[Changes in ATP-concentration by light in a chlorophyll-free Chlorella mutant].

The total amount of adenine nucleotides was not changed when non-growing cells of a chlorophyll-free, carotenoid-containing mutant of Chlorella vulgaris Beijerinck (211-11 h/20) were transferred from darkness into blue light (λ<550 nm, ∼300 μW cm(-2)). However the level of ATP increased significantly immediately after the onset of blue illumination, while that of both ADP and AMP decreased (Table 1). Induction period, intensity dependency and wave-length dependency of the light-induced change in ATP-concentration (Figs. 1-3) resemble those of the long-known enhancement of respiration by blue light. The observed increase in ATP does not support the often proposed idea of enhanced carbohydrate breakdown being the result of a reduced ATP-level, but rather seems to arise from enhanced substrate degradation.