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Sun K, Meesapyodsuk D, Qiu X. Biosynthetic mechanisms of omega-3 polyunsaturated fatty acids in microalgae. J Biol Chem 2024; 300:107699. [PMID: 39173949 PMCID: PMC11418110 DOI: 10.1016/j.jbc.2024.107699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2024] [Revised: 08/08/2024] [Accepted: 08/12/2024] [Indexed: 08/24/2024] Open
Abstract
Marine microalgae are the primary producers of ω3 polyunsaturated fatty acids (PUFAs), such as octadecapentaenoic acid (OPA, 18:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) for food chains. However, the biosynthetic mechanisms of these PUFAs in the algae remain elusive. To study how these fatty acids are synthesized in microalgae, a series of radiolabeled precursors were used to trace the biosynthetic process of PUFAs in Emiliania huxleyi. Feeding the alga with 14C-labeled acetic acid in a time course showed that OPA was solely found in glycoglycerolipids such as monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) synthesized plastidically by sequential desaturations while DHA was exclusively found in phospholipids synthesized extraplastidically. Feeding the alga with 14C-labeled α-linolenic acid (ALA), linoleic acid (LA), and oleic acid (OA) showed that DHA was synthesized extraplastidically from fed ALA and LA, but not from OA, implying that the aerobic pathway of DHA biosynthesis is incomplete with missing a Δ12 desaturation step. The in vitro enzymatic assays with 14C-labeled malonyl-CoA showed that DHA was synthesized from acetic acid by a PUFA synthase. These results provide the first and conclusive biochemistry evidence that OPA is synthesized by a plastidic aerobic pathway through sequential desaturations with the last step of Δ3 desaturation, while DHA is synthesized by an extraplastidic anaerobic pathway catalyzed by a PUFA synthase in the microalga.
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Affiliation(s)
- Kaiwen Sun
- Department of Food & Bioproduct Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | | | - Xiao Qiu
- Department of Food & Bioproduct Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
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2
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Shene C, Leyton A, Flores L, Chavez D, Asenjo JA, Chisti Y. Genome-scale metabolic modeling of Thraustochytrium sp. RT2316-16: Effects of nutrients on metabolism. Biotechnol Bioeng 2024; 121:1986-2001. [PMID: 38500406 DOI: 10.1002/bit.28689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 01/17/2024] [Accepted: 02/20/2024] [Indexed: 03/20/2024]
Abstract
Marine thraustochytrids produce metabolically important lipids such as the long-chain omega-3 polyunsaturated fatty acids, carotenoids, and sterols. The growth and lipid production in thraustochytrids depends on the composition of the culture medium that often contains yeast extract as a source of amino acids. This work discusses the effects of individual amino acids provided in the culture medium as the only source of nitrogen, on the production of biomass and lipids by the thraustochytrid Thraustochytrium sp. RT2316-16. A reconstructed metabolic network based on the annotated genome of RT2316-16 in combination with flux balance analysis was used to explain the observed growth and consumption of the nutrients. The culture kinetic parameters estimated from the experimental data were used to constrain the flux via the nutrient consumption rates and the specific growth rate of the triacylglycerol-free biomass in the genome-scale metabolic model (GEM) to predict the specific rate of ATP production for cell maintenance. A relationship was identified between the specific rate of ATP production for maintenance and the specific rate of glucose consumption. The GEM and the derived relationship for the production of ATP for maintenance were used in linear optimization problems, to successfully predict the specific growth rate of RT2316-16 in different experimental conditions.
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Affiliation(s)
- Carolina Shene
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN, and Centre of Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco, Chile
| | - Allison Leyton
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN, and Centre of Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco, Chile
| | - Liset Flores
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN, and Centre of Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco, Chile
| | - Daniela Chavez
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN, and Centre of Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco, Chile
| | - Juan A Asenjo
- Department of Chemical Engineering, Biotechnology and Materials, Centre for Biotechnology and Bioengineering (CeBiB), Universidad de Chile, Santiago, Chile
| | - Yusuf Chisti
- Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Nerus, Terengganu, Malaysia
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3
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Zhang Y, Cui X, Lin S, Lu T, Li H, Lu Y, Cao M, Lin X, Ling X. Knockout of a PLD gene in Schizochytrium limacinum SR21 enhances docosahexaenoic acid accumulation by modulation of the phospholipid profile. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:16. [PMID: 38291531 PMCID: PMC10826259 DOI: 10.1186/s13068-024-02465-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 01/18/2024] [Indexed: 02/01/2024]
Abstract
BACKGROUND The hydrolysis and transphosphatidylation of phospholipase D (PLD) play important roles in the interconversion of phospholipids (PLs), which has been shown to profoundly impact lipid metabolism in plants. In this study, the effect of the PLD1 gene of Schizochytrium limacinum SR21 (S. limacinum SR21) on lipid metabolism was investigated. RESULTS PLD1 knockout had little impact on cell growth and lipid production, but it significantly improved the percentage of polyunsaturated fatty acids in lipids, of which docosahexaenoic acid (DHA) content increased by 13.3% compared to the wild-type strain. Phospholipomics and real-time quantitative PCR analysis revealed the knockout of PLD1 reduced the interexchange and increased de novo synthesis of PLs, which altered the composition of PLs, accompanied by a final decrease in phosphatidylcholine (PC) and an increase in phosphatidylinositol, lysophosphatidylcholine, and phosphatidic acid levels. PLD1 knockout also increased DHA content in triglycerides (TAGs) and decreased it in PLs. CONCLUSIONS These results indicate that PLD1 mainly performs the transphosphatidylation activity in S. limacinum SR21, and its knockout promotes the migration of DHA from PLs to TAGs, which is conducive to DHA accumulation and storage in TAGs via an acyl CoA-independent pathway. This study provides a novel approach for identifying the mechanism of DHA accumulation and metabolic regulation strategies for DHA production in S. limacinum SR21.
