Fig. 6
Percent abundance of 5 methanogen ASVs in the control and hydrogen-supplemented reactors. The hydrogenotrophic Methanobacterium (a), acetoclastic Methanosaeta (b) and 3 ASVs of Methanosarcina (c–e), which may carry out both forms of methanogenesis, were detected among the top 100 most abundant ASVs. Datapoints in each figure indicate the abundance of the ASV in a reactor replicate sample at the time in days since reactor start-up. The solid line indicates the mean of control reactor abundances and the dashed line indicates that for the hydrogen-supplemented reactors, while symbol shape and fill indicate whether the datapoint corresponds to a reactor without H2 addition (control) or with (H2 supplemented), as indicated in the legend in the plot (a). Samples with less than 1000 sequences were omitted from the figure