FIG. 4.

Measurements of external cadaverine (i) in permeability buffer at various times after strain HS200/pBR322 (circles) and HS200/pCADA/pCADB (squares) cells had been washed and resuspended in this buffer and (ii) in medium at the end of growth (MLB; i.e., 15 min before resuspension in permeability buffer). Symbols represent the averages of four experiments (error bars indicate SEM and sometimes lie within the thickness of the symbol). For panel B, cells were spun at the 10-min time point (arrow) and resuspended in permeability buffer containing 10 mM lysine (Lys). The presence of external lysine does not interfere with the cadaverine assay (37).