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Affiliation(s)
- Yiting Zhang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China
| | - Xiaowen Cui
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China
| | - Shuizhi Lin
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China
| | - Tao Lu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China
| | - Hao Li
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China
| | - Yinghua Lu
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China
- Xiamen Key Laboratory of Synthetic Biotechnology, Xiamen University, Xiamen, People's Republic of China
- The Key Laboratory for Chemical Biology of Fujian Province (Xiamen University), Xiamen, People's Republic of China
| | - Mingfeng Cao
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China
- Xiamen Key Laboratory of Synthetic Biotechnology, Xiamen University, Xiamen, People's Republic of China
| | - Xihuang Lin
- Analysis and Test Center, Ministry of Natural Resources, Third Institute of Oceanography, Xiamen, 361005, People's Republic of China.
| | - Xueping Ling
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, People's Republic of China.
- Xiamen Key Laboratory of Synthetic Biotechnology, Xiamen University, Xiamen, People's Republic of China.
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4
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Prabhakaran P, Nazir MYM, Thananusak R, Hamid AA, Vongsangnak W, Song Y. Uncovering global lipid accumulation routes towards docosahexaenoic acid (DHA) production in Aurantiochytrium sp. SW1 using integrative proteomic analysis. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159381. [PMID: 37625782 DOI: 10.1016/j.bbalip.2023.159381] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/15/2023] [Accepted: 08/22/2023] [Indexed: 08/27/2023]
Abstract
Aurantiochytrium sp., a marine thraustochytrid possesses a remarkable ability to produce lipid rich in polyunsaturated fatty acids (PUFAs), such as docosahexaenoic acid (DHA). Although gene regulation underlying lipid biosynthesis has been previously reported, proteomic analysis is still limited. In this study, high DHA accumulating strain Aurantiochytrium sp. SW1 has been used as a study model to elucidate the alteration in proteome profile under different cultivation phases i.e. growth, nitrogen-limitation and lipid accumulation. Of the total of 5146 identified proteins, 852 proteins were differentially expressed proteins (DEPs). The largest number of DEPs (488 proteins) was found to be uniquely expressed between lipid accumulating phase and growth phase. Interestingly, there were up-regulated proteins involved in glycolysis, glycerolipid, carotenoid and glutathione metabolism which were preferable metabolic routes towards lipid accumulation and DHA production as well as cellular oxidative defence. Integrated proteomic and transcriptomic data were also conducted to comprehend the gene and protein regulation underlying the lipid and DHA biosynthesis. A significant up-regulation of acetyl-CoA synthetase was observed which suggests alternative route of acetate metabolism for acetyl-CoA producer. This study presents the holistic routes underlying lipid accumulation and DHA production in Aurantiochytrium sp. SW1 and other relevant thraustochytrid.
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Affiliation(s)
- Pranesha Prabhakaran
- Colin Ratledge Centre for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo, China; Interdisciplinary Graduate Programs in Bioscience, Faculty of Science, Kasetsart University, Bangkok 10900, Thailand
| | - Mohamed Yusuf Mohamed Nazir
- Colin Ratledge Centre for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo, China; Department of Food Sciences, Faculty of Science and Technology, University Kebangsaan Malaysia, UKM, Bangi, Malaysia
| | - Roypim Thananusak
- Duckweed Holobiont Resource & Research Center (DHbRC), Faculty of Science, Kasetsart University, Bangkok, Thailand; Omics Center for Agriculture, Bioresources, Food, and Health, Kasetsart University (OmiKU), Bangkok, Thailand
| | - Aidil Abdul Hamid
- Department of Biological Science and Biotechnology, Faculty of Science and Technology, National University of Malaysia, Bangi, Malaysia.
| | - Wanwipa Vongsangnak
- Omics Center for Agriculture, Bioresources, Food, and Health, Kasetsart University (OmiKU), Bangkok, Thailand; Department of Zoology, Faculty of Science, Kasetsart University, Bangkok, Thailand.
| | - Yuanda Song
- Colin Ratledge Centre for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo, China.
