Extremely 'vanadiphilic' multiply metal-resistant and halophilic aerobic anoxygenic phototrophs, strains EG13 and EG8, from hypersaline springs in Canada

Extremophiles. 2015 Jan;19(1):127-34. doi: 10.1007/s00792-014-0693-2. Epub 2014 Sep 11.

Abstract

Two pinkish peach-colored strains of obligately aerobic phototrophic bacteria, EG13 and EG8, were isolated from a saline spring effluent stream in west central Manitoba, Canada. The strains possessed bacteriochlorophyll a incorporated into a typical purple bacterial light-harvesting complex 1 (870 nm) and reaction center (801 nm). Analysis of 16S rRNA gene sequences indicated 100% identity among the isolates and 99% similarity to Roseovarius tolerans EL-172(T). The strains were physiologically well adapted to high salinity (0-22%), fluctuating pH (7-12) and temperature (7-40 °C) of the exposed hypersaline stream of East German Creek. EG8 and EG13 were also highly resistant to the toxic metal(loid) oxyanions tellurite, selenite and metavanadate (≥1000 μg/ml each). Most intriguingly, growth and pigment production of EG13 on glutamate minimal medium was stimulated by 1000-10000 μg/ml of sodium metavanadate compared to metal-free conditions. Phylogenetic analysis and phenotypic properties such as pigment composition and morphology indicate close relatedness to Roseovarius genus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aerobiosis
  • Bacteria / classification*
  • Bacteria / genetics
  • Bacteria / isolation & purification
  • Bacteriochlorophylls / chemistry
  • Biomass
  • Canada
  • DNA, Bacterial / genetics
  • Hydrogen-Ion Concentration
  • Metals / chemistry
  • Natural Springs / microbiology*
  • Photosynthesis
  • Phototropism
  • Phylogeny*
  • Pigmentation
  • RNA, Ribosomal, 16S / genetics
  • Salinity
  • Sequence Analysis, DNA
  • Temperature
  • Vanadium / chemistry
  • Water Microbiology*

Substances

  • Bacteriochlorophylls
  • DNA, Bacterial
  • Metals
  • RNA, Ribosomal, 16S
  • Vanadium