the present invention is further illustrated by means of examples below . however , the present invention is not thus limited within the scope of the examples . for experimental methods without any indicated specific conditions , conventional methods and conditions may be selected . otherwise , the selection can be made in accordance with the instructions of the description of the commercial products . the room temperature according to the present invention refers to the temperature of operating room for the experiment and is usually 25 ° c . the “ overnight ” according to the present invention is a conventional term in the art , and the preferred duration for it is 4 - 24 hours . paenibacillus hunanensis fel05 t ( accc 10718 t = cgmcc no . 1 . 8907 t ) and paenibacillus polymyxa atcc 842 t ( cgmcc no . 1 . 4261 t ) are purchased from china general microbiological culture collection center ( cgmcc ). example 1 acquisition of the new microorganism according to the present invention 1 ml yak milk samples collected at damxung county , tibet autonomous region , china is taken aseptically t and subjected to serial dilution with sterile normal saline . the diluent is spreaded onto the tyc agar evenly and then is cultured for 24 - 48 hours under 30 ° c . several snot - like , thread - drawing single colonies are selected and transferred respectively onto new tyc agar to obtain the purified colonies . example 2 acquisition of the new microorganism according to the present invention and the characteristics thereof biolog microbial automatic detector ( manufacturer : biolog inc .) identification assay is based on the differences in metabolism of individual carbon resource by different microorganisms . 95 types of carbon sources or other chemical substances are selected and fixed together with the color developing agent onto the 96 - well plate ( a1 well is the negative control well ). bacterial suspension is inoculated and cultured for certain time . characteristic fingerprint is generated by testing testing the turbidity caused by the growth of microorganisms . the final identification results are obtained by comparing the characteristic fingerprint with the standard strain profiles database . 1 ) a plurality of single colonies according to the above example 1 is taken and inoculated onto the liquid tyc respectively . they are cultured for a 24 hours under 30 ° c . 2 ) they are centrifuged for 20 min at the speed of 10000 r / min . the supernatant is discarded . 1 ml of sterilized saline is added . the mixture is shaken on a shaker for 5 min and centrifuged for 20 min at the speed of 10000 r / min to remove the carbon sources therein . the supernatant is discarded . 1 ml of sterilized saline is added , and the mixture is shaken on a shaker for 5 min . 3 ) the suspension is further diluted with sterile saline ( nacl , 0 . 85 %) to make a suspension of absorbance at 590 nm at 0 . 13 ± 0 . 02 . 4 ) the above suspension is added onto the biolog eco microplate ( 150 μl / well ). it is cultured under 20 ° c . the biolog bacteria automatic readout device reads the data every 12 hours for 2 days continuously . the results are shown in table 1 . three parameters should be taken into consideration to identify the results : probabilities ( prob ), similarities ( sim ), and distances ( dis ). sim and dis values are two important parameters , which indicates the matching degrees between the tested results and the corresponding data of the database . when dis & lt ; 5 . 0 and sim & gt ; 0 . 75 , the matching is good . the results show that the identified sim value of the strain bd3526 is 0 . 535 & lt ; 0 . 75 , indicating a low matching degree with the data of the database . this shows that it has a significant difference from the strains of the database in terms of metabolic characteristic . it probably is a new species of microorganism . the strain bd3526 has been deposited in china general microbiological culture collection center ( cgmcc ) since oct . 14 , 2013 , and the address for the deposition is : institute of microbiology , chinese academy of sciences , no . 1 - 3 west beichen road , chaoyang district , beijing 100101 . china . the deposit number for the strain is : cgmcc no . 8333 . the systematic name of the strain is paenibacillus sp ., with the name of bd3526 . example 3 characteristics of the new microorganism according to the present invention the single colonies of strain bd3526 is taken and transferred onto the tyc agar ( agar ). they are cultured aerobically at 30 ° c . for 24 hours , 36 h , and 48 h . the characteristics of colonies such as size , color , edge , embossment , smoothness , viscidity , and transparency are observed respectively . the results are shown in fig1 . the results show that on tyc agar , the strain bd3526 forms irregularly - edged , smooth , ropy , glossy - surfaced , and non - transparent colonies . the fresh cultures which have been cultured on tyc solid culture medium ( agar ) for 24 hours are picked up for physiological and biochemical tests . the results show that bd3526 is gram - positive bacillus with terminal spore , in the shape of an oval , and not expanded . the parameters for physical and chemical reactions of bd3526 are shown in table 2 . the acid produced from fermentable carbohydrates by strain bd3526 is determined using api 50 chb identification system ( manufacturer : biome &# 39 ; rieux ). in the reagent strips of api 50 chb , different serial numbers correspond to different carbon sources . meanwhile , the indicator is contained therein . thus , if the corresponding carbon source is metabolized and acids are produced from the corresponding substrate , the ph value of the culture solution will decrease , and the color of the indicator will change . it is easy to observe and record . 1 ) the components of api 50 chb basic culture medium are : 1 g of tryptone , 0 . 5 g of yeast extract , 2 g of ammonium sulfate , 0 . 18 g of phenol red , 10 ml of the inorganic salt base ( cohen - bazire ), and 1000 ml of phosphate buffer ( ph7 . 8 ). 2 ) freshly cultured colonies of bd3526 on tyc agar are picked and suspended into the sterilized saline , and transferred to the culture medium according to 1 ) to prepare a bacterial suspension with od 600 = 0 . 4 - 0 . 6 . 3 ) the bacterial suspension in 2 ) is then inoculated the the small tubes on api 50 chb test strips . a layer of sterilized paraffin oil is added into the tubes to cover the surface . 