Strain 121
Strain 121. At the time of its discovery, Strain 121 was the only known form of life that could tolerate such high temperatures, but in 2008 Methanopyrus kandleri was discovered to be able to reproduce at temperatures as high as 122 °C. Autoclaves, which are an important tool in sterilization, operate at temperatures of, marking Strain 121 a particularly notable discovery. Prior to the 2003 discovery of Strain 121, a fifteen-minute exposure to autoclave temperatures was believed to kill all living organisms. However, as Strain 121 is unable to reproduce at temperatures below, it cannot infect humans, who have an average body temperature of approximately.
It appears highly improbable that Strain 121 marks the upper limit of viable growth temperature. It may very well be the case that the true upper limit lies somewhere in the vicinity of, the temperature range where molecular repair and resynthesis becomes unsustainable.