Fig. 4

DNA relaxation assay used to evaluate the antioxidant activity of BR extract from strain MBLA0099. (a) Dose-dependent antioxidant activity of the bacterioruberin dissolved in DMSO extracted from strain MBLA0099. Lane 1, treated water (as negative control); lane 2, treated Fenton’s reagent (as positive control); lane 3, treated Fenton’s reagent plus DMSO (as blank); lane 4, treated Fenton’s reagent plus 0.25 µM BR extract ; lane 5, treated Fenton’s reagent plus 0.5 µM MBLA0099 extract; lane 6, treated Fenton’s reagent plus 1 µM MBLA0099 extract. (b) Antioxidant activity of BR extract from strain MBLA0099 compared to various C₄₀ carotenoids. Lane 1, treated water (as negative control); lane 2, treated Fenton’s reagent (as positive control); lane 3, treated Fenton’s reagent plus 3 µM lycopene; lane 4, treated Fenton’s reagent plus 3 µM β-carotene; lane 5, treated Fenton’s reagent plus 3 µM astaxanthin; lane 6, treated Fenton’s reagent plus 0.5 µM BR extract