JPH03220388A - Production of pulp - Google Patents

Abstract

PURPOSE:To accomplish pulping and bleaching causing no cellulose consumption and without the need for adding nutrient sources and/or cellulose degradation inhibitor by performing a biological treatment of wood chips, etc., using microorganisms capable of favorably growing in a culture medium with lignin as carbon source. CONSTITUTION:The objective pulp can be obtained by biological treatment of (A) wood chips put to chemical treatment or (B) pulp produced by refining the above chips using microorganisms capable of favorably growing in a culture medium with lignin as the sole carbon source [e.g. NK-1148 strain (FERM BP-1859), NK-729W (FERM BP-1860)].

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing pulp by pulping or bleaching by microbial treatment.

More specifically, the present invention relates to a method for producing pulp by pulping or bleaching by microbial treatment using microorganisms that grow well in a medium containing lignin as the sole carbon source.

In the present invention, during the pulp manufacturing process, by performing microbial treatment using microorganisms that grow well in a medium with lignin as the only carbon source, the consumption of cellulose can be minimized and excellent pulp can be manufactured. This made it possible.

(Prior Art and Problems) In general, many studies have been conducted for a long time regarding pulping or bleaching in the production of paper and pulp using microorganisms.

JP-A-50-46903 proposes a method for producing cellulose pulp by decomposing lignin using microorganisms capable of producing lignin-degrading enzymes under conditions that substantially decompose lignin.

However, in this method, the lignin decomposition activity of the microorganisms used is extremely weak and the lignin decomposition rate is low, and sugars and nitrogen compounds are added to suppress the microorganisms from assimilating cellulose. It has not yet reached industrial implementation.

Also, Phanerochaete chrysos
Bleaching of pulp due to porium has been reported (Bi
otechnol Lett,, 1347-353 (
(1979)), but the lignin decomposition activity is weak and a large amount of cellulose decomposition inhibitor is used, so it has not been implemented industrially.

Furthermore, bleaching by Coriolus versicolor was reported (May 1989 Tappi
Journal 217-220), but this method also has a high ability to assimilate cellulose, consumes a considerable amount of cellulose, and requires the addition of a large amount of bacterial culture using a nitrogen source and glucose. It has not yet been implemented industrially.

(Means for Solving the Problems) The present inventors have discovered that cellulose is not consumed in pulping or bleaching by microbial treatment, and
As a result of intensive research in search of a treatment method without adding nutrients or cellulose decomposition inhibitors, the present invention was able to achieve the objective.

That is, in the present invention, if microorganisms that grow well in a medium containing lignin as the sole carbon source are used, wood chips, pulp after refining, and unbleached pulp can be used as a substantial nutrient source or cellulose decomposition inhibitor. This makes it possible to perform pulping and/or bleaching in an extremely energy-saving and inexpensive manner without adding any additives.

The microorganisms used in the present invention are strains that were inoculated and cultured in a medium containing lignin as the sole carbon source and grew well.

As a medium, 1 to 10% of lignin is used as the sole carbon source.
%, preferably 2 to 4%, is prepared.

If an isolated source collected from nature is dispersed in this medium at an appropriate concentration and cultured at 25 to 35°C, and a colony showing good growth is collected, this becomes an effective microorganism for use in the present invention.

The present inventors have already developed the NK-1148 strain (FERM BP
-1859) and NK-7291 strain (FERM BP-1
860), etc., and these are extremely effective microorganisms in the present invention.

The mycological properties of the 1148 strain (FERM BP-1859) are as follows.

(1) Growth status in the medium Note-1 Medium p) l: 5.0 (before autoclave sterilization) Note-2 Culture conditions = 28°C x 7 days Note-3 Growth status Weak: + Moderate: ++ Vigorous: 10++ ( 2) Physiological and ecological properties■ Growth pH range (potato/glucose agar medium,
(Culture at 28°C for 4 days) It grows around pH 3 to 9 and does not grow at pH 2 and 10. The optimum pH is around 4-6.

() Temperature range of growth (potato glucose agar medium, pH 5, 4-day culture) Grows at around 10-45°C and does not grow at 50°C.

The optimum temperature is around 28-37°C.

