[Change in the ATP content in the cells of Anabaena variabilis].

The content of ATP in the cells of Anabaena variabilis does not change during one day in the darkness as compared to that in the cells grown in the light, this suggesting the endogenous energy reserve of the cell. The level of ATP gradually decreases when the cells are incubated in the darkness during 25 days, but does not reach zero. The content of ATP increases for a short period in the light in the cells that have been incubated in the darkness during several days (up to 7 days). On the contrary, the level of ATP increases to a small extent and then falls in the cells grown in the light. These differences suggest disturbed coupling of the synthesis and utilization of ATP in the cells grown in the darkness. The content of ATP increases again in the darkness, confirming that the alga is capable of synthesizing ATP in the darkness.