Carbohydrate composition of the phenol-soluble lipopolysaccharides of Citrobacter freundii.

Phenol-soluble lipopolysaccharides were obtained from the interphase and phenol phase fractions of 44% aqueous phenol-extracted Citrobacter species. Upon detailed investigation of C. freundii 8090, the two lipopolysaccharide fractions were found to contain different amounts of lipid A, although qualitative composition was similar. Both contained lipid A, 2-keto-deoxyoctonic acid, heptose, phosphate, d-glucose, galactose, rhamnose, 2-acetamido-2 deoxy-d-glucose, 3-acetamido-3,6-dideoxy-d-glucose, O-acetyl, and trace amino acids. Partially purified phenol-phase lipopolysaccharide partitioned into the phenol-soluble phase when refractionated with 44% aqueous phenol, and was further found to be soluble in 88% phenol, 95% ethyl alcohol, and chloroform-methanol (2:1).