4 ) the inoculated tubes are cultured at 30 ° c . the change of color of the medium in the tubes ( originally blue - purple , in the case of acid produced , the color would changed to yellow ) are recordered at 24 and 48 hours respectively . the results for acid produced from fermented carbohydrates by strain bd3526 are shown in tables 3 and 4 . as shown in table 4 , the strain bd3526 and paenibacillus hunanensis fel05 t ( accc 10718 1 ) displayed different ability in terms of acid production from metabolizable carbohydrates , indicating that the two strains belong to different species . example 4 growth characteristics of the new microorganism according to the present invention 1 ) 30 ml of tyc liquid culture medium is added to the 100 ml erlenmeyer flasks respectively , and sterilized at 121 ° c . for 15 minutes ; 2 ) the freshly cultured colonies of strain bd3526 on tyc solid culture medium ( agar ) for 24 hours are inoculated into the tyc liquid culture medium as mentioned above , and incubated on a shaker at 30 ° c . for 20 - 24 hours to obtain the inocula . 3 ) the inocula of bd3526 obtained in 2 ) are transferred to the fresh tyc liquid culture at a ratio of 2 % ( v / v ) and thoroughly mixed . the mixture is added into the wells on a costar 96 - well sterile microwell plate , 150 μl for each well , and the experiment is taken out in triplicates , employing non - inoculated tyc liquid culture medium as the control . the absorbance of the wells at 600 nm are recorded at an interval of 30 min . the results are shown in fig2 . the inocula of bd3526 obtained in 2 ) are transferred to tubes containing 5 ml of the fresh tyc liquid culture at a ratio of 2 % ( v / v ) and thoroughly mixed . the inoculated tubes are cultured in water bath at 4 ° c ., 15 ° c ., 30 ° c ., 37 ° c ., 40 ° c . and 60 ° c ., respectively , in triplicates for each temperature gradient . the turbidity of the tubes are recorded at 24 hours and 48 h respectively to determine the growth of the strain bd3526 , empolying non - inoculated tyc liquid culture medium as the control . the obtained growth temperature range of strain bd3526 is 15 - 40 ° c ., preferably , 30 ° c . the inocula of bd3526 obtained in 2 ) are transferred to at a ratio of 2 % ( v / v ) to tubes containing 5 ml of the fresh tyc liquid culture with a sodium chloride concentration of 0 . 0 %, 2 . 0 %, 5 . 0 %, 7 . 0 % and 10 . 0 % respectively and cultured at 30 ° c . the turbidity of the tubes are recorded at 24 hours and 48 h respectively to determine the growth of the strain bd3526 , empolying non - inoculated tyc liquid culture medium as the control . the results show that the nacl tolerance for strain bd3526 is 10 %. the ph value of the sterile tyc culture medium is adjusted to 3 . 0 , 4 . 0 , 5 . 0 , 5 . 5 , 6 . 0 , 6 . 5 , 7 . 0 , 8 . 0 , 8 . 5 , 9 . 0 and 10 . 0 using sterile hcl and naoh . the inocula of bd3526 obtained in 2 ) are transferred to at a ratio of 2 % ( v / v ) to tubes containing 5 ml of the fresh tyc liquid culture of individual ph value and cultured at 30 ° c . the turbidity of the tubes are recorded at 24 hours and 48 h respectively to determine the growth of the strain bd3526 , empolying non - inoculated tyc liquid culture medium with individual ph value as the control . the obtained ph range for growth of strain bd3526 is 5 . 5 - 8 . 5 , and preferably is 6 . 0 . example 5 the 168 phylogenetic characteristics for the new microorganism according to the present invention the genomic dna of strain bd3526 is obtained in accordance with the operation procedure for gram - positive bacteria using tianamp bacteria dna kit . the absorbance thereof is determined at 230 nm , 260 nm , and 280 nm . the a260 : a280 : a230 thereof is 1 : 0 . 510 : 0 . 445 . the fragment of 16s rdna of strain bd3526 is amplified using 27f , 1492r - primer . the amplified fragments are purified and then ligated to the ta cloning vector of pmd19 - t simple vector . then , they are put into the water bath of 16 ° c . overnight . they are transformed into the competent cell of e . coli dh5a . they are spread onto the lb agar culture medium plate with ampicillin . they are cultured under 37 ° c . for 16 - 20 hours . the positive transformants are picked up . the positive transformants mentioned above are sent to jie li biology co . in shanghai for sequencing . the results for sequencing are put into the database of ncbi and eztaxon , and the most similar strain found through comparing is paenibacillus hunanensis fel05 t with a similarity of 96 . 6 %. sequences for the primer pair mentioned above are : for 1492r : taccttgttacgacit , and for 27f : agagtitgatcctggctcag . the result of gene sequencing of 16s rrna of strain bd3526 is shown in seq id no . 1 . the sequence of 16s rrna mentioned above is compared by using the software of clustal_x program ( version 1 . 83 ) and the phylogenic tree is drawn by mega version 4 . 0 . 2 . software . using neighbor - joining for calculation with maximum - parsimony and maximum - likelihood for verification calculation , the bootstrap is set as 1000 cycles . the results are shown in fig3 . as shown in fig3 , through the analysis on phylogenetic tree of 16s rrna gene , strain bd3526 shall be classified as the cluster of paenibacillus hunanensis . however , the similarity between strain bd3526 and the type strain of paenibacillus hunanensis is 96 . 6 %. however , similarity of 16s rrna gene lower than 97 % is the threshold to descriminate different species strains in the same genus . moreover , much evidence has been proven that for some bacteria with the similarity over 99 % on gene sequence for 16s rrna are still classified as different species . thus , the strain bd3526 is likely to be a new species of microorganism with its other physiological and biochemical indexes to be verified . example 6 characteristics on fatty acid content for the new microorganism according to the present invention the following solutions are prepared : 1 , 45 g of sodium hydroxide is dissolved in 150 ml of methanol and 150 ml of distilled water ; ii , 190 ml of concentrated hydrochloric acid and 275 ml of methanol are dissolved in 135 ml of distilled water ; 1 , 200 ml of normal hexane is mixed with 200 ml of ethyl ether homogeneously . iv , 10 . 8 g of sodium hydroxide is dissolved in 900 ml of distilled water ; and v , saturated sodium chloride solution . 1 ) a certain amount of the bacterial culture is taken and added into a 8 ml - screwed glass tube . 1 ml of solution i is added . the screw cap of the tube is fastened and put into the boiling water bath for 5 min . it is taken out and shaken for 5 to 10 seconds . it is put into the boiling water bath for 25 min . 2 ) once the sample tube is cooled down , 2 ml of solution 11 is added into it . the tube is capped , shaken . and bathed for 10 min at 80 ± 1 ° c . with an accurate control . then , it is cooled down with ice bath . 3 ) 1 . 25 ml of solution ill is added into the solution mentioned above . it is rapidly shaken for about 10 min . the lower aqueous phase is discarded . 4 ) 3 ml of solution iv and 0 . 