Methanopyrus is a genus of methanogen, with a single described species, Methanopyrus kandleri (type strain AV19). It is a rod-shaped hyperthermophile, discovered on the wall of a black smoker from the Gulf of California at a depth of 2,000 m, at temperatures of 84–110 °C. Strain 116 was discovered in black smoker fluid of the Kairei hydrothermal field; it can survive and reproduce at 122 °C. M. kandleri also requires a high ionic concentration (>1 M) in order for growth and cellular activity. Due to the species' high resilience and extreme environment, M. kandleri is also classified as an extremophile. Although terpenoids are the main component of the membrane in M. kandleri, they are more of a supporting structure in eukaryote and bacteria.
Methanopyrus kandleri has a high concentration of cyclic 2,3-diphosphoglycerate. The increased concentration of cyclic 2,3-diphosphoglycerate protects the methanogen, helping it survive in an environment that many other organisms could not. Beyond this compound to help protect the proteins, M. kandleri also has a high salt concentration inside its membrane.
Metabolism
As a methanogen, M. kandleri utilizes hydrogen as an electron source and reduces carbon dioxide from the environment into methane, a process known as methanogenesis.
Future research
Methanopyrus kandleri is also the only species known to have topoisomerase V. Topoisomerase V allows for M. kandleri to survive in such high temperatures and helps to relax both positively and negatively supercoiled DNA . Although topoisomerase V is useful in this case, finding other hyperthermophiles that have topoisomerase V has proven difficult. This lack of topoisomerase V in other archaeon has led researchers to believe that the origin of the enzyme in M. kandleri is a result of viral gene transfer and the unusual amount of orphan genes in the species provides evidence for this theory.