Abstract
Thraustochytrids are estuarine to marine protists and serve as both decomposers and secondary producers in the marine detritus food chain. They degrade refractory organic matter such as cellulose derived from terrestrial refuse, whose ecological function has been attributed mainly to bacteria. Thraustochytrid cells, are 5-20μm in diameter, which is ten or more times greater than bacterial cells, which shorten trophic links in a food chain and thus yield more biological production at higher trophic levels. Higher C/N ratios (>10) of thraustochytrid cells, compared to bacterial C/N (<6), may contribute to carbon cycling, despite their low abundance (-103 cells 1-1) compared to bacterial abundance (-106 cells 1-1) in marine water columns. Thraustochytrids also produce and accumulate biologically active polyunsaturated fatty acids such as eicosapentaenoic and docosahexaenoic acids, and thus may be exploited for biotechnological puroposes.
