Physiological and Metabolic Responses of Freshwater and Brackish-Water Strains of Microcystis aeruginosa Acclimated to a Salinity Gradient: Insight into Salt Tolerance

Blooms ofMicrocystis aeruginosa and the production of microcystins are major issues in eutrophic freshwater bodies. Recently, an increasing number of proliferations ofM. aeruginosa in brackish water has been documented. The occurrence of bothM. aeruginosa and microcystins in coastal areas represents a new threat for human and environmental health. In order to better describe the mechanisms involved inMicrocystis sp. proliferation in brackish water, this study used twoM. aeruginosa strains isolated from fresh and brackish waters. High salinity reduced the growth rate and microcystin production rate ofM. aeruginosa . In order to cope with higher salinities, the strains accumulated different cyanobacterial compatible solutes, as well as unsaturated lipids, explaining their distinct salt tolerance.