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Vijayan J, Wase N, Liu K, Morse W, Zhang C, Riekhof WR. ROS-mediated thylakoid membrane remodeling and triacylglycerol biosynthesis under nitrogen starvation in the alga Chlorella sorokiniana. FRONTIERS IN PLANT SCIENCE 2024; 15:1418049. [PMID: 39040507 PMCID: PMC11261311 DOI: 10.3389/fpls.2024.1418049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 06/11/2024] [Indexed: 07/24/2024]
Abstract
Many microbes accumulate energy storage molecules such as triglycerides (TAG) and starch during nutrient limitation. In eukaryotic green algae grown under nitrogen-limiting conditions, triglyceride accumulation is coupled with chlorosis and growth arrest. In this study, we show that reactive oxygen species (ROS) actively accumulate during nitrogen limitation in the microalga Chlorella sorokiniana. Accumulation of ROS is mediated by the downregulation of genes encoding ROS-quenching enzymes, such as superoxide dismutases, catalase, peroxiredoxin, and glutathione peroxidase-like, and by the upregulation of enzymes involved in generating ROS, such as NADPH oxidase, xanthine oxidase, and amine oxidases. The expression of genes involved in ascorbate and glutathione metabolism is also affected under this condition. ROS accumulation contributes to the degradation of monogalactosyl diacylglycerol (MGDG) and thylakoid membrane remodeling, leading to chlorosis. Quenching ROS under nitrogen limitation reduces the degradation of MGDG and the accumulation of TAG. This work shows that ROS accumulation, membrane remodeling, and TAG accumulation under nitrogen limitation are intricately linked in the microalga C. sorokiniana.
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Affiliation(s)
- Jithesh Vijayan
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE, United States
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Nishikant Wase
- PPD, part of ThermoFisher Scientific, Henrico, VA, United States
| | - Kan Liu
- Mayo Clinic, Rochester, MN, United States
| | - Wyatt Morse
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Chi Zhang
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
- Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Wayne R. Riekhof
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
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2
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Chen J, Hu Y, Zhao T, Huang C, Chen J, He L, Dai F, Chen S, Wang L, Jin S, Zhang T. Comparative transcriptomic analysis provides insights into the genetic networks regulating oil differential production in oil crops. BMC Biol 2024; 22:110. [PMID: 38735918 PMCID: PMC11089805 DOI: 10.1186/s12915-024-01909-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 05/02/2024] [Indexed: 05/14/2024] Open
Abstract
BACKGROUND Plants differ more than threefold in seed oil contents (SOCs). Soybean (Glycine max), cotton (Gossypium hirsutum), rapeseed (Brassica napus), and sesame (Sesamum indicum) are four important oil crops with markedly different SOCs and fatty acid compositions. RESULTS Compared to grain crops like maize and rice, expanded acyl-lipid metabolism genes and relatively higher expression levels of genes involved in seed oil synthesis (SOS) in the oil crops contributed to the oil accumulation in seeds. Here, we conducted comparative transcriptomics on oil crops with two different SOC materials. In common, DIHYDROLIPOAMIDE DEHYDROGENASE, STEAROYL-ACYL CARRIER PROTEIN DESATURASE, PHOSPHOLIPID:DIACYLGLYCEROL ACYLTRANSFERASE, and oil-body protein genes were both differentially expressed between the high- and low-oil materials of each crop. By comparing functional components of SOS networks, we found that the strong correlations between genes in "glycolysis/gluconeogenesis" and "fatty acid synthesis" were conserved in both grain and oil crops, with PYRUVATE KINASE being the common factor affecting starch and lipid accumulation. Network alignment also found a conserved clique among oil crops affecting seed oil accumulation, which has been validated in Arabidopsis. Differently, secondary and protein metabolism affected oil synthesis to different degrees in different crops, and high SOC was due to less competition of the same precursors. The comparison of Arabidopsis mutants and wild type showed that CINNAMYL ALCOHOL DEHYDROGENASE 9, the conserved regulator we identified, was a factor resulting in different relative contents of lignins to oil in seeds. The interconnection of lipids and proteins was common but in different ways among crops, which partly led to differential oil production. CONCLUSIONS This study goes beyond the observations made in studies of individual species to provide new insights into which genes and networks may be fundamental to seed oil accumulation from a multispecies perspective.