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5
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Cheng Q, Li Z, Zhang J, Guo H, Ahmat M, Cheng J, Abbas Z, Hua Z, Wang J, Tong Y, Yang T, Si D, Zhang R. Soybean Oil Regulates the Fatty Acid Synthesis II System of Bacillus amyloliquefaciens LFB112 by Activating Acetyl-CoA Levels. Microorganisms 2023; 11:1164. [PMID: 37317138 DOI: 10.3390/microorganisms11051164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/14/2023] [Accepted: 04/18/2023] [Indexed: 06/16/2023] Open
Abstract
[Background] Bacillus LFB112 is a strain of Bacillus amyloliquefaciens screened in our laboratory. Previous studies found that it has a strong ability for fatty acid metabolism and can improve the lipid metabolism of broilers when used as feed additives. [Methods] This study aimed to confirm the fatty acid metabolism of Bacillus LFB112. Sterilized soybean oil (SSO) was added to the Beef Peptone Yeast (BPY) medium, and its effect on fatty acid content in the supernatant and bacteria, as well as expression levels of genes related to fatty acid metabolism, were studied. The control group was the original culture medium without oil. [Results] Acetic acid produced by the SSO group of Bacillus LFB112 decreased, but the content of unsaturated fatty acids increased. The 1.6% SSO group significantly increased the contents of pyruvate and acetyl-CoA in the pellets. Furthermore, the mRNA levels of enzymes involved in the type II fatty acid synthesis pathway of FabD, FabH, FabG, FabZ, FabI, and FabF were up-regulated. [Conclusions] Soybean oil increased the content of acetyl-CoA in Bacillus LFB112, activated its type II fatty acid synthesis pathway, and improved the fatty acid metabolism level of Bacillus LFB112. These intriguing results pave the way for further investigations into the intricate interplay between Bacillus LFB112 and fatty acid metabolism, with potential applications in animal nutrition and feed additive development.
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Affiliation(s)
- Qiang Cheng
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Zhongxuan Li
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
- College of Bioengineering, Sichuan University of Science & Engineering, Zigong 643000, China
| | - Jing Zhang
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Henan Guo
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Marhaba Ahmat
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
- Xinjiang Laboratory of Special Environmental Microbiology, Institute of Applied Microbiology, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China
| | - Junhao Cheng
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Zaheer Abbas
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Zhengchang Hua
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Junyong Wang
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Yucui Tong
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Tiantian Yang
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Dayong Si
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
| | - Rijun Zhang
- State Key Laboratory of Animal Nutrition, Laboratory of Feed Biotechnology, College of Animal Science & Technology, China Agricultural University, Beijing 100193, China
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6
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Rau EM, Aasen IM, Bartosova Z, Bruheim P, Ertesvåg H. Utilizing lipidomics and fatty acid synthase inhibitors to explore lipid accumulation in two thraustochytrid species. ALGAL RES 2023. [DOI: 10.1016/j.algal.2023.103091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
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7
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Valdebenito D, Urrutia S, Leyton A, Chisti Y, Asenjo JA, Shene C. Nitrogen Sources Affect the Long-Chain Polyunsaturated Fatty Acids Content in Thraustochytrium sp. RT2316-16. Mar Drugs 2022; 21:md21010015. [PMID: 36662188 PMCID: PMC9864179 DOI: 10.3390/md21010015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 12/21/2022] [Accepted: 12/22/2022] [Indexed: 12/28/2022] Open
Abstract
The psychrophilic marine microorganism Thraustochytrium sp. RT2316-16 can produce carotenoids as well as lipids containing the omega-3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid and docosahexaenoic acid. This work reports on the effects of the composition of the culture medium, including certain amino acids, on growth and lipid synthesis by RT2316-16. Compared with the culture on glutamate, the use of lysine, alanine, or serine, increased the content of the omega-3 PUFA in total lipids. In the media that contained yeast extract, glutamate, and glucose, lipid accumulation occurred when organic ammonium was exhausted earlier than glucose. In contrast, lipid mobilization was promoted if glucose was exhausted while organic ammonium (supplied by yeast extract and glutamate) remained in the medium. The total content of carotenoids in the lipid-free biomass decreased during the first 12 to 24 h of culture, simultaneously with a decrease in the total lipid content of the biomass. The experimental data suggested a possible interrelationship between the metabolism of carotenoids and lipids. A high content of omega-3 PUFA in the total lipids could be obtained by growing the thraustochytrid in a medium with a low glucose concentration (6 g L-1) and a high concentration of organic nitrogen (yeast extract 12 g L-1; glutamate 1.06 g L-1), after glucose was exhausted. These observations may guide the development of a strategy to enhance omega-3 PUFA in the biomass.
