For aerobic and anaerobic growth experiments, all S. oneidensis strains were cultured in a defined salts medium (M1) supplemented with 20 mM lactate as carbon/energy source (Myers & Nealson, 1988). Vibrio parahaemolyticus and V. harveyi were tested for anaerobic metal reduction activity in marine broth (Difco) growth medium. Bacterial growth experiments were carried out in a B. Braun Biostat

B batch reactor with automatic feedback control of pH, temperature, and dissolved O2 concentration. Electron acceptors were synthesized as previously described (Saffarini et al., 1994; Blakeney et al., 2000; Taratus et al., 2000; Payne & DiChristina, MAPK inhibitor 2006; Neal et al., 2007) and added at the following final concentrations: , 10 mM; , 2 mM; Fe(III) citrate, 50 mM; amorphous MnO2, 15 mM; trimethylamine-N-oxide (TMAO), 25 mM; , 10 mM; fumarate, 30 mM; and DMSO, 25 mM. Gentamycin was supplemented at 15 μg mL−1. Dabrafenib ic50 For the growth of E. coli β2155 λ pir, diaminopimelate was amended at 100 μg mL−1. Cell growth was monitored by direct cell counts via epifluorescence microscopy and by measuring terminal electron acceptor depletion or end product accumulation. Acridine

orange-stained cells were counted (Zeiss AxioImager Z1 Microscope) according to the previously described procedures (Burnes et al., 1998). Cell numbers at each time point were calculated as the average of 10 counts from two parallel yet independent anaerobic incubations. was measured spectrophotometrically with sulfanilic acid-N-1-naphthyl-ethylenediamine dihydrochloride solution (Montgomery & Dymock, 1962). Fe(III) reduction was monitored by measuring HCl-extractable Fe(II) production with ferrozine (Stookey, 1970). Mn(IV) concentration was Tolmetin measured colorimetrically after reaction with benzidine hydrochloride as previously described (Burnes et al., 1998). Mn(III)-pyrophosphate concentration was measured colorimetrically as previously described (Kostka et al., 1995). concentrations were measured by cyanolysis as previously described

(Kelly & Wood, 1994). Growth on O2, TMAO, DMSO, and fumarate was monitored by measuring increases in cell density at 600 nm. Control experiments consisted of incubations with cells that were heat-killed at 80 °C for 30 min prior to inoculation. Genome sequence data for S. oneidensis MR-1, S. putrefaciens 200, S. putrefaciens CN32, S. putrefaciens W3-18-1, S. amazonensis SB2B, S. denitrificans OS217, S. baltica OS155, S. baltica OS195, S. baltica OS185, S. baltica OS223, S. frigidimarina NCIMB400, S. pealeana ATCC 700345, S. woodyi ATCC 51908, S. sp. ANA-3, S. sp. MR-4, S. sp. MR-7, S. loihica PV-4, S. halifaxens HAW-EB4, S. piezotolerans WP3, S. sediminis HAW-EB3, and S. benthica KT99 were obtained from the National Center for Biotechnology Information (NCBI, http://www.ncbi.nlm.nih.gov) or the Department of Energy Joint Genome Institute (DOE-JGI, http://jgi.doe.gov).