Abstract: A method and a few compositions are disclosed, which are adapted to depollute fresh and sea water bodies from crude oil and petroleum product pollution by microbial action. The growth of micro-organisms capable of metabolizing hydrocarbons is exalted by certain combination of nutrients, such as lecithin as a phosphorus source, hydantoins, amides allophanates, polyamines, acyl-ureas and esters of the hydantoic and allantoic acids as the nitrogen sources. Ureido-derivatives of amides are also contemplated as additional nutrients.

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.