Fig. 2.

RubisCO amino-acid tree of functionally selected RubisCOs. The following colour scheme was used: RubisCO form I sequences (green), form II (blue), form II Gallionellaceae (pink), hybrid form II/III (black), form III (red), and form IV (gray). Sequences retrieved as part of this study are marked with a star filled with various colours identifying the nature of the strain: Enrichment (orange), Biofilm (gray), and Groundwater aquifer (black). RubisCO sequences employed as part of the five-organism control experiment are indicated by gray-filled circles. Enrichment RubisCO sequences noted with asterisks are partial sequences encompassing aa 130–458 according to R. rubrum numbering for the form II and aa 80–410 according to Synechococcus PCC6301 numbering for the form I sequences. The rest of the sequences are full-length RubisCO sequences. Representative full-length RubisCO sequences were obtained from the NCBI ref seq database (Table S1). The distance-based RubisCO amino acid tree was made in GENEIOUS using the Jukes-Cantor genetic distance model and the neighbour-joining tree building method. Bacillus subtilis form IV RubisCO served as the outgroup. The tree was re-sampled using bootstrapping with 100 replicates.