Abstract
A polymer isolated from E. saburreum strain L49 contained O-acetylated glycero-galacto-heptose as the main constituent, and in addition an unknown aldose. The polymer was located at the outer part of the bacterial cell wall. The polymer reacted with antiserum to L49 microorganisms by precipitation and complement fixation. Two antigenic specificities were detected, one of which was destroyed by de-acetylation. The rabbit antibodies to both specificities were low-molecular-weight antibodies.