1 - 0 . 2 ml of solution v are added into the remaining organic phase . it is rapidly shaken for about 5 min . two thirds of the upper organic phase is taken and put into the sample bottle of chromatography . the hp6890 gas chromatograph is equipped with split / splitless inlet , hydrogenation flame ionization detector ( fid ) and hp gas chromatograph chemstation ; the chromatographic column is ultra - 2 column with the length of 25 m , the inner diameter of 0 . 2 mm , and the liquid film thickness of 0 . 331 μm . the furnace temperature is two step programmed rising temperature . the initial temperature is 170 ° c . the temperature is raised up to 260 ° c . in the rate of 5 ° c ./ min and then raised up to 310 ° c . in the rate of 40 ° c ./ min and maintained for 1 . 5 min . the temperature at inlet is 250 ° c . and the carrier gas is hydrogen with the flow rate of 0 . 5 ml / min in split mode . the split ratio is 100 : 1 . the sample size is 2 μl . the temperature for test is 300 ° c ., the flow rate of hydrogen is 30 ml / min , the flow rate of air is 216 ml / min and the flow rate of supplemental gas ( nitrogen ) is 30 ml / min . the results show that the main cellular fatty acids of strain bd3526 are anteiso saturated fatty acid c 15 : 0 , anteiso heptadecenoic saturated fatty acid , and hexadecanoyl saturated fatty acid . the percentages of the contents are 59 . 02 %, 11 . 09 %, and 7 . 66 % respectively . the main fatty acid in accordance with the paenibacillus is anteiso saturated fatty acid c 15 : 0 . both the type and the content of the fatty acid thereof are different from those of the similar strains . therefore , the strain is determined as a different species from similar strains . example 7 characteristics on g + c mol % content for the new microorganism according to the present invention the determination for g + c mol / o content of genomic dna for strain bd3526 . the melting temperature ( tm ) method is used . e . coli k12 , as 1 . 365 is used as the reference control . the device used is the lambda35 uv / vis spectrometer of perkin / elmer . the temperature is controlled by ptp - 1 temperature digital controller . the steps are as follows : 1 ) the sample dna to be tested is diluted with 0 . 1 × ssc such that its od 260 mm value ranges from 0 . 3 to 0 . 4 ; 2 ) the od value is recorded under 25 ° c . at the wavelength of 260 nm firstly . then the temperature raising procedures is set up to raise the temperature from 65 ° c . to 95 ° c . at the rate of rising 1 ° c . per minute ; 3 ) the raising of od value indicates the beginning of denaturation . the temperature of cuvette and the od value are recorded until the od value remains unchanging , which indicates the completion of denaturation ; and 4 ) the melting temperature ( tm ) is obtained based on the thermal denaturation curve and calculating the g + c mol % content . g + c mol %= g + c mol % as 1 . 365 + 2 . 08 ( tm unknown − tm as1 . 365 ) the tm of e . coli k12 , as 1 . 365 determined in the test is 75 . 810 ° c . the tm value and g + c mol % of the strain to be tested . the results of g + c mol % of strain bd3526 are shown in table 5 . the g + c mol % of strain bd3526 is 47 . 48 %, the g + c mol % of paenibacillus hunemensis fel05 t ( accc 10718t = cgmcc 1 . 8907 t = dsm22170 t ) g + c mol % is 53 . 3 %. the difference between the two strains is greater than 5 %. the g + c content of paenibacillus range is within 45 - 54 mol %. according to the “ common bacteria identification system manual ” ( dongfang xiu , cai miaoying ), the g + c content of paenibacillus range is within 45 - 54 mol %; the difference of g + c mol % between the two strains is greater than 5 %. therefore , these two strains can be determined as different species ( such determination can be made even if other characteristics are similar ). therefore , the strain bd3526 is classified as paenibacillus sp . which belongs to a different species with respect to its most - similar strain paenibacillus hunanensis fel05 t ( accc 10718 t = cgmcc 1 . 8907 t = dsm22170 t ). example 8 hybridization experiment for the new microorganism according to the present invention the hybridization experiment between strain bd3526 and the strain with the most related genetic relationship , and the hybridization experiment between strain bd3526 and the type strain of paenibacillus . referring to the results of 16s rrna , dna - dna hybridization experiment between strain bd3526 and the species of pamibacillus hunanensis fel05 t ( accc10718 t = cgmcc 1 . 8907 t = dsm 22170 t ) with the most related genetic relationship is conducted , and dna - dna hybridization experiment between strain bd3526 and the type strain pamibacillus polymyxa atcc 842 t (= cgmcc 1 . 4261 t = dsm 36 t = kctc 3858 t ) of pamibacillus is conducted . the method of liquid phase renaturation rate is used . the device used is the perkin elmer lambda35 uv / vis spectrophotometer . the temperature is controlled by ptp - 1 peltier system digital temperature controlling system . the steps are as follows . 1 ) dna sample processing : the dna sample is extracted as described in example 5 above . before the experiment , it is ice - bathed and zapped with the ultrasonic wave of 40 w for 24 minutes ( the setting is : zapping for 3 seconds / pausing for 3 seconds ). the concentration of dna sample is od 260 nm of 2 . 0 . the dna sample is cut into fragments of 2 - 5 × 10 5 daltons . 2 ) the dna samples ( a , b ) to be tested are precisely prepared using 0 . 1 × ssc respectively into a status where the od 260 nm value range is 1 . 8 - 2 . 0 . the od 260 nm value for both of them shall be consistent ( as accurate as 0 . 001 ). 3 ) after entering the uv winlab program ( manufacturer : perkin elmer ), the method window appears . the “ time - driven ” ( td ) method in the method window is selected . proper parameters are set on the “ timed , inst . sample .” setting page . the wavelength for determination is 260 nm and the total time for determination is set as 30 minutes . the optimal renaturation temperature ( tor ) on the basis of the g + c mol %. the temperature of cuvette is kept stable at the optimal renaturation temperature . in 2 × ssc reaction liquid , the optimal renaturation temperature is calculated by the formula : tor = 0 . 51 × ( g + c ) mol %+ 47 . 4 ) 400 μl of the dna samples of each of the two strains is added into two centrifugal tubes separately . 200 μl of the dna samples of each of the two strains is added into the same centrifugal tube to form the mixed sample . 