Some bioengineering is investigated in high carbon dioxide environments. Are there any microbes like bacteria or Archaea capable of living and multiplying in such environments?
These aren't technically extremophiles, but one paper identified twenty species of bacteria that grow under a low pressure, mostly CO₂ atmosphere1.
One relatively well studied species is Serratia liquefaciens (a Proteobacterium) that has been shown to grow under
low temperature (0 °C), low pressure (0.7 kPa), and anoxic, CO2-dominated atmosphere-conditions intended to simulate the near-subsurface environment of Mars2.
1: Schuerger, A. C., & Nicholson, W. L. (2016). Twenty species of hypobarophilic bacteria recovered from diverse soils exhibit growth under simulated martian conditions at 0.7 kPa. Astrobiology, 16(12), 964-976.
2: Fajardo-Cavazos, P., Morrison, M. D., Miller, K. M., Schuerger, A. C., & Nicholson, W. L. (2018). Transcriptomic responses of Serratia liquefaciens cells grown under simulated Martian conditions of low temperature, low pressure, and CO 2-enriched anoxic atmosphere. Scientific reports, 8(1), 1-10.
Many organisms present in the cow rumen are capnophiles by necessity, as CO2 is the major gas product of rumen fermentation (66% by molarity). One such organism is Mannheimia succiniciproducens, which was shown to thrive in a pure CO2 atmosphere when compared to pure N2 and equimolar H2:CO2 --
Under N2 atmosphere, cell growth and glucose consumption rates were much lower, suggesting that M. succiniciproducens, like other capnophilic bacteria, relies on a CO2-dependent metabolism. The glycolytic flux under CO2 was four times greater than that obtained under N2.
When H2 was present, cell growth rate and the glycolytic flux were lower. However, the relative succinic acid flux increased by 30% under CO2-H2, and the relative formation rates of ATP and NADH were higher in the presence of H2.
Some pathogens are also capnophiles, including species of Campylobacter, Neisseria gonorrhoeae, and Haemophilus influenzae, though ideal culture conditions for these organisms call for CO2 concentrations around 5 - 10%.