Steady state protein levels in Geobacter metallireducens grown with iron (III) citrate or nitrate as terminal electron acceptor.

TitleSteady state protein levels in Geobacter metallireducens grown with iron (III) citrate or nitrate as terminal electron acceptor.
Publication TypeJournal Article
Year of Publication2007
AuthorsAhrendt AJ, Tollaksen SL, Lindberg C, Zhu W, Yates JR, Nevin KP, Babnigg G, Lovley DR, Giometti CS
JournalProteomics
Volume7
Issue22
Pagination4148-57
Date Published2007 Nov
ISSN1615-9853
KeywordsBacterial Proteins, Cell Proliferation, Electrons, Electrophoresis, Gel, Two-Dimensional, Ferric Compounds, Geobacter, Hydrogen-Ion Concentration, Nitrates, Oxidation-Reduction, Proteomics, Tandem Mass Spectrometry
Abstract

Geobacter species predominate in aquatic sediments and submerged soils where organic carbon sources are oxidized with the reduction of Fe(III). The natural occurrence of Geobacter in some waste sites suggests this microorganism could be useful for bioremediation if growth and metabolic activity can be regulated. 2-DE was used to monitor the steady state protein levels of Geobacter metallireducens grown with either Fe(III) citrate or nitrate to elucidate metabolic differences in response to different terminal electron acceptors present in natural environments populated by Geobacter. Forty-six protein spots varied significantly in abundance (p<0.05) between the two growth conditions; proteins were identified by tryptic peptide mass and peptide sequence determined by MS/MS. Enzymes involved in pyruvate metabolism and the tricarboxylic acid (TCA) cycle were more abundant in cells grown with Fe(III) citrate, while proteins associated with nitrate metabolism and sensing cellular redox status along with several proteins of unknown function were more abundant in cells grown with nitrate. These results indicate a higher level of flux through the TCA cycle in the presence of Fe(III) compared to nitrate. The oxidative stress response observed in previous studies of Geobacter sulfurreducens grown with Fe(III) citrate was not seen in G. metallireducens.

DOI10.1002/pmic.200600955
Alternate JournalProteomics
PubMed ID17994620