JPH06113873A - Production of microbial cellulose - Google Patents

Abstract

PURPOSE:To obtain a method for producing a microbial cellulose in which the yield of the microbial cellulose is enhanced and the inexpensive microbial cellulose can efficiently be provided by effectively utilizing a pulp waste liquor. CONSTITUTION:The objective method for producing a microbial cellulose is characterized by adding a sulfite pulp waste liquor and/or a permeate obtained by ultrafiltering the sulfite pulp waste liquor into a culture medium containing a microorganism capable of synthesizing cellulose together with a carbon, a nitrogen and an organic minor nutrient sources and an inorganic salt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing cellulose using pulp effluent, and more particularly to a method for producing microbial cellulose.

[0002]

As is well known, cellulose is mainly produced from wood, but recently, microbial cellulose using a cellulose-synthesizing microorganism such as acetic acid bacteria has been industrialized. In recent years, new applications of cellulose have been positively pioneered, and in the food field, it is used as a water retention agent, thickener, emulsifier, dietary fiber, etc., and also has a network structure and high crystallinity of microbial cellulose. It is also practiced to produce a highly elastic film by hot pressing microbial cellulose, and to use it as an acoustic material such as headphones.

However, in the production of microbial cellulose, saccharides such as glucose are required as a carbon source, and in addition, amino acids, peptone as a micronutrient source, enzyme extract and the like are required. Since the additives are expensive, there is a drawback that the microbial cellulose obtained must be very expensive.

On the other hand, although the pulp effluent which has been simply discarded in the past has been applied to a cement water reducing agent in recent years, a method of utilizing it for producing microbial cellulose has not yet been known. The present inventors have conducted intensive studies on a method for producing microbial cellulose, and have found that the productivity of microbial cellulose can be improved by utilizing a sulfite pulp effluent, and arrived at the present invention.

[0005]

SUMMARY OF THE INVENTION Therefore, a first object of the present invention is to provide an efficient and inexpensive method for producing microbial cellulose. A second object of the present invention is to provide a method for producing microbial cellulose capable of effectively utilizing pulp effluent.

[0006]

Means for Solving the Problems The above-described objects of the present invention are to provide a sulfite pulp effluent in a medium having a microorganism capable of synthesizing cellulose together with a carbon source, a nitrogen source, an organic micronutrient source and an inorganic salt. And / or a permeate obtained by ultrafiltration of a sulfite pulp effluent is added, which is achieved by a method for producing microbial cellulose.

The microorganism capable of synthesizing cellulose to be used in the present invention is not particularly limited as long as it is capable of synthesizing cellulose, but generally, a bacterium of the genus Acetobacter or Gluconobacter is used. It is preferable. Specific examples of particularly preferable microorganisms include, for example, Acetobacter xylinum ATCC-10.
245, and Acetobacter xylinum IFO-136
93 etc. can be mentioned.

The sulfite pulp effluent (hereinafter abbreviated as SSL) used in the present invention is a by-product of the production of sulfite pulp from softwood or hardwood, and is a calcium salt of ligninsulfonic acid. Including magnesium salt, sodium salt, sugar modified products (sugar sulfonic acid,
Aldonic acid, etc.) and reducing sugars such as xylose and glucose are mainly contained.

Further, in the present invention, a permeate obtained by applying the above SSL to an ultrafiltration device (hereinafter abbreviated as SSL-UFP) can be used instead of SSL. In UFP, the SS
The lignin sulfonic acid metal salt contained in L and low molecular weight ones of sugar modified products and reducing sugars are mainly contained.

In the present invention, from the viewpoint of easy handling, it is preferable to use a powder product obtained by powder mist drying in both cases of SSL and SSL-UFP. That is, SSL and SSL-UF in the present invention
P is SSL or SSL-UF in a state of being dissolved in water.
Includes all that are substantially the same as P. Examples of industrially produced SSL include Sun Extract P
201 (trade name of Sanyo Kokusaku Pulp Co., Ltd.), SSL
Examples of -UFP include Sunpearl CP (trade name of Sanyo Kokusaku Pulp Co., Ltd.).

