FIG. 4.

Uptake of nanomolar concentrations of osmoprotectants by confined cultures of E. coli MC4100 exposed to natural seawater. Osmoadapted cultures (ca. 10⁹ CFU ml⁻¹) were pregrown in M63 medium supplemented with 0.3 M NaCl and were incubated in the presence of 1 nM [¹⁴C]GB (●), 1 nM [¹⁴C]DMSA (■), or 50 nM [¹⁴C]DMSP (▴). Uptake assays were performed as described in Materials and Methods.