Fig. 6

Fitness profiling of a Rs. rubrum transposon mutant library grown on butyrate. The colored markers indicate the fitness values of strains with mutation in genes encoding related enzymes, ranging from green (deleterious mutation; gene required for optimal growth on butyrate) to orange (beneficial mutation; gene deleterious for optimal growth on butyrate). Strikethrough markers stand for unavailable data due to exclusion according to our robustness criteria or due to the absence of mutated strains in the mutant library. The enzymes marked with a star have yet to be confirmed due to either possible multiple assignations in proposed pathways or to uncertain enzymatic activity. ETF stands for electron transfer flavoproteins. Fd stands for ferredoxins