Changes in the chemical, physical-chemical and biological properties of Ochrobactrum cytisi IPA7.2 lipopolysaccharide during О-deacylation

Abstract

Lipopolysaccharides are compounds of bacterial origin that have biological activity against plants, animals and humans. This work provides information on the preparation and characterization of the properties of modifi ed lipopolysaccharide derivatives of the rhizosphere bacterium Ochrobactrum cytisi IPA7.2. Deacylation has been carried out using alkaline hydrolysis, followed by chromatographic separation of the fractions. O-deacetylation of O-polysaccharide led to a 2-fold increase in the extinction of the products of the phenol-sulfuric acid reaction. The fatty acid composition of lipid A did not change during alkaline hydrolysis. A comparison of supramolecular particles in an aqueous medium of native and deacylated forms of lipopolysaccharide using dynamic light scattering revealed that, as a result of modifi cation, the size of micelles decreased from 65 nm to 35 nm and their negative zeta potential increased from –22 mV to –30 mV. It has been found that non-stoichiometric acetylation of lipopolysaccharide O. cytisi IPA7.2 did not aff ect the interaction with specifi c antibodies but was important for the manifestation of growth-stimulating activity towards potato microplants.

Keywords

• lipopolysaccharide
• ochrobactrum cytisi ipa7.2
• acetylation
• dynamic light scatting
• supramolecular particles
• potato
• in vitro