Proteome analysis of xylose metabolism in Rhodotorula toruloides during lipid production
Journal article, 2019

Background: Rhodotorula toruloides is a promising platform organism for production of lipids from lignocellulosic substrates. Little is known about the metabolic aspects of lipid production from the lignocellolosic sugar xylose by oleaginous yeasts in general and R. toruloides in particular. This study presents the first proteome analysis of the metabolism of R. toruloides during conversion of xylose to lipids. Results: Rhodotorula toruloides cultivated on either glucose or xylose was subjected to comparative analysis of its growth dynamics, lipid composition, fatty acid profiles and proteome. The maximum growth and sugar uptake rate of glucose-grown R. toruloides cells were almost twice that of xylose-grown cells. Cultivation on xylose medium resulted in a lower final biomass yield although final cellular lipid content was similar between glucose- and xylose-grown cells. Analysis of lipid classes revealed the presence of monoacylglycerol in the early exponential growth phase as well as a high proportion of free fatty acids. Carbon source-specific changes in lipid profiles were only observed at early exponential growth phase, where C18 fatty acids were more saturated in xylose-grown cells. Proteins involved in sugar transport, initial steps of xylose assimilation and NADPH regeneration were among the proteins whose levels increased the most in xylose-grown cells across all time points. The levels of enzymes involved in the mevalonate pathway, phospholipid biosynthesis and amino acids biosynthesis differed in response to carbon source. In addition, xylose-grown cells contained higher levels of enzymes involved in peroxisomal beta-oxidation and oxidative stress response compared to cells cultivated on glucose. Conclusions: The results obtained in the present study suggest that sugar import is the limiting step during xylose conversion by R. toruloides into lipids. NADPH appeared to be regenerated primarily through pentose phosphate pathway although it may also involve malic enzyme as well as alcohol and aldehyde dehydrogenases. Increases in enzyme levels of both fatty acid biosynthesis and beta-oxidation in xylose-grown cells was predicted to result in a futile cycle. The results presented here are valuable for the development of lipid production processes employing R. toruloides on xylose-containing substrates.

Proteome

Lipid production

Rhodotorula toruloides

Xylose

Author

Ievgeniia Tiukova

Swedish University of Agricultural Sciences (SLU)

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

Jule Brandenburg

Swedish University of Agricultural Sciences (SLU)

Johanna Blomqvist

Swedish University of Agricultural Sciences (SLU)

Norwegian University of Life Sciences

Sabine Sampels

Swedish University of Agricultural Sciences (SLU)

Nils Mikkelsen

Swedish University of Agricultural Sciences (SLU)

Morten Skaugen

Norwegian University of Life Sciences

Magnus Arntzen

Norwegian University of Life Sciences

Jens B Nielsen

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

Mats Sandgren

Swedish University of Agricultural Sciences (SLU)

Eduard Kerkhoven

Chalmers, Biology and Biological Engineering, Systems and Synthetic Biology

Biotechnology for Biofuels

1754-6834 (eISSN)

Vol. 12 1 137

Design of yeast strains with increased sugar affinity for improved industrial performance

Formas, 2017-11-01 -- 2021-12-31.

Subject Categories

Cell Biology

Biochemistry and Molecular Biology

Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)

DOI

10.1186/s13068-019-1478-8

More information

Latest update

7/15/2019