ENZYMATIC GENERATION AND RECOVERY OF GROUP B STREPTOCOCCUS TYPE III CAPSULAR OLIGOSACCHARIDES

摘要

Selectively digesting the Group B Streptococcus type III (GBS-III) polysaccharide capsule (PC) to yield fragments consisting of intact GBS-III polysaccharide capsule repeating units. GBS-III polysaccharide capsule is digested by reacting it with a bacterial endo- beta -galactosidase that is specific for the galactose-glucose glycosidic linkage in the GBS-III CP backbone, and that substantially does not hydrolyse any other GBS-III CP glycosidic linkages. The resulting polysaccharide fragments are recovered and are immunologically useful. The endo- beta -galactosidase is produced in a multiphase culture that comprises: i) a liquid aqueous phase; ii) a second phase that is aqueous insoluble and in contact with the liquid aqueous phase at an interface therebetween, and iii) bacterial cells positioned generally in the liquid aqueous phase and at the interface between the liquid aqueous phase and the second phase. The endo- beta -galactosidase is recovered from the liquid aqueous phase.