Structure, gene cluster of the O antigen and biological activity of the lipopolysaccharide from the rhizospheric bacterium Ochrobactrum cytisi IPA7.2.

Lipopolysaccharide (LPS) of Ochrobactrum cytisi IPA7.2, a bacterium isolated from the roots of Solanum tuberosum L., was extracted from dry bacterial cells and chemically characterized. The O-specific polysaccharide was obtained by mild acid hydrolysis of the LPS and studied by sugar analysis and ¹ H and ¹³ C NMR spectroscopy, including ¹ H, ¹ H COSY, ¹ H, ¹ H TOCSY, ¹ H, ¹ H ROESY, ¹ H, ¹³ C HSQC, and ¹ H, ¹³ C HMBC experiments. The polysaccharide was linear and consisted of trisaccharide repeating units of the following structure: A putative O-antigen gene cluster of O. cytisi IPA7.2 was identified and found to be consistent with the O-specific polysaccharide structure. The LPS of Ochrobactrum cytisi IPA7.2 promoted the growth of potato microplants in vitro.
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