Isolation of a factor from cotton leaf that recognizes Beijerinckia

The selective retention of Beijerinckia, a nitrogen-fixing bacterium on cotton leaf surfaces was shown to be due to a binding factor. Gel diffusion and inhibition studies suggested that the factor from the leaf binds to lipopolysaccharide of the bacterium. SDS—polyacrylamide gel electrophoresis of the purified factor gave a single band corresponding to M r ∼ 19 500. The organism showed agglutination activity with the factor when it reached stationary phase of growth. A positive correlation between encapsulation of the organism and agglutination activity was also observed.