FIG. 1.

Depletion curves showing levels of acetate and 2-CP present in cell suspensions of strain 2CP-C during acetate threshold measurements, with two initial acetate concentrations of 20 (A) and 40 μM (B). 2-CP was the electron acceptor, and acetate was the electron donor. The insets show the acetate concentration in the vicinity of the threshold value. Note that the scale of the y axis is in nM measurements in the insets. Data points were averages of triplicate cultures. No acetate depletion was observed in control cultures that did not receive 2-CP.