JPH027639B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for producing polysaccharides. Polysaccharides produced by the genus Xanthomonas are generally called xanthan gum and are used in a variety of industrial applications. Aqueous solutions of xanthan gum have special rheological properties and are used in a variety of fields such as oil drilling, paints, inks, agrochemicals, cosmetics, pharmaceuticals, and foods. (Prior art) Conventionally, in order to generally produce xanthan gum,
Strains of Xanthomonas campestris species as carbon sources,
It is produced by culturing it in a medium containing a nitrogen source and inorganic salts by a batch method or a continuous fermentation method, removing the bacterial cells from this culture solution, adding an organic solvent such as alcohol, selectively precipitating xanthan gum, and drying it. There is. (For example, “Newly expanded water-soluble polymers” supervised by Nobuo Nakamura)
(April 1, 1982), Kagaku Kogyo Co., Ltd. P132-151). Among the microorganisms of the genus Xanthomonas, in addition to Xanthomonas cyampestris, X. phaseoli, X. oryzae (X.
oryzae) is also known to produce polysaccharides. (For example, "Comprehensive Polysaccharide Science (Part 2) (December 1, 1972), edited by Atsuya Harada and Akira Misaki, Kodansha Co., Ltd., pp. 145-149).
In addition, as shown in JP-A-48-92563, Xanthomonas malvacearum, X. carotae, and X. translucens are Kaisho 52-90696
In the publication, Xanthomonas begoniae (X.
begoniae), Xanthomonas incane (X.
incanae), Xanthomonas vesicatoria (X.
vasicatoria) is known to produce polysaccharides. (Problems to be Solved by the Invention) Among the strains of the genus Xanthomonas, the strains used commercially for the production of xanthan gum are strains of the species Xanthomonas campestris;
Other strains are inferior to strains of Xanthomonas campestris species in terms of their ability to produce polysaccharides;
Not used in actual production. However, the NRRLB-1459 strain (Agric
ultural Research Service Culture Collection)
is a pathogenic bacterium of cabbage and is an imported harmful bacterium based on the Plant Protection Law. When used in the production of xanthan gum in Japan, there is a risk of the bacterium leaking out, and extreme care must be taken in culture management. Another disadvantage is that the polysaccharide production ability of the fungus decreases as the strain is inherited. This is thought to be due to an increase in the proportion of bacteria incapable of producing polysaccharides. (Means for Solving the Problems) In order to solve the above problems, the present inventor conducted polysaccharide production tests on various strains of the genus Xanthomonas, and found that
We have completed the present invention by discovering that strains belonging to Xanthomonas pisci and Xanthomonas prunii have good polysaccharide-producing ability, and that their polysaccharide-producing ability hardly decreases by subplanting. That is, the present invention provides Xanthomonas yukiyurbitae IFO 13552, Xanthomonas fuisariideicola IFO 13555,
This method for producing polysaccharides is characterized by culturing microorganisms selected from the group consisting of IFO03780 and collecting polysaccharides from the culture. (Function) Since the present invention is configured as described above, the strain used for polysaccharide production has excellent polysaccharide production ability and stability of that ability. For this reason. The cost of polysaccharide production is reduced, and polysaccharides can be stably produced. In addition, since it is not an imported harmful strain, it is highly safe in the polysaccharide manufacturing process. (Example) The present invention will be explained in more detail below with reference to Examples. Example 50g glucose, 4g Detailers Dry Soluble, 5g dipotassium phosphate, 1g magnesium sulfate heptahydrate dissolved in 100% water
A 500 ml Erlenmeyer flask containing 1.0 ml of the sample was heat sterilized at 120°C for 15 minutes. In the Erlenmeyer flask containing this medium,
Xanthomonas kiyukiyurbitae IFO13552,
Xanthomonas fuisaridaycola IFO13556,
One platinum loop of each of Xanthomonas pisci IFO13556 and Xanthomonas prunii IFO3780 (obtained from Fermentation Research Institute (Yodogawa-ku, Osaka)) was inoculated and incubated at 30°C on an orbital shaker while shaking at 200 rpm. Cultured for 96 hours. 5 ml of this culture solution was further inoculated into an Erlenmeyer flask containing a new medium, and cultured under the above conditions. Perform the above steps 5
Repeated times. The culture solution was heat sterilized at 120℃ for 20 minutes.
After sterilization by centrifugation, ethanol in an amount twice that of the culture solution was added to precipitate polysaccharides, which was dried and weighed. Table 1 shows the results of the amount of polysaccharide in the initial culture solution and the amount of polysaccharide in the culture solution after subculture five times. Comparative example Xanthomonas kiyukiyurbitae IFO13552
Xanthomonas campestris instead of
The same operation as in Example was performed except that IFO13303 (derived from NRRLB-1459 strain, obtained from Fermentation Research Institute) was used. The results are shown in Table 1.

[Table] (Effects of the invention) As is clear from the results of the above examples, the strain used in the present invention has good polysaccharide production ability,
Moreover, the polysaccharide production ability hardly decreases even by sub-planting. Therefore, the cost of producing polysaccharides can be reduced, and polysaccharides can be produced stably. In addition, since it is not an imported harmful strain, there is little risk of bacterial leakage during the polysaccharide manufacturing process.

Claims (1)

[Claims] 1 Xanthomonas kiyukiyurbitae (Xan-
thomonas cucurbitae) IFO13552,
physali-dicola) IFO13555, Xanthomonas
Xanthomonas pisi IFO13556, Xanthomonas pruni
A method for producing polysaccharides, which comprises culturing microorganisms selected from the group consisting of IFO03780 and collecting polysaccharides from the culture.