5 ) before testing , the single dna sample and mixed dna sample should be degenerated for 15 min under 100 ° c . through ptp - 1 temperature - control system ( manufacturer : perkin elmer ), respectively . they are cooled down to the optimal renaturation temperature . the od 260 nm value is recorded . the reading does not stop until 30 - min of the reaction . the temperature of samples should not be lower than tor during the whole process . finally , a straight line showing a gradually decreased absorbance value with time is be obtained . 6 ) based on the software uv winlab , select “ slope ” in “ algorithm ” column therein to obtain the renaturation rate ( v ), namely , slope (“ v ” usually represents the reduced amount of absorbance per minute ). homogenous hybridization rate ( h )%= 4 vm −( va + vb )/ 2 √{ square root over ( vavb )}= 100 % the results show that the dna homology between the strains bd3526 and paenibacillus hunanensis fel05 t ( accc 10718 t = cgmcc 1 . 8907 1 = dsm 22170 1 ) is 39 . 82 ˜ 42 . 10 %. with respect to the type strain paenibacillus polymyxa atcc 842 t (= cgmcc 1 . 4261 t = dsm 36 t = kctc 3858 t ) of paenibacillus , the dna homology is 41 . 62 - 48 . 60 %. based on “ bergey &# 39 ; s manual of determinative bacteriology ”, under the optimum conditions , if the dna homology is greater than 70 %, they belong to the same species ; and if the dna homology is greater than 20 %, they belong to the same genus . together with the data of examples 2 , 3 , 4 , 5 and 6 , it is determined that the strain bd3526 belong to a new species of paenibacillus . the taxonomic status of this strain is paenibacillus sp . it is likely to be named as paenibacillus dainxungensis sp . nov . in accordance with the naming method of international committee systematic bacteriology . moreover , the strain bd3526 is selected as the type strain of this species . example 9 use of the new microorganism according to the present invention as shown in fig1 , the colonies of strain bd3526 are viscous , indicating a high yield of extracellular polysaccharide thereof . the single colonies mentioned above are picked up and inoculated onto the tyc liquid culture medium for fermentation . the products are obtained after ethanol precipitation . they are identified as polysaccharides . the polysaccharide is produced by the natural fermentation of strain bd3526 . it is safe , nontoxic , and may serve as an emulsifier , thickener , stabilizer , gelatinizer , and etc . for industrial applications . strain bd3526 can also be used directly in the form of a microbial therapeutic agent . ( 1 ) the fermentation of paenibacillus and the preparation for fermentation broth 10 . 0 mg of the freeze - dried powder of paenibacillus bd3526 is dissolved with 1 ml of sterile distilled water ( 100 mg / 0 . 1 ml , impossible !). one loop of the suspension is picked and streaked on the solid polysaccharide - producing culture medium ( the solid polysaccharide - producing culture medium is consisted of 1 . 2 % of agar , 10 %/ o of saccharose , 1 % of casein tryptone , 5 % of yeast extract , 5 % of k 2 hpo 4 , 0 . 034 % of cacl 2 , and distilled water , wherein the percentages refer to the mass percentages with respect to the solid - polysaccharide - producing culture medium ). it is aerobically cultured for 24 hours at 30 ° c . the single colony formed on the solid polysaccharide - producing culture medium is picked up and transferred into the liquid polysaccharide - producing culture medium ( consisting of 10 % of saccharose , 1 % of casein tryptone , 0 . 5 % of yeast extract , 0 . 5 % of k 2 hpo 4 , 0 . 034 % of cacl 2 , and distilled water , wherein the percentages refer to the mass percentages with respect to the liquid polysaccharide - producing culture medium ). it is cultured for 24 hours under 30 ° c . to obtain the inocula . the inocula is transferred intofresh liquid polysaccharide - producing culture medium at a ratio of 2 % ( v / v ). it is cultured for 72 hours under 30 ° c . to obtain the fermentation broth . ( 2 ) the preparation of the crude product of extracellular polysaccharide in the fermentation broth ( 2 . 1 ) the fermentation broth obtained in step ( 1 ) is heated under 100 ° c . for 10 minutes . it is cooled down to 25 ° c . the ph value is adjusted to 4 . 60 with food - grade lactic acid or hydrochloric acid . it stands for 4 hours . it is centrifuged for 10 min ( 14000 g ). the supernatant is taken . 3 volumes of 95 %- ethanol solution to that of the supernatant are added under gentle stirring and the mixture stands overnight . it is centrifuged for 10 min ( 14000 g ). the precipitates are collected . the percentage refers to the mass percentage of the ethanol with respect to the ethanol solution . ( 2 . 2 ) the precipitate obtained in step ( 2 . 1 ) is dissolved in distilled water at 60 ° c . to reach a final concentration of 0 . 8 %. the percentage refers to the mass - volume percentage of the solution of precipitates . when the solution is cooled down to 25 ° c ., trichloroacetic acid is added into the solution to a final concentration of 4 % ( w / v ). the solution stands for 16 hours under 4 ° c . it is centrifuged or filtered to remove precipitates . the supernatant is dialyzed using a dialysis bag ( spectrumlabs , u . s .) with a molecular weight cut - off of 1000 da against distilled water for 72 hours . water is changed every 12 hours . the retentate is obtained . ( 2 . 3 ) the retentate obtained in step ( 2 . 2 ) is vacuum freeze dried under the condition of 0 . 160 mbar , − 30 ° c . for 72 hours to obtain the crude product of extracellular polysaccharide . the purity of the crude extracellular polysaccharide is checked by determining its absorbance at 490 nm via sulfuric - phenol method or directly at 280 nm . the results are shown in fig4 . a 490 nm is the characteristic peak of polysaccharide . a280 nm is the characteristic peak of protein . the results show that there is only one symmetric peak at 490 nm , indicating that the content of crude proteins in extracellular polysaccharide is ignorable . meanwhile , based on the calibration curve of standards ( glucose or bovine serum albamin respectively ) at a490 nm and a280 nm , it is known that the crude product of extracellular polysaccharide has a high purity . the extracellular polysaccharide content is 95 . 7 %, the percentage refers to the mass percentage of the crude product of extracellular polysaccharide . ( 1 ) 100 mg of the crude product of the extracellular polysaccharide obtained in example 10 is dissolved in tris - hcl buffer ( 0 . 05 mol / l , ph 7 . 60 ) to prepare the solution with a concentration of 10 . 0 mg / ml . the chromatography is performed on the deae - sepharose ff column ( d1 . 6 × 100 cm ) ( ge healthcare ). the linear gradient elution is conducted with the tris - hcl buffer and in turn the tris - hcl buffer ( 0 . 05 mol / l , ph 7 . 60 ) which contains 0 . 2 - 1 . 