[Characteristics of oxygen metabolism in the obligate phototrophic blue-green alga Anabaena variabilis in darkness].

The rate of endogenous respiration of the cells of Anabaena variabilis in the mineral medium in the darkness decreases gradually during 30 to 40 days and is then maintained at a low level. The rate of oxygen uptake was the same in the cells grown in aerobic and anaerobic conditions in the darkness. The ability for oxygen evolution in the light is maintained in the anaerobic cells for a longer time, and the biomass yield and the content of phycocyanin in the cells decrease at a lower rate in anaerobic conditions. Therefore, under certain conditions of the medium, the processes related to the cell survival in the darkness are directed to preserve the photosynthesizing apparatus, and oxygen is a factor accelerating the death while anaerobic conditions delay destruction of the cells in the darkness.