137 results about "Welan gum" patented technology

The invention relates to Sphingomonas sp. TP-5 and a method and an application of the same for producing welan gum. A strain of the invention is prepared by separating and acclimating sugar-contained wastewater in a molasses plant, has a systematic name of Sphingomonas sp. and a preservation number of CGMCCNo.3097, not only can grow in nutrient media of beef broth, LB and nutrient agar, but also can grow in a sugar-contained inorganic-salt culture medium. The TP-5 strain can be fermented in the sterile culture medium containing sugar, inorganic salt and water at a temperature condition of 28-37 DEG C; ymotic fluid is extracted to obtain the welan gum achieving a temperature-resistant limit value of 150 DEG C; and potassium chloride in different concentrations is added so that a welan gum solution remarkably improves the viscosity, enhances the temperature stability, does not vary the viscosity with temperature and presents stronger temperature tolerance, thereby being applied to seawater drilling mud and a high salinity reservoir viscous water flooding system.

The invention relates to a modified cellulose / graphene oxide composite microsphere and a preparation method thereof. The composite microsphere is formed by compounding cellulose and a graphene oxide material and is further modified by welan gum. By the compounding of cellulose and graphene oxide, the mechanical strength of a composite adsorption material is enhanced, and the adsorption capacity of an adsorbent is further improved, so that the performance of the adsorbent is well improved; the surface of the cellulose / graphene oxide composite microsphere is modified by welan gum; a branch chain structure and a functional group are introduced, so that multi-layer adsorption can be realized, and the adsorption performance of the adsorbent is further enhanced. The modified cellulose / graphene oxide composite microsphere has the characteristics of no toxicity, no pollution, high bio-compatibility and the like and can be applied to the field of sewage treatment, environment treatment and the like.

The invention provides a high-temperature spacer fluid suspension stabilizer for well cementation, a preparation method of the high-temperature spacer fluid suspension stabilizer and application of the high-temperature spacer fluid suspension stabilizer. The high-temperature spacer fluid suspension stabilizer for well cementation comprises the following ingredients in part by weight: 58-85 parts of clay substances, 8-20 parts of welan gum, 0-5 parts of xanthan gum, 5-10 parts of inorganic salt and 2-8 parts of high-molecular polymer. The high-molecular polymer comprises one or more than one of polyvinyl alcohol, hydroxymethyl cellulose, hydroxyethyl cellulose and hydroxypropyl starch ether. The suspension stabilizer serves as an additive and is added into spacer fluid; and after being added with the suspension stabilizer, the spacer fluid has high suspension stability, high consistency, high rheological property and high resistance to elevated temperature.

The invention relates to a Welan gum producing marine strain, which belongs to Sphingomonas sp.WG, and has a preservation number of CCTCC No: M2013161. According to the present invention, the strain can be cultured in a liquid culture medium so as to obtain the Welan gum, and the production efficiency is high; the requirements of the strain of the present invention on the carbon source and the nitrogen source are low; the fermentation process comprises: (1) seed liquid culture and (2) fermentation production of Welan gum; the extraction and purification steps comprise: (1) fermentation broth pretreatment, (2) crude product precipitation, (3) impurity removing, and (4) drying so as to obtain the Welan gum product; with application of the marine strain to produce the Welan gum in the fermentation manner, the yield can be up to 33 g / L, and the extraction and purification yield can be up to 95%; and with the strain and the method of the present invention, the low-cost, high-efficiency and high-quality Welan gum production can be achieved.

Rheology modifying admixture comprising a) from 80 to 99% w / w of hydroxyalkyl guar, cellulose ether, or mixture thereof; b) from 1 to 20% w / w of biopolymer selected from diutan gum and welan gum, and hydraulic compositions containing the rheology modifier admixture together with a superplasticizer.

The invention discloses a sphingol pseudoalteromonas genetically engineered bacterium and relates to sphingol pseudoalteromonas which stress resistance gene is guided into. The stress resistance geneis from extreme microorganisms. The invention further discloses a method for constructing the sphingol pseudoalteromonas genetically engineered bacterium through a three-parent combining method. The invention further discloses application of the sphingol pseudoalteromonas genetically engineered bacterium in fermentation to prepare welan gum or gellan gum. The sphingol pseudoalteromonas geneticallyengineered bacterium disclosed by the invention obviously improves temperature tolerance and acid-base tolerance of the sphingol pseudoalteromonas, a temperature tolerance range is 30 to 42 DEG C, and a pH tolerance range is 4.0 to 10.0. When the sphingol pseudoalteromonas genetically engineered bacterium is used in fermentation to prepare the welan gum, a microbial polysaccharide yield can reach20 to 30g / L under the condition that a pH is not regulated by an external source; when the sphingol pseudoalteromonas genetically engineered bacterium is used in fermentation to prepare the gellan gum, a microbial polysaccharide yield can reach 15 to 22g / L under the condition that a pH is not regulated by an external source; a production efficiency of microbial polysaccharides of the gellan gum,the welan gum and the like is enhanced.

Rheology modifying admixture comprising a) from 80 to 99% w / w of hydroxyalkyl guar, cellulose ether, or mixture thereof; b) from 1 to 20% w / w of biopolymer selected from diutan gum and welan gum, and hydraulic compositions containing the rheology modifier admixture together with a superplasticizer.