101
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Wang H, Zhang Y, Zhou W, Noppol L, Liu T. Mechanism and enhancement of lipid accumulation in filamentous oleaginous microalgae Tribonema minus under heterotrophic condition. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:328. [PMID: 30559837 PMCID: PMC6290495 DOI: 10.1186/s13068-018-1329-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 12/03/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The filamentous microalgae Tribonema minus accumulates large amounts of lipids under photoautotrophic condition, while under heterotrophic condition, the lipid content decreased dramatically. Determination of the differences in metabolic pathways between photoautotrophic and heterotrophic growth will provide targets and strategies for improvement of lipid accumulation in heterotrophic cells. METHODS The metabolic differences between photoautotrophically and heterotrophically cultivated T. minus cells were studied by comparing the growth, biochemical compositions and transcriptomic and metabolomic profiles of the cells. Based on comparative transcriptomic and metabolomic studies, we generated a global model of the changes in central carbon metabolism and lipid biosynthetic pathways that occur under photoautotrophic and heterotrophic growth conditions. Moreover, the specific effects of supplementation with exogenous key metabolic intermediates on the lipid accumulation in heterotrophic culture were analyzed. RESULTS Compared to photoautotrophic cultures, heterotrophic cultures exhibited enhanced biomass levels and carbohydrate content, but decreased lipid accumulation. These effects were accompanied by low expression levels of genes involved in glycolysis, de novo fatty acids biosynthesis and lipid biosynthesis, and high levels of genes involved in gluconeogenesis. In addition, the levels of key metabolites involved in glycolysis/gluconeogenesis were elevated in abundance, whereas those of certain fatty acids and citric acid were decreased in heterotrophic cultures. Upon supplementation with exogenous potassium palmitate, the lipid content increased dramatically in heterotrophically cultivated T. minus. CONCLUSION An insufficient supply of carbon precursors caused the low levels of lipid accumulation during heterotrophic cultivation. Appropriate carbon metabolite supplementation based on the metabolomic data was shown to promote lipid accumulation. Moreover, gene regulatory metabolic targets were also identified via omics analysis.
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Affiliation(s)
- Hui Wang
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong People’s Republic of China
| | - Yan Zhang
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong People’s Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049 People’s Republic of China
| | - Wenjun Zhou
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong People’s Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049 People’s Republic of China
| | - Leksawasdi Noppol
- Bioprocess Research Cluster, School of Agro-Industry, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Tianzhong Liu
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong People’s Republic of China
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102
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Adelfi MG, Vitale RM, d'Ippolito G, Nuzzo G, Gallo C, Amodeo P, Manzo E, Pagano D, Landi S, Picariello G, Ferrante MI, Fontana A. Patatin-like lipolytic acyl hydrolases and galactolipid metabolism in marine diatoms of the genus Pseudo-nitzschia. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:181-190. [PMID: 30521937 DOI: 10.1016/j.bbalip.2018.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 08/18/2018] [Accepted: 11/28/2018] [Indexed: 02/07/2023]
Abstract
Diatoms are eukaryotic microalgae that play a pivotal role in biological and geochemical marine cycles. These microorganisms are at the basis of the trophic chain and their lipids are essential components (e.g. eicosapentaenoic acid, EPA) of aquatic food webs. Galactolipids are the primary lipid components of plastid membranes and form the largest lipid family of diatoms. As source of polyunsaturated fatty acids (PUFAs), these compounds are also involved in the synthesis of lipoxygenase (LOX) products such as non-volatile oxylipins and polyunsaturated aldehydes. Here, we report the first identification of two genes, namely PmLAH1 and PaLAH1, coding for lipolytic enzymes in two diatoms of the genus Pseudo-nitzschia. Functional and modeling studies evidence a patatin-like domain endowed with galactolipase and phospholipase activity at the C-terminus of both proteins. Homologues of Pseudo-nitzschia LAH1 genes were retrieved in other diatom species so far sequenced in agreement with conservation of the functional role of these proteins within the lineage.
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Affiliation(s)
- Maria Grazia Adelfi
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy; Stazione Zoologica Anton Dohrn, Villa Comunale 1, 80121 Naples, Italy
| | - Rosa Maria Vitale
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Giuliana d'Ippolito
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Genoveffa Nuzzo
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Carmela Gallo
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Pietro Amodeo
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Emiliano Manzo
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Dario Pagano
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Simone Landi
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Gianluca Picariello
- CNR-Istituto di Scienze dell'Alimentazione, Via Roma, 52, 83100 Avellino, Italy
| | | | - Angelo Fontana
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy.
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103
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Ma Y, Balamurugan S, Yuan W, Yang F, Tang C, Hu H, Zhang H, Shu X, Li M, Huang S, Li H, Wu L. Quercetin potentiates the concurrent hyper-accumulation of cellular biomass and lipids in Chlorella vulgaris. BIORESOURCE TECHNOLOGY 2018; 269:434-442. [PMID: 30093226 DOI: 10.1016/j.biortech.2018.07.151] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Revised: 07/28/2018] [Accepted: 07/30/2018] [Indexed: 06/08/2023]
Abstract
Provision of chemical modulators has emerged as an effective strategy to govern cell growth and development. Here, the impact of flavonoid quercetin on algal growth, lipid accumulation and transcriptional patterns was investigated in the green microalga Chlorella vulgaris. These results demonstrated that quercetin (15 μg/l) significantly enhanced the cellular biomass and photosynthetic efficiency, with up to 2.5-fold in the biomass in the stationary phase. Lipidomic analyses revealed that lipid content was increased by 1.8-fold. Furthermore, the functional mechanism of quercetin on the molecular level was dissected by transcriptomic analysis. Results revealed that quercetin upregulated the expression pattern of key genes involved in cellular signaling mechanisms such as phosphatidylinositol 4-kinase α, thus consequently enhanced cell growth. Altogether, the data present in this study demonstrate the dramatic role of quercetin on enhancing microalgal biomass and lipid accumulation by unprecedented regulation, of key metabolic nodes, for the first time and provide a novel insight into microalgal metabolism and regulation.
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Affiliation(s)
- Yuhan Ma
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Srinivasan Balamurugan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, Guangdong 510632, China
| | - Wasiqi Yuan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, Guangdong 510632, China
| | - Fan Yang
- School of Forestry and Landscape Architecture, Anhui Agriculture University, Hefei, Anhui 230031, China
| | - Caiguo Tang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Hao Hu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Huilan Zhang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Xian Shu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Minghao Li
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Shengwei Huang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China
| | - Hongye Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, Guangdong 510632, China
| | - Lifang Wu
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, 350 Shushanhu Road, Hefei, Anhui 230031, China.
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104
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Zuo Z, Ni B, Yang L. Production of primary metabolites in Microcystis aeruginosa in regulation of nitrogen limitation. BIORESOURCE TECHNOLOGY 2018; 270:588-595. [PMID: 30266031 DOI: 10.1016/j.biortech.2018.09.079] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 09/14/2018] [Accepted: 09/15/2018] [Indexed: 06/08/2023]
Abstract
The aim of this work was to study the regulatory effect of nitrogen (N) deficiency on primary metabolites in Microcystis aeruginosa, and promote the utilization of the alga. Low-N and Non-N conditions, especially Non-N, reduced the cell growth and photosynthetic abilities compared to Normal-N, as N deficiency triggered the down-regulation of genes involving in the photosynthetic process. Non-N not changed lipid content, due to no up-regulation of genes that promoted lipid synthesis. Soluble protein content significantly decreased under Non-N, which may result from the declined expression of genes relating to amino acid and histidyl-transfer RNA synthesis. Soluble and insoluble carbohydrate content significantly increased under Non-N, as the expression variation of genes blocked sugar degradation and promoted lipopolysaccharide synthesis. Therefore, M. aeruginosa can be used as the feedstock to produce carbohydrates under N deficiency for bioethanol production, and the remainder lipids after carbohydrate extraction can be used to produce biodiesel.
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Affiliation(s)
- Zhaojiang Zuo
- School of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou 311300, China.
| | - Binbin Ni
- School of Forestry and Biotechnology, Zhejiang A & F University, Hangzhou 311300, China
| | - Lin Yang
- Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, Tianjin, 300387, China
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105
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Xue J, Chen TT, Zheng JW, Balamurugan S, Cai JX, Liu YH, Yang WD, Liu JS, Li HY. The role of diatom glucose-6-phosphate dehydrogenase on lipogenic NADPH supply in green microalgae through plastidial oxidative pentose phosphate pathway. Appl Microbiol Biotechnol 2018; 102:10803-10815. [PMID: 30349933 DOI: 10.1007/s00253-018-9415-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 08/23/2018] [Accepted: 09/20/2018] [Indexed: 11/27/2022]
Abstract
Commercial production of biofuel from oleaginous microalgae is often impeded by their slow growth rate than other fast-growing algal species. A promising strategy is to genetically engineer the fast-growing algae to accumulate lipids by expressing key lipogenic genes from oleaginous microalgae. However, lacking of strong expression cassette to transform most of the algal species and potential metabolic target to engineer lipid metabolism has hindered its biotechnological applications. In this study, we engineered the oxidative pentose phosphate pathway (PPP) of green microalga Chlorella pyrenoidosa for lipid enhancement by expressing a glucose-6-phosphate dehydrogenase (G6PD) from oleaginous diatom Phaeodactylum tricornutum. Molecular characterization of transformed lines revealed that heterologous PtG6PD was transcribed and expressed successfully. Interestingly, subcellular localization analyses revealed that PtG6PD was targeted to chloroplasts of C. pyrenoidosa. PtG6PD expression remarkably elevated NADPH content and consequently enhanced the lipid content without affecting growth rate. Collectively, this report represents a promising candidate to engineer lipid biosynthesis in heterologous hosts with notable commercial significance, and it highlights the potential role of plastidial PPP in supplying lipogenic NADPH in microalgae.
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Affiliation(s)
- Jiao Xue
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Ting-Ting Chen
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Jian-Wei Zheng
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Srinivasan Balamurugan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Jia-Xi Cai
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Yu-Hong Liu
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Wei-Dong Yang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Jie-Sheng Liu
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Hong-Ye Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.
