A novel sphingophosphonolipid head group 1‐hydroxy‐2‐aminoethyl phosphonate in Bdellovibrio stolpii

Abstract

Members of the bacterial genus Bdellovibrio include strains that are free-living, whereas others are known to invade and parasitize larger Gram-negative bacteria. The bacterium can synthesize several sphingophospholipid compounds including those with phosphoryl bonds as well as phosphonyl bonds. In the present study, the dominant sphingophosphonolipid component was isolated by column chromatography, and the long-chain bases, fatty acids, and polar head groups were identified by thin-layer and gas-liquid chromatographic procedures. The definitive structural identity of the sphingolipid was established by nuclear magnetic resonance and mass spectrometry of hydrolysis products and the intact compound. The compound was identified as N-2'-hydroxypentadecanoyl-2-amino-3,4-dihydroxyheptadecan-1-phosphono-(1-hydroxy-2-aminoethane).

Detection and identification of Bacteriovorax stolpii UKi2 sphingophosphonolipid molecular species

“…Bacteriovorax stolpii UKi2 was obtained from the American Type Culture Collection (ATCC 27,052) and cultured axenically in 0.3% yeast extract and 1% bactopeptone as described previously [29].°Cell°density°as determined by Abs 660 nm indicated that cultures grown in the enriched medium yielded ϳ28% higher bacterial numbers than when grown with 0.3% yeast extract alone. Standing cultures were incubated at 30°C until they reached stationary phase.…”

“…The cell pellet was extracted for total lipids using chloroform (CHCl 3 ):methanol (MeOH)°(2:1,°vol/vol)° [29]°or°by°the°method°of°Bligh and°Dyer° [36].…”

“…Sphingolipids are not widely distributed among prokaryotes, and have been mainly studied among organisms in the genus Sphingomonas [27] but these compounds have been reported in Bacteroides melaninogenicus [28] and Bacteriovorax stolpii [4,29]. Furthermore, naturally occurring phosphonolipids are rare, and most reports of these compounds have been from analyses of the ethananolamine glycerophosphonolipids and SPNLs of protozoa [8 -12, 15, 30 -32].…”

“…Furthermore, naturally occurring phosphonolipids are rare, and most reports of these compounds have been from analyses of the ethananolamine glycerophosphonolipids and SPNLs of protozoa [8 -12, 15, 30 -32]. Thus, it is significant that these compounds are present in B. stolpii [4,29]. As the finding of SPNLs in prokaryotes is novel and significant, and despite the elegant work performed previously on these B. stolpii compounds [4], state-of-the-art MS-MS technologies [33][34][35] available today can provide much more information and far greater sensitivity than was available when these lipids were first examined.…”

Molecular Characterization of Membrane-Associated Soluble Serine Palmitoyltransferases from Sphingobacterium multivorum and Bdellovibrio stolpii

“…Bdellovibrio is characterized by the unique predatory behavior by which it invades various other larger gram-negative bacteria and grows as a parasite in the intraperiplasmic space of the prey (46,47,56,57). Bdellovibrio contains a phosphono ceramide, which carries the characteristic head group 1-hydroxy-2-aminoethyl phosphonate (62). The bacteria listed above are exceptions in gram-negative bacteria in that they lack lipopolysaccharides and instead contain a large amount of sphingolipids, including glycosphingolipids (33,(67)(68)(69)(70)72); most gram-negative bacteria contain lipopolysaccharides, the major pathogenic glycolipids of the outer membrane.…”