Acidophile: An organism that grows best at acidic (low) pH values.
Alkaliphile: An organism that grows best at high pH values.
Anaerobe: An organism that can grow in the absence of oxygen.
Endolith: An organism that lives inside rock or in the pores between mineral grains. (Check out the video at right to learn about how research on endoliths done by one of our former Earth Sciences MSc. students might inform the search for life on other planets.)
Halophile: An organism requiring high concentrations of salt for growth.
Methanogen: An organism that produces methane from the reaction of hydrogen and carbon dioxide, a member of the Archaea.
Oligotroph: An organism with optimal growth in nutrient limited conditions.
Piezophile (Barophile): An organism that lives optimally at high hydrostatic pressure.
Psychrophile: An organism with optimal growth at temperature 15 °C or lower.
Thermophile: An organism with optimal growth at temperature 40 °C or higher.
Hyperthermophile: An organism with optimal growth at temperature 80 °C or higher.
Toxitolerant: An organism able to withstand high levels of damaging elements (e.g., pools of benzene, nuclear waste).
Xerophile: An organism capable of growth at very low water activity.