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106
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Li DW, Xie WH, Hao TB, Cai JX, Zhou TB, Balamurugan S, Yang WD, Liu JS, Li HY. Constitutive and Chloroplast Targeted Expression of Acetyl-CoA Carboxylase in Oleaginous Microalgae Elevates Fatty Acid Biosynthesis. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2018; 20:566-572. [PMID: 29931608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Accepted: 06/11/2018] [Indexed: 06/08/2023]
Abstract
Photosynthetic microalgae are of burgeoning interest in the generation of commercial bioproducts. Microalgae accumulate high lipid content under adverse conditions, which in turn compromise their growth and hinder their commercial potential. Hence, it is necessary to engineer microalgae to mitigate elevated lipid accumulation and biomass. In this study, we identified acetyl-CoA carboxylase (ACCase) in oleaginous microalga Phaeodactylum tricornutum (PtACC2) and expressed constitutively in the chloroplast to demonstrate the potential of chloroplast engineering. Molecular characterization of transplastomic microalgae revealed that PtACC2 was integrated, transcribed and expressed successfully, and localized in the chloroplast. Enzymatic activity of ACCase was elevated by 3.3-fold, and the relative neutral lipid content increased substantially by 1.77-fold, and lipid content reached up to 40.8% of dry weight. Accordingly, the number and size of oil bodies markedly increased. Fatty acid profiling showed that the content of monounsaturated fatty acids increased, while polyunsaturated fatty acids decreased. This method provides a valuable genetic engineering toolbox for microalgal bioreactors with industrial significance.
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Affiliation(s)
- Da-Wei Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, 510632, China
| | - Wei-Hong Xie
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, 510632, China
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Ting-Bin Hao
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, 510632, China
| | - Jia-Xi Cai
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, 510632, China
| | - Tian-Bao Zhou
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, 510632, China
| | - Srinivasan Balamurugan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, 510632, China
| | - Wei-Dong Yang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, 510632, China
| | - Jie-Sheng Liu
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, 510632, China
| | - Hong-Ye Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science, Jinan University, Guangzhou, 510632, China.
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107
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Rohit MV, Venkata Mohan S. Quantum Yield and Fatty Acid Profile Variations With Nutritional Mode During Microalgae Cultivation. Front Bioeng Biotechnol 2018; 6:111. [PMID: 30320078 PMCID: PMC6167444 DOI: 10.3389/fbioe.2018.00111] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 07/17/2018] [Indexed: 11/13/2022] Open
Abstract
Microalgae are gaining commercial interests in the areas food, feed and biofuel sector. They have intrinsic ability to harness energy from sunlight and photosynthetically valorize CO2 into various bio-based products viz., triacylglycerols (TAGs), mono/poly-unsaturated fatty acids (MUFA, PUFA), pigments etc. Microalgae have adapted to grow in various nutritional environments due to their metabolic versatility and resilience. Strategic evaluation of newly isolated strain Chlorella sp. from a residential lake was performed. The strain was investigated by varying the nutritional modes to gain insights into biomass and fatty acids production. Maximum biomass (3.59 g/L) was observed in mixotrophic condition followed by heterotrophic (1.58 g/L) and autotrophic condition (0.59 g/L). The maximum lipid yield (670 mg/g DCW) was observed in mixotrophic condition whereas maximum total lipid content (36%) was observed in heterotrophic condition. Significant correlation was noticed between fluorescence parameters measured by OJIP and non-photochemical quenching (NPQ) with the function of nutritional mode variations. Autotrophic condition showed higher photosynthetic activity which was well correlated with high fluorescence intensity as represented by OJIP, NPQ1, and NPQ2 curves. Good balance of saturated fatty acids (SFA) and unsaturated fatty acids was observed in autotrophic mode, whereas polyunsaturated fatty acids (PUFA) and mono unsaturated fatty acid (MUFA) content were relatively higher in mixotrophic and heterotrophic conditions.
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Affiliation(s)
- M. V. Rohit
- Bioengineering and Environmental Sciences Lab, EEFF Centre, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, India
- Academy for Scientific and Industrial Research (AcSIR), Ghaziabad, India
| | - S. Venkata Mohan
- Bioengineering and Environmental Sciences Lab, EEFF Centre, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad, India
- Academy for Scientific and Industrial Research (AcSIR), Ghaziabad, India
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108
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Ovide C, Kiefer-Meyer MC, Bérard C, Vergne N, Lecroq T, Plasson C, Burel C, Bernard S, Driouich A, Lerouge P, Tournier I, Dauchel H, Bardor M. Comparative in depth RNA sequencing of P. tricornutum's morphotypes reveals specific features of the oval morphotype. Sci Rep 2018; 8:14340. [PMID: 30254372 PMCID: PMC6156597 DOI: 10.1038/s41598-018-32519-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 08/21/2018] [Indexed: 11/09/2022] Open
Abstract
Phaeodactylum tricornutum is the most studied diatom encountered principally in coastal unstable environments. It has been hypothesized that the great adaptability of P. tricornutum is probably due to its pleomorphism. Indeed, P. tricornutum is an atypical diatom since it can display three morphotypes: fusiform, triradiate and oval. Currently, little information is available regarding the physiological significance of this morphogenesis. In this study, we adapted P. tricornutum Pt3 strain to obtain algal culture particularly enriched in one dominant morphotype: fusiform, triradiate or oval. These cultures were used to run high-throughput RNA-Sequencing. The whole mRNA transcriptome of each morphotype was determined. Pairwise comparisons highlighted biological processes and molecular functions which are up- and down-regulated. Finally, intersection analysis allowed us to identify the specific features from the oval morphotype which is of particular interest as it is often described to be more resistant to stresses. This study represent the first transcriptome wide characterization of the three morphotypes from P. tricornutum performed on cultures specifically enriched issued from the same Pt3 strain. This work represents an important step for the understanding of the morphogenesis in P. tricornutum and highlights the particular features of the oval morphotype.
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Affiliation(s)
- Clément Ovide
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | | | - Caroline Bérard
- Normandie Univ, UNIROUEN, LITIS EA 4108, 76000, Rouen, France
| | - Nicolas Vergne
- Normandie Univ, UNIROUEN, LMRS UMR 6085 CNRS, 76000, Rouen, France
| | - Thierry Lecroq
- Normandie Univ, UNIROUEN, LITIS EA 4108, 76000, Rouen, France
| | - Carole Plasson
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | - Carole Burel
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | - Sophie Bernard
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Plate-forme PRIMACEN, 76000, Rouen, France
| | - Azeddine Driouich
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France.,Normandie Univ, UNIROUEN, Plate-forme PRIMACEN, 76000, Rouen, France
| | - Patrice Lerouge
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France
| | - Isabelle Tournier
- Normandie Univ, UNIROUEN, Inserm U1079, IRIB Genomic Facility, 76000, Rouen, France
| | - Hélène Dauchel
- Normandie Univ, UNIROUEN, LITIS EA 4108, 76000, Rouen, France.
| | - Muriel Bardor
- Normandie Univ, UNIROUEN, Laboratoire Glyco-MEV EA4358, 76000, Rouen, France. .,Institut Universitaire de France (IUF), Paris, France.
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109
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Wang Y, Feng Y, Liu X, Zhong M, Chen W, Wang F, Du H. Response of Gracilaria lemaneiformis to nitrogen deprivation. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.07.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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110
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Maruyama Y, Toya Y, Kurokawa H, Fukano Y, Sato A, Umemura H, Yamada K, Iwasaki H, Tobori N, Shimizu H. Characterization of oil-producing yeast Lipomyces starkeyi on glycerol carbon source based on metabolomics and 13C-labeling. Appl Microbiol Biotechnol 2018; 102:8909-8920. [PMID: 30097695 DOI: 10.1007/s00253-018-9261-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 05/30/2018] [Accepted: 07/19/2018] [Indexed: 11/27/2022]
Abstract
Lipomyces starkeyi is an oil-producing yeast that can produce triacylglycerol (TAG) from glycerol as a carbon source. The TAG was mainly produced after nitrogen depletion alongside reduced cell proliferation. To obtain clues for enhancing the TAG production, cell metabolism during the TAG-producing phase was characterized by metabolomics with 13C labeling. The turnover analysis showed that the time constants of intermediates from glycerol to pyruvate (Pyr) were large, whereas those of tricarboxylic acid (TCA) cycle intermediates were much smaller than that of Pyr. Surprisingly, the time constants of intermediates in gluconeogenesis and the pentose phosphate (PP) pathway were large, suggesting that a large amount of the uptaken glycerol was metabolized via the PP pathway. To synthesize fatty acids that make up TAG from acetyl-CoA (AcCoA), 14 molecules of nicotinamide adenine dinucleotide phosphate (NADPH) per C16 fatty acid molecule are required. Because the oxidative PP pathway generates NADPH, this pathway would contribute to supply NADPH for fatty acid synthesis. To confirm that the oxidative PP pathway can supply the NADPH required for TAG production, flux analysis was conducted based on the measured specific rates and mass balances. Flux analysis revealed that the NADPH necessary for TAG production was supplied by metabolizing 48.2% of the uptaken glycerol through gluconeogenesis and the PP pathway. This result was consistent with the result of the 13C-labeling experiment. Furthermore, comparison of the actual flux distribution with the ideal flux distribution for TAG production suggested that it is necessary to flow more dihydroxyacetonephosphate (DHAP) through gluconeogenesis to improve TAG yield.
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Affiliation(s)
- Yuki Maruyama
- Analytical Technology Research Center, Research and Development Headquarters, Lion Corporation, 7-2-1 Hirai, Edogawa-ku, Tokyo, 132-0035, Japan.
