High molecular weight sodium hyaluronate

摘要

A novel mutant microorganism Streptococcus zooepidemicus HA-116 ATCC 39920, has been produced. The microorganism produces large amounts of high molecular weight hyaluronic acid. The invention provides a method of obtaining such microorganisms. The invention also concerns a method of obtaining sodium hyaluronate which comprises growing with vigorous agitation a microorganism of the genus Streptococcus under appropriate conditions in a suitable nutrient medium containing a sugar component as a carbon source. The sugar component is present in a substantially constant concentration between 0.2 and 10 grams per liter. The medium has a substantially constant pH between about 6.0 and 7.5 and includes a substantially constant magnesium ion concentration above 0.05 grams per liter. The sodium hyaluronate excreted into the medium by the organism is purified using methods involving precipitation, redissolving and reprecipitating the hyaluronate. Composition of sodium hyaluronate which are characterized by an absence of pyrogenicity and skin irritation are obtained.