Cargando…

Overexpression of Two New Acyl-CoA:Diacylglycerol Acyltransferase 2-Like Acyl-CoA:Sterol Acyltransferases Enhanced Squalene Accumulation in Aurantiochytrium limacinum

Thraustochytrids are heterotrophic marine eukaryotes known to accumulate large amounts of triacylglycerols, and they also synthesize terpenoids like carotenoids and squalene, which all have an increasing market demand. However, a more extensive knowledge of the lipid metabolism is needed to develop...

Descripción completa

Detalles Bibliográficos
Autores principales: Rau, E-Ming, Bartosova, Zdenka, Kristiansen, Kåre Andre, Aasen, Inga Marie, Bruheim, Per, Ertesvåg, Helga
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8821962/
https://www.ncbi.nlm.nih.gov/pubmed/35145505
http://dx.doi.org/10.3389/fmicb.2022.822254
_version_ 1784646506872045568
author Rau, E-Ming
Bartosova, Zdenka
Kristiansen, Kåre Andre
Aasen, Inga Marie
Bruheim, Per
Ertesvåg, Helga
author_facet Rau, E-Ming
Bartosova, Zdenka
Kristiansen, Kåre Andre
Aasen, Inga Marie
Bruheim, Per
Ertesvåg, Helga
author_sort Rau, E-Ming
collection PubMed
description Thraustochytrids are heterotrophic marine eukaryotes known to accumulate large amounts of triacylglycerols, and they also synthesize terpenoids like carotenoids and squalene, which all have an increasing market demand. However, a more extensive knowledge of the lipid metabolism is needed to develop thraustochytrids for profitable biomanufacturing. In this study, two putative type-2 Acyl-CoA:diacylglycerol acyltransferases (DGAT2) genes of Aurantiochytrium sp. T66, T66ASATa, and T66ASATb, and their homologs in Aurantiochytrium limacinum SR21, AlASATa and AlASATb, were characterized. In A. limacinum SR21, genomic knockout of AlASATb reduced the amount of the steryl esters of palmitic acid, SE (16:0), and docosahexaenoic acid, SE (22:6). The double mutant of AlASATa and AlASATb produced even less of these steryl esters. The expression and overexpression of T66ASATb and AlASATb, respectively, enhanced SE (16:0) and SE (22:6) production more significantly than those of T66ASATa and AlASATa. In contrast, these mutations did not significantly change the level of triacylglycerols or other lipid classes. The results suggest that the four genes encoded proteins possessing acyl-CoA:sterol acyltransferase (ASAT) activity synthesizing both SE (16:0) and SE (22:6), but with the contribution from AlASATb and T66ASATb being more important than that of AlASATa and T66ASATa. Furthermore, the expression and overexpression of T66ASATb and AlASATb enhanced squalene accumulation in SR21 by up to 88%. The discovery highlights the functional diversity of DGAT2-like proteins and provides valuable information on steryl ester and squalene synthesis in thraustochytrids, paving the way to enhance squalene production through metabolic engineering.
format Online
Article
Text
id pubmed-8821962
institution National Center for Biotechnology Information
language English
publishDate 2022
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-88219622022-02-09 Overexpression of Two New Acyl-CoA:Diacylglycerol Acyltransferase 2-Like Acyl-CoA:Sterol Acyltransferases Enhanced Squalene Accumulation in Aurantiochytrium limacinum Rau, E-Ming Bartosova, Zdenka Kristiansen, Kåre Andre Aasen, Inga Marie Bruheim, Per Ertesvåg, Helga Front Microbiol Microbiology Thraustochytrids are heterotrophic marine eukaryotes known to accumulate large amounts of triacylglycerols, and they also synthesize terpenoids like carotenoids and squalene, which all have an increasing market demand. However, a more extensive knowledge of the lipid metabolism is needed to develop thraustochytrids for profitable biomanufacturing. In this study, two putative type-2 Acyl-CoA:diacylglycerol acyltransferases (DGAT2) genes of Aurantiochytrium sp. T66, T66ASATa, and T66ASATb, and their homologs in Aurantiochytrium limacinum SR21, AlASATa and AlASATb, were