Fig. 7: The Ech2 enzyme is crucial for CO adaptation in T. kivui.

a Overview of the WLP and Ech2 locus organization on the chromosome and Tn_CO-1. b Genome editing design for the overexpression of Ech2. c Genome editing pipeline: direct selection of prototrophic cells, versus coupled selection of prototrophy and carboxydotrophy. The top bar plot shows OD₆₆₀ after 1 month of selection without uracil at 66 °C with 50% CO (2 bar). The bottom bar plot shows the carboxydotrophic growth of strain Ech2_KI after 3 days in triplicate serum bottle fermentations with 50% CO in mineral medium, starting from OD₆₆₀ = 0.03. NTC: no template control. The PCR genotyping of Ech2_KI was performed as a single experiment. d Large- and medium-scale rearrangements in the carboxydotrophic Ech2_KI strain. The red segment corresponds to a large inversion event. WT genome refers to isolate G-1 (GCA_963971585). Bold: mutated genes. Except for dnaA, names featured in (d) refer to loci and not genes. Source data are provided as a Source Data file.