JP2002105848A - Method for scouring cellulosic fiber using xylanase - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for scouring cellulosic fibers with an enzymic solution containing a xylanase. SOLUTION: This method for scouring the cellulosic fibers comprises a step of treating the cellulosic fibers with the enzymic solution containing the xylanase. In the method, a treatment with another enzyme such as a pectinase may be used in addition to the treatment with the xylanase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for refining cellulosic fibers.

[0002]

2. Description of the Related Art Cellulosic fibers represented by cotton fibers are composed of a secondary membrane and a primary membrane which covers this membrane via a winding layer. The primary membrane is composed of a cuticle layer containing wax, pectin and protein as main components, and the secondary membrane is composed of cellulose (Yasuo Ohno, "Fiber and Industry", Vol. 4, 325 (1971)). Before dyeing unprocessed cotton fiber, cotton fiber-containing fiber and its processed product, it is necessary to remove the primary film to give water absorption and to improve the dyeability and other processability by decolorizing. There is. This operation is called scouring.

[0003] Refining is conventionally performed by immersing fibers in sodium hydroxide to which an auxiliary agent such as a surfactant is added, and
(90 ° C. or higher). But,
This method is costly, such as high energy consumption and the need for wastewater neutralization. Further, improvement of the process is also desired from the viewpoint of environmental protection and energy saving, which are the current social needs.

[0004] From such a viewpoint, a scouring method using an enzyme has been proposed (Ryohei Yamamoto, "Dyeing Industry", Vol. 48, No. 6).
4 (2000)). Pectin-degrading enzymes are mainly used as enzymes, and scouring can be performed under mild conditions (about 50 to 65 ° C.) near neutrality. Low energy costs and no need for wastewater neutralization. In addition, in the treatment with sodium hydroxide, a large amount of neutralized salt is generated due to the neutralization of the waste liquid, which is discharged into rivers. However, the wastewater component when enzymes are used is mainly composed of biodegradable organic substances. It can be completely purified by equipment.

However, the method using an enzyme is mild,
The removal rate of impurities in the primary film is not always good. Therefore, a method of adding a cellulose-decomposing enzyme to a pectin-degrading enzyme or a method of adding an oil-and-fat-degrading enzyme (Japanese Patent Application Laid-Open No. 8-1279)
60) have been attempted. However, when a cellulase having a high cellulose decomposing ability is used, there is a problem that the strength of the fiber is reduced due to the decomposition of the cellulose. In addition, fat-decomposing enzymes decompose wax to improve water absorption,
Other impurities are not removed.

[0006] Xylan degrading enzymes have been proposed for use in the bleaching treatment of paper pulp, and have been actively studied. Xylan-degrading enzymes produced by several microorganisms have been isolated and purified, and their properties have been investigated in detail. However, the idea of the present invention of using xylan-degrading enzymes for refining cellulosic fibers has not been disclosed or suggested at all.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for effectively scouring cellulosic fibers.

[0008]

The present invention provides a method for treating a cellulosic fiber using an enzyme solution containing a xylan-degrading enzyme.
Provided is a method for refining cellulosic fibers.

[0009] In the method of the present invention, it is preferable to treat with another enzyme, for example, a pectin-degrading enzyme, in addition to the xylan-degrading enzyme. When using another enzyme, the treatment with the other enzyme should be performed before the treatment with the xylan-degrading enzyme.
It may be performed at any later stage, or may be scoured with an enzyme solution containing both the xylan-degrading enzyme and the other enzyme at the same time.

The xylan-degrading enzyme used in the method of the present invention is not particularly limited, and any known or commercially available xylan-degrading enzyme may be used. In particular, by using a heat-resistant enzyme and treating at a relatively high treatment temperature of 50 to 70 ° C., scouring can be performed efficiently.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Cellulose fibers which can be scoured according to the present invention are not particularly limited, and general fibers can be used. For example, cotton fiber, rayon,
Vegetable fibers such as hemp and hemp are exemplified. Further, the scouring method of the present invention can be applied to such fibers and processed products thereof, that is, yarns, woven fabrics, knitted fabrics, and nonwoven fabrics. Further, the present invention can be applied to a blended or interwoven fiber material composed of a combination with one or more non-cellulosic fibers.

