Fig. 1.

Hpx^- mutants exhibit growth and viability defects. Aerobic growth (A) and cell viability (B) of wild-type (SP63, circles) and Hpx^- (SP64, squares) strains were grown in anaerobic LB medium until early log phase and then diluted into aerobic LB medium. At intervals, the cells were removed to an anaerobic chamber and plated to determine cell viability. Filled symbols, no chelator. Open symbols, 2 mM of the cell-permeable iron chelator desferrioxamine (DF) was included in the aerobic medium.