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Affiliation(s)
- Diego Valdebenito
- Center for Biotechnology and Bioengineering (CeBiB), Center of Food Biotechnology and Bioseparations, BIOREN and Department of Chemical Engineering, Universidad de La Frontera, Francisco Salazar 01145, Temuco 4780000, Chile
| | - Sebastián Urrutia
- Center for Biotechnology and Bioengineering (CeBiB), Center of Food Biotechnology and Bioseparations, BIOREN and Department of Chemical Engineering, Universidad de La Frontera, Francisco Salazar 01145, Temuco 4780000, Chile
| | - Allison Leyton
- Center for Biotechnology and Bioengineering (CeBiB), Center of Food Biotechnology and Bioseparations, BIOREN and Department of Chemical Engineering, Universidad de La Frontera, Francisco Salazar 01145, Temuco 4780000, Chile
| | - Yusuf Chisti
- Institute of Tropical Aquaculture and Fisheries, Universiti Malaysia Terengganu, Kuala Nerus 21030, Terengganu, Malaysia
| | - Juan A. Asenjo
- Centre for Biotechnology and Bioengineering (CeBiB), Department of Chemical Engineering, Biotechnology and Materials, Universidad de Chile, Beauchef 851, Santiago 8370459, Chile
| | - Carolina Shene
- Center for Biotechnology and Bioengineering (CeBiB), Center of Food Biotechnology and Bioseparations, BIOREN and Department of Chemical Engineering, Universidad de La Frontera, Francisco Salazar 01145, Temuco 4780000, Chile
- Correspondence:
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8
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Nyunoya H, Ishibashi Y, Ito M, Okino N. Significance of mitochondrial fatty acid β-oxidation for the survivability of Aurantiochytrium limacinum ATCC MYA-1381 during sugar starvation. Biosci Biotechnol Biochem 2022; 86:1524-1535. [PMID: 35998312 DOI: 10.1093/bbb/zbac141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/10/2022] [Indexed: 11/12/2022]
Abstract
Thraustochytrids are marine protists that accumulate large amounts of palmitic acid and docosahexaenoic acid in lipid droplets. Random insertional mutagenesis was adopted for Aurantiochytrium limacinum ATCC MYA-1381 to search for genes that regulate lipid metabolism in thraustochytrids. A mutant strain, M17, was selected because of its significant decrease in myristic acid, palmitic acid, and triacylglycerol contents and cell growth defect. Genome analysis revealed that the gene encoding for mitochondrial electron-transfer flavoprotein ubiquinone oxidoreductase (ETFQO) was lacking in the M17 strain. This mutant strain exhibited a growth defect at the stationary phase, possibly due to stagnation of mitochondrial fatty acid β-oxidation and branched-chain amino acid degradation, both of which were caused by lack of ETFQO. This study shows the usability of random insertional mutagenesis to obtain mutants of lipid metabolism in A. limacinum and clarifies that ETFQO is integral for survival under sugar starvation in A. limacinum.
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Affiliation(s)
- Hayato Nyunoya
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Yohei Ishibashi
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Makoto Ito
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Nozomu Okino
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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9
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Gupta A, Barrow CJ, Puri M. Multiproduct biorefinery from marine thraustochytrids towards a circular bioeconomy. Trends Biotechnol 2021; 40:448-462. [PMID: 34627647 DOI: 10.1016/j.tibtech.2021.09.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/08/2021] [Accepted: 09/09/2021] [Indexed: 12/18/2022]
Abstract
Microalgal biotechnology research continues to expand due to largely unexplored marine environments and growing consumer interest in healthy products. Thraustochytrids, which are marine oleaginous protists, are known for their production of bioactives with significant applications in nutraceuticals, pharmaceuticals, and aquaculture. A wide range of high-value biochemicals, such as nutritional supplements (omega-3 fatty acids), squalene, exopolysaccharides (EPSs), enzymes, aquaculture feed, and biodiesel and pigment compounds, have been investigated. We discuss thraustochytrids as potential feedstocks to produce various bioactive compounds and advocate developing a biorefinery to offset production costs. We anticipate that future advances in cell manufacturing, lipidomic analysis, and nanotechnology-guided lipid extraction would facilitate large-scale cost-competitive production through these microbes.