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Affiliation(s)
- Jinwen Chen
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310029, Zhejiang, China
| | - Yan Hu
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310029, Zhejiang, China
- Hainan Institute of Zhejiang University, Sanya, 572025, Hainan, China
| | - Ting Zhao
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310029, Zhejiang, China
| | - Chujun Huang
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310029, Zhejiang, China
| | - Jiani Chen
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310029, Zhejiang, China
| | - Lu He
- Hainan Institute of Zhejiang University, Sanya, 572025, Hainan, China
| | - Fan Dai
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310029, Zhejiang, China
| | - Shuqi Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Agriculture, Nanjing Agricultural University, Nanjing, 210095, Jiangsu, China
| | - Luyao Wang
- Hainan Institute of Zhejiang University, Sanya, 572025, Hainan, China
| | - Shangkun Jin
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310029, Zhejiang, China
| | - Tianzhen Zhang
- Department of Agronomy, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, 310029, Zhejiang, China.
- Hainan Institute of Zhejiang University, Sanya, 572025, Hainan, China.
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3
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Sun C, Li X, Guo J. Relationship between photosystem activity and ultraweak luminescence excitation in Cerasus humilis leaves under salt stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 196:1032-1045. [PMID: 36898215 DOI: 10.1016/j.plaphy.2023.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 02/15/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Cerasus humilis (Bge.) Sok (C. humilis) is a wild fruit tree endemic to China. It mainly grows on saline land and often suffers from osmotic stress. Biophotons are ultraweak luminescence (UWL) radiations that are closely related to various biological processes and activities. UWL emission essentially originates from the oxidative stress process of organisms. However, it is unclear whether UWL production is related to the redox state of chloroplasts. Therefore, to understand the UWL emission mechanism in plants, we studied the effect of salt stress on the photosystem (PS) activity and UWL of C. humilis leaves and analyzed the correlation between PS activity and UWL. The results showed that salt stress severely inhibited the PS activity of C. humilis leaves and oxygen-evolving complex, damaged the integrity of the thylakoid membrane, decreased the photochemical efficiency of PSII, and hindered the QA-QB electron transfer. At the same time, the intensity of UWL also decreased. Further, correlation analyses of PS activity indices and UWL showed that UWL was significantly correlated with main parameters of photosystem activity such as PSII the maximum photochemical efficiency (Fv/Fm) and photosynthetic performance index based on absorbed light energy (PIABS), as well as the absorption, capture, and transfer of energy in the unit reaction center and unit leaf section. These results indicated that the PS activity of C. humilis was related to the production of UWL, and the intensity of UWL decreased with the decrease in PS activity.
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Affiliation(s)
- Cong Sun
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot Inner Mongolia, 010019, China; Hainan Yazhou Bay Seed Laboratory, Sanya, 572025, China; State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaoyan Li
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot Inner Mongolia, 010019, China
| | - Jinli Guo
- College of Horticulture and Plant Protection, Inner Mongolia Agricultural University, Hohhot Inner Mongolia, 010019, China.
