Differential sensitivity of fatty acids and lipid damage in Microcystis aeruginosa (cyanobacteria) exposed to increased temperature

DE TROCH, MARLEEN; DE LA ROSA, FLORENCIA; HERNANDO, MARCELO; MALANGA, GABRIELA

COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. TOXICOLOGY & PHARMACOLOGY

ELSEVIER SCIENCE INC

Año: 2020 vol. 235

1532-0456

Changes in fatty acid (FA) composition can mean a mechanism of acclimation of Cyanobacteria to climatechange. The objective of the present study was to evaluate the effects of increased temperature on M. aeruginosacultures in terms of FA content, lipid damage, biomass and reactive oxygen species (ROS). Unicellular cultureswere exposed to high (29 °C) and control (26 °C) temperature for 12 days. Differential sensitivity of ω3 FAs wasobserved after 2 days of exposure to elevated temperature (29 °C). Also, no significant differences in ROS contentat different temperatures were observed although there was a significant decrease compared to the value at thestart of the incubation. Thus, low FA peroxidation of selected ω6 PUFAs and potentially increased activation ofantioxidant systems, resulting in lower lipid damage (on average 35%), could explain the strong acclimation tohigh temperature as shown by the increased growth rate (11%) compared to the control conditions. In hightemperature conditions we found a retarded desaturation to 18:3ω3 and 18:4ω3 PUFAs which were 40% lowercompared with control at the end of incubation.Overall, growth rate and omega-6 FA were increased at high temperature as a mechanism of successfulacclimation. This is highly relevant for the ecological role of M. aeruginosa as food source for grazers. A reducedFA level can have serious implications for the flow of energy and thus the overall functioning of the ecosystem.