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Affiliation(s)
- Adarsha Gupta
- Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford Park, 5042, Adelaide, Australia; Flinders Health and Medical Research Institute (FHMRI), Flinders University, Bedford Park, 5042, Adelaide, Australia
| | - Colin J Barrow
- Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, 3216, Geelong, Australia
| | - Munish Puri
- Medical Biotechnology, College of Medicine and Public Health, Flinders University, Bedford Park, 5042, Adelaide, Australia; Flinders Health and Medical Research Institute (FHMRI), Flinders University, Bedford Park, 5042, Adelaide, Australia; Centre for Chemistry and Biotechnology, School of Life and Environmental Sciences, Deakin University, Waurn Ponds, 3216, Geelong, Australia.
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10
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Functional Analysis of an Acyltransferase-Like Domain from Polyunsaturated Fatty Acid Synthase in Thraustochytrium. Microorganisms 2021; 9:microorganisms9030626. [PMID: 33803061 PMCID: PMC8003026 DOI: 10.3390/microorganisms9030626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/15/2021] [Accepted: 03/15/2021] [Indexed: 12/19/2022] Open
Abstract
Biosynthesis of very long chain polyunsaturated fatty acids (VLCPUFA) such as docosahexaenoic acid (DHA, 22:6-4,7,10,13,16,19) and docosapentaenoic acid (DPA, 22:5-4,7,10,13,16) in protist Thraustochytrium is catalyzed by a polyunsaturated fatty acids (PUFA) synthase comprising three large subunits, each with multiple catalytic domains. This study used complementation test, in vitro assays, and functional expression to characterize an acyltransferase (AT)-like domain in Subunit-B of a PUFA synthase from Thraustochytrium. Complementation test in Escherichia coli showed that the AT-like domain could not restore the growth phenotype of a temperature-sensitive mutant (∆fabDts) defective in malonyl-CoA:ACP transacylase activity. In vitro assays showed that the AT-like domain possessed thioesterase activity towards a few acyl-CoAs tested where docosahexaenoyl-CoA (DHA-CoA) was the preferred substrate. Expression of this domain in an E. coli mutant (∆fadD) defective in acyl-CoA synthetase activity resulted in the increased accumulation of free fatty acids. Site-directed mutagenesis showed that the substitution of two putative active site residues, serine at 96 (S96) and histidine at 220 (H220), in the AT-like domain significantly reduced its activity towards DHA-CoA and accumulation of free fatty acids in the ∆fadD mutant. These results indicate that the AT-like domain of the PUFA synthase does not function as a malonyl-CoA:ACP transacylase, rather it functions as a thioesterase. It might catalyze the last step of the VLCPUFA biosynthesis by releasing freshly synthesized VLCPUFAs attached to ACP domains of the PUFA synthase in Thraustochytrium.
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11
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Bartosova Z, Ertesvåg H, Nyfløt EL, Kämpe K, Aasen IM, Bruheim P. Combined Metabolome and Lipidome Analyses for In-Depth Characterization of Lipid Accumulation in the DHA Producing Aurantiochytrium sp. T66. Metabolites 2021; 11:metabo11030135. [PMID: 33669117 PMCID: PMC7996494 DOI: 10.3390/metabo11030135] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/17/2021] [Accepted: 02/18/2021] [Indexed: 12/19/2022] Open
Abstract
Thraustochytrids are marine heterotrophic microorganisms known for their potential to accumulate docosahexaenoic acid (DHA)-enriched lipids. There have been many attempts to improve thraustochytrid DHA bioprocesses, especially through traditional optimization of cultivation and media conditions. Nevertheless, thraustochytrid-based bioprocesses are still not commercially competitive for high volume-low cost production of DHA. Thus, it is realized that genetic and metabolic engineering strategies are needed for the development of commercially competitive thraustochytrid DHA cell factories. Here, we present an analytical workflow for high resolution phenotyping at metabolite and lipid levels to generate deeper insight into the thraustochytrid physiology, with particular focus on central carbon and redox metabolism. We use time-series sampling during unlimited growth and nitrogen depleted triggering of DHA synthesis and lipid accumulation (LA) to show-case our methodology. The mass spectrometric absolute quantitative metabolite profiling covered glycolytic, pentose phosphate pathway (PPP) and tricarboxylic acid cycle (TCA) metabolites, amino acids, complete (deoxy)nucleoside phosphate pools, CoA and NAD metabolites, while semiquantitative high-resolution supercritical fluid chromatography MS/MS was applied for the lipid profiling. Interestingly, trace amounts of a triacylglycerols (TG) with DHA incorporated in all three acyl positions was detected, while TGs 16:0_16:0_22:6 and 16:0_22:6_22:6 were among the dominant lipid species. The metabolite profiling data indicated that lipid accumulation is not limited by availability of the acyl chain carbon precursor acetyl-CoA nor reducing power (NADPH) but rather points to the TG head group precursor glycerol-3-phosphate as the potential cause at the metabolite level for the gradual decline in lipid production throughout the cultivation. This high-resolution phenotyping provides new knowledge of changes in the central metabolism during growth and LA in thraustochytrids and will guide target selection for metabolic engineering needed for further improvements of this DHA cell factory.
