An antigenic lipopolysaccharide, serratigen isolated from Serratia marcescens was mainly made up of galactose and contained 18.4% of galacturonic acid. It had α-(1→3) galactan moiety in the molecule. The chemical structure of serratimannan isolated from the same strain was shown to have α-(1→2) and α-(1→3) linkages in mannan.
