In the present study, to evaluate a microalga’s responses to a macronutrient’s limitation and the excess to a micronutrient, we acclimated the well-distributed freshwater microalga Ankistrodesmus densus to N- or P-limited medium before exposing it to sublethal copper (Cu) concentrations. | Environmental Advances 4 2021 100070 Contents lists available at ScienceDirect Environmental Advances journal homepage locate envadv Copper affects photosynthetic parameters of N- or P-limited Ankistrodesmus densus Giseli Swerts Rocha Evaldo . Espíndola NEEA CRHEA São Carlos School of Engineering University of São Paulo USP Avenida Trabalhador Sãocarlense 400 Parque Arnold Schmidt CEP 13566-590 São Carlos SP Brazil a r t i c l e i n f o a b s t r a c t Keywords Algae require micro- and macronutrients for optimal growth and metabolism. Under limitation or excess of the Metal nutrients in the environment they can adapt their photosynthetic machinery to cope with the new concentrations Nitrogen available to decrease damage to their performance. In the present study to evaluate a microalga s responses to Phosphorus a macronutrient s limitation and the excess to a micronutrient we acclimated the well-distributed freshwater Photosynthesis microalga Ankistrodesmus densus to N- or P-limited medium before exposing it to sublethal copper Cu concen- Quenching trations. Our results indicate that Cu affected the chlorophyll a concentration in N- and P-replete conditions while the N- or P-limitation affected chlorophyll a concentration maximum and effective quantum yield of pho- tosystem II PS II . Within the time frame of 72 h and the maximum Cu concentration used μM Cu2 the addition of Cu to N- or P-limited algae resulted in synergism in all of these parameters except in chlorophyll concentration under P limitation. In addition the combination of Cu with N- or P-limited algae decreased the photochemical quenching qP and increased the non-photochemical quenching qN and NPQ . The values ob- tained in Y NPQ . the quenching of regulated energy loss in PS II indicate that the combination of Cu and N- or P-limited algae induced the activation of photoprotective mechanisms. Under the highest Cu exposure the changes obtained from N- or P-limited algae were .
