Quantitative analysis of the green microalga Coccomyxa subellipsoidea C169 reveals homeostasis of complex lipid synthesis retained during nitrogen stress (605.14)

Abstract

The inevitable decline of fossil fuel availability and the destructive escalation of atmospheric carbon dioxide concentration are pressing problems that scientific innovation can potentially address. Algae accumulate large amounts of oil when exposed to abiotic stress, enough to possibility use their cultivation to produce carbon‐neutral replacements of conventional transportation fuels. Unraveling the intricacies of triglyceride (TG) synthesis during abiotic stress is a means to generate genetic intervention strategies for improving lipid productivity. Our research is focused on understanding TG accumulation in the context of lipid biosynthesis for Coccomyxa subellipsoidea C169, a sequenced relative of Chlorella and a sensible proxy for biofuel production species. A thorough analysis of lipid synthesis was conducted including GC‐MS fatty acid profiles of isolated lipid pools and LC‐MS/MS quantification of membrane lipid (ML) and TG pools through a time course of N starvation. Stable isotopic labeling studies were done with 13CO2 and D2O to analyze the roles of photosynthesis and de novo synthesis from previously reduced carbon in TG synthesis. The data quantify an initial redistribution of membrane lipids into the TG pool followed by synthesis and incorporation of fatty acids into all complex lipid pools. Reproductive growth is inhibited by N stress, however lipid synthesis continues normally.Grant Funding Source: Supported by NSF‐EPSCoR, Nebraska Center for Algal Biology and Biotechnology