The gradual accumulation of oxygen that accompanied the evolution of photosynthetic organisms approximately 1.5 to 2 billion years ago was most signicant in that an appropriate environment had been provided for the genesis of aerobic organisms. The transition from anaerobic to aerobic life required intense work of adaptation, in particular, genotypic adaptation (Porter and Wujek 1988). However, molecular oxygen is a paradoxical element of nature: It is a vital component of several biological reactions in which, stepwise, the enzymatically controlled oxidation of biomolecules is used to release energy and compounds essential for life; on the other hand, oxygen could be toxic to cells, and oxidative reactions are tightly controlled in biological systems (Kanner et al. 1987).