Effects of nitrogen source on the physiology and metal nutrition of Emiliania huxleyi grown under different iron and light conditions

Abstract

Emiliania huxleyi, a small oceanic coccolithophore, was isolated from the NE subarctic Pacific and maintained under oceanic conditions. Coccolith-forming cultures were grown with either NO3-or NH,' as the primary nitrogen source. Fe-stress was induced experimentally, and physiological parameters including metal quotas (Fe, Mn, Zn, Cu) were measured for both NO3--and NH,'-grown cells to determine whether ~t was advantageous for the cells to grow on NH,' rather than NO3-under Fe-stressed conditions The parameters used to observe the cell's physiological status were specific growth rate M), cell volume (CV), carbon (C), chlorophyll a (chl a), and nitrogen (N) per cell volume.