The composition and characterization of the organic-walled resting cysts of dinoflagellates: Implications for the preservation of organic matte

Abstract

This cumulative work represents the most comprehensive attempt to characterize the chemical composition of organic-walled dinoflagellate resting cysts (dinocysts) to date. Dinocysts are composed of a refractory biopolymer called dinosporin. The chemical composition of dinosporin, evaluated in three separate studies using micro-Fourier transform infrared spectroscopy, was shown to be variable and may, in fact, be taxon specific. Factors that seemed to exhibit an influence on dinosporin composition include the ecology of the cyst-producing dinoflagellate species, environmental conditions of the upper water column prior to and/or during cyst formation, and post-depositional alteration. The effects of these factors on the dinosporin composition are important to understand for (1) accurate oceanographic and climate reconstructions, as it may influence the preservation potential of dinocysts, and for (2) describing the chemical transformations that organic matter undergoes after deposition, which is a crucial component for a better understanding of the global carbon cycle.