[0012] The xylan-degrading enzyme used in the method of the present invention is not particularly limited.
izophyllum commune), Aspergillus
Genus, Trichoderma, Aureobasidium, Streptomyces
Genus, genus Chainia, genus Bacillus, genus Pseudomonas, ruminococcus (Rumino
All those extracted from cultures of microorganisms such as filamentous fungi of the genus Coccus) or bacteria are preferably used.

The xylan-degrading enzyme used in the present invention comprises:
The microorganism can be obtained by culturing the microorganism in an appropriate medium, and isolating and purifying from the culture. Regarding the culture conditions of the microorganism and the method of isolating the xylan-degrading enzyme, those reported for each microorganism may be appropriately employed. Moreover, you may use a commercial thing as a xylan decomposing enzyme.

In the method of the present invention, it is particularly preferable to use a thermostable xylan-degrading enzyme, for example, an operating temperature of 50 to 90.
A thermostable enzyme having an extremely high temperature range of 70 to 80 ° C is used. Such a thermostable xylan enzyme is disclosed in, for example, JP-A-8-224081. Bacillus sp. 2113 disclosed in the official gazette (Department No. FERM, Biotechnology and Industrial Technology Research Institute, Ministry of International Trade and Industry)
BP-5264) and Bacillus SP 208 (Accession No. F, Biotechnology and Industrial Technology Research Institute, Ministry of International Trade and Industry)
A thermostable enzyme produced by ERM BP-5321) is suitably used in the method of the present invention. Further, the enzyme produced by the genetically modified product disclosed in the publication also includes
It is suitably used in the present invention.

In the method of the present invention, an enzyme solution containing a xylan-degrading enzyme is allowed to act on cellulosic fibers. In order to cause the enzyme solution containing the xylan-decomposing enzyme to act on the cellulosic fiber, any conventionally known method may be used. Examples of the method include immersing the fiber to be treated in the enzyme solution, passing the fiber to be treated through the enzyme solution, and spraying the enzyme solution.

When an enzyme solution containing a xylan-decomposing enzyme is allowed to act, scouring treatment can be performed using a device conventionally used for scouring fibers, such as a batch scouring device or a continuous scouring device.

In the method of the present invention, the enzyme solution containing the xylan-degrading enzyme contains 1 to 100 xylan-degrading enzymes.
It is preferable that the content is unit / ml, particularly 1 to 10 unit / ml. Here, one unit of the xylan-degrading enzyme is the amount of the enzyme that releases 1 micromol of xylose per minute from the xylan.

In the present invention, the conditions for treatment with the xylan-decomposing enzyme may be appropriately determined in consideration of the stability of the enzyme used, the optimum pH, economy, and the like, but it is usually preferable to perform the treatment under the following conditions.

PH of enzyme solution containing xylan-degrading enzyme
Is preferably 3 to 10, particularly preferably 3 to 8. For pH adjustment, a buffer well known to those skilled in the art, such as a phosphate buffer, a Tris buffer, and a glycine-NaOH buffer, may be used as a medium for the enzyme solution.

The temperature of the enzyme solution at the time of the treatment may be appropriately selected depending on the type of the enzyme.
Preferably, the treatment is performed at 0 to 70 ° C. When a heat-resistant enzyme is used, the optimal temperature of the enzyme, for example, 70 to 80 ° C.
May be processed. The treatment time is appropriately selected depending on the treatment temperature, the titer of the enzyme to be used, and its concentration.
~ 60 minutes.

In the method of the present invention, when treating a glued material such as a cotton fabric, a pretreatment is performed before scouring to remove the glue, or a scouring is performed using an enzyme solution to which a desizing agent is added. May be. As the desizing agent, any of those used in ordinary desizing processes are preferably used, and α
-Amylase-containing enzyme preparations.

The enzyme solution containing the xylan-degrading enzyme of the present invention may contain a chelating agent. The chelating agent is not particularly limited as long as it is a substance having an effect of sequestering a metal ion. For example, ethylenediaminetetraacetic acid, ethylene glycol bis (2-aminoethyl ether) tetraacetic acid,
Examples include diethylenetriaminepentaacetic acid, hydroxyethylenediaminetriacetic acid, citric acid, and nitrilotriacetic acid.

