FIG. 4.
Protein release from P. putida CMC4 (PA1-04/03::gef) and CMC12 (PA1-04/03::gene E) after induction of the expression of killing genes. P. putida cells growing exponentially in M9 minimal medium with glucose and 3-methylbenzoate were harvested by centrifugation, washed twice in M9 minimal medium without a C source, and resuspended in M9 minimal medium with glucose and 1 mM IPTG. Samples were taken at 0 h (lanes 1 and 3) and 6 h after induction (lanes 2 and 4). The released proteins were analyzed by SDS-polyacrylamide gel electrophoresis as described in Materials and Methods. Numbers to the left of each panel indicate molecular masses (M) in kilodaltons.