| | - Yoshihiro Toya
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Hiroshi Kurokawa
- Functional Materials Science Research Laboratories, Research and Development Headquarters, Lion Corporation, 7-2-1 Hirai, Edogawa-ku, Tokyo, 132-0035, Japan
| | - Yuka Fukano
- Functional Materials Science Research Laboratories, Research and Development Headquarters, Lion Corporation, 7-2-1 Hirai, Edogawa-ku, Tokyo, 132-0035, Japan
| | - Atsushi Sato
- Analytical Technology Research Center, Research and Development Headquarters, Lion Corporation, 7-2-1 Hirai, Edogawa-ku, Tokyo, 132-0035, Japan
| | - Hiroyasu Umemura
- Analytical Technology Research Center, Research and Development Headquarters, Lion Corporation, 7-2-1 Hirai, Edogawa-ku, Tokyo, 132-0035, Japan
| | - Kaoru Yamada
- Analytical Technology Research Center, Research and Development Headquarters, Lion Corporation, 7-2-1 Hirai, Edogawa-ku, Tokyo, 132-0035, Japan
| | - Hideaki Iwasaki
- Analytical Technology Research Center, Research and Development Headquarters, Lion Corporation, 7-2-1 Hirai, Edogawa-ku, Tokyo, 132-0035, Japan
| | - Norio Tobori
- Functional Materials Science Research Laboratories, Research and Development Headquarters, Lion Corporation, 7-2-1 Hirai, Edogawa-ku, Tokyo, 132-0035, Japan
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
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111
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Ewe D, Tachibana M, Kikutani S, Gruber A, Río Bártulos C, Konert G, Kaplan A, Matsuda Y, Kroth PG. The intracellular distribution of inorganic carbon fixing enzymes does not support the presence of a C4 pathway in the diatom Phaeodactylum tricornutum. PHOTOSYNTHESIS RESEARCH 2018; 137:263-280. [PMID: 29572588 DOI: 10.1007/s11120-018-0500-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 03/18/2018] [Indexed: 05/20/2023]
Abstract
Diatoms are unicellular algae and important primary producers. The process of carbon fixation in diatoms is very efficient even though the availability of dissolved CO2 in sea water is very low. The operation of a carbon concentrating mechanism (CCM) also makes the more abundant bicarbonate accessible for photosynthetic carbon fixation. Diatoms possess carbonic anhydrases as well as metabolic enzymes potentially involved in C4 pathways; however, the question as to whether a C4 pathway plays a general role in diatoms is not yet solved. While genome analyses indicate that the diatom Phaeodactylum tricornutum possesses all the enzymes required to operate a C4 pathway, silencing of the pyruvate orthophosphate dikinase (PPDK) in a genetically transformed cell line does not lead to reduced photosynthetic carbon fixation. In this study, we have determined the intracellular location of all enzymes potentially involved in C4-like carbon fixing pathways in P. tricornutum by expression of the respective proteins fused to green fluorescent protein (GFP), followed by fluorescence microscopy. Furthermore, we compared the results to known pathways and locations of enzymes in higher plants performing C3 or C4 photosynthesis. This approach revealed that the intracellular distribution of the investigated enzymes is quite different from the one observed in higher plants. In particular, the apparent lack of a plastidic decarboxylase in P. tricornutum indicates that this diatom does not perform a C4-like CCM.
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Affiliation(s)
- Daniela Ewe
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany.
- Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czech Republic.
| | - Masaaki Tachibana
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, 669-1337, Japan
- Lion Corporation Pharmaceutical Laboratories No.1, Odawara, Kanagawa, 256-0811, Japan
| | - Sae Kikutani
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, 669-1337, Japan
- Tech Manage Corp., Tokyo, 160-0023, Japan
| | - Ansgar Gruber
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany
- Biology Centre, Institute of Parasitology, Czech Academy of Sciences, České Budějovice, Czech Republic
| | | | - Grzegorz Konert
- Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czech Republic
| | - Aaron Kaplan
- Department of Plant and Environmental Sciences, Edmond J. Safra Campus-Givat Ram, Hebrew University of Jerusalem, 91904, Jerusalem, Israel
| | - Yusuke Matsuda
- Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, 669-1337, Japan
| | - Peter G Kroth
- Fachbereich Biologie, Universität Konstanz, 78457, Konstanz, Germany
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112
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Ryu KH, Sung M, Kim B, Heo S, Chang YK, Lee JH. A mathematical model of intracellular behavior of microalgae for predicting growth and intracellular components syntheses under nutrient‐replete and ‐deplete conditions. Biotechnol Bioeng 2018; 115:2441-2455. [DOI: 10.1002/bit.26744] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 05/13/2018] [Accepted: 06/05/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Kyung Hwan Ryu
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Min‐Gyu Sung
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Boeun Kim
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Seongmin Heo
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
- Advanced Biomass R&D Center, Korea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Jay H. Lee
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
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113
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Systems-level analysis of metabolic mechanism following nitrogen limitation in benthic dinoflagellate Prorocentrum lima. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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114
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Zhu J, Yu Z, He L, Cao X, Liu S, Song X. Molecular Mechanism of Modified Clay Controlling the Brown Tide Organism Aureococcus anophagefferens Revealed by Transcriptome Analysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:7006-7014. [PMID: 29768919 DOI: 10.1021/acs.est.7b05172] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The data and experiences in mitigating harmful algal blooms (HABs) by modified clay (MC) show that a bloom does not continue after the dispersal of the MC, even though the density of the residual cells in the water is still high, at 20-30% of the initial cell density. This interesting phenomenon indicates that in addition to flocculation, MC has an additional control mechanism. Here, transcriptome sequencing technology was used to study the molecular mechanism of MC in controlling HABs. In residual cells treated with MC, the photosynthetic light reaction was the most affected physiological process. Some genes related to the light harvesting complex, photosystem (PS) I and PS II, were significantly up-regulated ( p < 0.05), and several transcripts increased by as much as 6-fold. In contrast, genes associated with the dark reaction did not significantly change. In addition to genes associated with photosynthesis, numerous genes related to energy metabolism, stress adaptation, cytoskeletal functioning, and cell division also responded to MC treatment. These results indicated that following treatment with MC, the normal physiological processes of algal cells were disrupted, which inhibited cell proliferation and growth. Thus, these findings provide scientific proof that HABs are controlled by MC.
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Affiliation(s)
- Jianan Zhu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology , Chinese Academy of Sciences , Qingdao 266071 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Zhiming Yu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology , Chinese Academy of Sciences , Qingdao 266071 , China
- Functional Laboratory of Marine Ecology and Environmental Science , Qingdao National Laboratory for Marine Science and Technology , Qingdao 266237 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Liyan He
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology , Chinese Academy of Sciences , Qingdao 266071 , China
- Functional Laboratory of Marine Ecology and Environmental Science , Qingdao National Laboratory for Marine Science and Technology , Qingdao 266237 , China
| | - Xihua Cao
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology , Chinese Academy of Sciences , Qingdao 266071 , China
- Functional Laboratory of Marine Ecology and Environmental Science , Qingdao National Laboratory for Marine Science and Technology , Qingdao 266237 , China
| | - Shuya Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology , Chinese Academy of Sciences , Qingdao 266071 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
| | - Xiuxian Song
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology , Chinese Academy of Sciences , Qingdao 266071 , China
- Functional Laboratory of Marine Ecology and Environmental Science , Qingdao National Laboratory for Marine Science and Technology , Qingdao 266237 , China
- University of Chinese Academy of Sciences , Beijing 100049 , China
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115
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Abbriano R, Vardar N, Yee D, Hildebrand M. Manipulation of a glycolytic regulator alters growth and carbon partitioning in the marine diatom Thalassiosira pseudonana. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.03.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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116
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Arora N, Pienkos PT, Pruthi V, Poluri KM, Guarnieri MT. Leveraging algal omics to reveal potential targets for augmenting TAG accumulation. Biotechnol Adv 2018; 36:1274-1292. [PMID: 29678388 DOI: 10.1016/j.biotechadv.2018.04.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 04/11/2018] [Accepted: 04/15/2018] [Indexed: 02/08/2023]
Abstract
Ongoing global efforts to commercialize microalgal biofuels have expedited the use of multi-omics techniques to gain insights into lipid biosynthetic pathways. Functional genomics analyses have recently been employed to complement existing sequence-level omics studies, shedding light on the dynamics of lipid synthesis and its interplay with other cellular metabolic pathways, thus revealing possible targets for metabolic engineering. Here, we review the current status of algal omics studies to reveal potential targets to augment TAG accumulation in various microalgae. This review specifically aims to examine and catalog systems level data related to stress-induced TAG accumulation in oleaginous microalgae and inform future metabolic engineering strategies to develop strains with enhanced bioproductivity, which could pave a path for sustainable green energy.
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Affiliation(s)
- Neha Arora
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand 247667, India
| | - Philip T Pienkos
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Vikas Pruthi
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand 247667, India
| | - Krishna Mohan Poluri
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand 247667, India
| | - Michael T Guarnieri
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.
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117
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Maeda Y, Nojima D, Yoshino T, Tanaka T. Structure and properties of oil bodies in diatoms. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0408. [PMID: 28717018 DOI: 10.1098/rstb.2016.0408] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2017] [Indexed: 01/23/2023] Open
Abstract
Diatoms accumulate triacylglycerols in spherical organelles called oil bodies when exposed to nutrient deprivation conditions. Oil body biology in diatoms has attracted significant attention due to the complexity of the intracellular organelles and the unique combination of genes generated by the evolutionary history of secondary endosymbiosis. The demand for biofuel production has further increased the interest in and importance of a better understanding of oil body biology in diatoms, because it could provide targets for genetic engineering to further enhance their promising lipid accumulation. This review describes recent progress in studies of the structure and properties of diatom oil bodies. Firstly, the general features of diatom oil bodies are described, in particular, their number, size and morphology, as well as the quantity and quality of lipids they contain. Subsequently, the diatom oil body-associated proteins, which were recently discovered through oil body proteomics, are introduced. Then, the metabolic pathways responsible for the biogenesis and degradation of diatom oil bodies are summarized. During biogenesis and degradation, oil bodies interact with other organelles, including chloroplasts, the endoplasmic reticulum and mitochondria, suggesting their dynamic nature in response to environmental changes. Finally, the functions of oil bodies in diatoms are discussed.This article is part of the themed issue 'The peculiar carbon metabolism in diatoms'.
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Affiliation(s)
- Yoshiaki Maeda
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Daisuke Nojima
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Tomoko Yoshino
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
| | - Tsuyoshi Tanaka
- Division of Biotechnology and Life Science, Institute of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan
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118
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Zou LG, Chen JW, Zheng DL, Balamurugan S, Li DW, Yang WD, Liu JS, Li HY. High-efficiency promoter-driven coordinated regulation of multiple metabolic nodes elevates lipid accumulation in the model microalga Phaeodactylum tricornutum. Microb Cell Fact 2018; 17:54. [PMID: 29618383 PMCID: PMC5885374 DOI: 10.1186/s12934-018-0906-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Accepted: 03/31/2018] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Microalgal metabolic engineering holds great promise for the overproduction of a wide range of commercial bioproducts. It demands simultaneous manipulation of multiple metabolic nodes. However, high-efficiency promoters have been lacking. RESULTS Here we report a strong constitutive promoter Pt211 in expressing multiple target genes in oleaginous microalga Phaeodactylum tricornutum. Pt211 was revealed to contain significant cis-acting elements. GUS reporter and principal genes glycerol-3-phosphate acyltransferase (GPAT) and diacylglycerol acyltransferase 2 (DGAT2) involved in triacylglycerol biosynthesis were tested under driven of Pt211 in P. tricornutum. GUS staining and qPCR analysis showed strong GUS expression. DGAT2 and GPAT linked with a designed 2A sequence exhibited higher transcript abundances than WT, while algal growth and photosynthesis were not impaired. CONCLUSION The total lipid content increased notably by 2.6-fold compared to WT and reached up to 57.5% (dry cell weight). Overall, our findings report a strong promoter and a strategy for coordinated manipulation of complex metabolic pathways.
