摘要:
Mutational inactivation of proteins involved in para-cresol production in certain milk products results in improved taste and odor. The undesirable para-cresol forms over time as a result of enzymes produced by the bacterium that produces gellan gum. Since the gellan is typically used in a relatively unpurified form, the enzymes are added to the milk along with the gellan. Inactivation of the enzymes is a genetic means of eliminating the enzymes without requiring any additional purification or processing.
摘要:
Sphingomonas strains have extracellular polysaccharide (e.g., gellan, diutan) that is firmly attached to the cell surface. This attachment may limit polysaccharide production by impairing uptake of nutrients into the cell or due to limited sites for polysaccharide biosynthesis on the cell surface. Two genes for polysaccharide biosynthesis, designated gelM and gelN in gellan-producing strains and dpsM and dpsN in diutan-producing strains, have been inactivated by deletion mutations and shown to produce polysaccharide that is not firmly attached to the cell surface, i.e., slime form. Another gene for polysaccharide biosynthesis, designated gelI in gellan producing strains, was inactivated by insertion mutation and also shown to produce the slime phenotype. The homologous gene dpsi in the diutan producing strain should also be involved in the attachment of the polysaccharide to the cell surface. The slime characteristic was demonstrated by the ability of the cells to be centrifuged and the lack of cell clumping as seen under the microscope or in diluted suspensions. The diutan slime mutants had somewhat increased productivity and the recovered diutan product had significantly improved rheology. Gellan slime mutants had lower broth viscosity which facilitates mixing during fermentation; however, the recovered gellan product had lower gel strength than the gellan produced from a capsular strain. A deletion in a gene gelR, which encodes a protein with homology to surface proteins and outer membrane proteins and weak homology to proteins with polysaccharide degradation activity, was shown to restore higher gel strength to the slime form of gellan, and to produce gellan of higher gel strength than that of the capsular gellan producing strains.
摘要翻译:鞘氨醇单胞菌属菌株具有牢固附着于细胞表面的细胞外多糖(例如,结冷糖,二氘)。 这种附着可能通过损害营养物质进入细胞或由于细胞表面上多糖生物合成的有限位点而限制多糖产生。 用于多糖生物合成的两个基因,在凝胶产生菌株中命名为gelM和gelN,并且在产生二萜的菌株中的dpsM和dpsN已经被缺失突变失活,并且显示产生不牢固附着于细胞表面的多糖,即粘液形式 。 用于多糖生物合成的另一基因,在凝胶产生菌株中称为gelI,通过插入突变失活,并且还显示产生粘液表型。 二萜生产菌株中的同源基因dpsi也应参与多糖与细胞表面的连接。 通过细胞离心的能力和在显微镜下或在稀释的悬浮液中观察到的细胞团聚的缺乏证明了粘液特性。 di an sl ime mut mut ants。。。。。。。。。。。。。。。。。。。。 凝胶粘液突变体具有较低的肉汤粘度,有利于发酵期间的混合; 然而,回收的结冷胶产品的凝胶强度低于从荚膜菌株产生的结冷胶。 基因gelR中的缺失,其编码与表面蛋白质和外膜蛋白质具有同源性的蛋白质和与具有多糖降解活性的蛋白质具有弱同源性的蛋白质,被证明能够恢复与粘液形式的结冷胶的更高的凝胶强度,并且产生更高的结晶 凝胶强度高于荚膜凝胶产生菌株。
摘要:
The production of a diutan polysaccharide exhibiting increased viscosity properties as compared with previously produced polysaccharide of the same type of repeating units. Such an improved diutan polysaccharide is produced through the generation of a derivative of Sphingomonas sp. ATCC 53159 that harbors a multicopy broad host-range plasmid into which genes for biosynthesis of diutan polysaccharide have been cloned. The inventive methods of production of such an improved diutan polysaccharide, as well as the novel cloned genes required to produce the improved diutan within such a method, are also encompassed within this invention. Additionally, the novel engineered Sphingomonas strain including the needed DNA sequence is encompassed within this invention.
摘要:
A portable inflatable race track comprising a base, at least one wall, and a race surface, wherein the base is at least partially inflatable from a collapsed position to an inflated position, the race surface is inclined relative to horizontal and includes at least one lane configured to accept a vehicle comprising wheels, wherein at least gravity causes the vehicle to travel down the race surface. The race track may include a starting section, a sloped section, a finish section, and a stopping section. The race track may be configured to allow two or more vehicles to simultaneously race down the race surface.
