Preliminary characterisation of the blue-green pigment marennine from the marine tychopelagic diatom Haslea ostrearia (Gaillon/Bory) Simonsen

Haslea ostrearia is a common marine tychopelagic diatom which has the particularity of synthesizing a blue-green hydrosoluble pigment called marennine. This pigment, when released into the external medium, is known to be responsible for the colour of oyster gills. Here we present results for main biophysical and biochemical characteristics of pure intra- and extracellular marennine. Tests for chemical determination show that the nature of the two forms of marennine cannot be distinguished and could be related to a polyphenolic compound. Nevertheless, based on spectral properties and the molecular weight, which is about 10751 +/- 1 and 9893 +/- 1 Da, for the intracellular and extracellular forms respectively, we assess that the pigment accumulated in the apex of the cell and the one released in the external medium have probably distinct molecular structures.