These include Methanomethylovorans hollandica, which degrades dimethyl sulphide and methanethiol (Lomans et al., 1999), and Methanosarcina lacustris, which can produce methane from methanol, methylamine or H2/CO2 (Simankova et al.,
2001). Lake Pavin in France (GPS coordinates 45u 29.749 N 2u 53.289 E) is a natural and deep (92 m) freshwater lake that is unusual because the water column has been stratified for a very long period without mixing (Michardet al., 1994).