FIG. 1.
Induction of cyanase activity in media containing both ammonium and cyanate simultaneously. Cells were cultured in 1 liter of M9 media containing ammonium and cyanate at a 5-mM final concentration as N sources. At the indicated times, the amount of cell growth (OD600 nm) was determined and 50 ml of the cultures was harvested by centrifugation and used to determine the level of cyanase activity (dashed bars) as indicated in Materials and Methods. Cyanate and ammonium concentrations in the supernatants were determined. The data correspond to a single experiment, and two other independent experiments gave similar results.