Effect of oxygen on the cyanobacterium Oscillatoria limnetica

Oscillatoria limnetica grown photoautotrophically under aerobic or anaerobic conditions contained a single superoxide dismutase (SOD) of identical electrophoretic mobility in both cases. Its activity was cyanide resistant and H₂O₂ sensitive, implicating Fe-SOD. The enzyme level was high in aerobically and low in anaerobically growing cells. Anaerobically grown cells were more sensitive than aerobic to photooxidation, as expressed by bleaching of phycocyanin and disintegration of the trichomes.Abbreviations DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea - SOD superoxide dismutase