Formation and Transformation of Clay Minerals: the Role of Bacteria

Bacteria are the most abundant forms of life we know on our planet that can be able to survive in a variety of habitats, from hot to cold springs, from soils to deep sedimentary rocks, in radioactive wastes and in living organisms. It has been estimated (Whitman et al., 1998; Lipp et al., 2008) that the prokaryote number is 3.5 5.0·1030 and although global subseafloor sedimentary microbial abundance has been recently reduced to 2.9·1029 (Kallmeyer et al., 2012), number of these single-celled organisms remain truly impressive and their mass exceeds that of all plants and animals on Earth. Therefore to modelling mineral equilibria it is imperative to take into account the presence of bacteria in geological environments.