Development of Thiobacillus biofilms for metal recovery.

CURUTCHET, G., DONATI, E., OLIVER, C., POGLIANI, C., VIERA, M.R.

Methods in Enzymology

Academic Press

Año: 2001; p. 171 - 186

This chapter describes the preparation of two types of biofilms: (1) Thiobacillus ferrooxidans, immobilized by the two more widely used techniques?attachment and entrapment?for the production of sulfuric acid and (2) attached Thiobacillus ferrooxidans cells for the ferrous iron oxidation. In both cases, whole and viable cells are used. These bacteria are all gram-negative, mesophilic, autotrophic, and obligately acidophilic. T.ferrooxidans is able to use ferrous iron or reduced sulfur compounds as electron donors, whereas T. thiooxidans is only capable of using reduced sulfur compounds. Ferric iron and sulfuric acid are the final products of these oxidation processes. The ability of acidophilic bacteria to assist in the recovery of metals by the dissolution of sulfide minerals is well known, but the mechanism is not fully understood. The chapter also relates the application of these biofilms to recover metals from the leaching of a sulfide ore.