2 mol / l - nacl . the flow rate is 3 ml / min . the liquid is collected in tubes ( 6 ml per tube ). the sulfuric acid - phenol method ( dubois , m ., k . a . gilles , j . k . hamilton , p . a . rebers , and f . smith , 1956 . colorimeteric method for determination of sugars and related substances . anal . chem . 28 : 350 - 356 ) is used for tracking and monitoring . the absorbance is determined at the wavelength of 490 nm ( i . e . the characteristic wavelength for the polysaccharide ). based on tube numbers corresponding to the absorbance , the plot is drawn to obtain the elution curve a . the data of the elution curve are shown in table 6 . thus , the primarily purified component of polysaccharide is obtained . that is , peak f 1 ( refer to fig5 ) may comprise two or more different polysaccharide components . further purification for verification is required . ( 2 ) the aqueous solution obtained through the elution from the tube with the number corresponding to the single peak ( f 1 ) obtained in fig5 in step ( 1 ) is collected . it is dialyzed with a 1000 da - dialysis bag in deionized water for 72 hours . the vacuum freeze drying ( 0 . 160 mbar , − 30 ° c .) is conducted for 72 hours to obtain the component b of extracellular polysaccharide . ( 3 ) the component b of extracellular polysaccharide obtained in step ( 2 ) is dissolved in the tris - hcl buffer to prepare the solution with the concentration of 10 . 0 mg / ml . the chromatography is performed on the ion exchange column ( the packing is deae - sepharose cl - 4b ; column : d1 . 6 × 100 cm , ge healthcare ). the elution is conducted using the tris - hcl buffer which contains 0 . 2 - 1 . 2 mol / l nacl . the flow rate is 3 ml / min . the eluent is collected in tubes ( 6 ml per tube ). the sulfuric acid - phenol method is used for tracking and monitoring . the absorbance at the wavelength of 490 nm is determined . based on the tube numbers corresponding to the absorbance , the plot is drawn to obtain the elution curve b . the experimental results are shown in fig6 . there is only one single peak f 2 in fig6 , indicating that only one component of polysaccharide is contained . moreover , f 2 is the component of polysaccharide obtained through the further purification of the primarily purified component f 1 of polysaccharide . ( 4 ) the aqueous solution obtained through chromatography from the tubes with numbers corresponding to the single peak ( f 2 ) in fig6 in step ( 3 ) is collected . it is dialyzed with a 1000 - da - dialysis bag in deionized water for 72 hours . the vacuum freeze drying is conducted under the condition of 0 . 160 mbar , − 30 ° c . for 72 hours to obtain the purified extracellular polysaccharide , wherein the polysaccharide content is 100 % with no proteins contained . the percentage refers to the mass percentage of the extracellular polysaccharide . the purified extracellular polysaccharide prepared in example 10 and 11 will be used in examples 14 to 18 . ( 1 ) the fermentation of paenibacillus and the preparation for fermentation broth 10 . 0 mg of the freeze - dried powder of paenibacillus bd3526 is dissolved in 0 . 1 ml of sterile distilled water . the strain is picked up with an inoculating loop and streaked on the solid polysaccharide - producing culture medium ( consisting of 1 . 2 % of agar , 10 % of saccharose , 1 % of casein tryptone , 0 . 5 % of yeast extract , 0 . 5 % of k 2 hpo 4 , 0 . 034 % of cacl 2 , and distilled water , wherein the percentages refer to the mass percentages with respect to the solid polysaccharide - producing culture medium ) and cultured aerobically at 30 ° c . for 24 hours . the single colonies are picked up from the solid polysaccharide - producing culture medium and transferred into the liquid polysaccharide - producing culture medium ( consisting of 10 % of saccharose , 1 % of casein tryptone , 0 . 5 % of yeast extract , 0 . 5 % of k 2 hpo 4 , 0 . 034 % of cacl 2 , and distilled water , wherein percentages refer to the mass percentages of the liquid polysaccharide - producing culture medium ) for a 24 hours - culture under 30 ° c . to obtain the seed liquid . it is cultured for 24 hours under 30 ° c . to obtain the inocula . the inocula is transferred intofresh liquid polysaccharide - producing culture medium at a ratio of 2 % ( v / v ). it is cultured for 72 hours under 30 ° c . to obtain the fermentation broth . ( 2 ) the preparation of the crude product of extracellular polysaccharide in the fermentation broth ( 2 . 1 ) the fermentation broth obtained in step ( 1 ) is heated under 95 ° c . for 10 min . once cooled down to 15 ° c ., the ph value is adjusted to 4 . 4 with food - grade lactic acid or hydrochloric acid . it stands for 3 hours . it is centrifuged for 10 min ( 14000 g ) the supernatant is taken . 4 volumes of 80 %- ethanol solution of the supernatant is added under gentle stirring and the mixture is left to stand overnight . it is centrifuged for 10 min ( 14000 g ). the precipitates are collected . the percentage refers to the mass percentage of the ethanol solution . ( 2 . 2 ) the precipitate obtained in step ( 2 . 1 ) is dissolved in distilled water whose temperature is 50 ° c . to reach a final concentration of 0 . 5 %. which percentage refers to the mass - volume percentage of the solution of precipitate . once cooled down to 25 ° c . trichloroacetic acid is added to the solution , such that the final percentage of trichloroacetic acid is 10 %. the percentage refers to the mass - volume percentage of the solution . the solution stands for 16 hours under 4 ° c . it is centrifuged or filtered to remove precipitates . the supernatant is obtained . the supernatant is dialyzed with a dialysis bag ( spectrumlabs , u . s .) with a molecular weight cut - off of 1000 da against distilled water for 72 hours . the water is changed every 12 hours to obtain the dialyzed aqueous solution . ( 2 . 3 ) the dialyzed aqueous solution obtained in step ( 2 . 2 ) is vacuum freeze dried directly . it is vacuum freeze dried under the condition of 0 . 160 mbar , − 30 ° c . for 72 hours to obtain the crude product of extracellular polysaccharide . the absorbance at a 490 nm by sulfuric acid - phenol method and a280 nm are determined to determine the purity . ( 1 ) 100 mg of the crude product of the extracellular polysaccharide obtained in example 10 is dissolved in the tris - hcl buffer ( 0 . 05 mol / l , ph 7 . 60 ) to prepare a solution with the concentration of 5 mg / ml . the chromatography is performed on the deae - sepharose ff column ( d1 . 6 × 100 cm ) ( ge healthcare ). the linear gradient elution is conducted with the tris - hcl buffer and in turn the tris - hcl buffer ( 0 . 05 mol / l , ph7 . 60 ) which contains 0 . 2 - 1 . 