Long-term acclimatization of Scenedesmus bicellularis to high-frequency intermittent lighting (100 Hz). I. Growth, photosynthesis and photosystem II activity

Responses of the green microalga, Scenedesmus bicellularis tohigh-frequency intermittent lighting (II., 100 Hz) were assessedafter a 4 week acclimatization. Effects of IL on growth, photosynthesisand photosystem II (PSII) activity were studied at limitingand saturating irradiances, and compared to those of continuouslight (CL) of the same instantaneous and daily irradiances.Even after a 4 week acclimatization period, the photosyntheticcapacity (P_max), the photosynthetic efficiency () and the photosyntheticactivity at growth irradiance, either expressed on a per cellor a chlorophyll a basis, showed little difference, neitherdid the index of light adaptation (I_k) or PSII activity. Incontrast, growth was lower under IL at saturating irradiance.Results are discussed considering the non-linearity of the relationshipbetween growth or photosynthesis and irradiance.