|ERSP Rifle - Ground_Water_2007
Study of Geobacter physiology during stimulated uranium bioremediation
|Home Genomic Databases MS Analysis Supplemental PNNL - Rifle|
The efficacy of soluble U(VI) reduction to insoluble U(IV) by iron-reducing bacteria
changes as geochemical conditions evolve during bioremediation. Three planktonic
Geobacter-dominated communities were recovered from the U-contaminated Rifle, CO
aquifer during in situ acetate amendment. Over 2,500 proteins were identified per sample
by matching LC MS/MS spectra to peptides predicted from 7 isolate Geobacter genomes.
Genome-specific peptides indicate early proliferation of multiple M21 and G.
bemidjiensis like strains and later dominance by M21 and G. bemidjiensis like strains
more closely related to G. lovleyi. Throughout biostimulation, the proteome is dominated
by enzymes that convert acetate to acetyl-CoA and pyruvate for central metabolism.
Later in bioreduction, decreasing abundances of ribosomal proteins, ATP synthase, and
phosphate and nitrogen acquisition proteins indicate slowing biomass production whereas
increases in TCA cycle proteins and flagellin suggest a transition toward attachment,
possibly driven by dependence on less readily reducible iron oxides. Results demonstrate
that metagenomics-independent proteomics can resolve population physiology and strain
composition of subsurface communities.