Abstract
The recent discovery of several marine microalgal species which biosynthesize nonhydrolyzable, aliphatic biomacromolecules, termed algaenans, has provided new insights about the nature and origin of the organic matter preserved in marine sediments. This paper reports the examination of 12 new species of marine microalgae from five different classes; the results are discussed together with previous observations on marine algaenans. None of the diatoms and prymnesiophytes and only one of the dinoflagellates examined in the present study produced algaenan, whereas all the eustigmatophytes biosynthesize a very specific algaenan composed of polyether-linked long-chain alkyl units. Many of the chlorophytes investigated, as with their freshwater counterparts, also produce algaenan. The location of the algaenan in the algal cells and the resistance of these materials to chemical and bacterial attack are discussed with respect to their role as a potential sink of organic carbon in aquatic environments.