Evidence for the Involvement of Mitochondrial Respiration in Calcification in a Marine Coccolithophorid, Emiliania huxleyi

In the marine coccolithophorid, Emiliania huxleyi, CaCO3 production under illumination showed a lag phase for about 3 h and then increased greatly. During the lag phase the rate of CaCO3 production in the light was similar to that in the dark. The production of CaCO3 in the dark was inhibited by the addition of 170 μM CCCP, 1 mM KCN and 1 mM SHAM. These results suggest that a little production of CaCO3 is supported by energy from mitochondrial respiration, but that large amount of CaCO3 production requires photosynthesis.