Chemical Structure of Bacteriovorax stolpii Lipid A

Bdellovibrionales is a phylogenetically diverse group of predatory prokaryotes, which consists of the two families Bdellovibrionaceae and Bacteriovoracaceae . We describe LPS and lipid A of the type strain Bacteriovorax stolpii DSM 12778, representing the first characterized endotoxin of a Bacteriovoracaceae member. It has a smooth form LPS, which was identified by SDS‐polyacrylamide gel electrophoresis. The lipid A structure was determined by combined gas chromatography–mass spectrometry, electrospray ionization mass spectrometry and NMR spectroscopy. Its backbone consists of two β‐(1 → 6)‐linked 2,3‐diamino‐2,3‐dideoxy‐ d ‐glucopyranoses (Glc p N3N) carrying a pyrophosphoethanolamine at O‐4′ of the non‐reducing sugar and a phosphate group linked to O‐1 of the reducing Glc p N3N. Positions 2, 3, 2′ and 3′ of the two Glc p N3N are acylated with primary 3‐hydroxy fatty acids and one of those carries a secondary fatty acid.