In the present invention, SSL and / or SS
By adding L-UFP to the medium at 0.1 to 10% by weight, preferably 0.5 to 5% by weight,
The yield of cellulose is greatly improved. If it is less than 0.1% by weight, the effect of addition is not sufficient, and even if it is added in an amount of more than 10% by weight, the yield does not further increase. Here, the medium means an environment having a carbon source, a nitrogen source, an organic micronutrient source and an inorganic salt, and capable of synthesizing cellulose by a cellulose-synthesizing microorganism.

The carbon source contained in the medium is, for example, glucose and / or sucrose, and the nitrogen source is, for example, inorganic salts such as ammonium sulfate and ammonium phosphate, as well as organic substances such as peptone, and organic trace nutrient sources. Examples thereof include peptone and yeast extract, and examples of the inorganic salt include phosphate and magnesium salt. The above carbon source, nitrogen source, organic micronutrient source and inorganic salts are contained in the medium at 1.0 to 2.0%, 0.5 to 1.0%,
It is added so as to be 0.2 to 0.5% and 0.1 to 0.5%.

The pH of the culture solution having the above composition is adjusted to 5 to 6 using dilute hydrochloric acid or caustic soda aqueous solution. The culture temperature is preferably 20 to 40 ° C, and particularly preferably 25 to 35 ° C. Cellulose is produced in the surface layer of the medium by inoculating the above-prepared culture ground with a cellulose-synthesizing microorganism and statically culturing for 1 to 10 days.

The cellulose thus produced is isolated by washing with water, washing with about 1% alkali, neutralizing with about 1% acetic acid, washing again with water and drying. By changing the type and ratio of carbon source, nitrogen source, organic micronutrient source, etc., and selecting the type of microorganism, it is possible to obtain pure cellulose or cellulose having heteropolysaccharide or glucan in the side chain. it can.

[0015]

As described above in detail, in the present invention,
By using an inexpensive substance such as sulfite drainage,
Since the production efficiency of microbial cellulose can be greatly improved, it is suitable for mass production of microbial cellulose.

[0016]

EXAMPLES The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto.
In addition,% in an Example represents weight%.

Embodiment 1. The basic medium composition is 2% glucose, 0.5% yeast extract, 0.5 peptone.
%, Citric acid (monohydrate) 0.115%, and disodium phosphate (anhydrous) 0.27% in 30 ml of the culture solution, and powdered SSL (Sun Extract P201: Sanyo Kokusaku Pulp) (Trade name, manufactured by Co., Ltd.) is added so as to be 0 to 10% as shown in Table 1 and the pH of the solution is adjusted to 6, and then in a 100 ml Erlenmeyer flask,
A liquid medium was prepared by sterilizing at 120 ° C. for 30 minutes.

Meanwhile, Acetobacter xylinum ATCC-10245 was added to the agar medium having the above basic medium composition.
Was inoculated and cultured for 48 hours, and this was used as a seed mother. The seed medium was inoculated into the above liquid medium and then statically cultured at 29 ° C. for 7 days. The produced cellulose was washed with water and then immersed in 1% caustic soda at 90 ° C. for 15 minutes. After cooling, 1%
Neutralize with acetic acid of 10%, wash again with water, and then
It was dried at 5 ° C. The relationship between the powdered SSL addition rate and the amount of cellulose produced (mg / 30 ml) is as shown in Table 1.

[0019]

[Table 1]

From the results shown in Table 1, it was confirmed that adding 0.1% or more of SSL increases the amount of cellulose produced, and adding 10% or more is almost meaningless. Example 2. SSL-UF obtained by ultrafiltration of SSL
For P, an experiment was conducted in the same manner as in Example 1 regarding the relationship between the addition rate and the amount of cellulose produced. The results are shown in Table 2.

[0021]

[Table 2]

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Claims (3)

[Claims] 1. Obtained by ultrafiltration of sulfite pulp effluent and / or sulfite pulp effluent in a medium having a microorganism capable of synthesizing cellulose together with a carbon source, a nitrogen source, an organic micronutrient source and an inorganic salt. A method for producing microbial cellulose, which comprises adding the obtained permeate. 2. The method for producing microbial cellulose according to claim 1, wherein the microorganism is a bacterium of the genus Acetobacter and / or Gluconobacter. 3. The Acetobacter microorganism is Acetobacter xylinum ATCC-10245 and / or Acetobacter xylinum IFO-13693.
The method for producing microbial cellulose according to 1.