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Expression profile of genes associated with the accumulation of triacylglycerol (TAG) in Auxenochlorella protothecoides KP7 under alkaline pH and nitrogen starvation conditions. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2023. [DOI: 10.1016/j.bcab.2023.102628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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5
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Neusius D, Kleinknecht L, Teh JT, Ostermeier M, Kelterborn S, Eirich J, Hegemann P, Finkemeier I, Bohne AV, Nickelsen J. Lysine acetylation regulates moonlighting activity of the E2 subunit of the chloroplast pyruvate dehydrogenase complex in Chlamydomonas. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 111:1780-1800. [PMID: 35899410 DOI: 10.1111/tpj.15924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/08/2022] [Accepted: 07/18/2022] [Indexed: 06/15/2023]
Abstract
The dihydrolipoamide acetyltransferase subunit DLA2 of the chloroplast pyruvate dehydrogenase complex (cpPDC) in the green alga Chlamydomonas reinhardtii has previously been shown to possess moonlighting activity in chloroplast gene expression. Under mixotrophic growth conditions, DLA2 forms part of a ribonucleoprotein particle (RNP) with the psbA mRNA that encodes the D1 protein of the photosystem II (PSII) reaction center. Here, we report on the characterization of the molecular switch that regulates shuttling of DLA2 between its functions in carbon metabolism and D1 synthesis. Determination of RNA-binding affinities by microscale thermophoresis demonstrated that the E3-binding domain (E3BD) of DLA2 mediates psbA-specific RNA recognition. Analyses of cpPDC formation and activity, as well as RNP complex formation, showed that acetylation of a single lysine residue (K197) in E3BD induces the release of DLA2 from the cpPDC, and its functional shift towards RNA binding. Moreover, Förster resonance energy transfer microscopy revealed that psbA mRNA/DLA2 complexes localize around the chloroplast's pyrenoid. Pulse labeling and D1 re-accumulation after induced PSII degradation strongly suggest that DLA2 is important for D1 synthesis during de novo PSII biogenesis.
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Affiliation(s)
- Daniel Neusius
- Molecular Plant Sciences, Faculty of Biology, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-, Martinsried, Germany
| | - Laura Kleinknecht
- Molecular Plant Sciences, Faculty of Biology, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-, Martinsried, Germany
| | - Jing Tsong Teh
- Molecular Plant Sciences, Faculty of Biology, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-, Martinsried, Germany
| | - Matthias Ostermeier
- Molecular Plant Sciences, Faculty of Biology, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-, Martinsried, Germany
| | - Simon Kelterborn
- Experimental Biophysics, Institute of Biology, Humboldt University of Berlin, Invalidenstr. 42, 10115, Berlin, Germany
| | - Jürgen Eirich
- Institute of Plant Biology and Biotechnology, University of Muenster, Schlossplatz 7, 48149, Münster, Germany
| | - Peter Hegemann
- Experimental Biophysics, Institute of Biology, Humboldt University of Berlin, Invalidenstr. 42, 10115, Berlin, Germany
| | - Iris Finkemeier
- Institute of Plant Biology and Biotechnology, University of Muenster, Schlossplatz 7, 48149, Münster, Germany
| | - Alexandra-Viola Bohne
- Molecular Plant Sciences, Faculty of Biology, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-, Martinsried, Germany
| | - Jörg Nickelsen
- Molecular Plant Sciences, Faculty of Biology, LMU Munich, Großhaderner Str. 2-4, 82152 Planegg-, Martinsried, Germany
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Wood EE, Ross ME, Jubeau S, Montalescot V, Stanley MS. Progress towards a targeted biorefinery of Chromochloris zofingiensis: a review. BIOMASS CONVERSION AND BIOREFINERY 2022; 14:8127-8152. [PMID: 38510795 PMCID: PMC10948469 DOI: 10.1007/s13399-022-02955-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 06/09/2022] [Accepted: 06/13/2022] [Indexed: 03/22/2024]
Abstract
Biorefinery approaches offer the potential to improve the economics of the microalgae industry by producing multiple products from a single source of biomass. Chromochloris zofingiensis shows great promise for biorefinery due to high biomass productivity and a diverse range of products including secondary carotenoids, predominantly astaxanthin; lipids such as TAGs; carbohydrates including starch; and proteins and essential amino acids. Whilst this species has been demonstrated to accumulate multiple products, the development of an integrated downstream process to obtain these is lacking. The objective of this review paper is to assess the research that has taken place and to identify the steps that must be taken to establish a biorefinery approach for C. zofingiensis. In particular, the reasons why C. zofingiensis is a promising species to target for biorefinery are discussed in terms of cellular structure, potential products, and means to accumulate desirable components via the alteration of culture conditions. Future advances and the challenges that lie ahead for successful biorefinery of this species are also reviewed along with potential solutions to address them. Supplementary Information The online version contains supplementary material available at 10.1007/s13399-022-02955-7.