2 mol / l nacl . the flow rate is 2 ml / min . the liquid is collected in tubes ( 6 ml per tube ). the sulfuric acid - phenol method is used to determine the absorbance at the wavelength of 490 nm ( i . e . the characteristic wavelength for polysaccharide ). based on the tube numbers corresponding to the absorbance , the plot is drawn to obtain the elution curve a . thus , a primarily purified component of polysaccharide is obtained , namely , the single peak f 1 . ( 2 ) the aqueous solution obtained from the tube with the number corresponding to the single peak ( f 1 ) through elution in step ( 1 ) is collected . it is dialyzed with a 1000 da - dialysis bag in deionized water for 72 hours . the vacuum freeze drying ( 0 . 160 mbar , − 30 ° c .) is conducted for 72 hours . the component b of extracellular polysaccharide is obtained . ( 3 ) the component b of extracellular polysaccharide obtained in step ( 2 ) is dissolved in the tris - hcl buffer to prepare a solution with the concentration of 5 mg / ml . the chromatography is performed on ion exchange column ( wherein the packing is deae - sepharose cl - 4b ; column : d1 . 6 × 100 cm , ge healthcare ). the elution is conducted with the tris - hcl buffer which contains 0 . 2 - 1 . 2 mol / l nacl . the flow rate is 2 ml / min . the liquid is collected in tubes ( 6 ml per tube ). the sulfuric acid - phenol method is used for tracking and monitoring . the absorbance is determined at the wavelength of 490 nm . based on the tube numbers corresponding to the absorbance , the plot is drawn to obtain the elution curve b . thus , the further purified component of polysaccharide is obtained on the basis of component f 1 , namely , the single peak f 2 . ( 4 ) the aqueous solution obtained from the tube with the number corresponding to the single peak ( f 2 ) through chromatography in step ( 3 ) is collected . it is dialyzed with a 1000 da - dialysis bag in deionized water for 72 hours . the vacuum freeze drying ( 0 . 160 mbar , − 30 ° c .) is conducted for 72 hours to obtain the purified extracellular polysaccharide . example 13 preparation and purification for extracellular polysaccharide of the strain bd3526 ( 1 ) the fermentation of paenibacillus and the preparation for fermentation broth 10 . 0 mg of the freeze - dried powder of paenibacillus bd3526 is dissolved with 1 ml of sterile distilled water ( 100 mg / 0 . 1 ml , impossible !). one loop of the suspension is picked and streaked on the solid polysaccharide - producing culture medium ( the solid polysaccharide - producing culture medium is consisted of 1 . 2 % of agar , 10 % of saccharose , 1 % of casein tryptone , 5 % of yeast extract , 5 % of k 2 hpo 4 , 0 . 034 % of cacl 2 , and distilled water , wherein the percentages refer to the mass percentages with respect to the solid - polysaccharide - producing culture medium ). it is aerobically cultured for 24 hours at 30 ° c . the single colony formed on the solid polysaccharide - producing culture medium is picked up and transferred into the liquid polysaccharide - producing culture medium ( consisting of 10 % of saccharose , 1 % of casein tryptone , 0 . 5 % of yeast extract , 0 . 5 % of k 2 hpo 4 , 0 . 034 % of cacl 2 , and distilled water , wherein the percentages refer to the mass percentages with respect to the liquid polysaccharide - producing culture medium ). it is cultured for 24 hours under 30 ° c . to obtain the inocula . the inocula is transferred intofresh liquid polysaccharide - producing culture medium at a ratio of 1 % ( v / v ). it is cultured for 72 hours under 30 ° c . to obtain the fermentation broth . ( 2 ) the preparation of the crude product of extracellular polysaccharide in the fermentation broth ( 2 . 1 ) the fermentation broth obtained in step ( 1 ) is heated under 100 ° c . for 30 min . it is cooled down to 25 ° c . the ph value is adjusted to 4 . 8 with food - grade lactic acid or hydrochloric acid . it stands for 5 hours . it is centrifuged for 10 min ( 14000 g ). the supernatant is taken . 80 %- ethanol solution with the volume twice as much as that of the supernatant is added into the centrifuged supernatant mentioned above . it stands overnight . it is centrifuged for 10 min ( 14000 g ). the precipitates are collected . the percentage refers to the mass percentage of the ethanol with respect to the ethanol solution . ( 2 . 2 ) the precipitates obtained in step ( 2 . 1 ) is dissolved with distilled water whose temperature is 80 ° c . to reach a final concentration of 1 %. the percentage refers to the mass - volume percentage of the solution of precipitates . when the solution is cooled down to 25 ° c ., the trichloroacetic acid is added , such that the final percentage of the trichloroacetic acid is of 6 %. the percentage refers to the mass - volume percentage of the solution . the solution stands for 16 hours under 4 ° c . it is centrifuged or filtered to remove precipitates . the supernatant is obtained . the supernatant is dialyzed using a dialysis bag ( spectrumlabs , u . s .) which has a molecular weight cut - off of 1000 da in distilled water for 72 hours . the water is changed every 12 hours . the dialyzed aqueous solution is obtained . ( 2 . 3 ) the dialyzed aqueous solution obtained in step ( 2 . 2 ) is vacuum freeze dried directly . it is vacuum freeze dried under the condition of 0 . 160 mbar , − 30 ° c . for 72 hours to obtain the crude product of extracellular polysaccharide . the absorbance at a 490 nm and a 280 nm is determined to determine the purity . ( 1 ) 100 mg of the crude product of the extracellular polysaccharide obtained in example 10 is dissolved in the tris - hcl buffer ( 0 . 05 mol / l , ph7 . 60 ) to prepare a solution with the concentration of 20 mg / ml . the chromatography is performed on the deae - sepharose ff column ( d1 . 6 × 100 cm ) ( ge healthcare ). the linear gradient elution is conducted with the tris - hcl buffer and in turn the tris - hcl buffer ( 0 . 05 mol / l , ph7 . 60 ) which contains 0 . 2 - 1 . 2 mol / l nacl . the flow rate is 6 ml / min . the liquid is collected in tubes ( 6 ml per tube ). the sulfuric acid - phenol method is used to determine the absorbance at the wavelength of 490 nm ( i . e . the characteristic wavelength for polysaccharide ). based on tube numbers corresponding to the absorbance , the plot is drawn to obtain the elution curve a . thus , the primarily purified component of polysaccharide is obtained , namely , the single peak f 1 . ( 2 ) the aqueous solution obtained from the tube with the number corresponding to the single peak ( f 1 ) through the elution in step ( 1 ) is collected . it is dialyzed with a 1000 da - dialysis bag in deionized water for 72 hours . the vacuum freeze drying ( 0 . 