. 5 (400 ×) and FIG. 6 (1000 ×), the SEM photographs show that almost homogeneous and spherical starch granules are present closely and many starch particles are in the form of a film. You can see that it is covered with. In this way, many starch particles remain in the dregs from potatoes grated with a grater,
Since it is covered with a film-like material, even in the usual crushing treatment for collecting starch, similarly, the amount of starch obtained is greatly restricted, and the starch in cassava potato cannot be sufficiently extracted.

[0009]

If the cellulose or hemicellulose in the film covering the starch particles existing in the residue is damaged, cut or decomposed, the starch particles leak out, leading to an improvement in the yield. In turn, it is thought to contribute to a significant cost reduction of the amino acid fermentation industry, and the present invention has been made by paying attention to such a viewpoint, and a method for efficiently separating and obtaining starch from cassava potato and manufacturing and obtaining in this way. An object of the present invention is to provide a fermentative production method for amino acids using tapioca starch as an enzymatic saccharification to form a sugar solution, which is used as a fermentation raw material.

[0010]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors further mechanically grind cassava potatoes which have been subjected to ordinary crushing treatment for starch collection, Alternatively, the cellulase is acted after mechanical grinding to break, cut or decompose the membrane covering the starch particles. As a result, the starch can be efficiently extracted and the yield of tapioca starch is improved. The present invention succeeded in establishing an industrially advantageous amino acid fermentation process using this as a starting material, and completed the present invention.

That is, according to the first aspect of the present invention, cassava potatoes are subjected to a usual crushing treatment for collecting starch, crushed to a particle size of 1 to 10 mm, and then subjected to mechanical grinding to obtain a cassava potato.
After the 0 mesh pass, the starch suspension and scum were separated,
A method for producing tapioca starch, comprising recovering starch from a starch suspension. The invention according to claim 2 is characterized in that cassava potatoes are subjected to a normal crushing treatment for collecting starch to obtain a particle size of 1 to 10 mm. After mechanically grinding, then enzymatic treatment with cellulase, separating the starch suspension and scum, and recovering the starch from the starch suspension. The invention according to claim 3 is a production method, wherein tapioca starch obtained by the production method according to claim 1 or 2 is suspended in water to form a slurry, which is then reacted with starch liquefying enzyme and saccharifying enzyme. This is a fermentation production method for amino acids using the obtained sugar solution as a fermentation raw material.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, the cassava potato used as a raw material may be a peeled potato in addition to a harvested raw potato.
Alternatively, a dried potato may be used. These are pulverized into particles of 1 to 10 mm using a raspar or the like according to a conventional method.
The crushed cassava potatoes are subjected to further mechanical grinding,
Alternatively, cellulase is allowed to act after mechanical grinding.

For the mechanical grinding in the present invention, any method for making the potato tissue finely reduced to 200 μm or less is applied. For example, it can be effectively performed by a different two-stage mechanical grinding treatment such as a combination of "grate with a grater" / "grind with a mortar" shown in the examples described later.

Apparatuses for performing mechanical grinding in large-scale processing on an industrial scale include a homogenizer and a ball mill. A wet pulverizer such as a jet mill can also be used.

[0015] By this grinding treatment, the potato flour crushed to 1 to 10 mm is crushed, and the degree of grinding is preferably 50 mesh pass, particularly preferably 100 mesh pass.

When a cellulase is allowed to act in addition to the mechanical grinding treatment, a commercially available cellulase such as "CELLULASE YC" (trade name, manufactured by Kikkoman Corporation) can be used, and cellulase produced by fungi of the genus Trichoderma can be used. It is preferably used. The amount used may be about 10 or more in terms of filter paper disintegration activity. The reaction is carried out at a temperature in the range of 40-50 ° C. and pH 5-7. The reaction time may be generally 1 to 5 hours.

After mechanical grinding or mechanical grinding / cellulase reaction, the starch suspension is separated from scum, and the starch suspension is subjected to a solid-liquid separation operation such as concentration, filtration or centrifugation. Starch is 35 to 40 based on raw potato
% In a good yield.

For use as a raw material for amino acid fermentation,
The starch liquefaction enzyme and the saccharification enzyme act directly on the starch suspension separated from the scum to liquefy and saccharify the starch. When the starch obtained by separation is used, water is added to prepare a starch suspension, and when a liquefaction enzyme and a saccharification enzyme are allowed to act on the suspension, the starch is liquefied and saccharified to become glucose and solubilized.