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Affiliation(s)
- Eleanor E. Wood
- University of the Highlands and Islands (UHI); Scottish Association for Marine Science (SAMS), Scottish Marine Institute, Oban, PA37 1QA UK
- Xanthella Ltd, Malin House, European Marine Science Park, Dunstaffnage, Argyll, Oban PA37 1SZ Scotland, UK
| | - Michael E. Ross
- University of the Highlands and Islands (UHI); Scottish Association for Marine Science (SAMS), Scottish Marine Institute, Oban, PA37 1QA UK
| | - Sébastien Jubeau
- Xanthella Ltd, Malin House, European Marine Science Park, Dunstaffnage, Argyll, Oban PA37 1SZ Scotland, UK
| | | | - Michele S. Stanley
- University of the Highlands and Islands (UHI); Scottish Association for Marine Science (SAMS), Scottish Marine Institute, Oban, PA37 1QA UK
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Ahirwar A, Kesharwani K, Deka R, Muthukumar S, Khan MJ, Rai A, Vinayak V, Varjani S, Joshi KB, Morjaria S. Microalgal drugs: A promising therapeutic reserve for the future. J Biotechnol 2022; 349:32-46. [PMID: 35339574 DOI: 10.1016/j.jbiotec.2022.03.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 02/17/2022] [Accepted: 03/20/2022] [Indexed: 12/16/2022]
Abstract
Over the decades, a variety of chemically synthesized drugs are being used to cure existing diseases but often these drugs could not be effectively employed for the treatment of serious and newly emerging diseases. Fortunately, in nature there occurs immense treasure of plants and microorganisms which are living jewels with respect to their richness of medically important metabolites of high value. Hence, amongst the existing microorganism(s), the marine world offers a plethora of biological entities that can contribute to alleviate numerous human ailments. Algae are one such photosynthetic microorganism found in both marine as well as fresh water which are rich source of metabolites known for their nutrient content and health benefits. Various algal species like Haematococcus, Diatoms, Griffithsia, Chlorella, Spirulina, Ulva, etc. have been identified and isolated to produce biologically active and pharmaceutically important high value compounds like astaxanthin, fucoxanthin, sulphur polysaccharides mainly galactose, rhamnose, xylose, fucose etc., which show antimicrobial, antifungal, anti-cancer, and antiviral activities. However, the production of either of these bio compounds is favored under conditions of stress. This review gives detailed information on various nutraceutical metabolites extracted from algae. Additionally focus has been made on the role of these bio compounds extracted from algae especially sulphur polysaccharides to treat several diseases with prospective treatment for SARS-CoV-2. Lastly it covers the knowledge gaps and future perspectives in this area of research.
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Affiliation(s)
- Ankesh Ahirwar
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. Harisingh Gour Central University, Sagar (MP) 470003, India
| | - Khushboo Kesharwani
- Department of Chemistry, Dr. Harisingh Gour Central University, Sagar (MP) 470003, India
| | - Rahul Deka
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. Harisingh Gour Central University, Sagar (MP) 470003, India
| | - Shreya Muthukumar
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. Harisingh Gour Central University, Sagar (MP) 470003, India
| | - Mohd Jahir Khan
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. Harisingh Gour Central University, Sagar (MP) 470003, India
| | - Anshuman Rai
- MMU, Deemed University, School of Engineering, Department of Biotechnology, Ambala, Haryana, 133203, India
| | - Vandana Vinayak
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. Harisingh Gour Central University, Sagar (MP) 470003, India.
