EVIDENCE FOR THE INVOLVEMENT OF MITOCHONDRIAL RESPIRATION IN CALCIFICATION IN A MARINE COCCOLITHOPHORID, EMILIANIA-HUXLEYI

In the marine coccolithophorid, Emiliania huxleyi, CaCO3 production un der illumination showed a lag phase for about 3 h and then increased g reatly. 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 mu M 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 Ca CO3 production requires photosynthesis.