Abstract: The present invention is directed to a Sphingomonas bacteria and a method of producing exopolysaccharides by culturing a Shpingomonas bacteria in a fermentation broth for a time and temperature effective for providing a sphingan exopolysaccharide in a slime form.

Abstract: The present invention is directed to a Sphingomonas bacteria and a method of producing exopolysaccharides by culturing a Shingomonas bacteria in a fermentation broth for a time and temperature effective for providing a sphingan exopolysaccharide in a slime form.

Abstract: A modified S7 polysaccharide is disclosed. The polysaccharide contains 20% less glucose that S7. An S7c6 gene cluster is disclosed. A mutated Sphingomonas is also disclosed.

Abstract: The present invention is directed to a Sphingomonas bacteria and a method of producing exopolysaccharides by culturing a Shingomonas bacteria in a fermentation broth for a time and temperature effective for providing a sphingan exopolysaccharide in a slime form.

Abstract: The present invention provides for a method for obtaining a polysaccharide substantially free from whole bacterial cells and bacterial cell debris including: (a) fermenting a Sphingomonas bacterium, which produces the polysaccharide, to produce an aqueous fermentation broth having the polysaccharide dissolved therein; (b) diluting the fermentation broth with an equal volume of deionized water; (c) partially hydrolyzing the polysaccharide by exposing the fermentation broth resulting from step (b) to a temperature in excess of 100° C.

Abstract: The present invention provides for a polysaccharide produced by subjecting a Sphingomonas bacterium modified with a S7c6 gene cluster or segment thereof to aerobic fermentation in a nutrient aqueous broth for a time sufficient to produce the polysaccharide dissolved therein, including L-Rhap, D-Glcp and 2-deoxy-&bgr;-D-arabino-HexpA in a molar ratio of 1:3:1, wherein the polysaccharide has at least 20% less glucose per repeat unit compared to a heteropolysaccharide S-7 produced by an unmodified Sphingomonas strain S7, and the segment includes at least the spsB and rhsACBD genes.

Abstract: A method for obtaining a substantially biologically pure culture strain of Aureobasidium pullulans from a wild type strain by enriching the collected strain for organisms which grow as fungal yeastlike cells, growing colonies from isolated yeastlike cells and selecting those yeastlike cells which exhibit reduced pigmentation. Biologically pure culture strains obtained by the invention as well as methods for producing pullulan having decreased pigmentation and/or increased molecular weight are disclosed.

Abstract: The present invention relates to DNA segments isolated from Sphingomonas sp. and involved in the biosynthetic production of sphingan polysaccharides to increase the production of the polysaccharide in engineered microorganisms. The present invention also relates to methods of engineering strains of Sphingomonas to produce bacteria which are hyperproducers of sphingan, methods of identifying and utilizing DNA fragments useful to enhance production of sphingan in bacteria and the hyperproducer bacteria.

Abstract: A process for saline-solution soluble xanthan gum which comprises the steps of precipitating xanthan gum by mixing, with stirring, an aqueous solution of xanthan gum with an organic solvent which is a non-solvent to xanthan gum but is hydrophilic, removing liquid from the precipitated xanthan gum to a liquid content of at most 50%, disintegrating the cake of xanthan gum after the liquid removal to an average grain size of from 0.3 to 2 cm in diameter, and drying the disintegrated xanthan gum by fluidizing the same at a temperature not exceeding 80° C.

Abstract: A fermenter for the production of xanthan gum is provided with an upper helical impeller and a lower turbine impeller which are positioned therewithin, and an agitator shaft for driving these helical impeller and turbine impeller. The helical impeller consists of a pair of vertically spaced arms extending from the agitator shaft in opposite directions and arranged in twisted relationship, and at least one shearing paddle bridging these arms, and the turbine impeller consists of a rotating disc having at least one turbine blade attached thereto.

Abstract: A new recombinant bacteria for the production of exopolysaccharides is disclosed as well as a method for making the recombinant bacteria and making an exopolysaccharide from the bacteria by submerged aerobic fermentation of the bacteria utilizing a sugar substrate. The exopolysaccharides obtained from the inventive bacteria exhibit improved, more desirable or different properties from the exopolysaccharide produced by the non-recombinant bacteria from which the recombinant bacteria was derived. In addition, the present invention provides a method of producing bacterial exopolysaccharides by fermentation from sugar substrates that the bacteria which the exopolysaccharides are native to cannot utilize.

