Thiothrix is a genus of filamentous sulfur-oxidizing bacteria, related to the genera Beggiatoa and Thioploca.
Sulfur is deposited in invaginations within the cell membrane.
[1][2] Thiothrix live primarily in flowing water containing a source of sulfide but are also present in activated-sludge waste water treatment systems.
Thiothrix species can be facultative autotrophs,[3] chemoorganotrophs[3] and mixotrophs.
[3][5] The temperature range for growth can vary from cold springs to hot vents while salinity can vary from fresh to ocean water.