FIG. 4.

Temperature and pH growth optima of Metallosphaera sp. strain MK1 grown on pyrite plus 0.005% yeast extract. The temperature experiment was performed at a constant pH, pH 3, while the pH experiment was performed at a constant temperature, 65°C. Maximum growth rates were observed at pH 2.5 and 75°C. The error bars indicate standard errors (n = 3) but are generally within the symbols; the y axis is a log₁₀ axis.