Thermoluminescence study of the in vivo effects of bicarbonate depletion and acetate/formate presence in the two algae and

We investigated the influence of CO/HCO-depletion and of the presence of acetate and formate on the in vivo photosynthetic electron transport in the two green algae and by means of thermoluminescence technique and mathematical glow curve analysis. The main effects of the removal of CO from the algal cultures was: (1) A shift of the glow curve peak position to lower temperatures resulting from a decrease of the B band and an increase of the Q band. (2) Treatment of CO-deficient with DCMU yielded two thermoluminescence bands in the Q band region peaking at around +12°C and +5°C; in case of DCMU treatment induced only one band with an emission maximum at +5°C. The presence of acetate or formate in CO-depleted algal cultures lowered the intensities of all of the individual TL bands but that of a HT band (TL+37). The effects of CO-depletion and of the presence of anions were fully reversible.