02/25/2016
Improving Lipid Yields for Biofuel Production
New insights into lipid metabolism in yeast could benefit biofuel production.
The Science
Using a comprehensive system-wide approach, researchers identified regulators of metabolic pathways that drive lipid accumulation in a genetically tractable yeast species.
The Impact
A better understanding of the metabolic pathways that regulate lipid accumulation in yeast could be harnessed to improve lipid yields and enhance the efficiency of biofuel production.
Summary
The yeast Yarrowia lipolytica is capable of accumulating a large amount of lipids when nitrogen is limited. This ability, along with its amenability to genetic methods, has made Y. lipolytica an attractive model for generating high-value lipids for biofuel production. However, relatively little is known about the factors that regulate enzymatic pathways responsible for lipid accumulation in this species. To address this knowledge gap, a team of researchers from Pacific Northwest National Laboratory (PNNL) integrated metabolome, proteome, and phosphoproteome data to characterize lipid accumulation in response to limited nitrogen in Y. lipolytica. The researchers used a microscopy system that integrates nonlinear two-photon excitation, laser-scanning confocal microscopy, and fluorescence lifetime imaging at the Environmental Molecular Sciences Laboratory (EMSL), a U.S. Department of Energy (DOE) scientific user facility. In this first global study of protein phosphorylation in Y. lipolytica, the researchers focused their analysis on changes in the expression and phosphorylation state of regulatory proteins, including kinases, phosphatases, and transcription factors. They found that lipid accumulation in response to nitrogen limitation results from two distinct processes: (1) higher production of malonyl-CoA from excess citrate increases the pool of building blocks for lipid production, and (2) decreased capacity for β-oxidation reduces lipid consumption. These findings provide new genetic targets that could be manipulated to improve lipid yields in future metabolic engineering efforts.
Principal Investigator(s)
Scott Baker
Environmental Molecular Sciences Laboratory
[email protected]
Funding
This work was supported by DOE’s Office of Science, Office of Biological and Environmental Research (BER), including support of EMSL, an Office of Science user facility; BER Genomic Science program; William Wiley Distinguished Postdoctoral Fellowship; and BER-funded Pan-omics program at PNNL.
References
Pomraning, K. R., Y.-M. Kim, C. D. Nicora, R. K. Chu, E. L. Bredeweg, S. O. Purvine, D. Hu, T. O. Metz, and S. E. Baker. 2016. “Multi-Omics Analysis Reveals Regulators of the Response to Nitrogen Limitation in Yarrowia lipolytica,” BMC Genomics 17(138). DOI: 10.1186/s12864-016-2471-2.