160 mbar , − 30 ° c .) is conducted for 72 hours to obtain the component b of extracellular polysaccharide . ( 3 ) the component b of extracellular polysaccharide obtained in step ( 2 ) is dissolved in the tris - hcl buffer to prepare a solution with the concentration of 20 mg / ml . the chromatography is performed on the ion exchange column ( the packing is deae - sepharose cl - 4b ; column : d1 . 6 × 100 cm , ge healthcare ). the elution is conducted using the tris - hcl buffer which contains 0 . 2 - 1 . 2 mol / l nacl . the flow rate is 6 ml / min . the liquid is collected in tubes ( 6 ml per tube ). the sulfuric acid - phenol method is used for tracking and monitoring . the absorbance at the wavelength of 490 nm is determined . based on the tube numbers corresponding to the absorbance , the plot is drawn to obtain the elution curve b . thus , a further purified component of polysaccharide is obtained on the basis of component f 1 , namely , the single peak f 2 . ( 4 ) the aqueous solution obtained from the tube with the number corresponding to the single peak ( f 2 ) through chromatography in step ( 3 ) is collected . it is dialyzed with a 1000 - da - dialysis bag in deionized water for 72 hours . the vacuum freeze drying is conducted under the condition of 0 . 160 mbar , − 30 ° c . for 72 hours to obtain the purified extracellular polysaccharide . 2 . 0 mg of the purified extracellular polysaccharide obtained in example 11 and kbr are ground and tableted . the infrared multispectral scan ( xu guangtong , yuan hongfu , lu wanzhen , et al , development of modern near infrared spectroscopic techniques and its applications , spectroscopy and spectral analysis , 2000 , 02 : 134 - 142 ) ( infrared spectrometer : thermo fisher scientific ) is conducted within the area of 4000 - 500 cm − 1 . the infrared spectrogram is shown in fig7 . detailed data are shown in table 7 . 10 mg of the purified extracellular polysaccharide obtained in example 11 is dissolved in 1 ml of heavy water ( d 2 o ). the 1h - nmr and 13 c - nmr spectrums are determined using jnm - a500 ( manufactured by nippon denshi ). the 13 c - nmr spectrum is shown in fig8 . the specific data of 1 h - nmr spectrum are as follows : δ ( 3 . 538 )-( 3 . 585 ) ppm is h - 6b , 6 ( 3 . 661 )-( 3 . 692 ) ppm is h - 1b ; δ ( 3 . 748 )-( 3 . 793 ) ppm is h - 1a : δ ( 3 . 894 ) ppm is h - 6a ; δ ( 3 . 935 ) ppm is h - 5 ; δ ( 4 . 082 )-( 4 . 132 ) ppm is h - 4 ; and δ ( 4 . 082 )-( 4 . 132 ) ppm is h - 4 , δ ( 4 . 184 )-( 4 . 205 ) ppm is h - 3 . in fig8 . δ ( 62 . 67 ) is c - 1 , δ ( 66 . 46 ) − δ ( 66 . 25 ) is c - 6 ; δ ( 77 . 38 ) − δ ( 77 . 98 ) is c - 4 ; δ ( 79 . 07 ) is c - 3 : δ ( 83 . 07 ) − δ ( 83 . 92 ) is c - 5 ; and δ ( 79 . 07 ) is c - 2 . therefore , comparing with the standard spectrum for glycosidic bond of fructose , these data indicate that the extracellular polysaccharide refers to the levan jointed with β ( 2 → 6 ) glycosidic bond . meanwhile , the results of nmr data also indicate that the purified extracellular polysaccharide obtained in example 11 comprises no characteristic peaks of a non - carbohydrate structure such as protein , sulfide and amidogen , namely , it is a pure levan with no impurities ( for example , protein ) contained . ( 1 ) the standard samples with different molecular weights are sampled consecutively . the retention time tr is recorded . a standard curve is drawn , wherein the horizontal axis refers to retention time rt and the vertical axis refers to igm , so as to get the regression equation between the molecular weight and the retention time rt . ( 2 ) the purified extracellular polysaccharide to be tested is dissolved in ddh 2 o to reach a concentration of 10 g / l . sampling is conducted to obtain tr . the relative molecular weights of the samples are calculated through regression equation . column temperature : 30 ° c . ; flow rate : 1 ml / min ; concentration of sample : 10 mg / ml the results of molecular weight distribution of the polysaccharide mentioned above are shown in fig9 . the results indicate that : an absorption peak appears at the retention time of 9 . 7 min . comparing with the chromatogram of polysaccharide which has a standard molecular weight , the polysaccharide is formed by single polysaccharide . the range of average molecular weight of the polysaccharide mentioned above is 2500 - 5000 da . about 90 % of the extracellular polysaccharide molecules have a molecular weight within the range of 2500 - 5000 da , wherein the percentage refers to the mole percentage of the extracellular polysaccharide . example 16 : analysis on monosaccharide composition of the purified extracellular polysaccharide 10 mg of the purified extracellular polysaccharide is dissolved in 2 ml of the 0 . 05 mol / l h 2 so 4 solution . it is hydrolyzed for 2 hours under 80 ° c . to obtain the hydrolysate a . the hydrolysate a is diluted 100 times to obtain the hydrolysate b . the monosaccharide composition of hydrolysate b is analyzed by the high performance ion chromatography ( hpaec - pad ) ( suo hui , the primary structure of garlic fructan ( d ). jinan university , guangdong , 2010 ) the determination conditions for ion chromatography are : chromatographic column : ( carbopac , china ): carbl , 4 × 250 mm ; flow rate : 1 . 0 ml / min ; sample size : 20 μl ; detector : pulsed amperometric detector ( carbopac , china ), gold electrode ; temperature for determination : 30 ° c . the isocratic elution is conducted with 15 mm naoh solution . the experimental results are shown in fig1 . the results show that a peak of about 4200 na is produced by fructose at 14 : 36 min . the sample of the purified extracellular polysaccharide produces a peak at 14 : 54 min . the peak appears at the same time as that of fructose . this indicates that the purified extracellular polysaccharide is consisting of single fructose . the results of examples 14 to 16 show that the constitutional repeating unit of extracellular polysaccharide is fructose . the fructose is jointed by means of → 2 , 6 - fructose → 2 , 6 - fructose , the extracellular polysaccharide refers to levan and the structural formula of the extracellular polysaccharide is shown as formula ( 1 ), wherein , n = 15 ˜ 30 , and the extracellular polysaccharide has an appearance of pure white filament or powder . example 17 the proliferation of b . infantis promoted by extracellular polysaccharide in vitro ( 1 ) the faeces of 30 infants ( with the age range from 6 to 24 months , excluding the those who have intestinal diseases or taking antibiotic drugs recently ) is collected . the standard culture solution of fecal flora is prepared in accordance with the method of minekus et al ( models of the gastrointestinal tract to study microbial interactions original research article biology of growing animals , 2005 , 2 : 142 - 154 ). ( 2 ) certain amount of standard ileum efflux culture medium ( siem , with 0 . 047 g / l pectin , 0 . 