FIG. 4.

Effect of the expression of NhaA on lithium accumulation and efflux kinetics. (A) Cells from strain RS-1045 (ENA1-4 NhaA) (triangles) and RS-997 (ENA1-4, control) (squares) were grown on medium with 50 mM LiCl and washed, and lithium efflux was measured as described in Materials and Methods. (B) Cells from strain RS-1041 (ena1-4 NhaA) (triangles) and RS-1043 (ena1-4, control) (squares) were grown on medium with 2 mM LiCl and washed, and lithium efflux was measured as described in Materials and Methods. Circles correspond to strain RS-1041 grown on medium with 50 mM LiCl. Values are averages from three experiments and the error bars indicate standard deviations.