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Oleaginicity of the yeast strain Saccharomyces cerevisiae D5A

BACKGROUND: The model yeast, Saccharomyces cerevisiae, is not known to be oleaginous. However, an industrial wild-type strain, D5A, was shown to accumulate over 20% storage lipids from glucose when growth is nitrogen-limited compared to no more than 7% lipid accumulation without nitrogen stress. MET...

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Autores principales: He, Qiaoning, Yang, Yongfu, Yang, Shihui, Donohoe, Bryon S., Van Wychen, Stefanie, Zhang, Min, Himmel, Michael E., Knoshaug, Eric P.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6151946/
https://www.ncbi.nlm.nih.gov/pubmed/30258492
http://dx.doi.org/10.1186/s13068-018-1256-z
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author He, Qiaoning
Yang, Yongfu
Yang, Shihui
Donohoe, Bryon S.
Van Wychen, Stefanie
Zhang, Min
Himmel, Michael E.
Knoshaug, Eric P.
author_facet He, Qiaoning
Yang, Yongfu
Yang, Shihui
Donohoe, Bryon S.
Van Wychen, Stefanie
Zhang, Min
Himmel, Michael E.
Knoshaug, Eric P.
author_sort He, Qiaoning
collection PubMed
description BACKGROUND: The model yeast, Saccharomyces cerevisiae, is not known to be oleaginous. However, an industrial wild-type strain, D5A, was shown to accumulate over 20% storage lipids from glucose when growth is nitrogen-limited compared to no more than 7% lipid accumulation without nitrogen stress. METHODS AND RESULTS: To elucidate the mechanisms of S. cerevisiae D5A oleaginicity, we compared physiological and metabolic changes; as well as the transcriptional profiles of the oleaginous industrial strain, D5A, and a non-oleaginous laboratory strain, BY4741, under normal and nitrogen-limited conditions using analytic techniques and next-generation sequencing-based RNA-Seq transcriptomics. Transcriptional levels for genes associated with fatty acid biosynthesis, nitrogen metabolism, amino acid catabolism, as well as the pentose phosphate pathway and ethanol oxidation in central carbon (C) metabolism, were up-regulated in D5A during nitrogen deprivation. Despite increased carbon flux to lipids, most gene-encoding enzymes involved in triacylglycerol (TAG) assembly were expressed at similar levels regardless of the varying nitrogen concentrations in the growth media and strain backgrounds. Phospholipid turnover also contributed to TAG accumulation through increased precursor production with the down-regulation of subsequent phospholipid synthesis steps. Our results also demonstrated that nitrogen assimilation via the glutamate–glutamine pathway and amino acid metabolism, as well as the fluxes of carbon and reductants from central C metabolism, are integral to the general oleaginicity of D5A, which resulted in the enhanced lipid storage during nitrogen deprivation. CONCLUSION: This work demonstrated the disequilibrium and rebalance of carbon and nitrogen contribution to the accumulation of lipids in the oleaginous yeast S. cerevisiae D5A. Rather than TAG assembly from acyl groups, the major switches for the enhanced lipid accumulation of D5A (i.e., fatty acid biosynthesis) are the increases of cytosolic pools of acetyl-CoA and NADPH, as well as alternative nitrogen assimilation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13068-018-1256-z) contains supplementary material, which is available to authorized users.
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spelling pubmed-61519462018-09-26 Oleaginicity of the yeast strain Saccharomyces cerevisiae D5A He, Qiaoning Yang, Yongfu Yang, Shihui Donohoe, Bryon S. Van Wychen, Stefanie Zhang, Min Himmel, Michael E. Knoshaug, Eric P. Biotechnol Biofuels Research BACKGROUND: The model yeast, Saccharomyces cerevisiae, is not known to be oleaginous. However, an industrial wild-type strain, D5A, was shown to accumulate over 20% storage lipids from glucose when growth is nitrogen-limited compared to no more than 7% lipid accumulation without nitrogen stress. METHODS AND RESULTS: To elucidate the mechanisms of S. cerevisiae D5A oleaginicity, we compared physiological and metabolic changes; as well as the transcriptional profiles of the oleaginous industrial strain, D5A, and a non-oleaginous laboratory strain, BY4741, under normal and nitrogen-limited conditions using analytic techniques and next-generation sequencing-based RNA-Seq transcriptomics. Transcriptional levels for genes associated with fatty acid biosynthesis, nitrogen metabolism, amino acid catabolism, as well as the pentose phosphate pathway and ethanol oxidation in central carbon (C) metabolism, were up-regulated in D5A during nitrogen deprivation. Despite increased carbon flux to lipids, most gene-encoding enzymes involved in triacylglycerol (TAG) assembly were expressed at similar levels regardless of the varying nitrogen concentrations in the growth media and strain backgrounds. Phospholipid turnover also contributed to TAG accumulation through increased precursor production with the down-regulation of subsequent phospholipid synthesis steps. Our results also demonstrated that nitrogen assimilation via the glutamate–glutamine pathway and amino acid metabolism, as well as the fluxes of carbon and reductants from central C metabolism, are integral to the general oleaginicity of D5A, which resulted in the enhanced lipid storage during nitrogen deprivation. CONCLUSION: This work demonstrated the disequilibrium and rebalance of carbon and nitrogen contribution to the accumulation of lipids in the oleaginous yeast S. cerevisiae D5A. Rather than TAG assembly from acyl groups, the major switches for the enhanced lipid accumulation of D5A (i.e., fatty acid biosynthesis) are the increases of cytosolic pools of acetyl-CoA and NADPH, as well as alternative nitrogen assimilation. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13068-018-1256-z) contains supplementary material, which is available to authorized users. BioMed Central 2018-09-24 /pmc/articles/PMC6151946/ /pubmed/30258492 http://dx.doi.org/10.1186/s13068-018-1256-z Text en © The Author(s) 2018 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
He, Qiaoning
Yang, Yongfu
Yang, Shihui
Donohoe, Bryon S.
Van Wychen, Stefanie
Zhang, Min
Himmel, Michael E.
Knoshaug, Eric P.
Oleaginicity of the yeast strain Saccharomyces cerevisiae D5A
title Oleaginicity of the yeast strain Saccharomyces cerevisiae D5A
title_full Oleaginicity of the yeast strain Saccharomyces cerevisiae D5A
title_fullStr Oleaginicity of the yeast strain Saccharomyces cerevisiae D5A
title_full_unstemmed Oleaginicity of the yeast strain Saccharomyces cerevisiae D5A
title_short Oleaginicity of the yeast strain Saccharomyces cerevisiae D5A
title_sort oleaginicity of the yeast strain saccharomyces cerevisiae d5a
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6151946/
https://www.ncbi.nlm.nih.gov/pubmed/30258492
http://dx.doi.org/10.1186/s13068-018-1256-z
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