Bacteria influence a variety of chemical reactions in soils and rocks, and many of these bacteria obtain metabolic energy through oxidation-reduction reactions associated with metal atoms that are trapped in minerals. A better understanding of these processes will require further examination of how bacteria attach to and interact with metal-containing minerals. Several papers, collected from two recent conferences by Haas and Fein, address the interaction between bacteria, particularly those that reduce or oxidize iron, and host silicate minerals in reactions ranging from weathering to the formation of stalagmites in caves to mineral deposition. There is a close correspondence between environmental conditions, such as pH, and the rate of solution or dissolution. Several studies have found that other minerals, particularly iron oxides, form during bacterial metabolism on silicate minerals and complicate these interactions. -- BH
Chem. Geol. 180, 1 (2001).