047 g / l xyloglucan , 0 . 047 g / l arabinogalactan , 0 . 047 g / l amylose , 0 . 392 g / l starch , 24 . 0 g / l casein , 17 . 0 g / l tween 80 , 24 . 0 g / l bacto peptone , 0 . 4 g / l oxgall , and 0 . 2 g / l cysteine ) is added into a 96 - well microtitration plate . then , the 0 . 1 % of the standard culture solution of fecal flora is added . the percentage refers to the volume percentage of the standard ileum efflux culture medium . then , 0 . 4 % of the purified extracellular polysaccharide (“ bd3526 extracellular polysaccharide ” for short ) obtained in example 11 and 0 . 4 % of the commercialized fructooligosaccharide ( fos for short ) are added into different wells among the 96 wells respectively . the final volume of liquid in each well is 1 . 5 ml . meanwhile , the blank control is arranged . they are anaerobically cultured for 8 hours under 37 ° c . the percentage refers to the mass - volume percentage of the final volume of the liquid in a well of the 96 - well microtitration plate . ( 3 ) once the culture is completed , the fermentation broth is mixed with 250 μl of lysis buffer , 2501 μl of zirconium bead liquid ( 0 . 1 mm ) and 200 μl of phenol solution . then they are homogenized on the bead beater ( bio spec inc . u . s .) for twice ( 2 minutes for each time ). the dna is extracted with dna kit ( tiangen biotech co ., ltd ). then , pcr - intestinal microarray detection method ( salazar n , gueimonde m , hernandez - barranco a m , et al . exopolysaccharides produced by intestinal bifidobacterium strains act as fermentable substrates for human intestinal bacteria . applied and environmental microbiology , 2008 , 74 ( 15 ): 4737 - 45 .) is used to analyze the number of floras in samples with respect to that of the blank control ( standard solution of fecal flora cultured without adding polysaccharide ). the experimental results are shown in fig1 and table 8 ( wherein , the log ( orf / ml ) value of all floras in the blank control is defined as 0 ). as shown in fig1 , comparing with the blank control group . paenibacillus bd3526 eps ( e . g , fod ) can also promote the proliferation of the bifidobacteria in infants &# 39 ; fecal flora , especially the proliferation of b . breve . as shown in table 8 , comparing with the blank control , the number of bifidobacteria in floras is increased for both samples with added fos and bd3526 extracellular polysaccharide . especially for b . breve , the increment of number ( log ( orf / ml ) value ) of the sample with added bd3526 extracellular polysaccharide is 0 . 81 , which almost reaches that ( 1 . 18 ) of the sample with added fos . for b . longum , the increment of number ( log ( orf / ml ) value ) of the sample with added bd3526 extracellular polysaccharide is 0 . 36 , which approximates that ( 0 . 37 ) of the sample with added fos added . ( 1 ) the faeces of a healthy adult ( male or female , with the age range from 23 to 25 , excluding those who have intestinal diseases or taking antibiotic drugs recently ). they are dissolved in ph7 . 3 - phosphate buffer ( 8 g / l - nacl , 0 . 2 g / l - kcl , 1 . 15 g / l - nahpo 4 , and 0 . 2 g / l - kh 2 po 4 ) and mixed uniformly . it is added into the culture system at a volume ratio of 1 : 10 . then , 0 . 4 % of the purified extracellular polysaccharide ( bd3526eps for short ) obtained in embodiment 11 and 0 . 4 % of the commercialized fructooligosaccharide ( fos for short ) are added into the culture system respectively . meanwhile , the blank control is arranged . they are anaerobically cultured for 24 hours under 37 ° c . the percentages refer to the mass - volume percentages of the culture system . ( 2 ) once the culture is completed , the phenol - chloroform method ( ercolini d , hill p j , dodd c e . bacterial community structure and location in stilton cheese . applied and environmental microbiology , 2003 , 69 ( 6 ): 3540 - 8 ) is used to extract the dna of the cultures and fecal flora . then pcr - dgge ( denaturing gel gradient electrophoresis ) method is used ( analysis of inherited and acquired mutations using pcr and denaturing gradient gel electrophoresis ( dgge ) mutation research / environmental mutagenesis and related subjects , volume 252 , issue 2 , 1991 , 175 - 176 . a .- l . borresen , e . hovig , b . smith - s0rensen , s . lystad , a . bragger ) to analyze the composition of the flora of the samples . that is , the universal primer 357f ( as shown in seq id no . 4 ) ( 5 ′- tacgggaggcagcag - 3 ′), 518r ( as shown in seq id no . 5 ) ( 5 ′- attaccgcggctgctgg - 3 ′) of 16s rdna for the bacteria , and gc - clamp ( as shown in seq id no . 6 ) ( 5 ′- cgcccgccgcgcgcggcgggggggcgggggcacggggggcc - 3 ′) are used . the pcr amplification system is 25 μl ( 8 . 5 μl of sterile double distilled water , 1 μl of each of primer 518r , 1 μl of gc - 357f , 2 μl of template , and 12 . 5 μl of 2 × plus - mix ). the amplification protocol is : 5 min under 94 ° c . ; then 30 s under 94 ° c ., 30 s under 56 ° c ., 40 s under 68 ° c ., 35 cycles ; at last , 10 min under 72 ° c . for extension . the amplification products are added onto the gel with a polyacrylamide concentration of 8 % ( wt ) and a denaturing gradient range from 40 % ( wt ) to 60 % ( wt ). electrophoresis is conducted under 60 ° c . using the voltage of 75v with 1xtae as the electrophoresis buffer . once the electrophoresis is completed , stain the gel with ethidium bromide . photographs are taken with the gel imaging system . the results are shown in fig1 . the stripes pointed by arrows in fig1 are significantly brighter than those of the fos group and the blank control group this indicates that bd3526eps can promote the proliferation of bacteria of this kind in human intestinal flora , and has the ability to adjust the composition of human intestinal flora . although descriptions above on embodiments of the present invention are given , those skilled in the art shall understand that all these are just examples of illustration and various changes or modifications may be executed in these embodiments without departing from the principle and essence of the present invention . therefore , the protection scope of the present invention shall be limited by the claims attached .
provided are a new paenibacillus sp . strain , the deposit number of which is cgmcc no . 8333 , and a method for culturing the exopolysaccharide ; and an exopolysaccharide having a structural formula as shown in formula being produced by the strain , as well as a production method thereof and its use in promoting the propagation of bifidobacterium . the exopolysaccharide shown by formula has a moderate degree of polymerization and has the functions of promoting the propagation of bifidobacterium , as well as adjusting human intestinal microflora .