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 new group of materials comprises intercalates of organometallic compounds in layered structures of water-insoluble salts comprised of a tetravalent metal cation and an acid phosphate, arsenate or vanadate anion. Related materials comprise intercalates of organometallic compounds in layered structures of uranyl and transuranyl phosphates, arsenates and vanadates. Intercalation hosts are represented either by the formula M(H.sub.1-y A.sub.y XO.sub.4).sub.2.nH.sub.2 O or by the formula H.sub.1-y A.sub.y TO.sub.2 XO.sub.4.nH.sub.