Dehalobacterium formicoaceticum proteomics data from dichloromethane (DCM)-only medium

Dehalobacterium formicoaceticum is recognised for its unusual ability to anaerobically ferment dichloromethane (DCM), and a catabolic model has recently been proposed. D. formicoaceticum is currently the only axenic culture representative of its class, the Dehalobacteriia, however much diversity has been revealed in this lineage through recent culture-independent exploration of anoxic habitats. Here we performed a comparative analysis of 10 members of the Dehalobacteriia, representing three orders, and infer that anaerobic DCM degradation is a recently acquired trait only present in some members of the order Dehalobacteriales. Inferred traits common to the class include the use of amino acids as sole carbon sources for growth, energy generation via a remarkable range of putative electron-bifurcating protein complexes, and S-layers. The ability of D. formicoaceticum to grow on serine alone was subsequently confirmed experimentally and a high abundance of the electron-bifurcating protein complexes and S-layer proteins was noted when this organism was grown on DCM. We conclude that members of the Dehalobacteriia are low abundance fermentative scavengers in anoxic habitats.