Figure 4

The pathways of energy metabolism in Pelobacter carbinolicus and the differences from respiratory Geobacteraceae species. Shown are the pathways of butanediol and acetoin ethanol fermentation and syntrophy used by P. carbinolicus. Vertically-inherited enzymes with orthologs in the other Geobacteraceae are shown in black. The vertically-inherited ATP synthase has been duplicated in P. carbinolicus and is shown in dark grey. Enzymes acquired by lateral gene transfer are shown in red: 1) butanediol dehydrogenase, 2) acetoin dehydrogenase, 3) hydrogenases, the RNF electron transfer complex, and possibly an ATP synthase (see text). Enzymes conserved in the respiratory Geobacteraceae but lost in P. carbinolicus are shown in white. Reactions with multiple enzymes encoded in the genome for which there are diverse conservation patterns are shown as dashed arrows.