Nature of freezing damage on the lipopolysaccharide molecule of Escherichia coli B.

The lipopolysaccharide, located on the surface of E. coli B, undergoes alteration by freezing. The results of these studies, as measured by the adsorption efficiency of LPS specific phages, indicated that this macromolecule may undergo both conformational alteraton and structural damage in the frozen cells. Biochemical analysis on purified LPS indicated that the structural damage is in the heptose region and might involve loss of heptose. Possible loss of phosphate in this region has been suggested. All these data indicated that alteraction is more conformational than structural in nature when subjected to freezing.