REGULATION OF PHOTOSYNTHETIC PIGMENTS IN MICROALGAE BY MULTIPLE ENVIRONMENTAL-FACTORS - A DYNAMIC BALANCE HYPOTHESIS

Environmental effects on the concentration of photosynthetic pigments in micro-algae can be explained by dynamics of photosystem synthesis a nd deactivation. A model that couples photosystem losses to the relati ve cellular rates of energy harvesting (light absorption) and assimila tion predicts optimal concentrations of light-harvesting pigments and balanced energy flow under environmental conditions that affect light availability and metabolic rates. Effects of light intensity, nutrient supply and temperature on growth rate and pigment levels were similar to general patterns observed across diverse micro-algal taxa. Results imply that dynamic behaviour associated with photophysical stress, an d independent of gene regulation, might constitute one mechanism for p hoto-acclimation of photosynthesis.