| Dinoflagellates are a diverse group of unicellular eukaryotic algae. Membrane-bound vesicles lie beneath their plasma membrane, and in thecate species, cellulosic thecal plates (CTPs) are formed within the vesicles and are assembled into a three dimensional structures. These unique cellulosic thecal plates are potential research tools in cell wall study and as bioinspired nanocomposites. The knowledge of CTPs, however, is very limited. To explore the assembly mechanism of CTPs, their ultrastructure, cellulose and proteins were characterized in this thesis.;CTPs were found to consist of at least two layers and possessed with several types of pores. In Lingulodinium polyedrum, the pore structures formation are probably related to the mini holes. Microfibril in CTPs were apparently deposited on different ways in different layers. Fourier Transform Infrared Spectrometry (FTIR) results confirmed the presence of cellulose. In nanoindentation results, thecal plates of Pyrocystis lunula and Prorocentrum micans had comparable hardness but the former had an obvious higher elasticity modulus.;Very long fine hydrolyzed cellulose microfibril were obtained and their aspect ratio was comparable to the highest ones reported. A large amount of non-crystalline cellulose was found in CTPs samples. These characteristics of dinoflagellate cellulose implacate a novel cellulose deposition mechanism. |