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Affiliation(s)
- Li-Gong Zou
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Jia-Wen Chen
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Dan-Lin Zheng
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Srinivasan Balamurugan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Da-Wei Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Wei-Dong Yang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Jie-Sheng Liu
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Hong-Ye Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.
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119
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Brembu T, Mühlroth A, Alipanah L, Bones AM. The effects of phosphorus limitation on carbon metabolism in diatoms. Philos Trans R Soc Lond B Biol Sci 2018; 372:rstb.2016.0406. [PMID: 28717016 PMCID: PMC5516115 DOI: 10.1098/rstb.2016.0406] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2017] [Indexed: 01/26/2023] Open
Abstract
Phosphorus is an essential element for life, serving as an integral component of nucleic acids, lipids and a diverse range of other metabolites. Concentrations of bioavailable phosphorus are low in many aquatic environments. Microalgae, including diatoms, apply physiological and molecular strategies such as phosphorus scavenging or recycling as well as adjusting cell growth in order to adapt to limiting phosphorus concentrations. Such strategies also involve adjustments of the carbon metabolism. Here, we review the effect of phosphorus limitation on carbon metabolism in diatoms. Two transcriptome studies are analysed in detail, supplemented by other transcriptome, proteome and metabolite data, to gain an overview of different pathways and their responses. Phosphorus, nitrogen and silicon limitation responses are compared, and similarities and differences discussed. We use the current knowledge to propose a suggestive model for the carbon flow in phosphorus-replete and phosphorus-limited diatom cells. This article is part of the themed issue ‘The peculiar carbon metabolism in diatoms’.
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Affiliation(s)
- Tore Brembu
- Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Alice Mühlroth
- Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Leila Alipanah
- Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Atle M Bones
- Department of Biology, Norwegian University of Science and Technology, 7491 Trondheim, Norway
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120
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Wang X, Wei W, Li NJ, Yuan W, Ding Y, Yang WD, Liu JS, Balamurugan S, Li HY. Heterogeneous expression of human PNPLA3 triggers algal lipid accumulation and lipid droplet enlargement. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.02.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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121
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Zulu NN, Zienkiewicz K, Vollheyde K, Feussner I. Current trends to comprehend lipid metabolism in diatoms. Prog Lipid Res 2018. [DOI: 10.1016/j.plipres.2018.03.001] [Citation(s) in RCA: 104] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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122
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Sirikhachornkit A, Suttangkakul A, Vuttipongchaikij S, Juntawong P. De novo transcriptome analysis and gene expression profiling of an oleaginous microalga Scenedesmus acutus TISTR8540 during nitrogen deprivation-induced lipid accumulation. Sci Rep 2018; 8:3668. [PMID: 29487383 PMCID: PMC5829077 DOI: 10.1038/s41598-018-22080-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 02/16/2018] [Indexed: 11/30/2022] Open
Abstract
Nitrogen deprivation (-N) has been used as a technique to promote lipid accumulation in various microalgae. Scenedesmus acutus is a promising oleaginous green microalga that can be cultivated in organic wastewater for biodiesel production. Nevertheless, the molecular mechanisms controlling S. acutus lipid accumulation in response to -N remain unidentified. Physiological study determined that -N reduced cell growth and photosynthetic pigments. On the other hand, it promoted carbohydrate and neutral lipid accumulation. To find the mechanisms underlying lipid accumulation, we performed de novo transcriptome profiling of the non-model S. acutus in response to -N. The transcriptome analysis revealed that glycolysis and starch degradation were up-regulated; on the contrary, gluconeogenesis, photosynthesis, triacylglycerol (TAG) degradation and starch synthesis were down-regulated by -N. Under -N, the carbon flux was shifted toward fatty acid and TAG synthesis, and the down regulation of TAG lipase genes may contribute to TAG accumulation. A comparative analysis of the -N transcriptomes of oleaginous microalgae identified that the down-regulation of multiple lipase genes was a specific mechanism found only in the -N transcriptome of S. acutus. Our study unraveled the mechanisms controlling -N-induced lipid accumulation in S. acutus, and provided new perspectives for the genetic manipulation of biodiesel-producing microalgae.
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Affiliation(s)
- Anchalee Sirikhachornkit
- Special Research Unit in Microalgal Molecular Genetics and Functional genomics, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Bangkok, Thailand
| | - Anongpat Suttangkakul
- Special Research Unit in Microalgal Molecular Genetics and Functional genomics, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Bangkok, Thailand
| | - Supachai Vuttipongchaikij
- Special Research Unit in Microalgal Molecular Genetics and Functional genomics, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Bangkok, Thailand
| | - Piyada Juntawong
- Special Research Unit in Microalgal Molecular Genetics and Functional genomics, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand.
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Bangkok, Thailand.
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Mao X, Wu T, Sun D, Zhang Z, Chen F. Differential responses of the green microalga Chlorella zofingiensis to the starvation of various nutrients for oil and astaxanthin production. BIORESOURCE TECHNOLOGY 2018; 249:791-798. [PMID: 29136934 DOI: 10.1016/j.biortech.2017.10.090] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/25/2017] [Accepted: 10/26/2017] [Indexed: 05/03/2023]
Abstract
Chlorella zofingiensis has been proposed as a potential producer of lipids and the high-value carotenoid astaxanthin. In this study, the responses of photoautotrophic C. zofingiensis with respect to growth, lipid profiles and astaxanthin accumulation were investigated upon the starvation of N (NS), P (PS) and S (SS). NS and SS stimulated triacylglycerol (TAG) accumulation, which reached 27% and 21% of dry weight (DW), respectively. Stresses also stimulated astaxanthin accumulation greatly, reaching 3.9 mg/g DW by NS. SS led to the highest TAG productivity (52.4 mg L-1 d-1) while NS gave rise to the highest astaxanthin productivity (0.624 mg L-1 d-1). In combination with transcriptional analysis, a working model for stress-associated TAG and astaxanthin biosynthesis was proposed. Taken together, these detailed data shed light on the elucidation of differential responses to nutrient stresses and may provide insights into future engineering of this promising alga for improving TAG and astaxanthin production.
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Affiliation(s)
- Xuemei Mao
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China; BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Tao Wu
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China; BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Dongzhe Sun
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China; BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Zhao Zhang
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China; BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China
| | - Feng Chen
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China; BIC-ESAT, College of Engineering, Peking University, Beijing 100871, China.
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Wang X, Dong HP, Wei W, Balamurugan S, Yang WD, Liu JS, Li HY. Dual expression of plastidial GPAT1 and LPAT1 regulates triacylglycerol production and the fatty acid profile in Phaeodactylum tricornutum. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:318. [PMID: 30479663 PMCID: PMC6249879 DOI: 10.1186/s13068-018-1317-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/13/2018] [Indexed: 05/03/2023]
Abstract
BACKGROUND Metabolic engineering has emerged as a potential strategy for improving microalgal lipid content through targeted changes to lipid metabolic networks. However, the intricate nature of lipogenesis has impeded metabolic engineering. Therefore, it is very important to identify the crucial metabolic nodes and develop strategies to exploit multiple genes for transgenesis. In an attempt to unravel the microalgal triacylglycerol (TAG) pathway, we overexpressed two key lipogenic genes, glycerol-3-phosphate acyltransferase (GPAT1) and lysophosphatidic acid acyltransferase (LPAT1), in oleaginous Phaeodactylum tricornutum and determined their roles in microalgal lipogenesis. RESULTS Engineered P. tricornutum strains showed enhanced growth and photosynthetic efficiency compared with that of the wild-type during the growth phase of the cultivation period. However, both the cell types reached stationary phase on day 7. Overexpression of GPAT1 and LPAT1 increased the TAG content by 2.3-fold under nitrogen-replete conditions without compromising cell growth, and they also orchestrated the expression of other key genes involved in TAG synthesis. The transgenic expression of GPAT1 and LPAT1 influenced the expression of malic enzyme and glucose 6-phosphate dehydrogenase, which enhanced the levels of lipogenic NADPH in the transgenic lines. In addition, GPAT1 and LPAT1 preferred C16 over C18 at the sn-2 position of the glycerol backbone. CONCLUSION Overexpression of GPAT1 together with LPAT1 significantly enhanced lipid content without affecting growth and photosynthetic efficiency, and they orchestrated the expression of other key photosynthetic and lipogenic genes. The lipid profile for elevated fatty acid content (C16-CoA) demonstrated the involvement of the prokaryotic TAG pathway in marine diatoms. The results suggested that engineering dual metabolic nodes should be possible in microalgal lipid metabolism. This study also provides the first demonstration of the role of the prokaryotic TAG biosynthetic pathway in lipid overproduction and indicates that the fatty acid profile can be tailored to improve lipid production.
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Affiliation(s)
- Xiang Wang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, 510632 China
| | - Hong-Po Dong
- School of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088 China
- State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai, 200062 China
| | - Wei Wei
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, 510632 China
| | - Srinivasan Balamurugan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, 510632 China
| | - Wei-Dong Yang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, 510632 China
| | - Jie-Sheng Liu
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, 510632 China
| | - Hong-Ye Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science, Jinan University, Guangzhou, 510632 China
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Wu G, Gao Z, Du H, Lin B, Yan Y, Li G, Guo Y, Fu S, Wei G, Wang M, Cui M, Meng C. The effects of abscisic acid, salicylic acid and jasmonic acid on lipid accumulation in two freshwater Chlorella strains. J GEN APPL MICROBIOL 2018; 64:42-49. [DOI: 10.2323/jgam.2017.06.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Guanxun Wu
- School of Life Sciences, Shandong University of Technology
| | - Zhengquan Gao
- School of Life Sciences, Shandong University of Technology
| | - Huanmin Du
- School of Life Sciences, Shandong University of Technology
| | - Bin Lin
- School of Life Sciences, Shandong University of Technology
| | - Yuchen Yan
- The Undergraduate Brigade, Second Military Medical University
| | - Guoqiang Li
- School of Life Sciences, Shandong University of Technology
| | - Yanyun Guo
- School of Life Sciences, Shandong University of Technology
| | - Shenggui Fu
- School of Sciences, Shandong University of Technology
| | - Gongxiang Wei
- School of Sciences, Shandong University of Technology
| | - Miaomiao Wang
- School of Life Sciences, Shandong University of Technology
| | - Meng Cui
- School of Life Sciences, Shandong University of Technology
| | - Chunxiao Meng
- School of Life Sciences, Shandong University of Technology
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126
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Zhu S, Feng P, Feng J, Xu J, Wang Z, Xu J, Yuan Z. The roles of starch and lipid in Chlorella sp. during cell recovery from nitrogen starvation. BIORESOURCE TECHNOLOGY 2018; 247:58-65. [PMID: 28946095 DOI: 10.1016/j.biortech.2017.08.120] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Revised: 08/17/2017] [Accepted: 08/18/2017] [Indexed: 06/07/2023]
Abstract
The influence of N-replenishment on cell growth, chlorophyll content, nitrogen uptake, and accumulation of starch and lipid was studied in Chlorella sp. N-starved algal cells were fully recovered within 2days after N-replenishment. Stored starch in N-deficient culture was degraded immediately during recovery process. However, lipid response had a period of delay when suffered from long starvation. During the recovery process, neutral lipid was reduced accompanied by an increase in membrane lipid. It was speculated that starch served as a source of carbon and energy catabolized to support quick recovery of the culture, while lipid preferred to play a structural role that specific fatty acid species were released from storage lipid and as building blocks for quick synthesis of membrane lipid. In light of rapid growth recovery and no net degradation in total fatty acids, a semi-continuous cultivation process might be a potential way to enhance lipid productivity.
