Shubchyns'kyy V. Lipopolysaccharides Pragia fontium: chemical characterization and biological activity.

The dissertation is devoted to investigations of Pragia fontium lipopolyssaccharides (LPS). LPS were isolated by water-phenol procedure from 8 strains of P. fontium 20125, 29671, 28203, 28652, 97U116, 27480, 96U101, 97U124 and its yields varied from 9 to 22 % (depending on strain tested), that a little higher than in other representatives of family Enterobacteriaceae (5%). Purified preparations of LPS contained significant amounts of carbohydrates (42 - 81%), minor amounts of nucleic acids (1 - 7%) and minute amounts of proteins (depending on strains). Their chemical identification showed that LPS tested contain all components which are characteristic for this type of polymers. Macromolecular organization of LPS investigated strains were represented by S-, R- і SR-forms. Divergence of P. fontium LPS properties was established in order: lipid A - O-specific polysaccharides (O-PS) - core oligosaccharides (1, 4 and 5 chemotypes corresponding).The LPS tested were toxic, pyrogenic and participated in adhesion processes. Modifications of LPS lead to the loss of their serological activity and decrease pyrogenicity. LPS isolated from strain 20125 that cultivated in different temperatures were differed by composition of fatty acids, level of toxicity, pyrogenicity and participation in adhesion processes.