Figure 1. Schematic description of hypothesis and microfluidic approach for analysis of phototactic response.

(a) Schematic showing contribution of fast phototactic response to improving photosynthetic efficiency. Fine tuning of light capture by fast phototactic response (light green cell) can provide optimal condition for photosynthesis, whereas cells exhibiting slow responses (dark green cell) are less competitive in finding optimal light condition, resulting in low photosynthetic productivity. (b) Experimental scheme showing analysis of negative phototactic response using a microfluidic device. Cells grown exponentially were loaded into inlet chamber in a microfluidic device and exposed to green LED (70 μmol photons m^-2s^-1). The phototactic movements of cells were monitored under an inverted microscope and analysed using video analysing software.