The Eco-Physiological Role of Microcystis aeruginosa in a Changing World

Abstract

Among the bloom-forming cyanobacteria, Microcystis aeruginosa is one of the mostharmful species. The prevalence of toxic species and their toxicity profiles vary each yeardepending on environmental variables, despite their dynamics being not well understood.Imbalances in nutrient concentrations, the greater frequency and intensity of higher averagetemperatures and less severe winters, and the alternation between periods of positive andnegative precipitation anomalies were identified as conditions favoring the prevalence of M.aeruginosa. Similarly, dry periods (corresponding to a prevailing La Niña condition) wereeven more conducive to the formation of harmful algal blooms of pronounced intensity.Moreover, toxin production is temperature-dependent and some strains are capable ofproducing multiple microsystins (MCs). Thus, the role of environmental variables incontrolling the genetic expression of toxin synthetase of individual toxin-producing genesis still unknown.