Xanthan is the major exopolysaccharide secreted by Xanthomonas spp. Despite its diverse roles in bacterial pathogenesis of plants, little is known about the real implication of this molecule in Xanthomonas pathogenesis. In this study we show that in contrast to Xanthomonas campestris pv campestris strain 8004 (wild type), the xanthan minus mutant (strain 8397) and the mutant strain 8396, which ...

An enzymatic route for the depolymerization of a heteropolysaccharide (xanthan) in Bacillus sp. strain GL1, which was closely related to Brevibacillus thermoruber, was determined by analyzing the structures of xanthan depolymerization products. The bacterium produces extracellular xanthan lyase catalyzing the cleavage of the glycosidic bond between pyruvylated mannosyl and glucuronyl residues i...

Olive mill wastewaters (OMW) are a by-product from olive oil manufacture that cause environmental pollution. These wastes have been used as substrate for the production of the extracellular polysaccharide xanthan by Xanthomonas campestris NRRL 31459-S4L41. Growth and xanthan production on dilute OMW as a sole source of nutrients were obtained at OMW concentrations below 60%, yielding a maxima1 ...

Xanthan is a polysaccharide secreted by Xanthomonas campestris that contains pentameric repeat units. The biosynthesis of xanthan involves an operon composed of 12 genes (gumB to gumM). In this study, we analyzed the proteins encoded by gumB and gumC. Membrane fractionation showed that GumB was mainly associated with the outer membrane, whereas GumC was an inner membrane protein. By in silico a...

-----------------------------------------------------ABSTRACT----------------------------------------------------Xanthan gum is a natural polysaccharide having an industrial importance. It is commonly called as heteropolysaccharide which is produced by Xanthomonas campestris. In the present investigation Xanthan gum fermentation by local isolates of Xanthomonas campestris NRRL-B-1449 from sugar...

Xanthan gum is an extra cellular microbial hetero polysaccharide of great commercial importance, secreted by the yellow pigmented bacterium Xanthomonas malvacearum. Polysaccharides are macromolecules with diverse applications in the food, chemical, energy production and pharmaceutical Industries. The nutrient factors influencing the production of Xanthan polymer by Xanthomonas malvacearum isola...

A novel xanthan depolymerase (endo-beta-1,4-glucanase) was isolated from a salt-tolerant bacteria culture (HD1) grown on xanthan. The depolymerase was purified 55-fold through chromatography on ion-exchange and molecular sieve columns, including high-performance liquid chromatography. The purified enzyme fraction was homogeneous as judged by polyacrylamide gel electrophoresis. The molecular wei...

Waste residual molasses, a non-edible portion produced during the processing of sugarcane juice for the preparation of molasses, may be an alternative low-cost renewable substrate to the pricey food-grade molasses for xanthan production. Systematic strategies were applied to improve xanthan production with a newly isolated indigenous strain Xanthomonas campestris originated from Tezpur, Assam. ...

Xanthan gum is a microbial polysaccharide of great commercial significance. This review focuses on various aspects of xanthan production, including the producing organism Xanthomonas campestris, the kinetics of growth and production, the downstream recovery of the polysaccharide, and the solution properties of xanthan.

An extracellular cell lytic enzyme from Pseudomonas sp. was active on heat killed cells of Xanthomonas campestris. The lytic activity caused enzymatic digestion of X.campestris xanthan gum. Digestion was effective for highly viscous native xanthan 2.0% (w/v) and 2.5% (w/v) commercial Sigma xanthan. Scanning electron microscopy and SDS-PAGE observations confirmed the cell lytic action on X.campe...