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Affiliation(s)
- Shunni Zhu
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
| | - Pingzhong Feng
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
| | - Jia Feng
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
| | - Jin Xu
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
| | - Zhongming Wang
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
| | - Jingliang Xu
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China
| | - Zhenhong Yuan
- Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China; Key Laboratory of Renewable Energy, Chinese Academy of Sciences, Guangzhou 510640, China; Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China.
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127
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Mühlroth A, Winge P, El Assimi A, Jouhet J, Maréchal E, Hohmann-Marriott MF, Vadstein O, Bones AM. Mechanisms of Phosphorus Acquisition and Lipid Class Remodeling under P Limitation in a Marine Microalga. PLANT PHYSIOLOGY 2017; 175:1543-1559. [PMID: 29051196 PMCID: PMC5717724 DOI: 10.1104/pp.17.00621] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 10/17/2017] [Indexed: 05/03/2023]
Abstract
Molecular mechanisms of phosphorus (P) limitation are of great interest for understanding algal production in aquatic ecosystems. Previous studies point to P limitation-induced changes in lipid composition. As, in microalgae, the molecular mechanisms of this specific P stress adaptation remain unresolved, we reveal a detailed phospholipid-recycling scheme in Nannochloropsis oceanica and describe important P acquisition genes based on highly corresponding transcriptome and lipidome data. Initial responses to P limitation showed increased expression of genes involved in P uptake and an expansion of the P substrate spectrum based on purple acid phosphatases. Increase in P trafficking displayed a rearrangement between compartments by supplying P to the chloroplast and carbon to the cytosol for lipid synthesis. We propose a novel phospholipid-recycling scheme for algae that leads to the rapid reduction of phospholipids and synthesis of the P-free lipid classes. P mobilization through membrane lipid degradation is mediated mainly by two glycerophosphoryldiester phosphodiesterases and three patatin-like phospholipases A on the transcriptome level. To compensate for low phospholipids in exponential growth, N. oceanica synthesized sulfoquinovosyldiacylglycerol and diacylglyceroltrimethylhomoserine. In this study, it was shown that an N. oceanica strain has a unique repertoire of genes that facilitate P acquisition and the degradation of phospholipids compared with other stramenopiles. The novel phospholipid-recycling scheme opens new avenues for metabolic engineering of lipid composition in algae.
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Affiliation(s)
- Alice Mühlroth
- Department of Biology, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Per Winge
- Department of Biology, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Aimen El Assimi
- Department of Biology, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Institut National de la Recherche Agronomique, Université Grenoble Alpes, 38000 Grenoble, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire Végétale, Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Institut National de la Recherche Agronomique, Université Grenoble Alpes, 38000 Grenoble, France
| | - Martin F Hohmann-Marriott
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Olav Vadstein
- Department of Biotechnology and Food Science, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Atle M Bones
- Department of Biology, NTNU Norwegian University of Science and Technology, 7491 Trondheim, Norway
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128
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Sabu S, Singh ISB, Joseph V. Optimisation of critical medium components and culture conditions for enhanced biomass and lipid production in the oleaginous diatom Navicula phyllepta: a statistical approach. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:26763-26777. [PMID: 28963632 DOI: 10.1007/s11356-017-0274-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 09/19/2017] [Indexed: 06/07/2023]
Abstract
Diatoms hold great promise as potential sources of biofuel production. In the present study, the biomass and lipid production in the marine diatom Navicula phyllepta, isolated from Cochin estuary, India and identified as a potential biodiesel feedstock, were optimized using Plackett-Burman (PB) statistical experimental design followed by central composite design (CCD) and response surface methodology (RSM). The growth analyses of the isolate in different nitrogen sources, salinities and five different enriched sea water media showed the best growth in the cheapest medium with minimum components using urea as nitrogen source at salinity between 25 and 40 g kg-1. Plackett-Burman experimental analyses for screening urea, sodium metasilicate, sodium dihydrogen phosphate, ferric chloride, salinity, temperature, pH and agitation influencing lipid and biomass production showed that silicate and temperature had a positive coefficient on biomass production, and temperature had a significant positive coefficient, while urea and phosphate showed a negative coefficient on lipid content. A 24 factorial central composite design (FCCD) was used to optimize the concentration of the factors selected. The optimized media resulted in 1.62-fold increase (64%) in biomass (1.2 ± 0.08 g L-1) and 1.2-fold increase (22%) in estimated total lipid production (0.11 ± 0.003 g L-1) compared to original media within 12 days of culturing. A significantly higher biomass and lipid production in the optimized medium demands further development of a two-stage strategy of biomass production followed by induction of high lipid production under nutrient limitation or varying culture conditions for large-scale production of biodiesel from the marine diatom.
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Affiliation(s)
- Sanyo Sabu
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Kochi, Kerala, 682016, India
| | - Isaac Sarojini Bright Singh
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Kochi, Kerala, 682016, India
| | - Valsamma Joseph
- National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Kochi, Kerala, 682016, India.
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129
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Lim DKY, Schuhmann H, Thomas-Hall SR, Chan KCK, Wass TJ, Aguilera F, Adarme-Vega TC, Dal'Molin CGO, Thorpe GJ, Batley J, Edwards D, Schenk PM. RNA-Seq and metabolic flux analysis of Tetraselmis sp. M8 during nitrogen starvation reveals a two-stage lipid accumulation mechanism. BIORESOURCE TECHNOLOGY 2017; 244:1281-1293. [PMID: 28625352 DOI: 10.1016/j.biortech.2017.06.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 05/31/2017] [Accepted: 06/01/2017] [Indexed: 05/18/2023]
Abstract
To map out key lipid-related pathways that lead to rapid triacylglyceride accumulation in oleaginous microalgae, RNA-Seq was performed with Tetraselmis sp. M8 at 24h after exhaustion of exogenous nitrogen to reveal molecular changes during early stationary phase. Further gene expression profiling by quantitative real-time PCR at 16-72h revealed a distinct shift in expression of the fatty acid/triacylglyceride biosynthesis and β-oxidation pathways, when cells transitioned from log-phase into early-stationary and stationary phase. Metabolic reconstruction modeling combined with real-time PCR and RNA-Seq gene expression data indicates that the increased lipid accumulation is a result of a decrease in lipid catabolism during the early-stationary phase combined with increased metabolic fluxes in lipid biosynthesis during the stationary phase. During these two stages, Tetraselmis shifts from reduced lipid consumption to active lipid production. This process appears to be independent from DGAT expression, a key gene for lipid accumulation in microalgae.
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Affiliation(s)
- David K Y Lim
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia
| | - Holger Schuhmann
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia
| | - Skye R Thomas-Hall
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia
| | - Kenneth C K Chan
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia; School of Plant Biology, The University of Western Australia, Perth 6009, Australia
| | - Taylor J Wass
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia
| | - Felipe Aguilera
- School of Biological Sciences, The University of Queensland, Brisbane 4072, Australia
| | - T Catalina Adarme-Vega
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia
| | - Cristiana G O Dal'Molin
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane 4072, Australia
| | - Glen J Thorpe
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane 4072, Australia
| | - Jacqueline Batley
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia; School of Plant Biology, The University of Western Australia, Perth 6009, Australia
| | - David Edwards
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia; School of Plant Biology, The University of Western Australia, Perth 6009, Australia
| | - Peer M Schenk
- School of Agriculture and Food Sciences, The University of Queensland, Brisbane 4072, Australia.
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130
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Chen Z, Luo L, Chen R, Hu H, Pan Y, Jiang H, Wan X, Jin H, Gong Y. Acetylome Profiling Reveals Extensive Lysine Acetylation of the Fatty Acid Metabolism Pathway in the Diatom Phaeodactylum tricornutum. Mol Cell Proteomics 2017; 17:399-412. [PMID: 29093020 DOI: 10.1074/mcp.ra117.000339] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Indexed: 02/05/2023] Open
Abstract
Nε-lysine acetylation represents a highly dynamic and reversibly regulated post-translational modification widespread in almost all organisms, and plays important roles for regulation of protein function in diverse metabolic pathways. However, little is known about the role of lysine acetylation in photosynthetic eukaryotic microalgae. We integrated proteomic approaches to comprehensively characterize the lysine acetylome in the model diatom Phaeodactylum tricornutum In total, 2324 acetylation sites from 1220 acetylated proteins were identified, representing the largest data set of the lysine acetylome in plants to date. Almost all enzymes involved in fatty acid synthesis were found to be lysine acetylated. Six putative lysine acetylation sites were identified in a plastid-localized long-chain acyl-CoA synthetase. Site-directed mutagenesis and site-specific incorporation of N-acetyllysine in acyl-CoA synthetase show that acetylation at K407 and K425 increases its enzyme activity. Moreover, the nonenzymatically catalyzed overall hyperacetylation of acyl-CoA synthetase by acetyl-phosphate can be effectively deacetylated and reversed by a sirtuin-type NAD+-dependent deacetylase with subcellular localization of both the plastid and nucleus in Phaeodactylum This work indicates the regulation of acyl-CoA synthetase activity by site-specific lysine acetylation and highlights the potential regulation of fatty acid metabolism by lysine actetylation in the plastid of the diatom Phaeodactylum.
