Lipidomic investigation reveals distinct lipid metabolite patterning of an oil-producing microalga (Vischeria sp. WL1) cultured by different nitrogen nutrients.

Microalgae are photosynthetic organisms with potentials in sustainable production of valuable metabolites such as polyunsaturated oil. Low nitrogen cultivation is widely used for induction of microalgal oil production. Previously we found that low inorganic nitrogen (low N, 4.5 mM NaNO3) favored oil production in a dryland-isolated eustigmatophyte microalga Vischeria sp. WL1, relative to the usually used nitrogen level (18 mM NaNO3), while low organic nitrogen (low pepN, 4.5 mM peptone) led to both rapider growth and higher oil yield than low N. Here we analyzed the lipidome profiles of Vischeria sp. WL1 under low N and low pepN conditions. Our results revealed that the lipidome profiles induced by both conditions were apparently different. Overall, low N had a much weaker impact on the lipidome profile than low pepN. Notably, low N uniquely induced a significant increase of phosphatidylinositol (PI), phosphatidylinositol phosphate (PIP), phosphatidylinositol bisphosphate (PIP2) and phosphatidylinositol trisphosphate (PIP3), whereas low pepN induced a significant increase of phosphatidylcholine (PC) and phosphatidylethanolamine (PE). In addition, low pepN induced a significant increase of neutral glycerolipids. This research deepens our understanding on the lipid metabolism of Vischeria sp. WL1 under different nitrogen conditions and could also guide oil production strategy in microalgae by adopting suitable nitrogen resources. [ABSTRACT FROM AUTHOR]