[Functional and Biological Activity of Pantoea agglomerans Lipopolysaccharides]

The lipopolysaccharides (LPS) of the seven strains of Pantoea agglomerans were isolated and chemically identified. It was established that the investigated strains characterized by different relative output of LPS from 5.2 to 14.0 % by dry weight of bacteria. LPS were characterized quite high content of carbohydrates - from 22 to 54 % 2-keto-3-deoxyoctonic acid (KDO) - from 0.39 to 2.22 % and heptose - from 3.3 to 14.00 %. Fatty acids, containing in the chain of 12 to 16 carbon atoms were identified. Lipids A of all tested LPS were characterized by predominant 3-OH-C14:0 acid from 31.7 to 39.3 % depending on the strain. Since all the studied strains of P. agglomerans were sensitive to polymyxin B, it can be concluded that the LPS do not contain in the structure of lipid A, such a substitute as 4-amino-4-deoxy-L-arabinose. One of the ways of changes in the functional and biological properties of LPS is the chemical modification. As modifiers were used complexes of germanium and tin. In the study of serological activity and toxicity of modified LPS it was found that some of them lost both serological and toxic activity. It was revealed that all investigated P. agglomerans LPS decreased the median adhesion and the index of the adhesiveness. The higher concentration of P. agglomerans LPS in the reaction mixture, the less interactions between surface structures of red blood cells and E. coli cells.