Pyrolobus fumarrii currently holds the record for the most thermophilic of all known organisms - its growth temperature maximum is 113°C. Notably,
P. fumarrii is unable to grow below 90°C because it is too cold! Cultures of
P. fumarrii survive autoclaving (121°C) for 1 h, a condition that even bacterial endospores cannot withstand. For more information on the genus
Pyrolobus,
click here.
Taken from the text Brock Biology of Microorganisms (10th ed.). Madigan, M.T., Martinko, J.M., and Parker, J. 2003. Prentice Hall. 466-467p.