Alkalithermophilic Chemolithoautotrophic Crenarchaeota

Created by George Rice, Montana State University


  • Most terrestrial and aquatic systems have pH values between 5 and 8 making them neutral in pH (pH 7 is neutral; below 7 is acidic, above 7 is alkaline). However, the Nevada hot springs studied in this project are all quite alkaline, with pHs ranging as high as 10 (on a scale of 0-14) and with water temperatures as hot as 60 degrees Centigrade (~140 degrees Fahrenheit). The alkaline conditions combined with hotter water temperatures dictate the alkalithermophilic portion of the organisms names.
  • Chemolithoautotrophic means that these organisms obtain the necessary carbon for metabolic processes from carbon dioxide in their environment. They also use inorganic compounds such as nitrogen, iron, or sulfur for the energy to power these processes. Learn about where different chemolithoautotrophic bacteria get their energy. 

    Figure breaking down the definition of chemolithoautotroph
  • Crenarchaeota comprise the major portion of Archaea which is one of the three major domains forming the tree of life shown below. 

    Figure graphicly depecting a ribosomal based tree of life

Copyright on all images and material (excluding figures on this page) by Zhang and the Nevada hot spring team, 2005.