The enzyme solution containing the xylan-degrading enzyme of the present invention preferably contains a surfactant. Examples of the surfactant include anionic, cationic, nonionic and amphoteric surfactants, and nonionic surfactants are particularly preferably used. Surfactants are usually 0.01% to 3% (w /
v), more preferably 0.1% to 1% (w / v).

The enzyme solution containing the xylan-degrading enzyme of the present invention may further contain components conventionally added at the time of refining cellulose-containing fibers as long as the effects of the present invention are not affected. Examples of such components include small amounts of organic solvents (ethanol, methanol, glycerin, etc.).

Further, other auxiliaries for improving the scouring effect may be added. The auxiliary agent is not particularly limited as long as it is conventionally used in enzyme scouring.

In the scouring method of the present invention, a xylan-decomposing enzyme may be used in combination with one or more other enzymes. As the enzyme used in combination, any enzyme conventionally used for refining cellulosic fibers is suitably used, and examples thereof include pectin-degrading enzyme, fat / oil-degrading enzyme, and exo-type cellulose-degrading enzyme. These other enzymes may be appropriately selected from commercially available enzymes and used, or may be appropriately separated from a culture of a known microorganism producing each enzyme.

Particularly preferred are pectin degrading enzymes. As the pectin-degrading enzyme, any derived from a filamentous fungus such as Aspergillus, a bacterium such as Bacillus, or a yeast is preferably used. Various pectin-degrading enzymes are commercially available, and preferred ones may be selected from these commercially available enzymes, or may be used by isolating them from appropriately cultured known pectin-degrading enzyme-producing microorganisms.

In the scouring method of the present invention, when an enzyme other than the xylan-degrading enzyme is used in combination with the xylan-degrading enzyme, the treatment with the other enzyme is performed before or after the treatment with the enzyme solution containing the xylan-degrading enzyme. Alternatively, the enzyme may be added to an enzyme solution containing the xylan-degrading enzyme at the same time and subjected to the treatment.

When enzymes other than xylan-decomposing enzymes are used in combination, the concentration of the enzyme solution containing each enzyme depends on the type and condition of the fiber to be treated, and may be a concentration that can be suitably scoured, or an appropriate concentration from an economic viewpoint. May be selected, and there is no particular limitation.

For example, when pectinase is used, 1
The concentration is preferably from 0 to 1000 units / ml. Here, one unit of pectinase is an amount defined as an amount of an enzyme that degrades the albedo layer of lemon peel and releases pectin in an amount corresponding to 1 micromol of galacturonic acid per hour. When a commercially available pectin-degrading enzyme is used, it may be used after diluting it 100- to 10000-fold.

When an enzyme other than the xylan-degrading enzyme is used in combination, the enzyme solution containing the enzyme may contain an additive as described for the enzyme solution containing the xylan-degrading enzyme. The processing conditions may be appropriately selected according to each enzyme used.

The cellulosic fiber treated by the method of the present invention may be washed, dried and used as it is, subjected to a dyeing treatment, or subjected to a bleaching treatment if necessary. . According to the method of the present invention, under mild conditions similar to those of conventionally known enzyme treatments,
The pectin of the cellulosic fiber can be removed at a higher pectin removal rate than before.

Hereinafter, the present invention will be described in more detail with reference to examples. Preparation of xylan degrading enzyme: xylan (derived from hippopotamus, manufactured by Sigma) 0.6%, peptone 0.5%, yeast extract 0.5
%, K ₂ HPO ₄ 0.1%, MgSO ₄ .7H ₂ O 0.02
% Of a liquid medium (pH 7) was taken in a test tube having an inner diameter of 25 mm, stoppered with paper, and then sterilized with steam at 121 ° C. for 15 minutes. Here Bacillus SP 208 (Institute of Biotechnology, Institute of Industrial Science and Technology, Ministry of International Trade and Industry, accession number FERM
BP-5321) was inoculated with one platinum loop and cultured at 45 ° C. with reciprocal shaking (amplitude 25 mm, 300 reciprocations / minute). After the completion of the culture, the culture supernatant was separated by centrifugation (10,000 rpm × 10 minutes) to obtain a crude enzyme solution of thermostable xylanase. The activity of the obtained thermostable xylanase was measured by the following method.

