The deep-sea polyextremophile Halobacteroides lacunaris TB21 rough-type LPS: Structure and inhibitory activity towards toxic LPS
The structural characterization of the lipopolysaccharide (LPS) from extremophiles has
important implications in several biomedical and therapeutic applications. The polyextremophile
Gram-negative bacterium Halobacteroides lacunaris TB21, isolated from one of the most extreme
habitats on our planet, the deep-sea hypersaline anoxic basin Thetis, represents a fascinating
microorganism to investigate in terms of its LPS component. Here we report the elucidation of
the full structure of the R-type LPS isolated from H. lacunaris TB21 that was attained through a
multi-technique approach comprising chemical analyses, NMR spectroscopy, and Matrix-Assisted
Laser Desorption Ionization (MALDI) mass spectrometry. Furthermore, cellular immunology studies
were executed on the pure R-LPS revealing a very interesting effect on human innate immunity as an
inhibitor of the toxic Escherichia coli LPS.