Methanosarcina acetivorans is a versatile methane producing microbe which is found in such diverse environments as oil wells, trash dumps, deep-sea hydrothermal vents, and oxygen-depleted sediments beneath kelp beds.

[1] Methanosarcinides, including M. acetivorans, are also the only archaea capable of forming multicellular colonies, and even show cellular differentiation.

[3] M. acetivorans has been noted for its ability to metabolize carbon monoxide to form acetate and formate.

In such an environment, a primitive "protocell" could easily produce energy through this metabolic pathway, excreting acetate as waste.

Other pathways generate energy from ATP only through complex multi-enzyme reactions involving protein pumps and osmotic imbalances across a membrane.