The total amount of starch to be liquefied is not added all at once to the liquid containing the liquefying enzyme, but is added in small portions.
Since it can be suspended at a high concentration of 5-55 g / dl,
A high-concentration saccharified solution of 0% can be produced.

A liquefying enzyme, for example, "T-5" (trade name, manufactured by Daiwa Kasei Co., Ltd.) is added so as to be 20 per gram of powder, and the mixture is heated and stirred at 85 to 95 ° C. for 1 hour. After allowing to cool and adjusting the pH to 4.2 with dilute sulfuric acid, the saccharification enzyme, for example, "NC-4.2" [trade name, Amano Pharmaceutical Co., Ltd.]
Co., Ltd.] was added in an amount of 2 to 5 units per 1 g of powder, and heated to 55 to 65 ° C.
Heat and stir for 48 hours to complete the enzyme reaction.

When the starch is suspended in water, liquefaction proceeds more quickly if 20 units / g of powdered liquefaction enzyme are added in advance. The liquefaction and saccharification efficiency is increased by gradually adding the starch powder to the liquefied enzyme-containing solution at 40 to 60 ° C., and the starch having a high concentration (45 to 55 g / dl) is saccharified to form a sugar having a glucose concentration of 40 to 55 g / dl. A liquid can be produced. By this method, more than 95% of the starch can be saccharified.

The present invention is further characterized in that the sugar solution thus obtained is used as a raw material for amino acid fermentation.

The type of amino acid fermentation is not limited. For example, glutamic acid, lysine, methionine, tryptophan,
Threonine, serine, proline, alanine, valine, leucine, phenylalanine, histidine, arginine,
Fermentation of amino acids such as ornithine, glutamine and aspartic acid can be mentioned as an example.

As the microorganism used for these fermentations, those known for each fermentation can be used. An example is as follows. L-glutamic acid fermentation: Brevibacterium lactofermentum ATCC 13869 L-lysine fermentation: Brevibacterium lactofermentum ATCC 21800 L-tryptophan fermentation: Escherichia coli AGX1
7 (PGX44) [NRRL B-12263] L-phenylalanine fermentation: Brevibacterium lactofermentum AJ 12637 (FERM BP-4)
160) See French Patent Application Publication No. 2,686,898 L-Tyrosine fermentation: Brevibacterium lactofermentum AJ 12081 (FERM P-7249) See JP-A-60-70093 L-threonine fermentation: Corynebacterium Um acetoacidophilum AJ 12318 (FERM BP-117)
2) See US Patent No. 5,188,945 L-isoleucine fermentation: Brevibacterium flavum AJ 12149 (FERM BP-759) See US Patent No. 4,656,135.

The medium used for fermentation may be the same as a known medium except that the sugar solution of the present invention is used as a carbon source. The above sugar solution may be used for the entire amount of the carbon source, or may be used for a part thereof. The remaining carbon source when used for one part may be the same as that used conventionally. The fermentation method may be the same as the conventional one.

In the case of amino acids such as lysine, the main use is as feed. Therefore, when lysine or the like is used for the feed, the fermented liquid can be dried as it is to obtain a feed additive.

[0027]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Production of Tapioca Starch 10 g of cassava potatoes are grated using a grater to a size of about several mm. The suspension was suspended in 30 ml of water, and this was ground using a mortar. The processing time was 2 minutes and 15 minutes. It was filtered through a wire mesh of about 40 mesh. The filtrate was combined with treated water obtained by washing the net residue with 20 ml of water, and the combined amount was 300
The mixture was centrifuged at 0 rpm for 10 minutes, and the obtained precipitate (starch) was dried at 60 ° C. for 24 hours under reduced pressure. The residue (waste) on the net was dried under the same conditions.

The obtained results are shown in Table 2. Compared with the results (Table 1) obtained without mechanical grinding using a mortar, the yield of starch increased and the amount of scum decreased. The mechanical treatment for 2 minutes improved the yield by 10.4%, and the mechanical treatment for 15 minutes improved the yield by 32.9%.

