Article Figures & Data
Figures
- FIG. 1.
Primer extension analysis of surE in G. sulfurreducens DL1 (lanes 1 and 3) and rpoS mutant DLCN16 (lanes 2 and 4). Total RNA was extracted from mid-log (lanes 1 and 2) or stationary-phase (lanes 3 and 4) cultures. The transcription initiation site P1 is indicated. (B) DNA sequence of the surE regulatory region. The arrow indicates the transcription start point.
- FIG. 2.
(A) Growth of G. sulfurreducens DL1 (triangles) and rpoS mutant (circles) in media containing acetate as the electron donor and fumarate as the electron acceptor. Data are means of triplicates. The arrow indicates time zero of the survival curve. OD 600, optical density at 60 nm. (B) Stationary-phase survival of DL1 (triangles) and rpoS mutant DLCN16 (circles). Percent viability is expressed as the viable cell number at each time point divided by the viable cell number at time zero. Similar results were obtained in three experiments.
- FIG. 3.
Fe(III) citrate (A) or poorly crystalline Fe(III) oxide (B) reduction in the wild-type strain DL1 (triangles) and rpoS mutant (circles) in media containing acetate as electron donor. Determination of Fe(II) was carried out as previously described (30). Data are means of triplicates.
- FIG. 4.
Aerotolerance of DL1 (wild type) (triangles), DLCN46(rpoS::Cm) (circles), and DLCN52(rpoS::Cm/rpoS+) (diamonds) after 0, 1, 2, and 4 days of air exposure. Data are means of triplicates. Survival was estimated as the lag time of growth of a culture derived from oxygen-exposed cells as described previously (21); determination of CFU was not feasible due to the fact that G. sulfurreducens forms cellular aggregates when exposed to oxygen, a trait that was enhanced by the rpoS mutation. OD 600, optical density at 600 nm.