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Affiliation(s)
- Zdenka Bartosova
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway; (Z.B.); (H.E.); (E.L.N.); (K.K.)
| | - Helga Ertesvåg
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway; (Z.B.); (H.E.); (E.L.N.); (K.K.)
| | - Eirin Lishaugen Nyfløt
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway; (Z.B.); (H.E.); (E.L.N.); (K.K.)
| | - Kristoffer Kämpe
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway; (Z.B.); (H.E.); (E.L.N.); (K.K.)
| | - Inga Marie Aasen
- Biotechnology and Nanomedicine, SINTEF Industry, 4730 Trondheim, Norway;
| | - Per Bruheim
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway; (Z.B.); (H.E.); (E.L.N.); (K.K.)
- Correspondence:
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12
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Patel A, Sarkar O, Rova U, Christakopoulos P, Matsakas L. Valorization of volatile fatty acids derived from low-cost organic waste for lipogenesis in oleaginous microorganisms-A review. BIORESOURCE TECHNOLOGY 2021; 321:124457. [PMID: 33316701 DOI: 10.1016/j.biortech.2020.124457] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 11/21/2020] [Accepted: 11/24/2020] [Indexed: 06/12/2023]
Abstract
To meet environmental sustainability goals, microbial oils have been suggested as an alternative to petroleum-based products. At present, microbial fermentation for oil production relies on pure sugar-based feedstocks. However, these feedstocks are expensive and are in limited supply. Volatile fatty acids, which are generated as intermediates during anaerobic digestion of organic waste have emerged as a renewable feedstock that has the potential to replace conventional sugar sources for microbial oil production. They comprise short-chain (C2 to C6) organic acids and are employed as building blocks in the chemical industry. The present review discusses the use of oleaginous microorganisms for the production of biofuels and added-value products starting from volatile fatty acids as feedstocks. The review describes the metabolic pathways enabling lipogenesis from volatile fatty acids, and focuses on strategies to enhance lipid accumulation in oleaginous microorganisms by tuning the ratios of volatile fatty acids generated via anaerobic fermentation.
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Affiliation(s)
- Alok Patel
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden
| | - Omprakash Sarkar
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden
| | - Ulrika Rova
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden
| | - Paul Christakopoulos
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden
| | - Leonidas Matsakas
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden.
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Jovanovic S, Dietrich D, Becker J, Kohlstedt M, Wittmann C. Microbial production of polyunsaturated fatty acids - high-value ingredients for aquafeed, superfoods, and pharmaceuticals. Curr Opin Biotechnol 2021; 69:199-211. [PMID: 33540327 DOI: 10.1016/j.copbio.2021.01.009] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 01/01/2021] [Accepted: 01/10/2021] [Indexed: 12/26/2022]
Abstract
Polyunsaturated fatty acids (PUFAs), primarily docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), have received worldwide attention in recent years due to an increasing awareness of their uniqueness in improving diet and human health and their apparently inevitable shortage in global availability. Microbial cell factories are a major solution to supplying these precious molecules in sufficient amounts and providing PUFA-rich aquafeed, superfoods, and medical formulations. This review assesses the PUFA world markets and highlights recent advances in upgrading and streamlining microalgae, yeasts, fungi, and bacteria for high-level PUFA production and broadening of the PUFA spectrum.
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Affiliation(s)
- Sofija Jovanovic
- Institute of Systems Biotechnology, Universität des Saarlandes, Germany
| | - Demian Dietrich
- Institute of Systems Biotechnology, Universität des Saarlandes, Germany
| | - Judith Becker
- Institute of Systems Biotechnology, Universität des Saarlandes, Germany
| | - Michael Kohlstedt
- Institute of Systems Biotechnology, Universität des Saarlandes, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Universität des Saarlandes, Germany.
