FIG. 2.

Accumulation of 2,5-dihydroxybenzoic acid (GA) in resting cell suspensions. Each histogram represents one strain grown on the substrate indicated; washed cells were incubated with the growth substrate (2 mM) in the presence or absence of 2,2′-dipyridyl (0, 1, or 5 mM). The bars represent the concentrations of substrate remaining and the concentrations of GA detected (if any) after incubation for 18 h at 40°C. The data shown represent the means of triplicate determinations; the error bars represent ±1 standard deviation. Hfx., Haloferax; Haa., Haloarcula.