Global molecular description of 16S rDNA from the bacterial microflora of anaerobic digestion of "animal" and "environmental" ecosystems. As a first stage, 20 ecosystems will be inventoried (10 human digestive flora and 10 anaerobic depollution digesters), for a total of 200 16S rDNA sequences per ecosystem.

The ecosystem of anaerobic digestion is composed of a succession of microorganisms which intervene in association and/or in syntrophy at the level of a trophic chain. Anaerobic digestion includes an ensemble of microbial processes (human digestive flora, rumen, termite, garbage, anaerobic digester (depollution), anoxic soil (rice paddy) which are essential to the carbon cycle and are practically unexplored.