<p>Bacteria were grown in LB medium, and absorbance was measured at 600 nm (solid circles, <i>psrA</i>-<i>lacZ</i>; open circles, <i>phlF</i>-<i>lacZ</i>). Expression of the fusions was assessed by measuring levels of β-galactosidase. Black shading represents <i>psrA</i>-<i>lacZ</i> expression, and grey shading represents <i>phlF</i>-<i>lacZ</i> expression. Triplicate cultures were assayed and the standard deviations are presented with error bars.</p
