Fig 3.
(a) Vmax values of enzymes containing coupling enzymes in assays without ammonium sulfate relative to those with ammonium sulfate in the assay. (b) Vmax values measured in batch-grown cell samples frozen for 3 days relative to those obtained in fresh cells. (c) Relative Vmax values showing loss of enzyme activity during storage of cell samples at −20°C at 4 days (white bars), 12 days (gray bars), and 4 months (black bars) from the day of harvesting the chemostat at D of 0.15 h−1. Error bars represent standard deviations of a ratio of average activities from at least three independent dilutions from two independent batch cultures for panels a and b and from the cell extract of the chemostat culture for panel c.