Fig 7.
Expression of the pelN and pelL transcriptional fusions in different conditions. (A) The effect of temperature on pelN and pelL expression was tested by growing the bacteria in M63 medium at 25, 30, or 37°C. (B) The effect of the external pH on pelN and pelL expression was tested by growing the bacteria in M63 medium buffered at pH 6, 6.5, 7, or 7.5. (C) The effect of osmolarity on pelN and pelL expression was tested by growing the bacteria in 2-fold-diluted M63 (M63 ½), M63, or M63 + 0.3 M NaCl. In each case, the medium was supplemented with 2 g of glycerol liter−1 as the sole carbon source. The β-glucuronidase (GUS) specific activity (SA) was determined to estimate the expression of the pelN::uidA and pelL::uidA fusions. The values reported are the averages of at least three independent experiments, and the standard deviations are indicated.