Effect of Cyanide-Mineral Interactions on Granite Weathering in a Glacier Forefield

The most essential biogeochemical interactions between microorganisms and mineral surfaces and their effect on mineral dissolution rates are not understood. In post-glaciated mountain areas, where terrestrial life has to evolve under harsh conditions with very little organic carbon, microbial colonization can nevertheless be rapid. Rock material from the Damma glacier area will be studied systematically with respect to proton- and ligand-promoted dissolution, considering cyanide as well as the organic ligands oxalate and salicylate.

Major findings

We studied the synergistic effect of iron(III) and phosphate on the cyanide formation by Pseudomonas fluorescens, which we used as model organism known for its ability to form HCN. In the absence of inorganic phosphate, cyanide formation was stimulated considerably by increasing concentrations of iron(III).

Participants

PD Dr. Helmut Brandl

Co-operation partners

Prof. Dr. Gerhard Furrer, ETHZ, Institute of Biogeochemistry and Pollutant Dynamics (Project Leader)
Dr. Michael Plötze, ETHZ, Institute for Geotechnical Engineering

Publications

Rudolf von Rohr M., Furrer G., Brandl H. (2009) Effect of iron and phosphate on bacterial cyanide formation determined by methemoglobin in two-dimensional gradient microcultivations. Journal of Microbiological Methods 79: 71-95.

Wongfun N., Furrer G., Plötze M., Brandl H. (2009) Cyanide-promoted mineral weathering in a glacier forefield. Abstract of the Goldschmidt 2009 Conference "Challenges to our volatile planet", Davos, Switzerland, June 21 – 26. Geochimica et Cosmochimica Acta 73(13): A1451.