FIG. 2.

Expression of alkB1 and alkB2 throughout the growth phase. Strains RR1B1 (strain RR1 containing a PalkB1::lacZ transcriptional fusion) and RR1B2 (strain RR1 containing a PalkB2::lacZ transcriptional fusion) were grown in minimal salts M9 medium containing tetradecane as the carbon source. Samples were taken at different times, and the amount of β-galactosidase present was measured (solid squares). Cells were washed and resuspended in M9 medium without alkanes prior to turbidity measurements (gray circles) to avoid errors induced by nondissolved alkanes.