摘要:
The production of a diutan polysaccharide exhibiting increased viscosity properties as compared with previously produced polysaccharide of the same type of repeating units. Such an improved diutan polysaccharide is produced through the generation of a derivative of Sphingomonas sp. ATCC 53159 that harbors a multicopy broad host range plasmid into which genes for biosynthesis of diutan polysaccharide have been cloned. The inventive methods of production of such an improved diutan polysaccharide, as well as the novel cloned genes required to produce the improved diutan within such a method, are also encompassed within this invention. Additionally, the novel engineered Sphingomonas strain including the needed DNA sequence is encompassed within this invention.
摘要:
An inflatable structure includes a plurality of inflatable walls arranged to form a room having an interior and one or more lockable compartments integrated into the plurality of inflatable walls. The lockable compartments can include a non-inflated recess formed within an inflatable wall and at least one flap configured to close an opening of the recess of the first lockable compartment. The inflatable structure can be themed, e.g., by installing themed skins on interior surfaces of the room to provide a user experience. The inflatable structure may also include integrated virtual reality components, including a virtual reality headset supported by the structure.
摘要:
An inflatable obstacle course having a base and one or more inflatable side walls connected to the base and forming a housing. The obstacle course can include one or more obstacles positioned within the housing. The side walls can be adhered to the base to form a water seal. A layer of fluid can be positioned within at least a portion of the housing to provide resistance to participants moving through the obstacle course and to add to the fun of traversing the obstacle course.
摘要:
The production of a diutan polysaccharide exhibiting increased viscosity properties as compared with previously produced polysaccharide of the same type of repeating units. Such an improved diutan polysaccharide is produced through the generation of a derivative of Sphingomonas sp. ATCC 53159 that harbors a multicopy broad host range plasmid into which genes for biosynthesis of diutan polysaccharide have been cloned. The inventive methods of production of such an improved diutan polysaccharide, as well as the novel cloned genes required to produce the improved diutan within such a method, are also encompassed within this invention. Additionally, the novel engineered Sphingomonas strain including the needed DNA sequence is encompassed within this invention.
摘要:
The production of a diutan polysaccharide exhibiting increased viscosity properties as compared with previously produced polysaccharide of the same type of repeating units. Such an improved diutan polysaccharide is produced through the generation of a derivative of Sphingomonas sp. ATCC 53159 that harbors a multicopy broad-host-range plasmid into which genes for biosynthesis of diutan polysaccharide have been cloned. The plasmid provides the capability within the host Sphingomonas strain to produce multiple copies of genes for such polysaccharide synthesis. In such a manner, a method of not just increased production of the target diutan polysaccharide, but also production of a diutan polysaccharide of improved physical properties (of the aforementioned higher viscosity) thereof is provided. Such a diutan polysaccharide has proven particularly useful as a possible viscosifier in oilfield applications and within cement materials. The inventive methods of production of such an improved diutan polysaccharide, as well as the novel cloned genes required to produce the improved diutan within such a method, are also encompassed within this invention. Additionally, the novel engineered Sphingomonas strain including the needed DNA sequence is encompassed within this invention.
摘要:
The production of a diutan polysaccharide exhibiting increased viscosity properties as compared with previously produced polysaccharide of the same type of repeating units. Such an improved diutan polysaccharide is produced through the generation of a derivative of Sphingomonas sp. ATCC 53159 that harbors a multicopy broad-host-range plasmid into which genes for biosynthesis of diutan polysaccharide have been cloned. The plasmid provides the capability within the host Sphingomonas strain to produce multiple copies of genes for such polysaccharide synthesis. In such a manner, a method of not just increased production of the target diutan polysaccharide, but also production of a diutan polysaccharide of improved physical properties (of the aforementioned higher viscosity) thereof is provided. Such a diutan polysaccharide has proven particularly useful as a possible viscosifier in oilfield applications and within cement materials. The inventive methods of production of such an improved diutan polysaccharide, as well as the novel cloned genes required to produce the improved diutan within such a method, are also encompassed within this invention. Additionally, the novel engineered Sphingomonas strain including the needed DNA sequence is encompassed within this invention.