Methanomicrobia was represented by 5 families of the order Methanomicrobiales (Methanocalculus, Methanoregulaceae,Methanocorpusculaceae, Methanospirillaceae, Methanomicrobiaceae)
and 2 families of the order Methanosarcinales (Methanosaetaceae and Methanosarcinaceae) (Table 2).