special features of methane producing bacteriaReading time:
Methane producing bacteria are strictly anaerobic and therefore immobilised as soon as a few fractions of ppm of dissolved O2 are present. They can be identified by the presence of coenzymes or of very specific factors such as factor F420 whose fluorescent properties mean that these methane producing bacteria can be seen under a microscope with the help of a UV lamp. Factor F430 contains nickel, making this an essential element for population growth.
The main species are given below (table 12).
Depending on the substrate used, doubling times vary significantly from a few hours for hydrogenophillic bacteria to several days for acetoclastic bacteria.
Affinity constants with regard to substrates also vary widely; therefore, low acetate contents tend to favour the presence of Methanothrix in anaerobic ecosystems.