[Role of oxygen in the photoinactivation of the spores of microscopic fungi].

The photo-induced damage of DNa is the principal factor causing photoinactivation of fungal spores in the absence of oxygen. Cytochromes and flavins can be involved in the process as sensitizers of the photochemical effect in the presence of oxygen. If fungi are irradiated with visible light having a short wave length (violet-blue light) when their reproductive organs are being formed, the resultant spores will have different photoresistance manifested only in the presence of oxygen. The differences seem to be due to nonuniform development of biological systems including photosensitizers.