Figure 4.
Heterogeneity of S. roseus isolates near an SO2-polluted coking plant site. Independent isolates of S. roseus obtained from control (□) or SO2-polluted (▪) locations at Site 3 were spread plated to MYP agar supplemented with different concentrations of sodium metabisulphite (Na2S2O5), which reproduces the toxic action of SO2 (Wellburn, 1994). Colonies were enumerated after 14 days, and dose-response curves were constructed. Heterogeneity (A) and IC50 (B) determinations were as described in the legend to Fig. 2. * P < 0.05.