Insights into microalgal oils, the oil body, and the limits of nutrient limitation
Chlamydomonas reinhardtii is a commonly used model unicellular green alga. Popular for studies since the 19th century it has earned a place as a model for higher plants, photosynthesis, genetics, flagella, light perception and as a model for countless of its other myriad of fascinating features. As the world moves towards the post-peak era in oil production its focus has been shifting away from a dependency on fossil derived oil. Plant oils have become a hot topic and special attention has been paid to the long-chain hydrocarbons made in algae which can prosper in non-arable non-traditional agricultural settings. By genomic scale investigation of an oil producing mutant alga, our research has shown that light intensity can be a key element in carbon flux within the cell. The link between light intensity and oil production was further studied in the standard wildtype alga, 137-C mt+. In the majority of peer reviewed scientific publications on oil production in Chlamydomonas, nutrient limitation is used to ilicit a lipogenesis response. However in replete growth conditions, we show it is still possible for microalgae to produce oils. We characterize the organelle in which the oils are assembled, and we show the types of oils produced, in a combination of lipidomics and proteomics. In the context of biofuels, this work suggests that light intensity may be a factor more useful to industrial scale biofuel production than nutrient limitation.