Figure 8
Performance of biosensor cells against environmental water samples spiked with different concentrations of Hg(II). LB-incubated exponential-phase cultures (A) or LB-incubated lag-phase cultures (B) of whole-cell biosensor TOP10/pPmer-vio were exposed to varying concentrations of Hg(II) in the following water samples: sterile distilled water, unsterilized tap water and unsterilized lake water. After culturing at 37 °C for 12 h, the bacterial density (OD600) was first determined (point line diagram, right-Y scale), and then the butanol-extracted violacein was determined at 490 nm (bar chart, left-Y scale). Relative standard deviation (RSD) is shown in the table embodied in the figure.
