Microbiological Oxidation of Ferrous Iron at Low Temperatures

Abstract

Acidophilic iron-oxidizing bacteria were enriched from mine water samples with ferrous sulfate as the substrate at incubation temperatures in the range of 4 to 46°C. After several subcultures at each test temperature except 46°C, which was prohibitive to growth, the rates of iron oxidation were determined in batch cultures. The results yielded linear rates in a semilogarithmic scale. The rate constants of iron oxidation by growing cultures were fitted into the Arrhenius equation, which displayed linearity in the 4 to 28°C range and yielded an activation energy value of 83 ± 3 kJ/mol.