Figure 4.

Phylogenetic tree of deduced protein sequence of CoA-dependent propionaldehyde dehydrogenase pduP. Database matches to R. inulinivorans (ABC25528) of at least 60% as well as the top hits below this cutoff (Clostridium methylpentosum ZP_03705305, 57% Geobacillus thermoglucosidasius YP_004587980, 54%) are shown. The number of hits within the metagenomic data set of Qin et al. (2010) with at least 55% identity is indicated to the right (sequences with at least 95% identity were grouped; for a list of all hits see Supplementary Table S6). Numbers of sequences from clone library analysis of a human faecal sample (⩾95% identity grouped) are shaded. Grey tree branches indicate gene with lower identity to R. inulinivorans assumed not to be bona fide pduP genes.