Figure 1.

Carbon cycle-specific genes. The six carbon fixation pathways (3-hydtroxypropionate bicycle, Calvin cycle, dicarboxylate-hydroxybutyrate cycle, hydroxypropionate-hydroxybutyrate cycle, reductive acetyl-CoA cycle and reductive citric acid cycle) and other important C-cycling genes are listed on the x axis. The intensity of each block corresponds to the percent relative abundance (see legend) of each class (y axis) within a given individual gene/pathway (x axis). Gray squares indicate that no sequences were observed meeting the given criteria. At the top of each column is a bar chart that indicates the total abundance of each gene/pathway in the metagenome. The KEGG accessions for the genes used to annotate the six carbon fixation pathways are provided in Supplementary Table S4.