The Influence of Fluctuating Light on the Growth and Photosynthesis of Skeletonema Costatum
The marine diatom Skeletonema costatum was grown in two light-limited continuous cultures with a 8h light:16h dark period. Although the total amount of light energy received by both cultures was the same, the way in which they received it was different. Culture 1 received one sinusoidal cycle (with the maximum 4h after the onset of light). In culture two, a pattern of vertical mixing was simulated: the light intensity changed in such a way that it simulated three times a mixing from the surface to the bottom of the euphotic zone and back. The simulation was performed by a computer-controlled stepper motor connected to a Venetian Blind system.