Hg2+ was measured by cold vapour atomic absorption spectrophotometry.
The dry weight of cells was determined from the OD600 by using the value of 0.35 g dry weight per litre of OD6001.0 that was found for these cells previously [7]. Hg2+-uptake (q) was calculated from q (mg/g cell dry weight) = V(CiCt)/mt, where V was the sample volume (L),