Abundances of the 22 operational taxonomic units (OUTs) with a maximum intra-group distance of 5% (AA) in the clone library.

Clones were derived from samples taken before (‘start’, based on DNA) and after (‘control’ and 3.85% CH3F, based on transcripts) anoxic incubation for 14 days. OTU number and affiliation to families are given as in Figure 4. Msarc: Methanosarcinaceae, Mcell: Methanocellales, Mbac: Methanobacteriales, Msaeta = Methanosaetaceae, Fen = Fen cluster, Msarc-like = uncertain affiliation, but nearest to Methanosarcinaceae; NN = unknown cluster. Simulated p-values are from a Monte-Carlo simulation with 9999 replicates.