JPH0730121B2 - Polysaccharides, agglomeration / bulking suppression / thickener mainly composed of the same, and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polysaccharide, a coagulant / bulking inhibitor / thickener (hereinafter simply referred to as a coagulant) mainly composed of the polysaccharide, and a method for producing the same, more specifically, a wastewater coagulation treatment by an activated sludge method or the like. Law, treatment of various pollutants, wastewater treatment fields of various industries, municipal sewage, treatment of various fermentation liquors, and recovery and utilization of useful substances, etc. The manufacturing method is related.

[0002]

2. Description of the Related Art Flocculants are widely used in various processes and wastewater fields discharged from them in accordance with the progress of various industries. Flocculants are generally classified into synthetic polymer type (for example, polyacrylamide type), inorganic type flocculants (for example, sulfuric acid band), and biological type flocculants. Among them, the microbial-produced flocculant is a substance produced by microorganisms, which has a property of flocculating other substances and facilitating precipitation. Also, from the viewpoint of function, they can be classified into three types: cationic, nonionic, and anionic. Conventionally,
These synthetic polymers and inorganic flocculants have been widely used as clarification treatment agents from the field of wastewater treatment using the activated sludge method or the like to civil engineering dredging work and the like. Further, from the downstream processing field such as the water production field of the water supply and the central water supply, the separation of the fermentation liquid and the bacterial cells in the fermentation industry, and further to the food industry field, the coagulant is widely used. Use is expected. As described above, the use of coagulants is deeply incorporated into today's social life and is indispensable. Therefore, it is expected that the use will be further diversified and the amount of use will increase. . Therefore, it is considered that the use of the flocculant is directly connected to the environment and the human health.

[0003]

[Problems to be solved by the invention] However,
Synthetic polymeric flocculants that are currently widely used (for example,
Polyacrylamide) and the like are excellent in capacity and economical efficiency, but have been pointed out to have problems in safety and environment. Furthermore, considering the application to downstream processing in bioindustry, the use of synthetic polymeric flocculants may be problematic. The development of a new flocculant that eliminates and overcomes these drawbacks has been earnestly desired from all sides, and in particular, the development of a biodegradable, safe, and bioflocculating flocculant that is free from the risk of secondary pollution is an urgent issue. Has become. Further, the most important problem left in the activated sludge system in the wastewater coagulation method is the separation of the treated water and the activated sludge after the treatment, and the treated water and the activated sludge are separated from each other in the separation area which is a settling tank. It is desirable to quickly settle and separate the sludge, but the bulking phenomenon and deflocculation phenomenon caused by the generation of filamentous fungi, etc. occur in the separation area during standing, and the flocculating floc action of the activated sludge decreases, and the sedimentation and separation of the activated sludge becomes insufficient. The problem of outflow of activated sludge arises. As a method for promoting the separation of activated sludge and treated water, a method of using a polymer flocculant such as a cationic polymer or an inorganic flocculant such as a polyvalent metal ion is known. Due to its insufficient property, the problem of environmental pollution is caused by being discharged together with the treated water.
Therefore, an object of the present invention is to provide a novel polysaccharide which is biodegradable, safe, and free from the risk of secondary pollution in order to solve and overcome these problems, and to use the polysaccharide as a microorganism. In order to provide a flocculant derived from a microorganism, and also to provide a flocculant capable of efficiently separating activated sludge without causing a bulking phenomenon of activated sludge in a wastewater flocculation treatment method. , To provide a thickener having excellent properties.

[0004]

The above object can be achieved by the present invention described below. That is, the present invention is a polysaccharide having the physicochemical properties according to claim 1, an aggregating agent mainly composed of the polysaccharide, and a method for producing the same.

[0005]

According to the present invention, it is possible to provide a novel polysaccharide produced by a microorganism belonging to the following R-3 group and a flocculant mainly composed of the polysaccharide. The coagulant is excellent in safety and biodegradability and does not cause secondary pollution. Further, by adding an inorganic salt to this aggregating agent, a more excellent aggregating effect can be obtained.
Further, in a wastewater coagulation treatment method using activated sludge, by using the polysaccharide of the present invention as a coagulant, the occurrence of filamentous fungi, which is the main cause of the bulking phenomenon, is suppressed, and the separation of activated sludge and treated water Be efficient.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. The present inventor cultivates a large number of known flocculant-producing bacteria Rhodococcus erythropoles in a fructose medium, and in the process of measuring the flocculating effect (potency value), a culture in which the titer increases more than twice as much as usual. It was found that liquid was present. Several kinds of bacteria were mixed in this culture solution, and when the products of these bacteria were separated, it was discovered that they are novel polysaccharides showing particularly excellent titers.

The above flocculant-producing bacterium has a coagulant-producing ability belonging to at least one genus selected from the group consisting of Pseudomonas, Acinetobacter, Agrobacterium, Enterobacter, Aureobacteria, and Oerscovia. A bacterium that has the known Rhodococcus erythropoles KR-256-2 and FERM-
P No. 3923 and Lord Coccus Erythropoles K
It belongs to a genus different from R-S-1, FERM-P No. 3530, etc., and the aggregation ability of the product is 2
3 times or more. Of these genera, at least one selected from the group consisting of Pseudomonas, Acinetobacter, Agrobacterium, Enterobacter, Aureobacterium, and Oerscovia.
Although a microbial group including a genus is referred to as R-3 in the present invention,
They have already been deposited in the Institute of Mechanical Engineering, No. 11333 (FERM P-11333), No. 11334 (FERM P-11334), and No. 11335 (FER).
No. 11336), No. 11336 (FERM P-11336), No. 1
No. 1337 (FERM P-11337), No. 11357 (FERM P-
11357) and 11358 (FERM P-11358). The above flocculant-producing novel microorganism has the following mycological properties.

[Table 1] Table 1

[Table 2] (Continued from Table 1)

[Table 3] (Continued from Table 1)

[Table 4] (Continued from Table 1)

[Table 5] (Continued from Table 1)

Regarding the mycological properties shown in Table 1 above, Bergey's Manual of Systology Bacteology Vol.
Temic Bacteriology Volume 1, 2), (1984), the KYM-1 strain was consistent with Pseudomonas fluorescens described on page 165 of the same document, and KYM-
One strain was identified as Pseudomonas fluorescens and has been deposited as Microindustrial Research Deposit No. 11333 (FERM P-11333). The KYM-2 strain is appropriate when considered to be Pseudomonas cepacia described on page 175 of the same document, and is deposited by the Institute of Microscopy, No. 1
Deposited as 1334 (FERM P-11334). KY
The M-3 strain corresponds to the bacterium of the genus Acinetobacter described on page 303 of the same document, and has been deposited as Micromachine Research Deposit No. 11335 (FERM P-11335). Although the description of KYM-4 strain is almost the same as Agrobacterium reideobacter described on page 254 of the same book, it is taxonomically considered to be a related species because it is slightly different in details such as sugar assimilation. It is appropriate and the bacterium has been deposited as Microindustrial Research Deposit No. 11336 (FERMP-11336). The KYM-5 strain completely coincides with the genus Enterobacter bacteria described on page 465 of the same document at the genus level, and has been deposited as Microindustrial Research Deposit No. 11337 (FERM P-11337). The description of the KYM-6 strain is the same as that of the bacterium of the genus Aureobacterium described on page 1323 of the same book, and the description of the KYM-7 strain is the same as that of the bacterium of the genus Oerscovia described on page 1489 of the same book. The KYM-6 strain is a micromachine research deposit No. 11357 (FERM
P-11357), and KYM-7 strain are Micromachine Research Deposit No. 11358.
(FERM P-11358), respectively. The polysaccharide of the present invention is a product of the above-mentioned bacterium and has excellent aggregation, bulking inhibition or thickening activity.

[0009]

EXAMPLES An example of a method for culturing R-3 bacteria and its method are described below.
Indicates the physicochemical properties of the product. Culture method 5 liter jar with temperature, DO and pH meter
Add 3 liters of the following production medium to the armor, and
It was sterilized in a clave. Contact the culture solution with 2% (V / V).
Seed, temperature 25-27 ℃, air volume 3 liters / mi
n. The cells were cultured for 1 week under the conditions of stirring intensity of 200 rpm.
However, since the viscosity of the culture solution increased from the second day of culture, stirring
The stirring intensity was increased to 400 rpm. During this time 1-2 times / day 5
0ml sampling for cell growth, residual starch volume,
The cohesive activity and viscosity were measured. The culture solution is 500 ml
Shake culture in production medium for 5 days using Erlenmeyer flask
I used the one.Liquid medium composition Carbon source (soluble starch, manufactured by Kanto Kagaku) 10 g / liter K_TwoHPO_Four 5g / liter KH_TwoPO_Four 2 g / liter MgSO_Four 0.2 g / liter (NH_Four)_TwoSO_Four 0.5 g / liter NaCl 0.1 g / liter Yeast extract 0.5 g / liter

Residual starch content Measured by iodine-starch reaction. 0.2 ml of an iodine solution (I ₂ -KI solution) was added to the 20-fold diluted culture solution, shaken well, and OD580 was measured after standing for 5 minutes. 10% C in 80 ml of kaolin with agglutination activity of 5000 mg / liter
10 ml of aCl ₂ .2H ₂ O was added, 1.25 ml of a 20-fold diluted culture solution was added, the whole was adjusted to 100 ml with distilled water, and the pH was adjusted to 8.0 to 8.2. After stirring well with shaking, the mixture was allowed to stand for 5 minutes, and the OD ₅₅₀ of the supernatant was measured. Viscosity A B-type rotational viscometer (Vismetron viscometer) was used. 8-10 ml of the culture solution was put in a small amount adapter, and the sample was measured at a temperature of 26 ° C. and a rotation speed of 0.3-60 rpm.

Results The results are shown in FIG. As shown in the figure, the cell growth increased sharply after the start of the culture, and after 24 hours it was almost in a steady state.
After that, it increased slightly and decreased slightly after the third day.
It is considered that the amount of residual starch decreased sharply after the start of the culture and was almost decomposed after 48 hours. The tendency is inversely proportional to cell growth. Aggregation activity is 24
Although it slightly increased until the time, it increased sharply after 24 hours and reached the maximum value of 260 after 72 hours. The viscosity shows a pattern similar to that of agglutination activity with time, and
After that time, it began to increase rapidly and reached a steady state at 72 hours. At 72 hours the viscosity was 870 cps.

Separation of polysaccharides from the above culture solution and measurement of physical properties were carried out as follows. The separated culture solution was diluted 5 times with distilled water and centrifuged at 28,000 G for 30 minutes to separate the precipitate from the supernatant. The supernatant was concentrated under reduced pressure to ⅕ in volume, added with 2 to 3 times the amount of ethanol to cause precipitation, and centrifuged at 10000 G for 5 minutes to collect the precipitate. This was redissolved in distilled water, ethanol was added to precipitate it, and centrifugation was performed in the same manner as above, and this was repeated 4 times. Finally, what was precipitated with ethanol was washed three times with ethanol and acetone, and dried under reduced pressure for 1 day to obtain a dried polysaccharide. 10 of the above-mentioned polysaccharide (500 mg)
Dissolve in 0 ml distilled water, centrifuge at 10,000 G for 5 minutes, precipitate the supernatant with 2% 50 ml CPC, 1
Centrifuged at 0000G for 5 minutes. 0.5 for the above precipitation
Dissolve in N salt, precipitate with 2 volumes of ethanol, and
After centrifugation at 0000 G for 5 minutes, the precipitate was washed 5 times with ethanol and acetone and then dried under reduced pressure to obtain a dried polysaccharide (360 mg) as a CPC precipitate fraction.

Physical Properties The above-mentioned polysaccharide is a white powder, and the elemental analysis values (% by weight) are C: 40.3, H: 6.0, N: <0.1, P: <0.
5, S: <0.01, pH of aqueous solution is 7.0 to 7.5, especially 7.2, neutral (C = 0.2 wt% solution), ultraviolet absorption spectrum is from wavelength 240 nm as shown in FIG. Absorbance rapidly increases and reaches a peak near a wavelength of 195 nm. The infrared absorption spectrum is -OH (2700-3700) as shown in Fig. 3.
cm ⁻¹ ), —CH ₂ —CO—O—R (ester bond,
1730, 1160 cm ⁻¹ ), —COO ⁻ (ionized carboxyl group, near 1600 cm ⁻¹ , 1400 cm
^-1 ), the solubility in the solvent was soluble in water, easily soluble in alkali, and insoluble in methanol, ethanol and acetone. The color reaction was ninhydrin reaction = −, phenol sulfuric acid method = +, anthuron sulfuric acid method = +, carbazole sulfuric acid method = +, Elson-Morgan reaction = −. or,
Electrophoresis confirmed the unity of the substances by cellulose acetate membrane electrophoresis as shown in FIG. Molecular weight is 2 × 1
0 ⁶ (determined by gel chromatography), optical rotation ^{_{[α] D 24 = -17~-}} 15 ° (C = 0.2 wt% solution), the carbonized point was two hundred and forty-five to two hundred sixty-five ° C..

From the results of the above-mentioned elemental analysis, various color reactions and infrared absorption spectra, it was considered that the polysaccharide of the present invention is an acidic polysaccharide having an organic acid as a constituent component. The constituent sugars and constituent organic acids were analyzed by. Qualitative / Quantitative Analysis of Constituents (1) Qualitative / Quantitative Analysis of Constituent Sugars After hydrolyzing the purified sample obtained in the above example with trifluoroacetic acid, the constituent sugars were identified by thin layer chromatography and gas chromatography analysis. Was identified and quantified by. (A) Thin layer chromatography analysis 10 mg of the sample was put into a test tube with a screw, 1 ml of 2M trifluoroacetic acid was added thereto, the tube was sealed with nitrogen gas, and the temperature was 100 ° C.
The liquid hydrolyzed for 4 hours was dried under reduced pressure and the dried product was dissolved in distilled water.
Dip in 0.5 M NaH ₂ PO ₄ at 105 ° C. for 1 hour, developing phase: isopropyl alcohol / acetone / 0.1 M lactic acid (weight ratio 4/4/2), detection method: diphenylamine-
Thin-layer chromatography was performed under the analytical conditions of aniline-phosphoric acid, and the constituent sugars were identified by comparison with each standard sugar. The results are shown in Table 2 below.

[Table 6] Table 2

As a result, two spots having Rf values of 0.50 and 0.37 were detected in the purified sample, and these spots corresponded respectively to the standard sugars glucose and galactose, and the polysaccharide of the present invention was used as a constituent sugar. It has been clarified that glucose and galactose are components. (B) Analysis by gas chromatography From the analysis results by thin layer chromatography, it was revealed that the polysaccharide of the present invention was composed of glucose and galactose. The result was confirmed by gas chromatography, and , Quantified. The sample hydrolyzed as described in (a) above was placed in a 0.1 ml test tube, dried under reduced pressure for one day, 200 μl of a trimethylsilylating agent was added, reacted at 60 ° C. for 10 minutes, and diluted with pyridine to a predetermined concentration. The trimethylsilyl (TMS) derivatized product was analyzed by gas chromatography. The result is shown in FIG. As can be seen from FIG. 8, the trimethylsilyl derivative of the hydrolyzate of the purified sample was consistent with the silylated derivative of glucose and galactose, and it was confirmed that the polysaccharide of the present invention was composed of glucose and galactose. The molar ratio of constituent sugars was determined from the area ratio of each peak in gas chromatography. In obtaining the molar ratio of each constituent sugar, first, each standard sample with each specified concentration was subjected to gas chromatography to determine the area of each peak. Next, the hydrolyzate TMS derivative of the purified sample was subjected to gas chromatography to obtain peaks of each constituent sugar. Based on the area thus obtained, the molar ratio of each constituent sugar was calculated from the formula [peak area of constituent sugar / peak area of each standard substance × number of moles of each standard sugar].

(2) Qualitative / quantitative analysis of organic acid As a method of analysis, the samples obtained in the above-mentioned examples were first subjected to thin layer chromatography for analysis to identify the organic acid as a constituent component. Next, it was subjected to gas chromatography to confirm and quantify the TCL result. (A) Thin layer chromatography analysis 100 mg of a sample was placed in a test tube with a screw, 20 ml of 2N sulfuric acid was put therein, sealed with nitrogen gas, hydrolyzed at 100 ° C. for 2 hours, and then neutralized with barium hydroxide. After removing the precipitate by centrifugation, it was concentrated under reduced pressure and filtered through a 0.45 mm membrane filter to prepare a sample (filtrate).
This sample was adjusted to pH 2 with 0.1 N hydrochloric acid, extracted with ether, concentrated under reduced pressure, and a portion of the concentrate was subjected to TCL analysis (A), while other concentrates were subjected to 2,4-dinitrophenylhydrazine. A reagent was added, the mixture was allowed to stand for 1 hour, the precipitate was recovered by centrifugation, the recovered product was dissolved in ethanol, and TCL analysis (B) was performed on this to identify an organic acid. TC
L analysis (A): Plate: HPTLC (cellulose
F _254S ), developing phase: butanol / formic acid / water (weight ratio 4 /
1.5 / 1), detection method: It was carried out under the condition of xylol-aniline reagent. As a result, in the purified sample, two spots with Rf values of 0.82 and 0.38 were detected. Among these spots, the spot with Rf value of 0.82 coincided with the standard substance, succinic acid, but the spot with Rf of 0.38. Could not be identified because it spread thinly under these conditions. Analysis (B) was performed to identify this unknown organic acid. In the analysis (B), plate: HPTHC (silica gel F ₂₅₄ ), developing phase: amyl alcohol / 0.25N ammonia (weight ratio 20:
It carried out on the conditions of 1). As a result, the Rf value of the purified sample was
The Rf value of pyruvic acid as a standard substance was completely in agreement with 0.12. From the above results, it was revealed that the purified sample contained two kinds of organic acids, succinic acid and pyruvic acid, as constituent components.

(B) Gas Chromatographic Analysis The analysis results of TCL were confirmed by gas chromatography analysis, and the organic acid was quantified. 20 mg of the sample was placed in a test tube with a screw, 2 ml of 2M trifluoroacetic acid was added thereto, the tube was sealed with nitrogen gas, and hydrolysis was carried out at 100 ° C. for 4 hours. 0.5 ml of this hydrolyzed liquid was evaporated to dryness under reduced pressure, this dried product was dissolved in methanol, trimethylsilyldiazomethane was added and left to stand for 30 minutes, diluted with hexane to a predetermined concentration, and injected into a gas chromatograph for analysis. The analysis result is shown in FIG. As a result, it was confirmed that the purified sample used contained two kinds of organic acids, succinic acid and pyruvic acid, as constituent components. The constituent molar ratio of the organic acid was determined from the area ratio of each peak in gas chromatography. In obtaining the molar ratio of each constituent organic acid, first, the methylated derivative of each standard sample at each specified concentration was subjected to gas chromatography to determine the area of each peak. Next, the methylated derivative of the hydrolyzate of the purified sample was subjected to gas chromatography to obtain the peak of each organic acid. Based on the area thus obtained, the molar ratio of each constituent organic acid was calculated from the formula [peak area of each constituent organic acid / peak area of each standard substance × mol number of each standard]. The constituent sugars and the constituent organic acids were quantified several times by the above method, and the molar ratio was calculated. As a result, the constituent composition was glucose: galactose: succinic acid: pyruvic acid =
It was 4-7: 1: 0.2-1: 1.5-3.5. When this average value is taken, it is 5.5: 1: 0.6: 2.5.

The flocculant of the present invention is mainly composed of the above-mentioned polysaccharide or a culture or treated product of a microorganism containing the above-mentioned polysaccharide, and the culture solution itself, its concentrate, filtrate, its It may be in any form such as a filtration residue or a dried product thereof. In addition, the aggregating ability can be further improved by containing one or more cationic inorganic salts such as calcium ions in the aggregating agent or by including them at the time of use. As the inorganic salt used in combination for further promoting the aggregating effect of the aggregating agent, those capable of forming a cation in water are desirable, and those capable of forming a polyvalent cation having two or more valences are preferable, such as calcium chloride, Aluminum sulfate, magnesium sulfate, and ferrous sulfate can be effectively used. However, the addition amount of these inorganic salts used in combination is preferably determined by the type of the object to be aggregated, and is not particularly limited in general.
The target of the flocculant of the present invention is not particularly limited. A typical example is a suspension of kaolin (white clay), which is a type of clay, but is generally suitable for various types of agglomerates. In Figure 5,
The result of the experiment example which used the 5,000 mg / liter kaolin suspension as a test liquid is shown. The aggregating agent of the present invention exhibits excellent aggregating activity when the amount of the aggregating agent added is in the range of 0.2 to 10 mg / liter.

The feature of the wastewater coagulation treatment method of the present invention is that the above-mentioned polysaccharide of the present invention is used, and the wastewater to be applied may be any wastewater containing a suspension, but activated sludge is particularly used. In the wastewater coagulation treatment method described above, the generation and growth of filamentous fungi, which are the main cause of bulking, can be suppressed in the separation area between activated sludge and treated water. Therefore, the present invention is particularly effective for treating wastewater in which filamentous fungi are easily generated in treated water. A method for effluent coagulation treatment by an activated sludge system using microorganisms is well known, and the present invention is applicable to any of these well-known effluent coagulation treatment methods and is not particularly limited. FIG. 7 shows the results of studying the effect of suppressing the bulking by adding the flocculant according to the present invention to the activated sludge in which the bulking is artificially generated. Figure 7
As shown in (1), when the coagulant of the present invention is added in an amount of 0.05% by weight or more, a bulking suppressing effect is exhibited, and when 0.1% by weight or more is added, the effect is more excellent. In a preferred embodiment of the present invention, the pH in the separation area where the activated sludge and the treated water are to be separated is 7 to 9, particularly preferably 8.0.
By setting it in the range of 8.5, a more excellent force value can be obtained.

Generally, a polymeric substance has a thickening effect, but the polysaccharide of the present invention also has an excellent thickening effect. The polysaccharide powder separated according to the present invention (sample name: AP.R-
The characteristic of viscosity according to the concentration of 3) was measured. Zansan gum (manufactured by SIGMA) was used as a control for this sample. The sample was dissolved in pure water to 1% (wt / wt) and then diluted with pure water in the range of 0.1 to 1%. The viscosity of each sample adjusted to each concentration was measured with a B-type rotational viscometer (25 ° C., SS-3-rotor for small amount, 60 rpm). The results are shown in Figure 6. It was confirmed that this sample had a clearly higher viscosity characteristic than that of xanthan gum.

[0021]

[Effect] According to the present invention, a novel polysaccharide produced by a microorganism and a flocculant using the same can be provided. And this coagulant is excellent in safety and biodegradability and does not cause secondary pollution. Further, by adding an inorganic salt to this aggregating agent, a more excellent aggregating effect can be obtained. Further, in a wastewater coagulation treatment method using activated sludge, by using the polysaccharide of the present invention as a coagulant, the occurrence of filamentous fungi, which is the main cause of the bulking phenomenon, is suppressed, and the separation of activated sludge and treated water Be efficient. Further, the polysaccharide of the present invention has excellent thickening properties.

[0022]

[Brief description of drawings]

FIG. 1 is a view showing a change with time of a culture solution.

[Figure 2] Ultraviolet absorption spectrum

[Figure 3] Infrared absorption spectrum

FIG. 4 is a diagram showing electrophoresis.

FIG. 5 is a diagram explaining the aggregation activity of the polysaccharide of the present invention.

FIG. 6 is a diagram illustrating a change in viscosity according to the concentration of the polysaccharide of the present invention.

FIG. 7 is a diagram for explaining the bulking suppressing effect of the polysaccharide of the present invention.

FIG. 8: Analysis results of constituent sugars by gas chromatography

FIG. 9: Analysis results of constituent organic acids by gas chromatography

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C12P 19/04 C 7432-4B // (C12P 19/04 C12R 1:38) (C12P 19/04 (72) Inventor Naofumi Yamachi 1-5-7 Kajimachi, Chiyoda-ku, Tokyo Environmental Engineering Co., Ltd. (72) Hideaki Matsuyama 1-5-7 Kajimachi, Chiyoda-ku, Tokyo Environment Examiner at Engineering Co., Ltd. Hiroshi Taniguchi

Claims (8)

[Claims] 1. A polysaccharide having the following physicochemical properties. (1) Elemental analysis ratio (wt%): C: 40 ± 2 H: 6 ± 1 N: <0.2 P: <0.5 S: <0.1 (2) Color of substance: white (3) Aqueous solution pH: 7.0 to 7.5, neutral (C = 0.2
(Wt% solution) (4) Ultraviolet absorption spectrum: Absorbance sharply increases from wavelength 240 nm to wavelength 195
It peaks near nm. (5) Infrared absorption spectrum -OH 2700
~ 3700 cm ⁻¹ —CH ₂ —CO—O—R (ester bond) 173
0,1160cm ^-1 -COO ^- insoluble (ionized carboxyl group) 1600 cm around ^-1, 1400 cm ^-1 vicinity (6) soluble in solubility water to solvent, readily soluble in alkali, methanol, ethanol and acetone. (7) Color reaction Ninhydrin reaction-Phenol-sulfuric acid method + Anthuron-sulfuric acid method + Carbazole-sulfuric acid method + Elson-Morgan reaction- (8) Constituent sugar and constituent sugar ratio Glucose: Galactose = 4 to 7: 1 (molar ratio) (9 ) Organic acid and its content succinic acid: pyruvic acid = 0.2-1: 1.5-3.5
(To 1 mol of galactose) (10) Electrophoresis: The identity of the substance was confirmed by cellulose acetate membrane electrophoresis. (11) Molecular weight 2 × 10 ⁶ or more (by gel chromatography) (12) Optical rotation: [α] _D ²⁴ = −17 to −15 ° (C =
0.2 wt% solution) (13) Carbonization point: 245 to 265 ° C 2. The method according to claim 1, obtained from a bacterium belonging to at least one genus selected from the group consisting of Pseudomonas, Acinetobacter, Agrobacterium, Enterobacter, Aureobacteria and Oerscovia. Polysaccharides. 3. KYM1 strain (FERM P-1133)
3), KYM2 strain (FERM P-11334), KY
M3 strain (FERM P-11335), KYM4 strain (F
ERM P-11336), KYM5 strain (FERM P
-11337), KYM6 strain (FERM P-1135)
The polysaccharide according to claim 1, obtained from a bacterium belonging to at least one strain selected from the group consisting of 7) and KYM7 strain (FERM P-11358). 4. The method for producing a polysaccharide according to claim 1, wherein the microorganism according to any one of claims 2 to 3 is cultured in a medium, and the polysaccharide is collected from the culture. 5. A flocculant containing the polysaccharide according to claim 1 as an active ingredient. 6. A bulking inhibitor containing the polysaccharide according to claim 1 as an active ingredient. 7. A thickener containing the polysaccharide according to claim 1 as an active ingredient. 8. A method for coagulating wastewater, wherein the polysaccharide according to claim 1 is present in a treatment system to prevent bulking of the activated sludge in a separation area between activated sludge and treated water.