Thermococcus thrive at pH 5.6-7.8 wherein most members of this genus have been found in many hydrothermal vents. Amazingly, salt (NaCl) is not an essential substrate for the organism to survive yet it needs low concentration oflithium ion for growth.
Some species of this genus will aggregate and form white-gray plaques that mostly inhabit in temperatures from 60-100°C either in the presence of black smokers or freshwater springs. Species in this genus are strictly anaerobes. The genomes are sequenced and anticipated to encode genes that are responsible forhigh temperature habitats and various cellular functions.
Metabolisms of Thermococcus undergo different type of glycolysis where it metabolized peptides to amino acid through peptidases then conversion of amino acid to keto acid catalyzed by aminotransferases and as a final point,carbon dioxide is released through oxidative decarboxalytion by four different enzymes that produces coenzyme A derivatives. Some species especially Thermococcus kodakarensis generates enzyme Rubisco to metabolize nucleic acids, thus illustrates how integrated themetabolic system of this hyperthermophilic microorganisms.
Ecologically Thermococcus have a great advantage tocolonize hydrothermal environment where it produces carbon dioxide and elemental sulfur that are useful to other autotrophic organisms assisting the diversity of hydrothermal microbial communities.