Symbiotic Associations with Protists

Progress in understanding the symbiosis between protists and termites has not matched that between prokaryotes and termites. Methods are now available for the isolation of pure cultures of trichomonads and hypermastigids, although only a few have been cultivated. Sufficient molecular data are now available to construct tentative phylogenetic trees. Molecular data indicate that these organisms are amongst the most primitive eukaryotes lacking mitochondria; the trichomonads also use a prokaryote-like 70S ribosome. In metabolic terms, more is known about the cellulolytic protists but only in outline.