Iron-oxidising and leaching activities of sulphur-grown Thiobacillus ferrooxidans cells on other substrates: effect of culture pH

CURUTCHET, G.; DONATI, E,

Journal of Bioscience and Bioengineering

Elsevier

Año: 2000 vol. 90

1389-1723

The rate of iron (II) oxidation by sulphur-grown Thiobacillus ferrooxidans cells decreased when the pH of theoriginal growth medium was lowered. This behaviour was observed even after shifting from the original growthpH to a higher pH. After being suspended in medium at a pH higher than the growth pH, sulphur-grown cellscould leach covellite at a similar initial rate to iron-grown cells. Sulphur-grown cells exhibited a long lag phasewhen the original growth pH was low. These results were correlated with the number of protons associated withthe cell surface, rather than with cell hydrophobicity or cell capacity to attach to solid particles. Sulphur-growncells grown in very acidic media (without pH control) were not able to oxidize iron (II) or leach covellite evenafter shifting to a high pH.