Capnophile

[1] For example, the ability of capnophiles to tolerate (or utilize) the amount of oxygen that is also in their environment may vary widely and may be far more critical to their survival.

Species of Campylobacter are bacterial capnophiles that are more easily identified because they are also microaerophiles, organisms that can grow in high carbon dioxide as long as a small amount of free oxygen is present, but at a dramatically reduced concentration.

[1] (In the Earth's atmosphere carbon dioxide levels are approximately five hundred times lower than that of oxygen, 0.04% and 21% of the total, respectively.)

M. succiniciproducens can attach carbon dioxide to the three-carbon backbone of phosphoenolpyruvate, an endproduct in glycolysis, to generate the four-carbon compound, oxaloacetic acid, an intermediate in the Krebs cycle.

Although M. succiniciproducens has most of the intermediates in the Krebs cycle, it appears incapable of aerobic respiration, instead using fumarate as a final electron acceptor.