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Affiliation(s)
- Zhuo Chen
- From the ‡Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China.,§Key Laboratory of Plant Stress Research, College of Life Science, Shandong Normal University, Jinan 250014, Shandong, China
| | - Ling Luo
- From the ‡Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Runfa Chen
- From the ‡Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Hanhua Hu
- ¶Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yufang Pan
- ¶Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Haibo Jiang
- ‖School of Life Sciences and Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, China
| | - Xia Wan
- From the ‡Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Hu Jin
- ¶Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Yangmin Gong
- From the ‡Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China;
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131
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Wang X, Hao TB, Balamurugan S, Yang WD, Liu JS, Dong HP, Li HY. A lipid droplet-associated protein involved in lipid droplet biogenesis and triacylglycerol accumulation in the oleaginous microalga Phaeodactylum tricornutum. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.07.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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132
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Jian J, Zeng D, Wei W, Lin H, Li P, Liu W. The Combination of RNA and Protein Profiling Reveals the Response to Nitrogen Depletion in Thalassiosira pseudonana. Sci Rep 2017; 7:8989. [PMID: 28827639 PMCID: PMC5566445 DOI: 10.1038/s41598-017-09546-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 07/24/2017] [Indexed: 12/21/2022] Open
Abstract
Nitrogen (N) is essential for the growth of algae, and its concentration varies greatly in the ocean, which has been regarded as a limitation for phytoplankton growth. Despite its great importance, most of the existing studies on the mechanisms underlying the effects of N on diatoms have focused on physiology, biochemistry and a few target genes and have rarely involved whole genomic analyses. Therefore, in this study, we integrated physiological data with RNA and protein profiling data to reveal the response strategy of Thalassiosira pseudonana under N-depleted conditions. Physiological measurements indicated that the cell growth capacity and chlorophyll content of the cells decreased, as did the expression of photosynthesis- and chlorophyll biosynthesis-related genes or proteins. The RNA-Seq profile results showed that T. pseudonana responded to N deprivation through increases in glycolysis, the TCA cycle and N metabolism as well as down-regulation in the Calvin cycle, gluconeogenesis, pentose phosphate, oxidative phosphorylation and lipid synthesis. These results provide a basic understanding for further research addressing how N affects phytoplankton in terms of genomics.
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Affiliation(s)
- Jianbo Jian
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China
| | - Dezhi Zeng
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China
| | - Wei Wei
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China
| | - Hongmin Lin
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China
| | - Ping Li
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China.
| | - Wenhua Liu
- Marine Biology Institute, Shantou University, Shantou, Guangdong, 515063, P.R. China.
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133
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Hess SK, Lepetit B, Kroth PG, Mecking S. Production of chemicals from microalgae lipids - status and perspectives. EUR J LIPID SCI TECH 2017. [DOI: 10.1002/ejlt.201700152] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Sandra K. Hess
- Department of Chemistry; Chair of Chemical Materials Science; University of Konstanz; Konstanz Germany
| | - Bernard Lepetit
- Department of Biology; Plant Ecology; University of Konstanz; Konstanz Germany
| | - Peter G. Kroth
- Department of Biology; Plant Ecology; University of Konstanz; Konstanz Germany
| | - Stefan Mecking
- Department of Chemistry; Chair of Chemical Materials Science; University of Konstanz; Konstanz Germany
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134
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Jaeger D, Winkler A, Mussgnug JH, Kalinowski J, Goesmann A, Kruse O. Time-resolved transcriptome analysis and lipid pathway reconstruction of the oleaginous green microalga Monoraphidium neglectum reveal a model for triacylglycerol and lipid hyperaccumulation. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:197. [PMID: 28814974 PMCID: PMC5556983 DOI: 10.1186/s13068-017-0882-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/03/2017] [Indexed: 05/03/2023]
Abstract
BACKGROUND Oleaginous microalgae are promising production hosts for the sustainable generation of lipid-based bioproducts and as bioenergy carriers such as biodiesel. Transcriptomics of the lipid accumulation phase, triggered efficiently by nitrogen starvation, is a valuable approach for the identification of gene targets for metabolic engineering. RESULTS An explorative analysis of the detailed transcriptional response to different stages of nitrogen availability was performed in the oleaginous green alga Monoraphidium neglectum. Transcript data were correlated with metabolic data for cellular contents of starch and of different lipid fractions. A pronounced transcriptional down-regulation of photosynthesis became apparent in response to nitrogen starvation, whereas glucose catabolism was found to be up-regulated. An in-depth reconstruction and analysis of the pathways for glycerolipid, central carbon, and starch metabolism revealed that distinct transcriptional changes were generally found only for specific steps within a metabolic pathway. In addition to pathway analyses, the transcript data were also used to refine the current genome annotation. The transcriptome data were integrated into a database and complemented with data for other microalgae which were also subjected to nitrogen starvation. It is available at https://tdbmn.cebitec.uni-bielefeld.de. CONCLUSIONS Based on the transcriptional responses to different stages of nitrogen availability, a model for triacylglycerol and lipid hyperaccumulation is proposed, which involves transcriptional induction of thioesterases, differential regulation of lipases, and a re-routing of the central carbon metabolism. Over-expression of distinct thioesterases was identified to be a potential strategy to increase the oleaginous phenotype of M. neglectum, and furthermore specific lipases were identified as potential targets for future metabolic engineering approaches.
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Affiliation(s)
- Daniel Jaeger
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| | - Anika Winkler
- Microbial Genomics and Biotechnology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| | - Jan H. Mussgnug
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| | - Jörn Kalinowski
- Microbial Genomics and Biotechnology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
| | - Alexander Goesmann
- Bioinformatics and Systems Biology, Justus-Liebig-Universität, 35392 Gießen, Germany
| | - Olaf Kruse
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, 33615 Bielefeld, Germany
- Algae Biotechnology and Bioenergy, Faculty of Biology, Center for Biotechnology (CeBiTec), Bielefeld University, Universitaetsstrasse 27, 33615 Bielefeld, Germany
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135
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Dourou M, Mizerakis P, Papanikolaou S, Aggelis G. Storage lipid and polysaccharide metabolism in Yarrowia lipolytica and Umbelopsis isabellina. Appl Microbiol Biotechnol 2017; 101:7213-7226. [DOI: 10.1007/s00253-017-8455-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 07/13/2017] [Accepted: 07/30/2017] [Indexed: 11/28/2022]
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136
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McCarthy JK, Smith SR, McCrow JP, Tan M, Zheng H, Beeri K, Roth R, Lichtle C, Goodenough U, Bowler CP, Dupont CL, Allen AE. Nitrate Reductase Knockout Uncouples Nitrate Transport from Nitrate Assimilation and Drives Repartitioning of Carbon Flux in a Model Pennate Diatom. THE PLANT CELL 2017; 29:2047-2070. [PMID: 28765511 PMCID: PMC5590495 DOI: 10.1105/tpc.16.00910] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 06/06/2017] [Accepted: 07/29/2017] [Indexed: 05/03/2023]
Abstract
The ecological prominence of diatoms in the ocean environment largely results from their superior competitive ability for dissolved nitrate (NO3-). To investigate the cellular and genetic basis of diatom NO3- assimilation, we generated a knockout in the nitrate reductase gene (NR-KO) of the model pennate diatom Phaeodactylum tricornutum In NR-KO cells, N-assimilation was abolished although NO3- transport remained intact. Unassimilated NO3- accumulated in NR-KO cells, resulting in swelling and associated changes in biochemical composition and physiology. Elevated expression of genes encoding putative vacuolar NO3- chloride channel transporters plus electron micrographs indicating enlarged vacuoles suggested vacuolar storage of NO3- Triacylglycerol concentrations in the NR-KO cells increased immediately following the addition of NO3-, and these increases coincided with elevated gene expression of key triacylglycerol biosynthesis components. Simultaneously, induction of transcripts encoding proteins involved in thylakoid membrane lipid recycling suggested more abrupt repartitioning of carbon resources in NR-KO cells compared with the wild type. Conversely, ribosomal structure and photosystem genes were immediately deactivated in NR-KO cells following NO3- addition, followed within hours by deactivation of genes encoding enzymes for chlorophyll biosynthesis and carbon fixation and metabolism. N-assimilation pathway genes respond uniquely, apparently induced simultaneously by both NO3- replete and deplete conditions.
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Affiliation(s)
- James K McCarthy
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Sarah R Smith
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, California 92037
| | - John P McCrow
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Maxine Tan
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Hong Zheng
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Karen Beeri
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Robyn Roth
- Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Christian Lichtle
- Institut de Biologie de l'École Normale Supérieure, École Normale Supérieure, Paris Sciences et Lettres Research University, CNRS UMR8197 INSERM U1024, 75005 Paris, France
| | - Ursula Goodenough
- Department of Biology, Washington University, St. Louis, Missouri 63130
| | - Chris P Bowler
- Institut de Biologie de l'École Normale Supérieure, École Normale Supérieure, Paris Sciences et Lettres Research University, CNRS UMR8197 INSERM U1024, 75005 Paris, France
| | - Christopher L Dupont
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
| | - Andrew E Allen
- Microbial and Environmental Genomics, J. Craig Venter Institute, La Jolla, California 92037
- Integrative Oceanography Division, Scripps Institution of Oceanography, UC San Diego, La Jolla, California 92037
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137
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Shi K, Gao Z, Shi TQ, Song P, Ren LJ, Huang H, Ji XJ. Reactive Oxygen Species-Mediated Cellular Stress Response and Lipid Accumulation in Oleaginous Microorganisms: The State of the Art and Future Perspectives. Front Microbiol 2017; 8:793. [PMID: 28507542 PMCID: PMC5410592 DOI: 10.3389/fmicb.2017.00793] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 04/18/2017] [Indexed: 12/20/2022] Open
Abstract
Microbial oils, which are mainly extracted from yeasts, molds, and algae, have been of considerable interest as food additives and biofuel resources due to their high lipid content. While these oleaginous microorganisms generally produce only small amounts of lipids under optimal growth conditions, their lipid accumulation machinery can be induced by environmental stresses, such as nutrient limitation and an inhospitable physical environmental. As common second messengers of many stress factors, reactive oxygen species (ROS) may act as a regulator of cellular responses to extracellular environmental signaling. Furthermore, increasing evidence indicates that ROS may act as a mediator of lipid accumulation, which is associated with dramatic changes in the transcriptome, proteome, and metabolome. However, the specific mechanisms of ROS involvement in the crosstalk between extracellular stress signaling and intracellular lipid synthesis require further investigation. Here, we summarize current knowledge on stress-induced lipid biosynthesis and the putative role of ROS in the control of lipid accumulation in oleaginous microorganisms. Understanding such links may provide guidance for the development of stress-based strategies to enhance microbial lipid production.
