*4.4. Oxygen evolution*

In addition of fluorescence measurements, the biological activity used to check cell viability was photosynthetic activity. For these determinations, 1 mL samples of *Coccomyxa acidophila* cultures were placed into a Clark-type electrode (Hansatech, U.K.) to measure O2-evolution. Measurements were made at 25 ºC in the dark (endogenous respiration) or under saturating white light (1500 μE·mƺ2·sƺ1). 