Measurement of enzyme activity 1% xylan solution (beechwood xylan, Sigma 1 /
10 Mcllveine Buffer pH 6.3)
500 μl of the enzyme solution was added to 200 μl, and reacted at 70 ° C. for 5 minutes. 500 μl of DNS reagent was added and 5
After boiling for 1 minute, the mixture was immediately cooled on ice, 4 ml of distilled water was added, and the absorbance at 500 nm was measured. The amount of xylose in the solution was calculated based on a calibration curve prepared using xylose of a known concentration.

The xylanase activity represents the amount of an enzyme that produces 1 micromole of reducing sugar per minute under these conditions as one unit. Thermostable xylanase activity in the culture supernatant
400 U / ml 24 hours after the start of culture, 5 U after 48 hours
It was 00 U / ml. The obtained xylan degrading enzyme is
It was used in the following examples.

[0036]

EXAMPLE 1 One meter (220 g) of a 100% cotton fabric was treated with a desizing agent. This is added to a 20 mM phosphate buffer (pH
Pectin degrading enzyme (100
(Unit / ml) (Protopectinase Nagase, Nagase Seikagaku Corporation) and a surfactant (Sunmol BK-57N)
M, Nichika Chemical Co., Ltd.) was immersed in 2 liters of an enzyme solution containing 0.1%, and stirred at 55 ° C. for 30 minutes.

3 units / ml of xylan-degrading enzyme and a surfactant (Sunmol BK-57NM, Nichika Chemical Co., Ltd.)
A xylan-degrading enzyme-containing enzyme solution containing 0.1% in 20 mM phosphate buffer (pH 6) was prepared. A cotton cloth treated with an enzyme solution containing a pectin-degrading enzyme was immersed in 2 liters of the enzyme solution and stirred at 70 ° C. for 60 minutes. After the treatment, the cotton cloth was thoroughly washed with water and air-dried.

[0038]

Comparative Example 1 Using the enzyme solution containing the pectin-degrading enzyme and the xylan-degrading enzyme used in Example 1 alone, the same desizing cotton cloth as in Example 1 was treated with only one of the xylan-degrading enzyme and the pectin-degrading enzyme. , Under the same conditions as in Example 1.

Measurement of Pectin Content Each cotton cloth obtained in the unrefined, Example 1, and Comparative Example 1 was immersed in a 0.02% by weight ruthenium red aqueous solution at a bath ratio of 1:40, and at 30 ° C. for 10 minutes at 80 rpm. After dyeing by reciprocal shaking, the plate was lightly washed with water and shaken at 100 rpm in a 50 ° C. water bath at a bath ratio of 1:80 for 30 minutes. After dyeing, the cotton cloth is air-dried and the reflectance of visible light of 540 nm is measured by a spectrophotometer.
(U-4000 type self-recording spectrophotometer, manufactured by Hitachi, Ltd.), and the dyeing amount K / S (here,
K / S = (1−reflectance) ² / reflectance × 2. ) Was calculated and used as the amount of pectin. For comparison, 40 g of the same cotton cloth as in Example 1 was applied to a 1% aqueous sodium hydroxide solution 3.
The amount of pectin was measured in the same manner as in cotton cloth immersed in 2 L and subjected to stirring at 90 ° C. for 30 minutes to remove impurities, and in unrefined woven fabric.

Example 1 Assuming that the amount of pectin in the unrefined fabric is 100 and the amount of pectin in the cloth treated with sodium hydroxide is 0,
And the pectin removal rate by the scouring treatment of Comparative Example 1 was calculated. The higher the pectin removal rate, the higher the scouring degree.

The pectin removal rate of the cotton cloth treated in Example 1 was 85%. Of the cotton cloth treated in Comparative Example 1,
The pectin removal rate of the cotton cloth treated with the xylan-decomposing enzyme alone was 45%, and the removal rate by the pectin-degrading enzyme was 61%.