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Affiliation(s)
- Kun Shi
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech UniversityNanjing, China
| | - Zhen Gao
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech UniversityNanjing, China
| | - Tian-Qiong Shi
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech UniversityNanjing, China
| | - Ping Song
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech UniversityNanjing, China
| | - Lu-Jing Ren
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech UniversityNanjing, China.,Jiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing, China
| | - He Huang
- Jiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing, China.,School of Pharmaceutical Sciences, Nanjing Tech UniversityNanjing, China.,State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech UniversityNanjing, China
| | - Xiao-Jun Ji
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech UniversityNanjing, China.,Jiangsu National Synergetic Innovation Center for Advanced MaterialsNanjing, China
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138
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Xue J, Balamurugan S, Li DW, Liu YH, Zeng H, Wang L, Yang WD, Liu JS, Li HY. Glucose-6-phosphate dehydrogenase as a target for highly efficient fatty acid biosynthesis in microalgae by enhancing NADPH supply. Metab Eng 2017; 41:212-221. [PMID: 28465173 DOI: 10.1016/j.ymben.2017.04.008] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 04/27/2017] [Accepted: 04/28/2017] [Indexed: 01/10/2023]
Abstract
Oleaginous microalgae have great prospects in the fields of feed, nutrition, biofuel, etc. However, biomass and lipid productivity in microalgae remain a major economic and technological bottleneck. Here we present a novel regulatory target, glucose-6-phosphate dehydrogenase (G6PD) from the pentose phosphate pathway (PPP), in boosting microalgal lipid accumulation. G6PD, involved in the formation of NADPH demanded in fatty acid biosynthesis as reducing power, was characterized in oleaginous microalga Phaeodactylum tricornutum. In G6PD overexpressing microalgae, transcript abundance of G6PD increased by 4.4-fold, and G6PD enzyme activity increased by more than 3.1-fold with enhanced NADPH production. Consequently, the lipid content increased by 2.7-fold and reached up to 55.7% of dry weight, while cell growth was not apparently affected. The fatty acid composition exhibited significant changes, including a remarkable increase in monounsaturated fatty acids C16:1 and C18:1 concomitant with a decrease in polyunsaturated fatty acids C20:5 and C22:6. G6PD was localized to the chloroplast and its overexpression stimulated an increase in the number and size of oil bodies. Proteomic and metabolomic analyzes revealed that G6PD play a key role in regulating pentose phosphate pathway and subsequently upregulating NADPH consuming pathways such as fatty acid synthesis, thus eventually leading to lipid accumulation. Our findings show the critical role of G6PD in microalgal lipid accumulation by enhancing NADPH supply and demonstrate that G6PD is a promising target for metabolic engineering.
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Affiliation(s)
- Jiao Xue
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Srinivasan Balamurugan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Da-Wei Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Yu-Hong Liu
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Hao Zeng
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Lan Wang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Wei-Dong Yang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Jie-Sheng Liu
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China
| | - Hong-Ye Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, College of Life Science and Technology, Jinan University, Guangzhou 510632, China.
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139
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Liang MH, Qv XY, Chen H, Wang Q, Jiang JG. Effects of Salt Concentrations and Nitrogen and Phosphorus Starvations on Neutral Lipid Contents in the Green Microalga Dunaliella tertiolecta. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:3190-3197. [PMID: 28368591 DOI: 10.1021/acs.jafc.7b00552] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Dunaliella tertiolecta, a halotolerant alga, can accumulate large amounts of neutral lipid, which makes it a potential biodiesel feedstock. In this study, neutral lipids of D. tertiolecta induced by different salinities or N or P starvation were analyzed by thin-layer chromatography (TLC), flow cytometry (FCM), and confocal laser scanning microscopy (CLSM). High salinities or N or P starvation resulted in a decrease in cell growth and chlorophyll contents of D. tertiolecta. Neutral lipid contents increased markedly after 3-7 days of N starvation or at low NaCl concentrations (0.5-2.0 M). N starvation had a more dramatic effect on the neutral lipid contents of D. tertiolecta than P starvation. Four putative ME isozymes in different conditions can be detected by using isozyme electrophoresis. Two alternative acetyl-CoA producers, ACL and ACS genes, were up-regulated under low salinities and N starvation. It was suggested that low salinities and N starvation are considered efficient ways to stimulate lipid accumulation in D. tertiolecta.
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Affiliation(s)
- Ming-Hua Liang
- College of Food Science and Engineering, South China University of Technology , Guangzhou 510640, China
| | - Xiao-Ying Qv
- College of Food Science and Engineering, South China University of Technology , Guangzhou 510640, China
| | - Hui Chen
- Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan 430072, China
| | - Qiang Wang
- Institute of Hydrobiology, Chinese Academy of Sciences , Wuhan 430072, China
| | - Jian-Guo Jiang
- College of Food Science and Engineering, South China University of Technology , Guangzhou 510640, China
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140
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Matthijs M, Fabris M, Obata T, Foubert I, Franco-Zorrilla JM, Solano R, Fernie AR, Vyverman W, Goossens A. The transcription factor bZIP14 regulates the TCA cycle in the diatom Phaeodactylum tricornutum. EMBO J 2017; 36:1559-1576. [PMID: 28420744 DOI: 10.15252/embj.201696392] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/14/2017] [Accepted: 03/15/2017] [Indexed: 11/09/2022] Open
Abstract
Diatoms are amongst the most important marine microalgae in terms of biomass, but little is known concerning the molecular mechanisms that regulate their versatile metabolism. Here, the pennate diatom Phaeodactylum tricornutum was studied at the metabolite and transcriptome level during nitrogen starvation and following imposition of three other stresses that impede growth. The coordinated upregulation of the tricarboxylic acid (TCA) cycle during the nitrogen stress response was the most striking observation. Through co-expression analysis and DNA binding assays, the transcription factor bZIP14 was identified as a regulator of the TCA cycle, also beyond the nitrogen starvation response, namely in diurnal regulation. Accordingly, metabolic and transcriptional shifts were observed upon overexpression of bZIP14 in transformed P. tricornutum cells. Our data indicate that the TCA cycle is a tightly regulated and important hub for carbon reallocation in the diatom cell during nutrient starvation and that bZIP14 is a conserved regulator of this cycle.
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Affiliation(s)
- Michiel Matthijs
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,Center for Plant Systems Biology, VIB, Ghent, Belgium.,Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
| | - Michele Fabris
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium.,Center for Plant Systems Biology, VIB, Ghent, Belgium.,Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
| | - Toshihiro Obata
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Imogen Foubert
- Research Unit Food & Lipids, Department of Molecular and Microbial Systems Kulak, Leuven Food Science and Nutrition Research Centre (LFoRCe), Kortrijk, Belgium
| | | | - Roberto Solano
- Genomics Unit, Centro Nacional de Biotecnología-CSIC, Madrid, Spain.,Department of Plant Molecular Genetics, Centro Nacional de Biotecnología-CSIC, Madrid, Spain
| | - Alisdair R Fernie
- Max-Planck-Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
| | - Wim Vyverman
- Laboratory of Protistology and Aquatic Ecology, Department of Biology, Ghent University, Ghent, Belgium
| | - Alain Goossens
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium .,Center for Plant Systems Biology, VIB, Ghent, Belgium
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141
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Shang C, Zhu S, Wang Z, Qin L, Alam MA, Xie J, Yuan Z. Proteome response of Dunaliella parva induced by nitrogen limitation. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.01.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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142
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Osada K, Maeda Y, Yoshino T, Nojima D, Bowler C, Tanaka T. Enhanced NADPH production in the pentose phosphate pathway accelerates lipid accumulation in the oleaginous diatom Fistulifera solaris. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.01.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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143
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Interactive effects of light and temperature on pigments and n-3 LC-PUFA-enriched oil accumulation in batch-cultivated Pavlova lutheri using high-bicarbonate supply. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.02.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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144
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Wei L, Huang X. Long-duration effect of multi-factor stresses on the cellular biochemistry, oil-yielding performance and morphology of Nannochloropsis oculata. PLoS One 2017; 12:e0174646. [PMID: 28346505 PMCID: PMC5367823 DOI: 10.1371/journal.pone.0174646] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/13/2017] [Indexed: 12/03/2022] Open
Abstract
Microalga Nannochloropsis oculata is a promising alternative feedstock for biodiesel. Elevating its oil-yielding capacity is conducive to cost-saving biodiesel production. However, the regulatory processes of multi-factor collaborative stresses (MFCS) on the oil-yielding performance of N. oculata are unclear. The duration effects of MFCS (high irradiation, nitrogen deficiency and elevated iron supplementation) on N. oculata were investigated in an 18-d batch culture. Despite the reduction in cell division, the biomass concentration increased, resulting from the large accumulation of the carbon/energy-reservoir. However, different storage forms were found in different cellular storage compounds, and both the protein content and pigment composition swiftly and drastically changed. The analysis of four biodiesel properties using pertinent empirical equations indicated their progressive effective improvement in lipid classes and fatty acid composition. The variation curve of neutral lipid productivity was monitored with fluorescent Nile red and was closely correlated to the results from conventional methods. In addition, a series of changes in the organelles (e.g., chloroplast, lipid body and vacuole) and cell shape, dependent on the stress duration, were observed by TEM and LSCM. These changes presumably played an important role in the acclimation of N. oculata to MFCS and accordingly improved its oil-yielding performance.
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Affiliation(s)
- Likun Wei
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Xuxiong Huang
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- Shanghai Engineering Research Centre of Aquaculture, Shanghai, China
- Shanghai University Knowledge Service Platform, Shanghai Ocean University Aquatic Animal Breeding Centre (ZF1206), Shanghai, China
- * E-mail:
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145
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Chiriboga N. OG, Rorrer GL. Control of chitin nanofiber production by the lipid‐producing diatom Cyclotella Sp. through fed‐batch addition of dissolved silicon and nitrate in a bubble‐column photobioreactor. Biotechnol Prog 2017; 33:407-415. [DOI: 10.1002/btpr.2445] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 01/30/2017] [Indexed: 01/18/2023]
Affiliation(s)
- Omar G. Chiriboga N.
