ABSTRACT
Diatoms are photosynthetic microalgae and are among the most abundant, diverse and efficient aquatic primary producers. Because lipids are compounds with a high density of energy, diatoms reorient the carbon metabolism towards lipid production under stress. Beside its interest for basic sciences, the understanding of carbon reorientation is crucial for microalgal biotechnology. This review starts with a short overview of the lipid biochemistry in diatoms taking into account the particular cellular context of these organisms. Then, the effects of stress on the production of triacylglycerol accumulation and membrane remodeling are reviewed. Regulatory branch points influencing the supply of intermediate molecules and metabolic regulators controlling the fate of carbon into the different metabolic pathways will be highlighted. Altogether, the knowledge about the modulation of lipid biosynthesis in diatoms opens a new avenue for the biotechnological use of stress to produce algae enriched in specific lipids or lipids themselves. The progress in this field is described in the last part of the chapter.