Abstract: A recombinant bacteria for the production of exopolysaccharides is disclosed as well as a method for making the recombinant bacteria and making an exopolysaccharide from the bacteria by submerged aerobic fermentation of the bacteria utilizing a sugar substrate. In addition, the present invention provides a method of producing bacterial exopolysaccharides by fermentation from sugar substrates that the wild-type bacteria for producing the exopolysaccharide cannot utilize.

Abstract: A method for obtaining a substantially biologically pure culture strain of Aureobasidium pullulans from a wild type strain by enriching the collected strain for organisms which grow as fungal yeastlike cells, growing colonies from isolated yeastlike cells and selecting those yeastlike cells which exhibit reduced pigmentation. Biologically pure culture strains obtained by the invention as well as methods for producing pullulan having decreased pigmentation and/or increased molecular weight are disclosed.

Abstract: Xanthan gum is purified by heat-treating a xanthan gum fermented broth, and consecutively treating the broth first with alkaline protease and then with lysozyme or in reverse order, and thereafter recovering xanthan gum from the treated broth. A clear aqueous solution of xanthan gum may be obtained without complex procedures. The xanthan gum is separated and purified and 0.3% aqueous solution of the purified xanthan gum has a transmittance of at least 80%.

Abstract: The present invention relates to DNA segments isolated from Sphingomonas sp. and involved in the biosynthetic production of sphingan polysaccharides to increase the production of the polysaccharide in engineered microorganisms. The present invention also relates to methods of engineering strains of Sphingomonas to produce bacteria which are hyperproducers of sphingan, methods of identifying and utilizing DNA fragments useful to enhance production of sphingan in bacteria and the hyperproducer bacteria.

Abstract: A fermenter for the production of xanthan gum is provided with an upper helical impeller and a lower turbine impeller which are positioned therewithin, and an agitator shaft for driving these helical impeller and turbine impeller. The helical impeller consists of a pair of vertically spaced arms extending from the agitator shaft in opposite directions and arranged in twisted relationship, and at least one shearing paddle bridging these arms, and the turbine impeller consists of a rotating disc having at least one turbine blade attached thereto.

Abstract: A method of increasing xanthan gum production, comprising culturing a Xanthomonas campestris strain having a xanthan-increasing modification in a culture medium, wherein the modification is selected from the group consisting of (1) a mutation causing rifampicin-resistance; (2) a mutation causing bacitracin-resistance; or (3) exogenous genetic information controlling the synthesis of xanthan; and separating xanthan from the culture medium, is provided along with specific DNA sequences and Xanthomonas campestris strains showing increased xanthan gum production.

Abstract: A process for saline-solution soluble xanthan gum which comprises the steps of precipitating xanthan gum by mixing, with stirring, an aqueous solution of xanthan gum with an organic solvent which is a non-solvent to xanthan gum but is hydrophilic, removing liquid from the precipitated xanthan gum to a liquid content of at most 50%, disintegrating the cake of xanthan gum after the liquid removal to an average grain size of from 0.3 to 2 cm in diameter, and drying the disintegrated xanthan gum by fluidizing the same at a temperature not exceeding 80.degree. C.

Abstract: Pullulan is precipitated from an aqueous solution by mixing with a hydrophilic organic solvent incapable of dissolving pullulan. Solid pullulan is then separated from the liquid component of the dispersion by feeding the dispersion into a V-type disk press having a pair of discoid screens arranged so that the distance between them decreases as they are rotated. The pullulan dispersion is pressed by the discoid screens, recovering the liquid component through the screens. The resulting low-liquid-content pullulan continues to rotate together with the screens to an outlet, where it is discharged from the press.

Abstract: The process comprises heat-treating a xanthan gum fermented broth, and consecutively treating the broth first with alkaline protease and then with lysozyme or in reverse order, and thereafter recovering xanthan gum from the treated broth. A clear aqueous solution of xanthan gum may be obtained without complex procedures.