Isolation of lipopolysaccharide from the walls of Micropolyspora faeni: chemical composition and serological reactivity.

Extraction of mycelium or walls of Micropolyspora faeni with cold or hot aqueous phenol yielded a lipopolysaccharide consisting of lipid A, phosphate, galactose, arabinose, glucose, glucosamine, and a dideoxy sugar. Extraction with trichloroacetic acid (TCA) yielded an incomplete molecule lacking lipid A. Part of an O-chain was secreted into the culture medium. Phenol and TCA extracts gave three lines of precipitation with human serum from cases of farmer's lung disease, and one of these was given by the culture medium polysaccharide. Serologically-reactive sugars were arabinose, galactose and glucose. The lipopolysaccharide fixed on to red cells which agglutinated in the presence of specific antibody and lysed on the addition of complement. The lipopolysaccharide appeared to elicit mainly IgM antibodies in animals, but IgM and IgG antibodies in humans.