Fig. 2.

Effects of osmolarity on bacterial growth of wild-type cells (NU149, open bar), an ompR mutant (NU149 OmpR1, bold hatched bar), an ompR mutant complemented with the native ompR gene (NU149 OmpR1/pFR29*, filled bar), and an ompR mutant complemented with a mutated ompR gene (NU149 OmpR1/pD55A, hatched bar). Osmolarity effects were tested by using (a) NaCl, (b) urea and (c) sucrose as the osmolytes, at concentrations ranging from 0 to 800 mM. Growth was measured as the OD at 600 nm, and the values represent the means (±sd) from at least three separate runs.