The results of immunochemical analysis of 63 strains of associative rhizobakteria genus Azospirillum presented in this paper. Significant heterogeneity of O-antigens of strains of A. lipoferum and A. brasi lense have been demonstrated, as well as the high similarity of the antigenic properties of LPS strains of A. irakense. Serologically prov ed isolated strain A. amazonense. High conservatism of major protein antigens of these bacteria have been showed.
