Influence of red light on the activity of phosphofructokinase in Chlorella kessleri

In crude extracts of the unicellular green alga Chlorella kessleri Fott et Novákóva grown in red light the activity of the glycolytic enzyme phosphofructokinase (PFK, EC 2.7.1.11) is about 40% higher compared to white light conditions giving the same dry matter production. Application of cycloheximide and density labelling with D 2 O indicate that this increase depends on the de novo synthesis of the enzyme: Twelve h of illumination at a fluence rate of 7 × 10 18 quanta m −2 s −1 (11.6 μmol m −2 s −1 ) suffice to saturate the effect. In autotrophically grown algae maximal increase in enzyme saturate the effect. In autotrophically grown algae maximal increase in enzyme activity is reached in light of 680 nm, while in 3‐(3,4‐dichlorophenyl)‐1,1‐dimethyl urea (DCMU)‐poisoned, glucose‐fed cells, light of wavelengths around 727 nm is most effective. Involvement of a phytochrome‐like photoreceptor is discussed.