Chemolithotrophic Metal Mobilization from Dolomite

Abstract

The potential of indigenous chemolithotrophic bacteria to mobilize metals from dolomite in the presence of added ammonium or thiosulfate was studied in a laboratory experiment over a period of 35 days. The rock sample was collected in the Dolomites (Alps, Europe). The average mineralogical composition of the sample was dolomite (89%) and calcite (11%). After 35 days, mobilization of total metal in the rock sample amounted to 3.4% (Ca), 8.5% (Mg), 1% (Al), and 0.9% (Mn) in the presence of a nitrifying culture. In the presence of a sulfur-oxidizing culture, mobilization of total magnesium in the rock sample amounted to 34%.The results contribute to our understanding of interactions between atmospheric deposition of energy substrates, bacterial activity and metal mobilization in Alpine areas.

Keywords:

• dolomite
• chemolithotroph
• nitrifying bacteria
• sulfur-oxidizing bacteria
• metal
• metal mobilization

Acknowledgments

We thank Dr. Andreas Saxer for performing mineralogical analysis. Representative nt sequences of the bacterial species identified in this study have been submitted to GenBank with accession numbers HM134866-HM134886.