Heteropolysaccharides made by bacterial fermentation - useful as thickening agents and stabilizers in aq. systems

Heteropolysaccharide-10, contg. 3% protein and 97% carbohydrate, the latter consisting oF 19% uronic acid, 39% glucose, 29% galactose and 13% fructose, and which heteropolysaccharide is compatible with methylene blue chloride, is made by submerged culture under aerobic conditions at a temp. of 28-35 degrees C of a heteropolysaccharide-producing strain of Erwinia tahitica in an aq. culture medium contg. as nutrients hydrolysed starch with a dextrose equivalent of 20-35 as carbon source, a nitrogen source, a magnesium source and a phosphorus source, continuing growth until the medium has a considerable viscosity, and separating the polysaccharide. The method is a simple process for producing heteropolysaccharide-10, which is esp. useful as a thickener in foodstuffs such as salad cream, puddings, etc., as viscosity modifiers and moisture conservation agents, and for producing printing pastes for textile printing. The organism Erwinia tahitica (ATCC 2171) is new and is described in detail. Fermentation is generally carried out for 45-60 hours using maize starch hydrolysate as carbon source. The heteropolysaccharide may be recovered e.g. by precipitation with a low alkanol.