| | - Sunita Varjani
- Gujarat Pollution Control Board, Gandhinagar, Gujarat, 382 010, India.
| | - Khashti Ballabh Joshi
- Department of Chemistry, Dr. Harisingh Gour Central University, Sagar (MP) 470003, India
| | - Shruti Morjaria
- Diatom Nanoengineering and Metabolism Laboratory (DNM), School of Applied Science, Dr. Harisingh Gour Central University, Sagar (MP) 470003, India
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8
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Santin A, Russo MT, Ferrante MI, Balzano S, Orefice I, Sardo A. Highly Valuable Polyunsaturated Fatty Acids from Microalgae: Strategies to Improve Their Yields and Their Potential Exploitation in Aquaculture. Molecules 2021; 26:7697. [PMID: 34946780 PMCID: PMC8707597 DOI: 10.3390/molecules26247697] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/14/2021] [Accepted: 12/15/2021] [Indexed: 11/16/2022] Open
Abstract
Microalgae have a great potential for the production of healthy food and feed supplements. Their ability to convert carbon into high-value compounds and to be cultured in large scale without interfering with crop cultivation makes these photosynthetic microorganisms promising for the sustainable production of lipids. In particular, microalgae represent an alternative source of polyunsaturated fatty acids (PUFAs), whose consumption is related to various health benefits for humans and animals. In recent years, several strategies to improve PUFAs' production in microalgae have been investigated. Such strategies include selecting the best performing species and strains and the optimization of culturing conditions, with special emphasis on the different cultivation systems and the effect of different abiotic factors on PUFAs' accumulation in microalgae. Moreover, developments and results obtained through the most modern genetic and metabolic engineering techniques are described, focusing on the strategies that lead to an increased lipid production or an altered PUFAs' profile. Additionally, we provide an overview of biotechnological applications of PUFAs derived from microalgae as safe and sustainable organisms, such as aquafeed and food ingredients, and of the main techniques (and their related issues) for PUFAs' extraction and purification from microalgal biomass.
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Affiliation(s)
- Anna Santin
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.S.); (M.T.R.); (S.B.); (I.O.)
| | - Monia Teresa Russo
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.S.); (M.T.R.); (S.B.); (I.O.)
| | - Maria Immacolata Ferrante
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.S.); (M.T.R.); (S.B.); (I.O.)
| | - Sergio Balzano
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.S.); (M.T.R.); (S.B.); (I.O.)
- Department of Marine Microbiology and Biogeochemistry, Netherland Institute for Sea Research, Landsdiep 4, 1793 AB Texel, The Netherlands
| | - Ida Orefice
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.S.); (M.T.R.); (S.B.); (I.O.)
| | - Angela Sardo
- Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Naples, Italy; (A.S.); (M.T.R.); (S.B.); (I.O.)
- Istituto di Scienze Applicate e Sistemi Intelligenti “Eduardo Caianiello”, Via Campi Flegrei 34, 80078 Pozzuoli, Italy
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9
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Jia YL, Geng SS, Du F, Xu YS, Wang LR, Sun XM, Wang QZ, Li Q. Progress of metabolic engineering for the production of eicosapentaenoic acid. Crit Rev Biotechnol 2021; 42:838-855. [PMID: 34779326 DOI: 10.1080/07388551.2021.1971621] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Eicosapentaenoic Acid (EPA) is an essential ω-3 polyunsaturated fatty acid for human health. Currently, high-quality EPA production is largely dependent on the extraction of fish oil, but this unsustainable approach cannot meet its rising market demand. Biotechnological approaches for EPA production from microorganisms have received increasing attention due to their suitability for large-scale production and independence of the seasonal or climate restrictions. This review summarizes recent research on different microorganisms capable of producing EPA, such as microalgae, bacteria, and fungi, and introduces the different EPA biosynthesis pathways. Notably, some novel engineering strategies have been applied to endow and improve the abilities of microorganisms to synthesize EPA, including the construction and optimization of the EPA biosynthesis pathway, an increase in the acetyl-CoA pool supply, the increase of NADPH and the inhibition of competing pathways. This review aims to provide an updated summary of EPA production.
