Investigating Oiliness: Systems Comparison of Photoautotrophic and Heterotrophic Lipid Production in Auxenochlorella protothecoides.
EMSL Project ID
51920
Abstract
Auxenochlorella protothecoides is a photosynthetic, Trebouxiophyte alga, with a small, highly compact nuclear genome. Auxenochlorella strains are highly oleaginous, accumulating up to 60% of dry weight as triacylglycerides (TAG) under conditions where carbon supply is in excess, but other nutrients, especially nitrogen (N), are limiting. Auxenochlorella biomass is produced by heterotrophic fermentation at industrial scale for use as a vegan protein supplement, and for cosmetic applications of the extracted oil, but photoautotrophic biomass and lipid productivity is much lower and has not been commercialized. The objective of this proposal is to develop a systems-level understanding of the transition from growth to storage lipid biosynthesis in A. protothecoides, under both heterotrophic and photoautotrophic growth conditions. The mass spectrometry and chromatography expertise and capabilities of EMSL will be employed to analyze proteomic and metabolomic changes associated with the transition, triggered by N-limitation, from growth and cell division to cell cycle arrest and TAG biosynthesis. Specifically, we will compare and contrast lipid production in heterotrophic cells supplied with an excess of sugar, versus photoautotrophic cells subjected to high light stress and high levels of CO2. These analyses are expected to provide insight into the metabolic changes that lead to highly efficient TAG biosynthesis in heterotrophic cells, and suggest targets for metabolic engineering of A. protothecoides to improve photoautotrophic TAG production. Routine transformation and facile nuclear gene targeting via homologous recombination make A. protothecoides an ideal algae platform for genetic manipulation, and we can leverage our ability to perform gene knock-in and knock-outs for follow-up studies to test hypotheses that result from the systems analyses.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2021-10-01
End Date
2023-10-27
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members