[Effect of oxygen and substrates for growth on the superoxide dismutase and catalase activity of microorganisms]

The activity of superoxide dismutase (SOD) and catalase in Azotobacter vinelandii, Citrobacter freundii, Rhodopseudomonas capsulata, Thiocapsa roseopersicina and Spirulina platensis is far higher when the cultures are grown under the aerobic conditions. The activities of SOD and catalase are higher in R. capsulata cells cultivated in a medium with glucose in the dark under the aerobic conditions than in cells grown under the same conditions but in the light. R. capsulata grown in a medium with glucose and T. roseopersicina cultivated in a medium with formate or pyruvate had higher activities of SOD and catalase than R. capsulata grown in a medium with acetate and T. roseopersicina cultivated in a medium with glucose. Irrespective of the growth conditions, the highest activity of SOD was manifested by C. freundii while that of catalase by A. vinelandii 1. C. freundii and T. roseopersicina contained both Mn-SOD and Fe-SOD whereas A. vinelandii and Rh. capsulata contained only Mn-SOD. The SOD from R. capsulata was purified to a homogeneous state. Its molecular weight is about 40,000 and it contains 1 Mn mole per mole of the enzyme.