■ Phenol oxidase reaction (cultured at 28°C for 4 days) Shows weak or negative results.

■Characteristics of bacterial flora (potato/glucose agar medium, PH
5. Cultured at 28°C for 4 days) It is white and felt-like.

In addition, NK-7291 strain (FERM BP-1860)
(7) Mycological properties are as follows.

(L) Growth status in medium Note-1 Medium pH: 5.0 (before autoclave sterilization) Note-
2 Culture conditions: 28°C x 7 daysNote-3 Growth status: weak: moderate: ++ vigorous: +++ (2) Physiological and ecological properties■ Growth pH range (potato/glucose agar medium,
28° C., 4 days of culture) It grows at around pH 3 to 7, and does not grow at pH 2 and 8. The optimum pH is around 4-5.

(2. Temperature range for growth (potato/glucose agar medium,
(pH 5, culture for 4 days) It grows at around 10-32°C and does not grow at 37°C.

The optimum temperature is around 20-30°C.

■ Phenol oxidase reaction (28°C, cultured for 4 days) Shows positive.

■ Shape of bacterial flora (potato/glucose agar medium, pH
5.28°C, 4 days of culture) White and hairy.

■ Shape and size of fruiting body: Diameter 2-5+ am ・Shape: Inverted bowl shape (nose shape) ・Edge and surface: Edge curls inward, 1 surface is yellowish brown with brown hairs all over.

・Tube surface: Pale grayish white, concave in the shape of an inverted dish, and the pores are small.

・Meat quality: Flexible, leathery and almost white in color.

■　Spore shape It is colorless and smooth with a sausage shape of about 3 to 4 x 1μ.

The microorganism used in the present invention is a preservation bacterium N.
8 strains and NK-729II 1 strain, either selected isolates that grow well using lignin as the sole carbon source without mutation treatment or without mutation treatment, or isolates from nature that grow well using lignin as the sole carbon source. Isolated strains are better.

In the present invention, a microorganism that grows well using lignin as the sole carbon source is, for example, a microorganism that can be used to bleach unbleached kraft pulp without reducing its strength, and has a whiteness of 45% or more, preferably 50% or more, and more preferably refers to microorganisms that can bleach 60% or more.

The microorganisms used in the present invention can be cultured in any of a medium containing lignin as the sole carbon source, a normal lignin-free medium for basidiomycetes and molds, or a medium containing wood flour, wood chips, and pulp. I can do it.

On the other hand, the types of pulp are roughly classified into the following three types.

■ Mechanical pulp made by mechanically treating wood as it is to make it into a fibrous form ■ Semi-chemical pulp made by combining chemical and mechanical treatment ■ Chemical pulp made by removing most of the lignin through chemical treatment It can be applied to the production of pulp.

In mechanical pulping, chips are mechanically refined into pulp. In the present invention, wood chips and/or lightly refined pulp can be used, which is extremely energy efficient compared to conventional methods.
Moreover, it is possible to produce pulp with high strength.

semi-chemical pulp After chemical treatment, it is mechanically refined.

Pulp. In the present invention, wood chips or pulp obtained by lightly refining wood chips or pulp after refining can be used.

Additionally, wood chips that have been lightly treated with chemicals or pulp obtained by refining wood chips that have been lightly treated with chemicals can be used. Note that there is no problem in performing appropriate refining and/or chemical treatment after microbial treatment.

Microbial treatment requires only minor refining and chemical treatments, resulting in significant energy and chemical savings.

In addition, in chemical pulp, lignin is highly decomposed by chemical treatment under high temperature and high pressure to produce unbleached chemical pulp. In the present invention, wood chips or pulp obtained by lightly refining wood chips can be used. It is also possible to use wood chips that have been lightly treated with chemicals or pulp obtained by refining wood chips that have been lightly treated with chemicals. As in the case of semi-chemical pulp, there is no problem in performing appropriate refining and/or chemical treatment after microbial treatment.

Microbial treatment results in significant savings in cooking energy and chemicals.

Note that strongly colored lignin remains in unbleached chemical and semi-chemical pulps, so in order to use it for paper applications that require high whiteness, treatment is required to remove the residual lignin and impart whiteness. (Bleaching) is required.

