Abstract: A process for recovering crude oil from a subterranean formation using aqueous saline heteropolysaccharide solutions containing at least 0.5 wt. % of inorganic salts which are stabilized against viscosity loss on heat treatment. The stabilization process comprises preparing an aqueous solution containing heteropolysaccharide and inorganic salts, removing oxygen from the saline solution, heating to a temperature of at least 100.degree. C. in an inert atmosphere, then removing cell debris. The solutions also have improved filterability and are free of cell debris.

Abstract: A composition containing a heteropolysaccharide produced by the action of bacteria of the genus Xanthomonas, wherein the heteropolysaccharide has been modified by heating, at a temperature of at least 100.degree. C. for 1 to about 300 minutes, an aqueous solution containing native, untreated heteropolysaccharide produced by the action of bacteria of the genus Xanthomonas, and at least about 0.5 weight percent salt. The solution is preferably filtered or otherwise treated to separate the modified heteropolysaccharide from bacterial cells, cellular debris and other materials, prior to being put to use in, e.g., oil recovery processes, additive for foodstuffs, pharmaceutical preparations, etc.

Abstract: A process for producing modified heteropolysaccharides derived from a bacteria of the genus Xanthomonas, comprising the steps: (a) preparing an aqueous solution which contains (i) from about 200 to about 30,000 parts per million, by weight of an impure and unmodified heteropolysaccharide product and (ii) at least about 0.5 weight percent of at least one salt to obtain a saline heteropolysaccharide solution; (b) heating said saline heteropolysaccharide solution to a temperature of at least about 100.degree. C.; (c) maintaining said saline heteropolysaccharide solution at a temperature of at least about 100.degree. C.

Abstract: A method of preparation and application of a composition comprising specified microorganisms in combination with surfactants for a synergistic dispersal of oil slicks.