FIG. 1.

Leaching of ZnS by T. thiooxidans R20 (16). The strain had been adapted to grow on ZnS, before the experiment was started by addition of 10⁹ cells to 1 g of ZnS (pulverized) in 50 ml of salt solution in shake flasks at 28°C in the dark. Tt, assays with T. thiooxidans; c., sterile control assays. Data are means of three parallel assays. Standard deviations were less than 15%. The experiment was reproduced twice.