FIG. 10.

(A) A fur mutation relieves the aromatic amino acid auxotrophy of a SOD-deficient strain. Log-phase cultures grown under anaerobic conditions in minimal medium supplemented with all but the aromatic amino acids were diluted into an aerobic medium of the same composition. Symbols: rectangles, SM1105 (SOD⁻ fur); diamonds, AS237 (SOD⁻). (B) Fur derepression alone is not sufficient for suppression. Cultures growing logarithmically in LB medium were washed and resuspended in minimal medium containing all but the sulfurous amino acids. Symbols: solid rectangles, AN387 (SOD⁺); solid circles, AS237 (SOD⁻); open circles, SM1093 (SOD⁻ dapB); triangles, SM1116 (SOD⁻ dapB fur); diamonds, SM1105 (SOD⁻ fur); open rectangles, SM1123 (SOD⁻ dapB fur/pSM915 [dapB⁺]).