Fig. 2.

As(V) respiration by wild-type ANA-3 (circles) and mutant strains ARRA3 (ΔarrA) (squares) and ARRB1 (ΔarrB) (triangles). (A) The time course for growth inferred by optical density at 600 nm. (B) The As(V) concentration in the medium at the various time points. (C) Anaerobic growth on As(V) by strain ARRA3 (ΔarrA) and strain ARRB1 (ΔarrB) is restored by providing a wild-type copy of the arrA or arrB gene on a complementation vector (filled symbols). Open symbols in C represent strains containing the complementation vector alone. Points and error bars in each panel represent the averages and standard deviations of triplicate samples.