FIG. 3.

Effect of gluconate dosage on the expression of the engineered groE promoter-gluconate operator system in WB1200. WB1200 was cultured at 37°C in superrich medium containing different amounts of sodium gluconate. At 4 h of culture, cells were harvested and disrupted by French press. β-Galactosidase activity in the cell lysates was determined using ONPG as substrate. Miller units were as defined in the legend for Fig. 2.