Hydrogenosome

A hydrogenosome is a membrane-bound organelle of ciliates, trichomonads and fungi. It produces molecular hydrogen and ATP. This organelle is thought to have most likely evolved from mitochondria.

History
Hydrogenosomes were discovered in the early 1970s by Lindmark and Müller in the US.

Description
Hydrogenosomes are approximately 1 micrometre in diameter and are so called because they produce molecular hydrogen. Like mitochondria, they are bound by distinct double membranes and have an inner membrane with some cristae-like projections. Hydrogenosomes evolved from mitochondria by the concomitant loss of classical mitochondrial features, most notably its genome. A hydrogenosomal genome could not be detected in Neocallimastix, Trichomonas vaginalis and Trichomonas foetus. However, a hydrogenosomal genome has been detected in the coackroach ciliate Nyctotherus ovalis in 1998.