FIG. 3.

Amino acid uptake by P. putida KT2440 (open symbols) and the KTaauR mutant (closed symbols) during growth on 5 mM amino acids (circles) and on 22 mM glucose with amino acids (squares). The cells were pregrown on M9+ medium (see Materials and Methods) overnight and then transferred to M9 minimal medium supplemented with 5 mM amino acids as the sole carbon and nitrogen sources and amino acids in combination with 22 mM glucose. High initial cell densities (A₆₀₀ = 0.5 to 0.6) were used for these experiments. The concentrations of the amino acids remaining in the medium are shown as a function of incubation time (see Materials and Methods).