Immunological quantitation of a polysaccharide formed by Emiliania huxleyi

The principle of ELISA was adapted to measure quantitatively the concentration of an extracellular polysaccharide of the unicellular alga Emiliania huxleyi. This so called “coccolith polysaccharide” could be detected at concentrations as low as 0.02 mgl−1. The concentration of coccolithopolysaccharide was determined in the supernatant of actively growing calcifying and naked batch cultures of E. huxleyi and amounted to 0.56 and 0.87 pg cell−1, respectively. In these cultures, maximum concentrations of 0.26 and 10.1 mg l−1 coccolith polysaccharide, respectively, were reached in the late stationary phase of growth. These results suggest that in a bloom of E. huxleyi, the dissolved coccolith polysaccharide makes a modest contribution to the pool of dissolved organic carbon (DOC), and forms a small part of the E. huxleyi primary production.