Influence of lipopolysaccharide on the surface proton-binding behavior of Shewanella spp.

Vernon R. Phoenix, Anton A. Korenevsky, F. G. Ferris, Y. A. Gorby, T. J. Beveridge

Research output: Contribution to journalArticlepeer-review

10 Citations (Scopus)


This study investigates the potentiometric properties of several strains of Shewanella spp. and determines whether these properties can be correlated with lipopolysaccharide (LPS) type. The LPS of eight Shewanella strains was characterized using silver-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and their potentiometric properties determined using high-resolution acid-base titrations. Titrations showed that total ligand concentrations (L T ) ranged from 0.903 ± 0.007 μmol/mg (S. baltica 63) to 1.387 ± 0.007 μmol/mg (S. amazonensis SB2B). Smooth strains (possessing O-side chains) exhibited higher mean L T values than rough strains (no O-side chain). A Tukey's honestly significantly different (HSD) test revealed, smooth strains exhibited significantly higher L T values than rough strains in 69% of comparisons. Comparison of individual pK a concentrations revealed that smooth LPS strains of Shewanella were relatively enriched in reactive groups at pK a 5, suggesting their LPS O-side chains contained detectable carboxyl groups. Combined pKa spectra from all eight Shewanella strains produced a common trend indicating that the way in which the surface proton-buffering capacity changes with pH is similar for the species studied here.

Original languageEnglish
Pages (from-to)152-157
Number of pages6
JournalCurrent Microbiology
Issue number2
Early online date14 Jun 2007
Publication statusPublished - 31 Aug 2007
Externally publishedYes


  • Shewanella spp.
  • lipopolysaccharide
  • bacterial strain

Cite this