%0 Journal Article %A Hamadi, A. Falah %A Gallon, John R. %T Calcium Ions, Oxygen and Acetylene Reduction (Nitrogen Fixation) in the Unicellular Cyanobacterium Gloeocapsa sp. 1430/3 %D 1981 %J Microbiology, %V 125 %N 2 %P 391-398 %@ 1465-2080 %R https://doi.org/10.1099/00221287-125-2-391 %I Microbiology Society, %X Cultures of Gloeocapsa sp. 1430/3 rapidly and irreversibly lost their ability to reduce acetylene when incubated with 1 mm-EDTA, either in the light or aerobically in the dark. However, EDTA did not inhibit acetylene reduction by cultures of Gloeocapsa incubated anaerobically in the dark. It is suggested that EDTA depletes the cyanobacterial cells of Ca2+ and thereby destroys a Ca2+-dependent process by which nitrogenase is protected from inactivation by oxygen. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-125-2-391