FIG. 1.

Effect of oxygen on fumarase activity in continuous culture. Cells were grown in glucose (2.25 mM) minimum medium, and k was 0.6/h. (A) Total fumarase activity in W3110 (●); FumA+B activity in W3110 (○); FumC activity in W3110 (▴); FumC activity in DJ901 (■). (B) Total fumarase activity in EJ1535 (FumA⁻ FumC⁻) (▵); total fumarase activity (FumB+C) in the fumA mutant (●); total fumarase activity (FumA+C) in the fumB mutant (○); total fumarase activity (FumA+B) in the fumC mutant (▴). Units of fumarase activity are expressed as micromoles of fumarate formed per minute at 25°C and pH 7.3.