FIGURE 2.

Labeling proportions and identities of mxaF phylotypes in the ‘heavy’ and ‘middle’ fractions of all labeled mxaF phylotypes in substrate or pH treatments (A) and the relative frequencies of labeled phylotypes (i.e., gray shades, ‘labeling proportion’ >5%; dotted, ‘labeling proportion’ <5%) (B). Cross, additional [¹²C]-methanol supplementation in the substrate SIP experiment. Equal colors, the same family affiliation. Shading, ambiguous affiliation (i.e., sequence identity with BLASTn <90% and an ambiguous position in the phylogenetic tree). ‘H’ and ’M,’ ‘heavy’ and ‘middle’ fractions, respectively. Values in brackets, contribution of labeled OTUs to the total number of sequences. The ‘labeling proportions’ are indicators for the relative importance of different taxa assimilating the supplemented ¹³C (directly or indirectly). More detailed taxonomic information can be found in Supplementary Table S15.