characterized. In A. limacinum SR21, genomic knockout of AlASATb reduced the amount of the steryl esters of palmitic acid, SE (16:0), and docosahexaenoic acid, SE (22:6). The double mutant of AlASATa and AlASATb produced even less of these steryl esters. The expression and overexpression of T66ASATb and AlASATb, respectively, enhanced SE (16:0) and SE (22:6) production more significantly than those of T66ASATa and AlASATa. In contrast, these mutations did not significantly change the level of triacylglycerols or other lipid classes. The results suggest that the four genes encoded proteins possessing acyl-CoA:sterol acyltransferase (ASAT) activity synthesizing both SE (16:0) and SE (22:6), but with the contribution from AlASATb and T66ASATb being more important than that of AlASATa and T66ASATa. Furthermore, the expression and overexpression of T66ASATb and AlASATb enhanced squalene accumulation in SR21 by up to 88%. The discovery highlights the functional diversity of DGAT2-like proteins and provides valuable information on steryl ester and squalene synthesis in thraustochytrids, paving the way to enhance squalene production through metabolic engineering. Frontiers Media S.A. 2022-01-25 /pmc/articles/PMC8821962/ /pubmed/35145505 http://dx.doi.org/10.3389/fmicb.2022.822254 Text en Copyright © 2022 Rau, Bartosova, Kristiansen, Aasen, Bruheim and Ertesvåg. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Rau, E-Ming
Bartosova, Zdenka
Kristiansen, Kåre Andre
Aasen, Inga Marie
Bruheim, Per
Ertesvåg, Helga
Overexpression of Two New Acyl-CoA:Diacylglycerol Acyltransferase 2-Like Acyl-CoA:Sterol Acyltransferases Enhanced Squalene Accumulation in Aurantiochytrium limacinum
title Overexpression of Two New Acyl-CoA:Diacylglycerol Acyltransferase 2-Like Acyl-CoA:Sterol Acyltransferases Enhanced Squalene Accumulation in Aurantiochytrium limacinum
title_full Overexpression of Two New Acyl-CoA:Diacylglycerol Acyltransferase 2-Like Acyl-CoA:Sterol Acyltransferases Enhanced Squalene Accumulation in Aurantiochytrium limacinum
title_fullStr Overexpression of Two New Acyl-CoA:Diacylglycerol Acyltransferase 2-Like Acyl-CoA:Sterol Acyltransferases Enhanced Squalene Accumulation in Aurantiochytrium limacinum
title_full_unstemmed Overexpression of Two New Acyl-CoA:Diacylglycerol Acyltransferase 2-Like Acyl-CoA:Sterol Acyltransferases Enhanced Squalene Accumulation in Aurantiochytrium limacinum
title_short Overexpression of Two New Acyl-CoA:Diacylglycerol Acyltransferase 2-Like Acyl-CoA:Sterol Acyltransferases Enhanced Squalene Accumulation in Aurantiochytrium limacinum
title_sort overexpression of two new acyl-coa:diacylglycerol acyltransferase 2-like acyl-coa:sterol acyltransferases enhanced squalene accumulation in aurantiochytrium limacinum
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8821962/
https://www.ncbi.nlm.nih.gov/pubmed/35145505
http://dx.doi.org/10.3389/fmicb.2022.822254
work_keys_str_mv AT raueming overexpressionoftwonewacylcoadiacylglycerolacyltransferase2likeacylcoasterolacyltransferasesenhancedsqualeneaccumulationinaurantiochytriumlimacinum
AT bartosovazdenka overexpressionoftwonewacylcoadiacylglycerolacyltransferase2likeacylcoasterolacyltransferasesenhancedsqualeneaccumulationinaurantiochytriumlimacinum
AT kristiansenkareandre overexpressionoftwonewacylcoadiacylglycerolacyltransferase2likeacylcoasterolacyltransferasesenhancedsqualeneaccumulationinaurantiochytriumlimacinum
AT aaseningamarie overexpressionoftwonewacylcoadiacylglycerolacyltransferase2likeacylcoasterolacyltransferasesenhancedsqualeneaccumulationinaurantiochytriumlimacinum
AT bruheimper overexpressionoftwonewacylcoadiacylglycerolacyltransferase2likeacylcoasterolacyltransferasesenhancedsqualeneaccumulationinaurantiochytriumlimacinum
AT ertesvaghelga overexpressionoftwonewacylcoadiacylglycerolacyltransferase2likeacylcoasterolacyltransferasesenhancedsqualeneaccumulationinaurantiochytriumlimacinum