Comprehensive metabolomic, lipidomic and microscopic profiling of Yarrowia lipolytica during lipid accumulation identifies targets for increased lipogenesis

48Citations
Citations of this article
120Readers
Mendeley users who have this article in their library.

Abstract

Yarrowia lipolytica is an oleaginous ascomycete yeast that accumulates large amounts of lipids and has potential as a biofuel producing organism. Despite a growing scientific literature focused on lipid production by Y. lipolytica, there remain significant knowledge gaps regarding the key biological processes involved. We applied a combination of metabolomic and lipidomic profiling approaches as well as microscopic techniques to identify and characterize the key pathways involved in de novo lipid accumulation from glucose in batch cultured, wild-type Y. lipolytica. We found that lipids accumulated rapidly and peaked at 48 hours during the five day experiment, concurrent with a shift in amino acid metabolism. We also report that exhaustion of extracellular sugars coincided with thickening of the cell wall, suggesting that genes involved in cell wall biogenesis may be a useful target for improving the efficiency of lipid producing yeast strains.

Figures

  • Fig 1. Lipid accumulation over the course of five days during Y. lipolytica batch culture. (A) Wild-type Y. lipolytica (ATCC 20460TM) was grown in YNB-Rmedium for five days with samples collected at 12 h intervals. Extracellular glucose was exhausted by 72 h. (B) The volume of lipid bodies was calculated from z-stack images and binned into percentiles to indicate the size distribution. (C) Scanning laser confocal microscopy of cells stained for neutral lipids (red) and cell wall (blue) reveal lipid bodies making up much of the intracellular space. Scale bar: 5 μm. (D) Helium ion microscopy reveals detailed cell surface structure. Arrowhead denotes typical bud scarring, arrowhead with asterisks highlights unusual bud scar morphology and arrows show areas of lumpy cell wall characteristic of cells of 36 h and older age. Scale bar: 1 μm.
  • Fig 2. Transmission electronmicroscopy shows cell wall thickening during lipid accumulation. Both (A) confocal laser scanning microscopy and TEM show thickened cell wall morphology in later time points. Cells were stained for cell wall (blue) and lipid bodies (red) in (A). CW indicates the cell wall in (B).
  • Fig 3. Intracellular metabolism is dynamic during lipid accumulation. Ametabolic map including 43 measured intracellular metabolites was constructed based on the metabolic capabilities of the fungi Saccharomyces cerevisiae andNeurospora crassa. Each node represents a metabolite upon which median normalized z-scores for hours 24, 36, 48, 60, 72, 96, 108 and 120 are plotted left to right. Solid edges represent direct connections via an enzymatic reaction while dashed edges represent short sets of reactions where we did not measure any intermediates.
  • Fig 4. Clustering of metabolite profiles during lipid accumulation. Intracellular polar metabolite z-scores were clustered using a Euclidian approach to identify those that are metabolically linked. Z-scores are normalized by dry cell mass. *Metabolites that changed significantly during the time course by ANOVA (p < 0.01).
  • Fig 5. Extracellular metabolites during lipid accumulation. 89 metabolites were identified by GC-MS profiling in the medium after removal of the cells. Representative chromatographs are shown with peaks for identified metabolites indicated. Note the rapid appearance and disappearance of peaks representing a variety of disaccharides.
  • Fig 6. Lipid spectrum accumulated in batch culture is dynamic. Intracellular FAMEs and intact lipids were extracted at 12 hour intervals. (A) Extractable FAMEs accumulate to a maximum level at 48 h and drop in concentration as extracellular glucose is depleted. (B) Intact lipid z-scores were clustered using a Euclidian approach. PE, phosphatidylethanolamine; PC, phosphatidylcholine; TG, triacylglycerol; DG, diacylglycerol; CR, ceramide; FA, free fatty acid; UN, unknown headgroup. Underlines indicate intact lipids identified in negative ESI mode while lack of an underline indicates those identified in positive ESI mode. *Intact lipids that changed significantly during the time course by ANOVA (p < 0.01).

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Cite

CITATION STYLE

APA

Pomraning, K. R., Wei, S., Karagiosis, S. A., Kim, Y. M., Dohnalkova, A. C., Arey, B. W., … Baker, S. E. (2015). Comprehensive metabolomic, lipidomic and microscopic profiling of Yarrowia lipolytica during lipid accumulation identifies targets for increased lipogenesis. PLoS ONE, 10(4). https://doi.org/10.1371/journal.pone.0123188

Readers over time

‘15‘16‘17‘18‘19‘20‘21‘22‘23‘24‘2505101520

Readers' Seniority

Tooltip

PhD / Post grad / Masters / Doc 52

60%

Researcher 24

28%

Lecturer / Post doc 6

7%

Professor / Associate Prof. 4

5%

Readers' Discipline

Tooltip

Agricultural and Biological Sciences 40

51%

Biochemistry, Genetics and Molecular Bi... 23

29%

Chemistry 9

11%

Chemical Engineering 7

9%

Article Metrics

Tooltip
Mentions
Blog Mentions: 2
News Mentions: 2
Social Media
Shares, Likes & Comments: 17

Save time finding and organizing research with Mendeley

Sign up for free
0