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.