- School of Chemical, Biological, and Environmental EngineeringOregon State UniversityCorvallis OR97331
| | - Gregory L. Rorrer
- School of Chemical, Biological, and Environmental EngineeringOregon State UniversityCorvallis OR97331
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146
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Yao L, Tan KWM, Tan TW, Lee YK. Exploring the transcriptome of non-model oleaginous microalga Dunaliella tertiolecta through high-throughput sequencing and high performance computing. BMC Bioinformatics 2017; 18:122. [PMID: 28228091 PMCID: PMC5322580 DOI: 10.1186/s12859-017-1551-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 02/16/2017] [Indexed: 12/31/2022] Open
Abstract
Background RNA-Seq technology has received a lot of attention in recent years for microalgal global transcriptomic profiling. It is widely used in transcriptome-wide analysis of gene expression., particularly for microalgal strains with potential as biofuel sources. However, insufficient genomic or transcriptomic information of non-model microalgae has limited the understanding of their regulatory mechanisms and hampered genetic manipulation to enhance biofuel production. As such, an optimal microalgal transcriptomic database construction is a subject of urgent investigation. Results Dunaliella tertiolecta, a non-model oleaginous microalgal species, was sequenced via Illumina MISEQ and HISEQ 4000 in RNA-Seq studies. The high quality high-throughout sequencing data were explored using high performance computing (HPC) in a petascale data center and subjected to de novo assembly and parallelized mpiBLASTX search with multiple species. As a result, a transcriptome database of 17,845 was constructed (~95% completeness). This enlarged database constructed fueled the RNA-Seq data analysis, which was validated by a nitrogen deprivation (ND) study that induces triacylglycerol (TAG) production. Conclusions The new paralleled assembly and annotation method under HPC presented here allows the solution of large-scale data processing problems in acceptable computation time. There is significant increase in the number of transcriptomic data achieved and observable heterogeneity in the performance to identify differentially expressed genes in the ND treatment paradigm. The results provide new insights as to how response to ND treatment in microalgae is regulated. ND analyses highlight the advantages of this database generated in this study that could also serve as a useful resource for future gene manipulation and transcriptome-wide analysis. We thus demonstrate the usefulness of exploring the transcriptome as an informative platform for functional studies and genetic manipulations in similar species. Electronic supplementary material The online version of this article (doi:10.1186/s12859-017-1551-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lina Yao
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545, Singapore
| | - Kenneth Wei Min Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545, Singapore
| | - Tin Wee Tan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117596, Singapore.,National Supercomputing Centre (NSCC), Singapore, 138632, Singapore
| | - Yuan Kun Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545, Singapore.
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147
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del Rio-Chanona EA, Ahmed NR, Zhang D, Lu Y, Jing K. Kinetic modeling and process analysis for Desmodesmus
sp. lutein photo-production. AIChE J 2017. [DOI: 10.1002/aic.15667] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Nur rashid Ahmed
- Dept. of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering; Xiamen University; Xiamen 361005 China
| | - Dongda Zhang
- Dept. of Chemical Engineering and Biotechnology; University of Cambridge; Pembroke Street Cambridge CB2 3RA UK
- Centre for Process Systems Engineering; Imperial College London; South Kensington Campus London SW7 2AZ UK
| | - Yinghua Lu
- Dept. of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering; Xiamen University; Xiamen 361005 China
- The Key Lab for Synthetic Biotechnology of Xiamen City; Xiamen University; Xiamen 361005 China
| | - Keju Jing
- Dept. of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering; Xiamen University; Xiamen 361005 China
- The Key Lab for Synthetic Biotechnology of Xiamen City; Xiamen University; Xiamen 361005 China
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148
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Balamurugan S, Wang X, Wang HL, An CJ, Li H, Li DW, Yang WD, Liu JS, Li HY. Occurrence of plastidial triacylglycerol synthesis and the potential regulatory role of AGPAT in the model diatom Phaeodactylum tricornutum. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:97. [PMID: 28435443 PMCID: PMC5397801 DOI: 10.1186/s13068-017-0786-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 04/11/2017] [Indexed: 05/02/2023]
Abstract
BACKGROUND Microalgae have emerged as a potential feedstock for biofuels and bioactive components. However, lack of microalgal strains with promising triacylglycerol (TAG) content and desirable fatty acid composition have hindered its commercial feasibility. Attempts on lipid overproduction by metabolic engineering remain largely challenging in microalgae. RESULTS In this study, a microalgal 1-acyl-sn-glycerol-3-phosphate acyltransferase designated AGPAT1 was identified in the model diatom Phaeodactylum tricornutum. AGPAT1 contained four conserved acyltransferase motifs I-IV. Subcellular localization prediction and thereafter immuno-electron microscopy revealed the localization of AGPAT1 to plastid membranes. AGPAT1 overexpression significantly altered the primary metabolism, with increased total lipid content but decreased content of total carbohydrates and soluble proteins. Intriguingly, AGPAT1 overexpression coordinated the expression of other key genes such as DGAT2 and GPAT involved in TAG synthesis, and consequently increased TAG content by 1.81-fold with a significant increase in polyunsaturated fatty acids, particularly EPA and DHA. Moreover, besides increased lipid droplets in the cytosol, ultrastructural observation showed a number of TAG-rich plastoglobuli formed in plastids. CONCLUSION The results suggested that AGPAT1 overexpression could elevate TAG biosynthesis and, moreover, revealed the occurrence of plastidial TAG synthesis in the diatom. Overall, our data provide a new insight into microalgal lipid metabolism and candidate target for metabolic engineering.
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Affiliation(s)
- Srinivasan Balamurugan
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632 China
| | - Xiang Wang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632 China
| | - Hong-Lei Wang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632 China
| | - Chun-Jing An
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632 China
| | - Hui Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632 China
| | - Da-Wei Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632 China
| | - Wei-Dong Yang
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632 China
| | - Jie-Sheng Liu
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632 China
| | - Hong-Ye Li
- Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632 China
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149
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Ma C, Zhang YB, Ho SH, Xing DF, Ren NQ, Liu BF. Cell growth and lipid accumulation of a microalgal mutant Scenedesmus sp. Z-4 by combining light/dark cycle with temperature variation. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:260. [PMID: 29151889 PMCID: PMC5679341 DOI: 10.1186/s13068-017-0948-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Accepted: 11/01/2017] [Indexed: 05/11/2023]
Abstract
BACKGROUND The light/dark cycle is one of the most important factors affecting the microalgal growth and lipid accumulation. Biomass concentration and lipid productivity could be enhanced by optimization of light/dark cycles, and this is considered an effective control strategy for microalgal cultivation. Currently, most research on effects of light/dark cycles on algae is carried out under autotrophic conditions and little information is about the effects under mixotrophic cultivation. At the same time, many studies related to mixotrophic cultivation of microalgal strains, even at large scale, have been performed to obtain satisfactory biomass and lipid production. Therefore, it is necessary to investigate cellular metabolism under autotrophic and mixotrophic conditions at different light/dark cycles. Even though microalgal lipid production under optimal environmental factors has been reported by some researchers, the light/dark cycle and temperature are regarded as separate parameters in their studies. In practical cases, light/dark cycling and temperature variation during the day occur simultaneously. Therefore, studies about the combined effects of light/dark cycles and temperature variation on microalgal lipid production are of practical value, potentially providing significant guidelines for large-scale microalgal cultivation under natural conditions. RESULTS In this work, cell growth and lipid accumulation of an oleaginous microalgal mutant, Scenedesmus sp. Z-4, were investigated at five light/dark cycles (0 h/24 h, 8 h/16 h, 12 h/12 h, 16 h/8 h, and 24 h/0 h) in batch culture. The results showed that the optimal light/dark cycle was 12 h/12 h, when maximum lipid productivity rates of 56.8 and 182.6 mg L-1 day-1 were obtained under autotrophic and mixotrophic cultivation, respectively. Poor microalgal growth and lipid accumulation appeared in the light/dark cycles of 0 h/24 h and 24 h/0 h under autotrophic condition. Prolonging the light duration was unfavorable to the production of chlorophyll a and b, which was mainly due to photooxidation effect. Polysaccharide was converted into lipid and protein when the light irradiation time increased from 0 to 12 h; however, further increasing irradiation time had a negative effect on lipid accumulation. Due to the dependence of autotrophically cultured cells on light energy, the light/dark cycle has a more remarkable influence on cellular metabolism under autotrophic conditions. Furthermore, the combined effects of temperature variation and light/dark cycle of 12 h/12 h on cell growth and lipid accumulation of microalgal mutant Z-4 were investigated under mixotrophic cultivation, and the results showed that biomass was mainly produced at higher temperatures during the day, and a portion of biomass was converted into lipid under dark condition. CONCLUSIONS The extension of irradiation time was beneficial to biomass accumulation, but not in favor of lipid production. Even though effects of light/dark cycles on autotrophic and mixotrophic cells were not exactly the same, the optimal lipid productivities of Scenedesmus sp. Z-4 under both cultivation conditions were achieved at the light/dark of 12 h/12 h. This may be attributed to its long-term acclimation in natural environment. By combining temperature variation with optimal light/dark cycle of 12 h/12 h, this study will be of great significance for practical microalgae-biodiesel production in the outdoor conditions.
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Affiliation(s)
- Chao Ma
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, P.O. Box 2614, 73 Huanghe Road, Harbin, 150090 China
| | - Yan-Bo Zhang
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, P.O. Box 2614, 73 Huanghe Road, Harbin, 150090 China
| | - Shih-Hsin Ho
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, P.O. Box 2614, 73 Huanghe Road, Harbin, 150090 China
| | - De-Feng Xing
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, P.O. Box 2614, 73 Huanghe Road, Harbin, 150090 China
| | - Nan-Qi Ren
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, P.O. Box 2614, 73 Huanghe Road, Harbin, 150090 China
| | - Bing-Feng Liu
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, P.O. Box 2614, 73 Huanghe Road, Harbin, 150090 China
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150
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Tan KWM, Lee YK. The dilemma for lipid productivity in green microalgae: importance of substrate provision in improving oil yield without sacrificing growth. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:255. [PMID: 27895709 PMCID: PMC5120525 DOI: 10.1186/s13068-016-0671-2] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/16/2016] [Indexed: 05/02/2023]
Abstract
Rising oil prices and concerns over climate change have resulted in more emphasis on research into renewable biofuels from microalgae. Unlike plants, green microalgae have higher biomass productivity, will not compete with food and agriculture, and do not require fertile land for cultivation. However, microalgae biofuels currently suffer from high capital and operating costs due to low yields and costly extraction methods. Microalgae grown under optimal conditions produce large amounts of biomass but with low neutral lipid content, while microalgae grown in nutrient starvation accumulate high levels of neutral lipids but are slow growing. Producing lipids while maintaining high growth rates is vital for biofuel production because high biomass productivity increases yield per harvest volume while high lipid content decreases the cost of extraction per unit product. Therefore, there is a need for metabolic engineering of microalgae to constitutively produce high amounts of lipids without sacrificing growth. Substrate availability is a rate-limiting step in balancing growth and fatty acid (FA) production because both biomass and FA synthesis pathways compete for the same substrates, namely acetyl-CoA and NADPH. In this review, we discuss the efforts made for improving biofuel production in plants and microorganisms, the challenges faced in achieving lipid productivity, and the important role of precursor supply for FA synthesis. The main focus is placed on the enzymes which catalyzed the reactions supplying acetyl-CoA and NADPH.
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Affiliation(s)
- Kenneth Wei Min Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545 Singapore
| | - Yuan Kun Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545 Singapore
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