Figure 1.

Maximum likelihood analysis of partial 16S rRNA gene sequences from CO-oxidizing Paraburkholderia and Burkholderia isolates, and related taxa. Bootstrap support ≥ 50% is indicated below the branches. A discrete Gamma distribution was used to model evolutionary rate differences among sites. All gapped positions and positions with missing or ambiguous data were removed, leaving 1263 positions in the final dataset. Asterisks (^*) indicate confirmed CO oxidizers; ‡ indicates isolates with form I CO dehydrogenase genes identified in their genome sequences.