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Characterization of key triacylglycerol biosynthesis processes in rhodococci

Oleaginous microorganisms have considerable potential for biofuel and commodity chemical production. Under nitrogen-limitation, Rhodococcus jostii RHA1 grown on benzoate, an analog of lignin depolymerization products, accumulated triacylglycerols (TAGs) to 55% of its dry weight during transition to...

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Autores principales: Amara, Sawsan, Seghezzi, Nicolas, Otani, Hiroshi, Diaz-Salazar, Carlos, Liu, Jie, Eltis, Lindsay D.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4850399/
https://www.ncbi.nlm.nih.gov/pubmed/27126051
http://dx.doi.org/10.1038/srep24985
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author Amara, Sawsan
Seghezzi, Nicolas
Otani, Hiroshi
Diaz-Salazar, Carlos
Liu, Jie
Eltis, Lindsay D.
author_facet Amara, Sawsan
Seghezzi, Nicolas
Otani, Hiroshi
Diaz-Salazar, Carlos
Liu, Jie
Eltis, Lindsay D.
author_sort Amara, Sawsan
collection PubMed
description Oleaginous microorganisms have considerable potential for biofuel and commodity chemical production. Under nitrogen-limitation, Rhodococcus jostii RHA1 grown on benzoate, an analog of lignin depolymerization products, accumulated triacylglycerols (TAGs) to 55% of its dry weight during transition to stationary phase, with the predominant fatty acids being C16:0 and C17:0. Transcriptomic analyses of RHA1 grown under conditions of N-limitation and N-excess revealed 1,826 dysregulated genes. Genes whose transcripts were more abundant under N-limitation included those involved in ammonium assimilation, benzoate catabolism, fatty acid biosynthesis and the methylmalonyl-CoA pathway. Of the 16 atf genes potentially encoding diacylglycerol O-acyltransferases, atf8 transcripts were the most abundant during N-limitation (~50-fold more abundant than during N-excess). Consistent with Atf8 being a physiological determinant of TAG accumulation, a Δatf8 mutant accumulated 70% less TAG than wild-type RHA1 while atf8 overexpression increased TAG accumulation 20%. Genes encoding type-2 phosphatidic acid phosphatases were not significantly expressed. By contrast, three genes potentially encoding phosphatases of the haloacid dehalogenase superfamily and that cluster with, or are fused with other Kennedy pathway genes were dysregulated. Overall, these findings advance our understanding of TAG metabolism in mycolic acid-containing bacteria and provide a framework to engineer strains for increased TAG production.
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spelling pubmed-48503992016-05-05 Characterization of key triacylglycerol biosynthesis processes in rhodococci Amara, Sawsan Seghezzi, Nicolas Otani, Hiroshi Diaz-Salazar, Carlos Liu, Jie Eltis, Lindsay D. Sci Rep Article Oleaginous microorganisms have considerable potential for biofuel and commodity chemical production. Under nitrogen-limitation, Rhodococcus jostii RHA1 grown on benzoate, an analog of lignin depolymerization products, accumulated triacylglycerols (TAGs) to 55% of its dry weight during transition to stationary phase, with the predominant fatty acids being C16:0 and C17:0. Transcriptomic analyses of RHA1 grown under conditions of N-limitation and N-excess revealed 1,826 dysregulated genes. Genes whose transcripts were more abundant under N-limitation included those involved in ammonium assimilation, benzoate catabolism, fatty acid biosynthesis and the methylmalonyl-CoA pathway. Of the 16 atf genes potentially encoding diacylglycerol O-acyltransferases, atf8 transcripts were the most abundant during N-limitation (~50-fold more abundant than during N-excess). Consistent with Atf8 being a physiological determinant of TAG accumulation, a Δatf8 mutant accumulated 70% less TAG than wild-type RHA1 while atf8 overexpression increased TAG accumulation 20%. Genes encoding type-2 phosphatidic acid phosphatases were not significantly expressed. By contrast, three genes potentially encoding phosphatases of the haloacid dehalogenase superfamily and that cluster with, or are fused with other Kennedy pathway genes were dysregulated. Overall, these findings advance our understanding of TAG metabolism in mycolic acid-containing bacteria and provide a framework to engineer strains for increased TAG production. Nature Publishing Group 2016-04-29 /pmc/articles/PMC4850399/ /pubmed/27126051 http://dx.doi.org/10.1038/srep24985 Text en Copyright © 2016, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/
spellingShingle Article
Amara, Sawsan
Seghezzi, Nicolas
Otani, Hiroshi
Diaz-Salazar, Carlos
Liu, Jie
Eltis, Lindsay D.
Characterization of key triacylglycerol biosynthesis processes in rhodococci
title Characterization of key triacylglycerol biosynthesis processes in rhodococci
title_full Characterization of key triacylglycerol biosynthesis processes in rhodococci
title_fullStr Characterization of key triacylglycerol biosynthesis processes in rhodococci
title_full_unstemmed Characterization of key triacylglycerol biosynthesis processes in rhodococci
title_short Characterization of key triacylglycerol biosynthesis processes in rhodococci
title_sort characterization of key triacylglycerol biosynthesis processes in rhodococci
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4850399/
https://www.ncbi.nlm.nih.gov/pubmed/27126051
http://dx.doi.org/10.1038/srep24985
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