[0030]

[Table 2]

FIG. 1 (400 ×), FIG. 2 (1000 ×)
Shown in Even in this case, a state in which a considerable amount of starch particles remain is observed. However, as compared with the results obtained without mechanical grinding (FIGS. 5 and 6), a film-like shape covering the starch particles in some places was obtained. It can be seen that the material has been torn or torn away.

Example 2 Production of Tapioca Starch In Example 1, a suspension of cassava potatoes grated using a grater was subjected to a grinding treatment for 2 minutes using a mortar, and the results are shown in Table 3 below. Enzyme treatment was performed under the conditions, and the subsequent operation of separating starch and scum was performed in the same manner as in Example 1. Table 4 shows the obtained results.

[0033]

[Table 3] Note) *: Cellulase is "CELLULASE YC"
(Trade name, manufactured by Kikkoman Corporation) was used. **: Pullulanase is "DEXTROZYME plu"
s L "(trade name, manufactured by Novo) was used.

[0034]

[Table 4]

From the results shown in Table 4, it was found that the addition of cellulase treatment increased the amount of starch, decreased the amount of scum, and improved the yield in the same manner as in Example 1. In pullulanase (starch debranching enzyme) treatment, which acts on pulp, no significant effect was observed on the yield and yield of starch over the improvement by mechanical treatment.

SEM photographs of the residue after cellulase treatment are shown in FIG. 3 (400 times) and FIG.
Times). The cellulase treatment removes the film-like substance covering the starch particles as in the mechanical grinding treatment,
The remaining film is also very thin. From this, it is considered that this film-like substance was dissolved by the cellulase.

Reference Example 1 Production of Sugar Solution 450 g of tapioca starch obtained in Example 1 was suspended in water and adjusted to a total volume of 1 L. While stirring this 85
C., and 1.5 ml of liquefaction enzyme "T-5" was added.
The liquefaction reaction was performed for 1 hour. After the completion of liquefaction, when the temperature was cooled to 60 ° C., the pH was adjusted to 4.5 with dilute sulfuric acid, and 0.5 ml of saccharifying enzyme “NC-4.2” was added. The saccharification reaction is
This was performed by shaking and stirring at 60 ° C. for 48 hours. The glucose concentration in the sugar solution was 44.5 g / dl (saccharification rate 97%).

Example 3 L-glutamic acid fermentation medium contains 60 g / L of commercially available glucose and MgSO ₄
1 g / L, KH ₂ PO ₄ 1 g / L, soybean protein acid hydrolyzate 1
Substrate solution 2 containing 5 ml / L and biotin 300 μg / L
70 ml of the mixture was sterilized by heating at 120 ° C. for 15 minutes, and then filled into an S-shaped jar.

Glutamate-producing bacterium Brevibacterium lactofermentum (AT
CC 13869) and a total volume of 30 ml.
The volume was 0 ml, and the fermentation was started. Fermentation is 1 to 1.2 krp
m and agitation at 1/1 vvm, and the pH was maintained at 7.5 with ammonia. The fermentation temperature was set at 30 ° C., and 5 hours after the start of the culture, polyoxyethylene sorbitan monopalmitate was added to a concentration of 2000 mg / L.

The sugar solution obtained in Reference Example 1 was diluted to 42 g / dl in terms of glucose at 120 ° C.
For 15 minutes. The sugar solution was prepared by adding polyoxyethylene sorbitan monopalmitate to a concentration of 2000 mg / L, and reducing the sugar concentration in the fermentation solution to 1 as a substrate solution.
連 続 2 g / dl was continuously supplied. As a result of the fermentation, the yield was 56%.

The fermented liquor obtained above was subjected to membrane separation using a commercially available hollow fiber pencil type membrane module. Hydrochloric acid was added to the membrane permeate to adjust the pH to 3.2, and glutamic acid crystals were separated by crystallization.

