Microbial heteropolysaccharide

Claim 1

A process for the production of Biopolymer PS 87, a heteropolysaccharide which comprises from 40 to 45% by weight of glucose, from 10 to 20% by weight galactose, from 25 to 30% by weight mannose, from 6 to 13% by weight glucuronic acid and from 0 to 1.5% by weight fucose, a 1% by weight solution of Biopolymer PS 87 having pseudoplastic properties, a consistency at 20° C. of at least 150 poise and a yield stress value at 20° C. of at least 30 dynes/cm 2 which comprises the steps of: (i) cultivating a strain of a micro-organism contaiing genetic material specifying Biopolymer PS 87 synthesis under submerged aerobic conditions in an aqueous culture medium comprising a source of carbon, a source of nitrogen, a source of iron, a source of magnesium and a source of phosphorus, the pH of the culture medium being maintained at a value of from 4.5 to 7.5, until substantial formation of Biopolymer PS 87 has occurred, and (ii) isolating Biopolymer PS 87 from the culture medium.