To obtain a micro-algae propagating by an autotrophic photosynthesis process using carbon dioxide as carbon source, capable of producing heteropolysaccharide out side of the algae body in which productivity and low in cost, useful for thickener or the like by applying a biological separating treatment to a soil of a petroleum drilling field.
The micro-algae are Coccomyxa gloeobotrydiformis NY2F having ability of producing heteropolysaccharide coccogalactan (A) (practically, dissolves in a hot water of ≥100°C, the aqueous solution does not gel at room temperature, scarcely hydrolyzed by an acid or an alkali, hardly decomposing, having molecular weight ≥106, comprising 70% of galactose, 13% of mannose, 10% of xylose, 3% of arabinose, 2% of glucose and 2% of rhamnose), growing at 15 to 35°C, pH3 to 10, and carbon dioxide concentration of 0.03 to 40%. The constituent (A) obtained by culturing this micro-algae manifests high viscosity of 1,000 mPa.s(25°C) at 0.5% aqueous solution, and expected to be used as a dispersing agent of paints or the like.
YAMAMURA KENJI
KARUBE MASAO
SUMITOMO HEAVY INDUSTRIES