Acquisition of apparently intact and unmodified lipopolysaccharides from Escherichia coli by Bdellovibrio bacteriovorus

Abstract

The ability of Bdellovibrio bacteriovorus to relocalize the OmpF major outer membrane porins from its Escherichia coli prey to its own outer membranes is diminished in prey expressing smooth lipopolysaccharide (S-LPS). Since porins exist in the membrane complexed with LPS, we examined the LPS associated with relocalized porin to determine whether it had been acquired intact, mixed or replaced with Edegovibrio LPS, or derivatized by the bdellovibrios. The relocalized trimers were found associated with the same LPS onrginally bound to them in the E. coli. The bulk-phase LPS from bdellovibrios grown on various chemotypes of rough prey was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis to determine whether more than the trimer-bound LPS was acquired by the bdellovibrios. This analysis revealed bands ofBdeilovibrio LPS matching the LPS chemotype of the prey. One or two other bands were identical in migration to the LPS of prey-independent mutants of B. bacterovorus and represented bdellovibrio-synthesized LPS. The LPS of bdellovibrios grown on prey with radiolabeled lipid A showed radioactivity only in gel band positions identical with those of the prey's LPS. The amount-of this prey-derived LPS was shown by enzyme-linked immunosorbent assay to reach a constant value during the purification of the bdellovibrios, and it represented approximately 25% of the total Bdellovibrio LPS. Immunoelectron microscopy confirmed the presence of prey-derived LPS on the cell surface of bdellovibrios, and no evidence could be found for bdellovibrio-induced modifications of the relocalized prey LPS.

Bdellovibrio and Like Organisms

“…In contrast, BALOs lack the ability to synthesize and degrade various amino acids and riboflavin, which should be acquired from the host Rendulic et al 2004). Other prey cell components were thought to be imported and utilized as building blocks by the predator, such as lipopolysaccharide moieties (Kuenen and Rittenberg 1975;Stein et al 1992) and OMPs (Diedrich et al 1984). It was shown that in fact, B. bacteriovorus synthesizes its own lipopolysaccharides (Schwudke et al 2003) and does not import OMPs (Barel et al 2005;Beck et al 2004).…”

The Obligate Predatory Bdellovibrio bacteriovorus Possesses a Neutral Lipid A Containing α-D-Mannoses That Replace Phosphate Residues

“…It should be emphasized that our experiments cannot answer the question if B. bacteriovorus integrates complete lipid A or LPS molecules of the prey bacteria into its cell wall (39). We structurally determined the LPS of HD100 after completing its (11) showing no membrane fusion process during the invasion of B. bacteriovorus with the outer membrane of the prey.…”

Predation in the Presence of Decoys: An Inhibitory Factor on Pathogen Control by Bacteriophages or Bdellovibrios in Dense and Diverse Ecosystems

“…immunoglobulins in particular may cause problem, since these species incorporate complete cell wall structures and membrane protein fragments of the prey in their own outer envelope (Diedrich, 1988;Stein et al, 1992). If the host has mounted an immune response to the pathogen (prey) it is likely to a!ect the predator as well in such cases.…”