FIG. 1.

Effects of different concentrations of mercury in FSL soil on the total numbers of culturable CFU on 0.1× TSA (A) and the numbers of CFU resistant to mercuric chloride (20 μg ml⁻¹) (B). Symbols: •, no HgCl₂; ▴, 4 μg of HgCl₂ g of soil⁻¹; ▾, 28 μg of HgCl₂ g of soil⁻¹; ▪, 55 μg of HgCl₂ g of soil⁻¹. The variation at each data point was within the symbol dimensions. The data points marked with a or b (referring to both high-mercury-level treatments) were significantly higher than the corresponding data points for the low- and no-mercury treatments, with a > b (P < 0.05).