Vertical Distribution of Epibenthic Freshwater Cyanobacterial Synechococcus spp. Strains Depends on Their Ability for Photoprotection
Figure 1
Light intensity-dependent rates of photosynthetic oxygen evolution in different Synechococcus spp. strains.
Measurements were performed with 15 min dark adaptation, where the last 5 min were recorded, followed by 5 min exposure to light intensity of 8, 15, 22, 47, 60, 75, 97, 156, 420, 600, and 950 µmol photons·m−2·s−1 and a final 5 min measurement in the dark to estimate cellular respiration. Gross photosynthesis rate was obtained by addition of dark respiration to the amount of oxygen produced in light. A light intensity of 200 µmol photons m−2 s−1 was chosen for further light stress experiments because at this light intensity photosynthesis is saturated in all strains investigated. Error bars represent standard errors.