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Hu F, Clevenger AL, Zheng P, Huang Q, Wang Z. Low-temperature effects on docosahexaenoic acid biosynthesis in Schizochytrium sp. TIO01 and its proposed underlying mechanism. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:172. [PMID: 33088342 PMCID: PMC7565746 DOI: 10.1186/s13068-020-01811-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 10/06/2020] [Indexed: 05/25/2023]
Abstract
BACKGROUND Schizochytrium species are known for their abundant production of docosahexaenoic acid (DHA). Low temperatures can promote the biosynthesis of polyunsaturated fatty acids (PUFAs) in many species. This study investigates low-temperature effects on DHA biosynthesis in Schizochytrium sp. TIO01 and its underlying mechanism. RESULTS The Schizochytrium fatty acid biosynthesis pathway was evaluated based on de novo genome assembly (contig N50 = 2.86 Mb) and iTRAQ-based protein identification. Our findings revealed that desaturases, involved in DHA synthesis via the fatty acid synthase (FAS) pathway, were completely absent. The polyketide synthase (PKS) pathway and the FAS pathway are, respectively, responsible for DHA and saturated fatty acid synthesis in Schizochytrium. Analysis of fatty acid composition profiles indicates that low temperature has a significant impact on the production of DHA in Schizochytrium, increasing the DHA content from 43 to 65% of total fatty acids. However, the expression levels of PKS pathway genes were not significantly regulated as the DHA content increased. Further, gene expression analysis showed that pathways related to the production of substrates (acetyl-CoA and NADPH) for fatty acid synthesis (the branched-chain amino acid degradation pathway and the pentose phosphate pathway) and genes related to saturated fatty acid biosynthesis (the FAS pathway genes and malic enzyme) were, respectively, upregulated and downregulated. These results indicate that low temperatures increase the DHA content by likely promoting the entry of relatively large amounts of substrates into the PKS pathway. CONCLUSIONS In this study, we provide genomic, proteomic, and transcriptomic evidence for the fatty acid synthesis pathway in Schizochytrium and propose a mechanism by which low temperatures promote the accumulation of DHA in Schizochytrium. The high-quality and nearly complete genome sequence of Schizochytrium provides a valuable reference for investigating the regulation of polyunsaturated fatty acid biosynthesis and the evolutionary characteristics of Thraustochytriidae species.
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Affiliation(s)
- Fan Hu
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005 China
| | - April L. Clevenger
- Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK USA
| | - Peng Zheng
- College of Life Science and Health, Wuhan University of Science and Technology, Wuhan, 430065 China
| | - Qiongye Huang
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005 China
| | - Zhaokai Wang
- Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005 China
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15
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Molecular mechanisms for biosynthesis and assembly of nutritionally important very long chain polyunsaturated fatty acids in microorganisms. Prog Lipid Res 2020; 79:101047. [DOI: 10.1016/j.plipres.2020.101047] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/29/2020] [Accepted: 06/09/2020] [Indexed: 12/23/2022]
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16
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Tynio Y, Morozova GV, Biryukova Y, Sivokhin DA, Pozdniakova NV, Zylkova MV, Bogdanova ES, Smirnova MS, Shevelev AB. Synthesis of 13С- and 14С-labeled linoleic acids for use in diagnostic breath tests for hepatobiliary system disorders. BULLETIN OF RUSSIAN STATE MEDICAL UNIVERSITY 2020. [DOI: 10.24075/brsmu.2020.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
At present, there is a need for a simple, noninvasive, highly specific and sensitive diagnostic test for hepatobiliary system disorders. Compounds labeled with carbon isotopes are widely used in various diagnostic breath tests; they are safe and can reliably detect a metabolic disorder or enzyme deficiency. The aim of this study was to synthesize 13С- and 14С-labeled linoleic acids suitable for use in hepatobiliary breath tests in terms of purity. In the synthesis of 13С-labeled linoleic acid, the chemical yield for 1-bromo-8,11-heptadecadien was 86.4% and the chemical yield for barium carbonate-13С, 96.0%. In the synthesis of 14С-labeled linoleic acid, the chemical yield for 1-bromo-8,11-heptadecadien was 87.39%; for barium carbonate-14С it was 97.1%. The specific radioactivity of 14С-labeled linoleic acids was 45.36 ± 0.02 mCi/g. The radiochemical yield of the reaction was 96.0%. The proposed method is suitable for batch production.
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Affiliation(s)
- YaYa Tynio
- Russian State University of Physical Education, Sport, Youth and Tourism, Moscow, Russia
| | - GV Morozova
- Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology, Moscow, Russia
| | - YuK Biryukova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - DA Sivokhin
- I. M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - NV Pozdniakova
- Blokhin National Medical Research Center of Oncology, Moscow, Russia
| | - MV Zylkova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - ES Bogdanova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - MS Smirnova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia
| | - AB Shevelev
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, Russia; Plekhanov Russian University of Economics, Moscow, Russia
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Phytohormones as stimulators to improve arachidonic acid biosynthesis in Mortierella alpina. Enzyme Microb Technol 2019; 131:109381. [DOI: 10.1016/j.enzmictec.2019.109381] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 07/11/2019] [Accepted: 07/12/2019] [Indexed: 12/24/2022]
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18
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Yue XH, Chen WC, Wang ZM, Liu PY, Li XY, Lin CB, Lu SH, Huang FH, Wan X. Lipid Distribution Pattern and Transcriptomic Insights Revealed the Potential Mechanism of Docosahexaenoic Acid Traffics in Schizochytrium sp. A-2. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:9683-9693. [PMID: 31379160 DOI: 10.1021/acs.jafc.9b03536] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Schizochytrium sp. A-2 is a heterotrophic marine fungus used for the commercial production of docosahexaenoic acid (DHA). However, the pattern of the distribution of DHA and how DHA is channeled into phospholipid (PL) and triacylglycerol (TAG) are unknown. In this study, we systematically analyzed the distribution of DHA in TAG and PL during the growth of the cell. The migration of DHA from PL to TAG was presumed during the fermentation cycle. DHA and docosapentaenoic acid were accumulated in both TAG and phosphatidylcholine (PC), whereas eicosapentaenoic acid was mainly deposited in PC. RNA seq revealed that malic enzyme may provide lipogenic NADPH. In addition, long-chain acyl-CoA synthase and acyl-CoA:lysophosphatidylcholine acyltransferase may participate in the accumulation of DHA in PL. No phosphatidylcholine:diacylglycerol cholinephosphotransferase was identified from the genome sequence. In contrast, phospholipid:diacylglycerol acyltransferase-mediated acyl-CoA-independent TAG synthesis pathway and phospholipase C may contribute to the channeling of DHA from PC to TAG.