[0042]

Example 2 1 m (220 g) of a 100% cotton fabric was treated with a desizing agent in a conventional manner. This is added to 20 mM acetate buffer
(pH 5) Into 2 L, the same xylan degrading enzyme as in Example 1
(5 units / ml) and pectin-degrading enzyme (Pectinex, Novo Nordisk Bioindustry) (3 g)
/ L), a surfactant (Sunmol BK-57NM, Nichika Chemical Co., Ltd.) (1 g / l) and 1 mM of EDTA were added, and the desiccated fabric was added thereto, followed by stirring at 55 ° C for 45 minutes. The pectin removal rate of the treated cotton cloth was measured in the same manner as in Example 1, and it was 81%.

[0043]

Comparative Example 2 Same 20 mM acetate buffer (pH 5) containing 1 g / l of the same surfactant and 1 mM of EDTA as in Example 2.
The treatment was carried out under the same conditions as in Example 2 using an enzyme solution in which 2 units / ml of xylan-degrading enzyme and 3 g / l of pectin-degrading enzyme were independently added. The pectin removal rate of the treated cotton cloth was measured in the same manner as in Example 1. The pectin removal rate of the xylan-degrading enzyme alone was 40%.
%, Pectin removal rate by treatment with pectinolytic enzyme alone is 5%
8%.

[0044]

Example 3 The same cotton fabric as in Example 1 was treated with a desizing agent by a conventional method. Remove the cotton cloth after desizing with 20 mM phosphate buffer.
Pectinolytic enzyme solution diluted 2000 times (pH 8)
(Protopectinase Nagase, Nagase Seikagaku Corporation) 2
L, and stirred at 55 ° C. for 30 minutes.

The woven fabric is taken out, and then 3 units / ml of xylan-degrading enzyme and a surfactant (Sunmol BK-57NM, Nichika Chemical Co., Ltd.) in 20 mM phosphate buffer (pH 6).
Immerse in 2 L of an enzyme solution containing 0.1%,
The mixture was stirred for minutes. After the treatment, after the treatment, each cotton cloth was sufficiently washed with water and air-dried, and then the water absorption rate ratio was measured.

Comparative Example 3 Using the enzyme solution containing the pectin-degrading enzyme and the xylan-degrading enzyme used in Example 3 alone, the same desizing cotton cloth as in Example 1 was treated with either the xylan-degrading enzyme or the pectin-degrading enzyme. Processed. After treatment, thoroughly wash each cotton cloth with water and air-dry,
The water absorption speed ratio was measured.

Measurement of Water Absorption Rate Ratio The water absorption rate was the time during which the cotton cloth was brought into contact with the water surface and the water rose to a height of 3 cm. The water absorption rate ratio was the same as the water absorption rate of the cotton cloth treated in Example 3 except that 40 g of the same cotton cloth was immersed in 3.2 L of a 1% aqueous solution of sodium hydroxide and subjected to stirring at 90 ° C. for 30 minutes to remove impurities. It is divided by the water absorption rate, and the reciprocal is multiplied by 100. The higher the water absorption speed ratio, the higher the scouring degree.

The water absorption speed ratio of the woven fabric refined in Example 3 is 7
8%. In Comparative Example 3, the woven fabric scoured with each enzyme alone was 40% by xylan-decomposing enzyme alone and 63% by pectin-degrading enzyme alone.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukitoshi Maeda 14-5 Shimogita-cho, Neyagawa-shi, Osaka Kurashiki Textile Co., Ltd. C-103 (72) Inventor Jun Sugiura 1 Oji Paper Company Building 402, Miyazaki-ku, Miyazaki-ku, Kawasaki City, Kanagawa Prefecture

Claims (5)

[Claims] 1. A method for refining cellulosic fibers, comprising the step of treating cellulosic fibers with an enzyme solution containing xylan-degrading enzymes. 2. The xylan-degrading enzyme is added in an amount of 1 to 100 units /
2. The method according to claim 1, wherein the cellulosic fiber is treated using an enzyme solution containing 0.1 ml. 3. The method according to claim 1, further comprising treating the cellulosic fiber with an enzyme solution containing a pectin-degrading enzyme. 4. An enzyme solution containing xylan-degrading enzyme,
The method according to any one of claims 1 to 3, wherein H is 3 to 8. 5. The xylan degrading enzyme is a thermostable enzyme,
Performing the treatment of the cellulosic fibers at a temperature of 50 to 80 ° C.,
The method according to claim 1.