The green unicellular alga, Haematococcus pluvialis has two antioxidative mechanisms against environmental oxidative stress: antioxidative enzymes in vegetative cells and the antioxidative ketocarotenoid, astaxanthin, in cyst cells. We added a reagent that generates superoxide anion radicals (O2 ), methyl viologen, to mature and immature cysts of H. pluvialis. Tolerance to methyl viologen was h...
