In 1939, the German researcher Hans Gaffron (1902–1979), who was at that time attached to the University of Chicago, discovered the hydrogen metabolism of unicellular green algae.
En 1939, o investigador alemán Hans Gaffron (1902–1979), que daquela traballaba na Universidade de Chicago, descubriu o metabolismo do hidróxeno das algas verdes unicelulares.