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Affiliation(s)
- Xiu-Hong Yue
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
| | - Wen-Chao Chen
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops , Ministry of Agriculture , Wuhan 430062 , P. R. China
- Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory , Wuhan 430062 , P. R. China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition , Wuhan 430062 , P. R. China
| | - Zhi-Ming Wang
- CABIO Biotech (Wuhan) Co., Ltd , Wuhan 430223 , P. R. China
| | - Peng-Yang Liu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
| | - Xiang-Yu Li
- CABIO Biotech (Wuhan) Co., Ltd , Wuhan 430223 , P. R. China
| | - Chu-Bin Lin
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
| | - Shu-Huan Lu
- CABIO Biotech (Wuhan) Co., Ltd , Wuhan 430223 , P. R. China
| | - Feng-Hong Huang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops , Ministry of Agriculture , Wuhan 430062 , P. R. China
- Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory , Wuhan 430062 , P. R. China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition , Wuhan 430062 , P. R. China
| | - Xia Wan
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences , Wuhan 430062 , P. R. China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops , Ministry of Agriculture , Wuhan 430062 , P. R. China
- Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory , Wuhan 430062 , P. R. China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition , Wuhan 430062 , P. R. China
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19
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Sun XM, Ren LJ, Zhao QY, Ji XJ, Huang H. Enhancement of lipid accumulation in microalgae by metabolic engineering. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:552-566. [DOI: 10.1016/j.bbalip.2018.10.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/30/2018] [Accepted: 10/05/2018] [Indexed: 01/08/2023]
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20
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Zhao X, Qiu X. Very Long Chain Polyunsaturated Fatty Acids Accumulated in Triacylglycerol Are Channeled From Phosphatidylcholine in Thraustochytrium. Front Microbiol 2019; 10:645. [PMID: 30972054 PMCID: PMC6446058 DOI: 10.3389/fmicb.2019.00645] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 03/14/2019] [Indexed: 11/13/2022] Open
Abstract
Thraustochytrium is a marine protist that can accumulate a large amount of very long chain polyunsaturated fatty acids (VLCPUFA) in triacylglycerols (TAG). How these freshly synthesized VLCPUFAs are channeled into TAG remains unknown. In this study, the glycerolipid profile of Thraustochytrium at log and stationary growth stages was first analyzed by lipidomic tools, and then 14C-acetate and 14C-glycerol were used to trace the flux of fatty acids and backbone in glycerolipids. Lipidomic analysis showed that VLCPUFAs were mostly allocated to phosphatidylcholine (PC) and TAG. PC possessed a relatively stable profile of VLCPUFAs, whereas TAG carrying VLCPUFAs were significantly increased at the stationary phase. 14C-acetate labeled VLCPUFAs were predominately incorporated into PC initially but were mostly found in TAG at later time of labeling. Positional analysis showed that PC had either one VLCPUFA at its sn-2 position (PC1) or two VLCPUFAs (PC2), while TAG incorporated VLCPUFAs almost exclusively at the sn-2 position. Similarly, 14C-glycerol was more efficiently incorporated into PC1 than TAG initially but was mostly found in TAG at later time of labeling, and diacylglycerol and PC1 shared a similar incorporation pattern. These results indicate that VLCPUFAs in TAG are mainly channeled from PC likely through diacylglycerol as the intermediate.
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Affiliation(s)
| | - Xiao Qiu
- Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada
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Dellero Y, Cagnac O, Rose S, Seddiki K, Cussac M, Morabito C, Lupette J, Aiese Cigliano R, Sanseverino W, Kuntz M, Jouhet J, Maréchal E, Rébeillé F, Amato A. Proposal of a new thraustochytrid genus Hondaea gen. nov. and comparison of its lipid dynamics with the closely related pseudo-cryptic genus Aurantiochytrium. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.08.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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