Impact of environmental conditions on photosynthesis, growth and carbon allocation strategies of hypersaline species of Dunaliella

Hypersaline environments pose a number of ecological and metabolic challenges to the
organisms that live in them. Primary producers, such as halotolerant species of the green
microalgal genus Dunaliella, are no exception. In this paper we focus on the problems posed
to the acquisition and metabolism of inorganic nutrients and on the consequences of
exposure to high light and UV radiation. We show that not only does growth in high salinity
environments have repercussions on the flow of carbon into osmolytes such as glycerol, it
also affects speciation of inorganic carbon and the uptake of inorganic ions by the cells. The
strategies that Dunaliella adopt to optimize resource utilization and the interactions among
metabolic pathways are also discussed.