In the present invention, microorganisms can also be added to unbleached pulp to cause bleaching.

Unbleached pulp treated with microorganisms is considerably bleached, requiring only a light chemical treatment for subsequent bleaching, which also helps prevent pollution.

During pulping and/or bleaching, microbial cultures are added to the chips or various pulps in an amount of about 1/10,000 to 10/100 of the chips or pulp without adding any nutrients or cellulose decomposition inhibitors. ,2
The treatment can be carried out by culturing at about 0 to 35°C for 3 to 90 days. At this time, a small amount of a cellulose decomposition inhibitor may be added as appropriate.

Next, examples of the present invention will be shown.

Example 1 A medium containing 1.0 g of beech wood flour (60 to 80 mesh) and 2.5 mfl of water was placed in a 50 m 12 Erlenmeyer flask.
After heat sterilization at ℃ for 15 minutes, strain NK-1148 (FE
RM BP-1859) and cultured at 28°C for one week, and the resulting bacterial cells are suspended in water.

On the other hand, birch milled lignin 2.0%, NH4I, PO
120.40% medium containing 2% and agar 1.6%.
After heat sterilizing at ℃ for 15 minutes, dispense 20+aQ into petri dishes (diameter 90 mm) under aseptic conditions.

The above bacterial cell suspension was added to the medium and cultured at 28°C for 2 weeks, and a strain that showed good growth was isolated and designated as isolate A. Isolated strain A was named strain NK-1148-3, and has been deposited with the Institute of Fine Technology as FERM P-11182.

Example 2 The isolate NK-1148-3 obtained in Example 1 was added to commercially available potato dextrose broth (manufactured by DIFCO) 1.2
After heat sterilizing the medium containing % at 120°C for 15 minutes.

The cells were inoculated and cultured at 28°C for one week to serve as a seed culture.

Example 3 In the production of mechanical pulp, 10 kg of pulp obtained by mild primary refining of beech chips and 2 ml of water were used.
4.512 was mixed and sterilized at 120°C for 15 minutes, and 0.5 kg of the seed culture obtained in Example 2 was added and mixed,
After aerated culture at 28° C. for one week, secondary refining resulted in the production of mechanical pulp with high strength in an extremely energy-saving manner. The properties of the obtained biomechanical pulp are shown in Table 1 below.

Table 1 Biomechanical pulp characteristics of 8-3 strains, respectively unbleached kraft pulp (eucalyptus)
A medium prepared by mixing and stirring 10 kg and 25 m of water was sterilized at 120° C. for 15 minutes, then inoculated, and cultured with aeration at 28° C. for 2 weeks to obtain a seed culture.

Example 5 In bleaching chemical pulp, unbleached kraft pulp (
Mix 10kg of Eucalyptus and 25I2 of water and heat to 120℃
sterilized for 15 minutes, 1 kg of each seed culture obtained in Example 4 and 0.5 kg of glucose were added separately, mixed, and aerated at 28°C for 1 to 5 days, resulting in bleaching. A kraft pulp was obtained.

The increase in whiteness during the treatment period of 1 to 5 days is shown in FIG.

[Brief explanation of drawings]

Figure 1 shows the whiteness (
%). Example 4

Claims (5)

[Claims] (1) A method for producing pulp characterized by microbial treatment using microorganisms that grow well in a medium containing lignin as the only carbon source. (2) A pulp characterized by refining wood chips or wood chips and subjecting the resulting refined pulp to microbial treatment using microorganisms that grow well in a medium containing lignin as the sole carbon source. manufacturing method. (3) Microbial treatment of chemically treated wood chips or pulp obtained by refining chemically treated wood chips using microorganisms that grow well in a medium with lignin as the sole carbon source. A pulp manufacturing method characterized by: (4) The method for producing pulp according to claim 2 or 3, which comprises performing appropriate refining and/or chemical treatment after microbial treatment. (5) Cooking wood chips or refining wood chips, and microbial treatment of the resulting unbleached chemical and/or semichemical pulp using microorganisms that grow well in a medium with lignin as the sole carbon source. A method for bleaching chemical and/or semi-chemical pulp, characterized by: