CN104946572A - Thermal coagulation polysaccharide and fermentation bacterial strain and application thereof - Google Patents

Abstract

The invention discloses a bacterial strain producing novel thermal coagulation polysaccharide (PGHX), and application of bacterial strain, and belongs to the technical field of bioengineering. A method for applying the bacterial strain to prepare the novel thermal coagulation polysaccharide (PGHX) through fermentation, structural characteristics of the fermentation product (PGHX), thermal coagulation performance of the fermentation product (PGHX) and the like are involved. The invention specifically relates to an agrobacterium screening method, the bacterial strain is named as Agrobacterium HX1126 through authentication, and the preservation number is CGMCC10943. The method for producing the fermentation product (PGHX) through microorganisms is achieved. Fermentation liquid with the density of 24.9 g/L can be obtained by conducting fermentation cultivation on the microorganisms under the aerobiotic condition for 48 hours to 90 hours. The polysaccharide (PGHX) produced through the bacterial strain has good thermal coagulation performance, thermal gel can be formed after heating is conducted for 10 minutes under the concentration of 30 g/L at the temperature of 100 DEG C, the gel strength ranges from 245 g/cm<2> to 1450 g/cm<2>. Products have the pure white color and luster. Colloid is in a semitransparent shape and has elasticity.

Description

A thermocoagulable polysaccharide, its fermentation strain and application

technical field

The invention discloses a strain of Agrobacterium and a method for fermenting and preparing a novel thermocoagulable polysaccharide (PGHX), and discloses the structural characteristics and thermocoagulability of the fermentation product. It specifically relates to the Agrobacterium screening method, the strain identified as Agrobacterium sp. HX1126, and the preservation number is CGMCC 10943, and a method for producing PGHX using the microorganism.

Background technique

Every year, the global petrochemical industry produces up to tens of millions of tons of plastics, and some of them are used to produce various packaging boxes, bags, and agricultural mulch films with low added value and are easily lost. These products are scattered on the ground or float on the water surface after use. Difficult to recycle. What's more, due to its non-biodegradability, it has caused increasingly serious ecological environment pollution. The pressure of environmental pollution has led many countries to consider using biodegradable plastics to replace some chemically synthesized plastics, and have successively promulgated some regulations to ban certain plastic products, and at the same time encourage researchers to increase research on biodegradable plastics. In this type of research, due to their biocompatibility and biodegradability, the production of polyhydroxyalkanoates (Polyhydroxyalkanoate PHAs) and poly-β-hydroxybutyrate (PHB) by fermentation has become a research hotspot. However, compared with chemically synthesized plastics, the production cost is higher, so many researchers have been working on improving the production intensity of the fermentation method and adopting new extraction techniques in order to reduce production costs and improve market competition.

During the production of biodiesel, glycerol is one of the by-products. Due to the rapid development of biodiesel, a large number of by-products are produced. The accumulation of a large number of by-products has caused great pollution to the environment. It must be done.

Contents of the invention

The inventor of the present invention is more interested in the research of biodegradable materials. In the process of screening PHB-producing strains, a bacterial strain with thermocoagulation properties in the fermentation liquid was screened out. This bacterial strain was identified as Agrobacterium sp. and named Agrobacterium sp. . HX1126. During the research on the fermentation conditions and product extraction of the strain to produce thermocoagulable products, it is found that the strain can use glycerol as the only carbon source to ferment and produce thermocoagulable products. It was identified that the product was exopolysaccharide produced by Agrobacterium sp. HX1126, and the monosaccharide composition was galactose. It is worth mentioning that this product has good water absorption performance and can absorb more than 30 times its own weight of water. At the same time, this product has good thermal coagulation performance. At a concentration of 30 g/L, heating at 100 ° C for 10 minutes can form Thermal gels have a gel strength of 245-1450 g/cm ² , and, with the deepening of research, the gel strength is expected to continue to increase. The use of glycerol as a low-cost production raw material in the fermentation process to produce a new thermocoagulable polysaccharide (PGHX) with thermocoagulable properties and biodegradability not only has good economic prospects but also can promote environmental protection.

In addition, the extraction process is simpler and easier than the extraction process of polyhydroxyalkanoate (PHAs) and poly-β-hydroxybutyrate (PHB) produced by fermentation. As intracellular polysaccharides, PHAs or PHB usually need to break the cell wall during extraction, and the extraction cost is relatively high. However, the present invention describes a new type of polysaccharide (PGHX) with thermosetting properties. This polysaccharide is used as a water-insoluble exopolysaccharide. In the present invention, it can be obtained only by rinsing with alcohol and water, and the alcohol used can be recovered by rotary evaporation. Reuse. The color of the obtained product is pure white, and after gelation, the colloid is translucent and has good elasticity.

One object of the present invention, a strain of Agrobacterium sp. HX1126, has been preserved in the General Microorganism Center (CGMCC) of China Microbial Culture Collection Management Committee (CGMCC) on June 2, 2015, address: Beichen West Road, Chaoyang District, Beijing Institute No. 1, Institute of Microbiology, Chinese Academy of Sciences, Zip Code: 100101, and the deposit number is CGMCC No. 10943.

Another object of the present invention is to provide a method for fermenting and extracting water-absorbing polysaccharides using the above strain, comprising the following steps:

Step 1, slant culture: Streak inoculation of the bacterial strain in the slant medium for cultivation;

Step 2, seed cultivation: inoculate the slant seeds in the first step to the seed medium for cultivation;

Step 3, fermentation culture: insert the cultivated seeds into the fermentation medium according to the inoculum amount of 5-15% for cultivation, and obtain the fermentation liquid product;

Step 4, extracting the product: the extraction adopts one of the following two methods, the first one: filter the fermentation broth product to remove impurities, remove the supernatant, then add ethanol and water in turn to clean, remove the supernatant, and obtain the product after centrifugation , obtained after freeze-drying; the second method: filter the fermentation broth product to remove impurities, let it stand to remove the supernatant, then add NaOH solution, after centrifugation, collect the supernatant, then add HCl solution to the supernatant to adjust the pH To neutrality, after centrifugation, the precipitate was collected, washed with water, and freeze-dried.

In the first step, the slant medium contains the following components in mass percentage: 20-50 g/L glycerol or D-mannitol, 1-10 g/L yeast powder, 1-10 g/L peptone, 1～10g/L beef extract, 15～20 g/L agar, pH 6.5～7.5; fermentation temperature 28～32℃, culture time 40～60 hours.

In the second step, the seed medium contains the following components in mass percentage: 20-50 g/L glycerol or D-mannitol, 1-10 g/L yeast powder, 1-10 g/L peptone, 1～10 g/L beef extract, 1～5 g/L (NH ₄ ) ₂ HPO ₄ , 0.5～5 g/L KH ₂ PO ₄ , 5～20 ml/L corn liquor, pH 6.5～7.5; fermentation temperature 28～32℃, culture time 20～30 hours.

In the third step, the fermentation medium contains the following components in mass percentage: 5-60 g/L glycerol or D-mannitol, 1-10 g/L yeast powder, 1-10 g/L (NH ₄ ) ₂ HPO ₄ , 5-20 ml/L corn steep liquor, 0.5-3 g/L MgSO ₄ ·7H ₂ O, 0.2-1 g/L FeSO ₄ ·7H ₂ O, 0.02-1 g/L MnSO ₄ ·H ₂ O, 1g-20g/L NaHPO ₄ ·12H ₂ O, 1g-20g/L NaH ₂ PO ₄ ·2H ₂ O, pH 5.3-8.3; fermentation temperature 28-32°C, aerobic culture for 48-90 hours.

The sterilization temperature of the culture medium is 115-121°C for 20 minutes. The carbon source is sterilized separately and subpackaged, and the phosphate membrane is filtered to remove bacteria.

In the 4th step, the parameters of the first extraction method are: the added volume of ethanol is 0.5 to 2 times the volume of the fermentation broth, and the number of ethanol cleanings is more than 2 times; the added volume of water is 5 to 2 times the volume of the fermentation broth. 10 times, the number of times of water washing is more than 3 times; the parameters of the second extraction method are: the volume of NaOH solution is 1 to 3 times that of the fermentation broth, the concentration is 0.5N, and the concentration of HCl solution is 1N.

Another object of the present invention is to provide the application of the above bacterial strain in fermentation and extraction of PGHX.

Another object of the present invention is a polysaccharide with water absorption and thermosetting properties;

  Chemical name: β-1,3-polygalactose

Molecular formula: (C ₆ H ₁₀ O ₅ ) _n

n——polymerization degree, n>50.

Structural formula:

;

in:

(1) n>50, when the degree of polymerization is lower than 50, it will be difficult for this polysaccharide to form a thermal gel. The degree of polymerization is related to the gel strength, the greater the degree of polymerization, the greater the gel strength. In addition, the fermentation period is short, and the degree of polymerization of the product is low; the fermentation period is long, and the degree of polymerization of the product is high. The thermosetting polysaccharides with different degrees of polymerization, that is, different gel strengths, can be produced according to actual needs.

(2) The polysaccharide PGHX involved in the present invention is a straight-chain linear structure connected by β1-3 glycosidic bonds with galactose as the sugar unit.

(3) The product has good water absorption performance and can absorb 30 times or more water of its own mass;

(4) Good thermal coagulation performance. The above-mentioned polysaccharide is formulated into a 30 g/L aqueous solution and heated at 100°C for 10 minutes to form a thermal gel with a gel strength of 245-1450 g/cm ² .

The thermocoagulable polysaccharide-producing bacterial strain screened by the present invention is considered to belong to the genus Agrobacterium ( Agrobacterium sp. ) through 16S rRNA gene sequencing and physiological and biochemical identification according to "Bergey's Bacterial Identification Manual". The cells of the bacteria are short rod-shaped, Gram-negative, aerobic. After culturing on slant medium for 48 hours, the colonies were round, light yellow, smooth and neatly edged.

Preservation of biological sample materials: The Agrobacterium sp. strain HX1126 screened by the present invention has been preserved in the General Microorganism Collection Center of China Microbiological Culture Collection Management Committee in Zhongguancun, Beijing, China, with the preservation number CGMCC No. 10943, and the preservation date is June 2015 January 02.

Beneficial effect

1 The feature of the present invention is that Agrobacterium HX1126, which produces a new polysaccharide, is screened from a large number of microorganisms. Under suitable conditions, it can produce this polysaccharide, and the yield can reach more than 24.9 g/L.

2 Analyze the structure of this polysaccharide (monosaccharide composition, infrared spectroscopy, nuclear magnetic resonance), the monosaccharide composition of this polysaccharide is galactose, which is a new type of polysaccharide; at the same time, this polysaccharide has thermosetting properties and is biodegradable These properties make this polysaccharide have broad application prospects in biodegradable materials, medicine, cosmetics, food and other fields;

3. The extraction process of the present invention is simple, the color of the product is pure white, the colloid of the obtained product is translucent, and the gel strength of the product can reach 245-1450 g/cm ² .

Description of drawings

Figure 1a is the appearance of the product;

Figure 1b is the appearance of the gel;

Figure 1c is the apparent effect diagram showing the elasticity of the gel after being stretched;

Figure 2a is the monosaccharide composition analysis, the retention time diagram of the standard product, the legend 1 in the diagram is glucosamine, 2 is rhamnose, 3 is arabinose, 4 is galactosamine, 5 is galactose, 6 is glucose, 7 is xylose, 8 is mannitol, 9 is fructose, and 10 is ribose;

Figure 2b is the monosaccharide composition analysis of the extracted product, and the retention time diagram of the sample;

Fig. 3 is product infrared spectrum;

Fig. 4 is product hydrogen spectrum;

Fig. 5 is product carbon spectrum;

Figure 6 is a heteronuclear two-dimensional spectrum.

Detailed ways

The following is an example of Agrobacterium ( Agrobacterium ) CGMCC 10943 screening, identification and fermentation production of polygalactose research examples. However, the invention is not limited to the few examples listed.

Example 1 strain screening

Six soil samples were taken from Jiangnan University in the Wuxi section of the Beijing-Hangzhou Grand Canal. The sample was cultured in screening medium at 30°C and 180rpm for 20 hours, then diluted, spread on a screening plate, cultured at 30°C for 72 hours, and single colonies were selected and cultured by streaking. The strains were inoculated in a Erlenmeyer flask containing 30 ml of screening medium, and cultured at 30° C. and 180 rpm for 80 hours. One of the bottles of fermented liquid showed thermocoagulation properties during the boiling process, and the strain was selected for further research on its fermentation conditions and fermentation products.

Screening medium: 50 g/L glucose, 1.5 g/L yeast powder, 0.3 g/L peptone, 0.2 g/L beef extract, 1-2 g/L (NH ₄ ) ₂ SO ₄ , 1g/L KH ₂ PO ₄ , 2g/L CaCO ₃ , 0.5g/L MgSO ₄ ·7H ₂ O, pH 6.5-7.5.

Embodiment 2 fermentation culture produces PGHX

(1) Slant culture: Streak inoculate the strain on slant medium (20g/L glycerol, 5 g/L yeast powder, 2 g/L peptone, 2g/L beef extract, 20 g/L agar, pH 6.5-7.5 ), 28-32°C, incubate for 40-60 hours, and set aside.

(2) Seed culture: Inoculate the slanted seeds in step (1) into the seed medium (20g/L glycerol, 1-5 g/L yeast powder, 2 g/L peptone, 2 g/L beef extract, 1-2 g/L (NH ₄ ) ₂ HPO ₄ , 1 g/L KH ₂ PO ₄ , 10-20 ml/L corn steep liquor, pH 6.5-7.5), 40-100ml liquid in 250ml Erlenmeyer flask, cultured at 28-32℃ for 20 -30 hours.

(3) Fermentation culture: Insert the cultured seeds into the fermentation medium (50 g/L glycerol, 1-2 g/L yeast powder, 1-2 g/L (NH ₄ ) ₂ HPO ₄ , 2 ml/L corn steep liquor, 0.5g/L MgSO ₄ ·7H ₂ O, 0.2 g/L FeSO ₄ ·7H ₂ O, 0.02 g/L MnSO ₄ ·H ₂ O, 5g-10g/L NaHPO ₄ ·12H ₂ O, 5g-10g/L NaH ₂ PO ₄ ·2H ₂ O, pH 5.3-7.3), culture temperature 28-32℃, aerobic culture for 48-90 hours.

In the fermentation process of the above steps, the carbon source can be replaced by D-mannitol in addition to glycerol.

(4) Product extraction:

method one:

The fermentation product is a water-insoluble polysaccharide. After the fermentation, the fermentation liquid is filtered on gauze to remove some impurities; the fermentation liquid is collected and the supernatant is removed. Add 0.5-2 times the volume of ethanol, stir for 5 minutes, let stand, remove the supernatant, repeat twice; add 5-10 times the volume of tap water, stir for 5 minutes, let stand, remove the supernatant, repeat 3 times; centrifuge, collect product, freeze-dried. The appearance of the product is shown in Figure 1a. The purity of the product is >80%, and the gel strength is 245-1450 g/cm ² .

Method Two:

The fermentation product is a water-insoluble polysaccharide. After the fermentation is completed, the fermentation liquid is filtered on gauze to remove some impurities; the fermentation liquid is collected, and the supernatant is removed after standing. Add 1-3 times the volume of 0.5N NaOH solution, stir for 1 h, centrifuge at 10,000 rpm for 30 min, and collect the supernatant. Add 1 N HCl solution to the supernatant to adjust the pH of the solution to neutral, and a white precipitate will form. Centrifuge at 10000rpm for 30min, collect the white precipitate, wash with 10 times the volume of tap water, remove the supernatant, repeat 3 times; centrifuge, collect the product, freeze-dry. With this extraction method, the purity of the product is >90%, and the gel strength is 245-358 g/cm ² .

Embodiment 3 product structure analysis

(1) Monosaccharide composition

Take an appropriate amount of the sample prepared in Example 2 (extraction method 1), add 2 mol/L trifluoroacetic acid, hydrolyze at 120 ° C for 2 hours under nitrogen protection, remove trifluoroacetic acid, add appropriate amount of deionized water, and use ion chromatography ( HPAEC) to determine the monosaccharide composition. Instrument model: Dionex ICS-5000 (USA), column model: CarboPac PA20 (4 mm × 240 mm).

The results show (Figure 2a and Figure 2b, the retention time of the sample in Figure 2b is consistent with that of the standard in Figure 2a), the monosaccharide composition of this polysaccharide is galactose.

(2) Infrared Spectrum

The sample was mixed with KBr and ground in a mortar until it was very fine, and pressed into thin slices. The Nexus infrared chromatograph, Thermo Company, USA, was used to scan in the range of 400-4000 cm ^-1 .

As shown in Figure 3, the product has obvious polysaccharide characteristics, 889 cm ^-1 shows that the sugar is connected by β-glycosidic bonds, 3415.7 cm ^-1 is OH, and 2917.8 cm ^-1 is CH.

(3) Periodic acid oxidation

Take 25mg of polysaccharide sample, dissolve it in 30mM sodium periodate solution, dilute to 25mL, 4X: dark reaction, take 0.1mL samples at intervals of 0h, 6h, 12h, 24h, 36h, 48h...etc. Dilute water to 25mL, measure OD 223nm. When the OD value is stable, add ethylene glycol to destroy the excess periodic acid. Calculate periodate consumption. Take 2mL of the reaction solution, and determine the amount of formic acid generated by titration.

 The OD 223nm was measured at different time points, and the ultraviolet absorption photometry value remained constant, indicating that there was no consumption of periodate; at the same time, no formic acid was produced by sodium hydroxide titration analysis. According to the experimental results, it was concluded that the polysaccharide was linked by (1-3) glycosidic bonds with galactose residues that did not consume sodium periodate.

(4) NMR

An appropriate amount of sample was dissolved in deuterated dimethyl sulfoxide (DMSO), using an instrument: Bruker Avance III spectrometer, 400 MHz. Measure the product hydrogen spectrum and carbon spectrum.

According to the experimental results, the analysis draws the structural formula of this polysaccharide as:

As shown in Figure 4, Figure 5, and Figure 6, the hydrogen spectrum shows that the number of H is consistent with the number of hydrogen in the structural formula. The specific analysis results are as follows: 5.123 (s, 1H, OH-6), 4.568 (m, 2H, OH-2, OH-4), 4.447 (s, 1H, H-1), 3.633 (s, 1H, H- 6), 3.386-3.369 (m, 2H, H-3, H-6), 3.272-3.185 (m, 3H, H-4, H-2, H-5).

The carbon spectrum shows that the carbon frame of PGHX contains six carbons, which is consistent with its structural formula; in addition, there is only one set of signals in the anomeric carbon region, and the chemical shift is greater than 103, indicating that the polysaccharide is connected by a single β-glycosidic bond without branching; After analysis, the following conclusions were drawn: 103.52 (C-1), 86.68 (C-3), 73.32 (C-2), 68.89 (C-4), 76.80 (C-5), 61.35 (C-6).

According to the molecular weight, where n>50, by adjusting the fermentation parameters, polysaccharides with n>100, n>200, n>300, n>400, n>500... can also be obtained.

Embodiment 4 product performance

(1) Water absorption

Take an appropriate amount of product (mass m ₁ ) from Example 2 (extraction method 1, fermentation time 60 hours), add several times the volume of water, mix well, and bathe in boiling water for 10 minutes. After cooling, take out the colloid, remove the surface moisture, and weigh (m ₂ ).

Experiments have proved that this polysaccharide can absorb more than 30 times its own weight in water.

(2) Gel strength

Take 0.6 g sample (in embodiment 2, extraction method one) in 20 ml of water, stir for 5 min, then transfer the suspension to a 18mm x 180mm test tube, aerate for 3 min under vacuum, then put the test tube into boiling water Bath for 10 minutes, then cool in cold water for 20 minutes. Take out the gel from the test tube, take a section of 10mm from the bottom 10mm-20mm, and put it on a physical property analyzer (Rheo Meter Model CR-200D, Sun Scientific Co., Ltd., Japan; Load cell: 1,000 g .) Use the P/0.5 probe to measure the force B (g) when the gel is broken, and calculate the gel strength (Gel Strength) according to the following formula.

Gel Strength(g/cm ² ) = B/πr ²

In the formula, r is the radius (cm) of P/0.5 probe.

After testing, the gel strength of this polysaccharide can reach 245-1450 g/cm ² . The appearance of the gel is shown in Figure 1b and Figure 1c. It can be seen from the figure that the gel has good elasticity.

(5) Molecular weight determination

Use Sephadex G-200 gel chromatography to analyze the molecular weight of fermentation products: Sephadex G-200 gel chromatography column, 1% NaCl elution, automatic fractional collection, phenol-sulfuric acid method to detect the peak position of fermentation products. Using T series standard dextran as a reference, calculate the molecular weight.

  From the above table, it can be concluded that the higher the degree of polymerization, the greater the gel strength. In addition, the water absorption performance of the product also affects the gel strength.

Claims (9)

1. a strain edaphic bacillus ( agrobacterium sp.) HX1126, be preserved in China Committee for Culture Collection of Microorganisms's common micro-organisms center (CGMCC) on 06 02nd, 2015, deposit number is CGMCC No.10943.

2. utilize edaphic bacillus to carry out fermenting and extracting a method for water suction polysaccharide, it is characterized in that, comprise the steps:

1st step, slant culture: by edaphic bacillus according to claim 1 ( agrobacterium) streak inoculation of HX1126 bacterial strain cultivates in slant medium;

2nd step, seed culture: inclined-plane seed in the 1st step is seeded to seed culture medium and cultivates;

3rd step, fermentation culture: cultured seed access fermention medium is cultivated by the inoculum size by 5 ~ 15%, obtains fermented liquid product;

4th step, extract product: extract and adopt one of the following two kinds method, the first: by fermented liquid product filtering and impurity removing, except supernatant, then add second alcohol and water successively and carry out cleaning, except supernatant, after centrifugation, obtaining product, after lyophilize and get final product; The second: by fermented liquid product filtering and impurity removing, except supernatant, then add NaOH solution, after centrifugal, collect supernatant liquor, then in supernatant liquor, adds HCl solution, regulates pH to neutral, gets precipitation, wash with water after centrifugal, after lyophilize and get final product.

3. the method utilizing edaphic bacillus to carry out fermenting and extracting water suction polysaccharide according to claim 2, it is characterized in that: in the 1st described step, the component of following mass percent is comprised: 20 ~ 50 g/L glycerine or PEARLITOL 25Cs in slant medium, 1-10 g/L yeast powder, 1 ~ 10 g/L peptone, 1 ~ 10g/L extractum carnis, 15 ~ 20 g/L agar, pH 6.5 ~ 7.5; Leavening temperature 28 ~ 32 DEG C, incubation time 40 ~ 60 hours.

4. the method utilizing edaphic bacillus to carry out fermenting and extracting water suction polysaccharide according to claim 2, it is characterized in that: in the 2nd described step, the component of following mass percent is comprised: 20 ~ 50 g/L glycerine or PEARLITOL 25Cs in seed culture medium, 1 ~ 10 g/L yeast powder, 1 ~ 10 g/L peptone, 1 ~ 10 g/L extractum carnis, 1 ~ 5 g/L (NH ₄) ₂hPO ₄, 0.5 ~ 5 g/L KH ₂pO ₄, 5 ~ 20 ml/L corn steep liquors, pH 6.5 ~ 7.5; Leavening temperature 28 ~ 32 DEG C, incubation time 20 ~ 30 hours.

5. the method utilizing edaphic bacillus to carry out fermenting and extracting water suction polysaccharide according to claim 2, it is characterized in that: in the 3rd described step, the component of following mass percent is comprised: 5 ~ 60 g/L glycerine or PEARLITOL 25Cs in fermention medium, 1 ~ 10 g/L yeast powder, 1 ~ 10 g/L (NH ₄) ₂hPO ₄, 5 ~ 20 ml/L corn steep liquors, 0.5 ~ 3g/L MgSO ₄7H ₂o, 0.2 ~ 1 g/L FeSO ₄7H ₂o, 0.02 ~ 1 g/L MnSO ₄h ₂o, 1g ~ 20g/L NaHPO ₄12H ₂o, 1g ~ 20g/L NaH ₂pO ₄2H ₂o, pH 5.3 ~ 8.3; Leavening temperature 28 ~ 32 DEG C, aerobic cultivation 48 ~ 90 hours.

6. the method utilizing edaphic bacillus to carry out fermenting and extracting water suction polysaccharide according to claim 2, it is characterized in that: in the 4th described step, the extracting method parameter of the first is: ethanol add 0.5 ~ 2 times that volume is fermentating liquid volume, ethanol purge number of times is more than 2 times; Water add 5 ~ 10 times that volume is fermentating liquid volume, water wash number is more than 3 times; The extracting method parameter of the second is: the volume of NaOH solution is 1 ~ 3 times of fermented liquid, and concentration is 0.5N, HCl strength of solution is 1N.

7. edaphic bacillus according to claim 1 ( agrobacterium) HX1126 is in fermentation and extract the application absorbed water in polysaccharide.

8. have a polysaccharide for water-absorbent, thermosetting, it is characterized in that, its structure is as follows:

; Wherein, n>50.

9. according to claim 8 have absorptive polysaccharide, it is characterized in that: the weight of described polysaccharide absorption water is more than 30 times of own wt, and above-mentioned polysaccharide is configured to the aqueous solution of 30 g/L, and 100 DEG C are heated 10 minutes, form heat setting glue, gel-strength scope 245 ~ 1450 g/cm ².