Aluminum is the most abundant metallic element in Earth crust. It is widely present in living organisms and various environments, including seawater. However, no established biological role of Al has been found yet. In recent years, increasing evidence suggests that aluminum can impact carbon fixation by microalgae in the upper ocean, carbon export to the deep ocean, and carbon sequestration in deep depths and sediments, thus enabling Al to be a potential key factor in regulating the ocean's carbon sink capacity and influencing climate change. Especially, the beneficial effects of Al at trace levels on the growth of marine microalgae and related carbon fixation may arouse new enthusiasm to explore the biological function of aluminum. Here, we will 1) summarize the current understanding of the beneficial effects of Al, especially at trace levels, on the growth of marine microalgae, and 2) discuss the underlying mechanisms, including the roles of Al in influencing the use of dissolved organic phosphorus and iron, and the role of Al influencing chlorophyll biosynthesis.
 

aluminum, iron-aluminum hypothesis, dissolved organic phosphorous, iron, marine carbon sinks, chlorophyll biosynthesis