Fermentation example 2: L-lysine fermentation Commercially available glucose 30 g / L, ammonium chloride 10 g
/ L, urea 3g / L, KH ₂PO₄1g / L, MgSO₄・
7H₂O100mg / L, FeSO₄・ 7H₂O10m
g / L, MnSO₄・ 4H₂O8mg / L, soy protein acid
Hydrolyzate (as nitrogen) 1 g / L, thiamine hydrochloride
Contains 0.1 mg / L and biotin 0.3 mg / L
The medium (pH 7.0) was added to a 500 ml shake flask 3
20 mL each was dispensed into the book. Heat at 115 ° C for 10 minutes
After sterilization, add this medium to a broth slant for 48 hours in advance.
Brevibacterium lactofermentum grown
(ATCC 21800) inoculated with one platinum loop and 31.5 ° C
For 24 hours. The above is a seed culture. Molasses
80g / L, ammonium sulfate 50g / L, KH ₂P
O₄1g / L, MgSO₄・ 7H₂O1g / L, soybeans
White matter hydrolyzate (as nitrogen) 100mg / L, Sia
Min hydrochloride 0.1 mg / L and biotin 0.3 mg / L
L-containing medium (pH 7.0) was added to three 1-L glassware.
Into small fermenters made of stainless steel at 300 ° C for 15 minutes.
Heat sterilization for minutes. After cooling to 31.5 ° C,
The sco culture end solution is added at a rate of 15 mL per fermenter,
Temperature 31.5 ° C, aeration rate 1 / 2vvm, stirring number 700r
Culture was performed under pm conditions. The sugar concentration in the culture solution is 5 g /
Start feeding the feed medium from the point when the volume falls below L
did. For the culture medium, the sugar solution obtained in Reference Example 1 was converted to glucose.
Sugar solution, soy protein adjusted to 40 g / dl with
Hydrolysate (100 mg / L as nitrogen), thiamine
Hydrochloride (0.1 mg / L) and biotin (0.3 mg / L
L). Sugar concentration in culture solution is 5g / L or less
While adjusting the feed speed of the feed medium so that
Continue culturing and finish feeding 100mL of feed medium
After that, the culture is terminated when the sugar in the culture solution has been consumed.
Then, the concentration of L-lysine accumulated in the culture solution was quantified. Culture
As a result of the nutrition, the yield was 35%.

[0043]

According to the present invention, a part of the film-like substance is destroyed by further mechanical grinding in addition to the usual crushing, and the starch particles wrapped therein are extracted. The yield improved accordingly. In addition, by performing cellulase treatment in addition to mechanical attrition treatment, this film-like substance is decomposed, and most starch particles are extracted.
The advantage that the yield is greatly improved can be enjoyed. By continuously liquefying and saccharifying the starch, a sugar solution having a high concentration of 40% or more can be efficiently produced, and amino acids can be obtained at a high yield using the sugar solution. As described above, according to the present invention, most of cassava starch can be saccharified and used as a raw material for amino acid fermentation.

[Brief description of the drawings]

FIG. 1 Mechanical grinding treatment in Example 1 (15 minutes)
Shows a SEM photograph (× 400) of the residue obtained by performing the above.

FIG. 2 shows a mechanical grinding treatment in Example 1 (15 minutes).
A SEM photograph (1000 times) of the residue obtained by performing the above is shown.

FIG. 3 shows an SEM photograph (× 400) of a residue obtained by performing a cellulase treatment in Example 2.

FIG. 4 shows an SEM photograph (× 1000) of a scum obtained by performing a cellulase treatment in Example 2.

FIG. 5 is an SEM photograph (400) of a waste in a comparative example.
Times).

FIG. 6 is an SEM photograph (1000
Times).

FIG. 7 is a flow sheet showing an example of producing starch and scum from cassava potatoes.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C12S 3/02 C12S 3/02 (72) Inventor Yasushi Yamamoto 1-15-1, Kyobashi, Chuo-ku, Tokyo Ajinomoto Co., Inc. F term (reference) 4B064 AE19 AE25 AF12 CA02 CA21 CB07 CE06 DA10 4C090 AA04 BA13 BC10 CA01 DA27

Claims (3)

[Claims] 1. A cassava potato is subjected to a usual crushing treatment for collecting starch, crushed to a particle size of 1 to 10 mm, and then mechanically ground to a 50-mesh pass. And recovering the starch from the starch suspension. 2. The method for producing tapioca starch according to claim 1, wherein after mechanical grinding, an enzymatic treatment with cellulase is performed. 3. Tapioca starch obtained by the method according to claim 1 or 2 is suspended in water to form a slurry,
A fermentative production method for amino acids using a sugar liquid produced by allowing a starch liquefying enzyme and a saccharifying enzyme to act on the fermented raw material.