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Affiliation(s)
- Yu-Lei Jia
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Shan-Shan Geng
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Fei Du
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Ying-Shuang Xu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Ling-Ru Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Xiao-Man Sun
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Qing-Zhuo Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Qi Li
- College of Life Sciences, Sichuan Normal University, Chengdu, People's Republic of China
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10
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Chen H, Wang Q. Regulatory mechanisms of lipid biosynthesis in microalgae. Biol Rev Camb Philos Soc 2021; 96:2373-2391. [PMID: 34101323 DOI: 10.1111/brv.12759] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 02/01/2023]
Abstract
Microalgal lipids are highly promising feedstocks for biofuel production. Microalgal lipids, especially triacylglycerol, and practical applications of these compounds have received increasing attention in recent years. For the commercial use of microalgal lipids to be feasible, many fundamental biological questions must be addressed based on detailed studies of algal biology, including how lipid biosynthesis occurs and is regulated. Here, we review the current understanding of microalgal lipid biosynthesis, with a focus on the underlying regulatory mechanisms. We also present possible solutions for overcoming various obstacles to understanding the basic biology of microalgal lipid biosynthesis and the practical application of microalgae-based lipids. This review will provide a theoretical reference for both algal researchers and decision makers regarding the future directions of microalgal research, particularly pertaining to microalgal-based lipid biosynthesis.
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Affiliation(s)
- Hui Chen
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China
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11
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Lupette J, Benning C. Human health benefits of very-long-chain polyunsaturated fatty acids from microalgae. Biochimie 2020; 178:15-25. [PMID: 32389760 DOI: 10.1016/j.biochi.2020.04.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/06/2020] [Accepted: 04/21/2020] [Indexed: 02/06/2023]
Abstract
Microalgae are single-cell, photosynthetic organisms whose biodiversity places them at the forefront of biological producers of high-value molecules including lipids and pigments. Some of these organisms particular are capable of synthesizing n-3 very long chain polyunsaturated fatty acids (VLC-PUFAs), known to have beneficial effects on human health. Indeed, VLC-PUFAs are the precursors of many signaling molecules in humans involved in the complexities of inflammatory processes. This mini-review provides an inventory of knowledge on the synthesis of VLC-PUFAs in microalgae and on the diversity of signaling molecules (prostanoids, leukotrienes, SPMs, EFOX, isoprostanoids) that arise in humans from VLC-PUFAs.
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Affiliation(s)
- Josselin Lupette
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA.
| | - Christoph Benning
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA; Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA
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12
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Zienkiewicz A, Zienkiewicz K, Poliner E, Pulman JA, Du ZY, Stefano G, Tsai CH, Horn P, Feussner I, Farre EM, Childs KL, Brandizzi F, Benning C. The Microalga Nannochloropsis during Transition from Quiescence to Autotrophy in Response to Nitrogen Availability. PLANT PHYSIOLOGY 2020; 182:819-839. [PMID: 31740503 PMCID: PMC6997683 DOI: 10.1104/pp.19.00854] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/04/2019] [Indexed: 05/03/2023]
Abstract
The marine microalgae Nannochloropsis oceanica (CCMP1779) is a prolific producer of oil and is considered a viable and sustainable resource for biofuel feedstocks. Nitrogen (N) availability has a strong impact on the physiological status and metabolism of microalgal cells, but the exact nature of this response is poorly understood. To fill this gap we performed transcriptomic profiling combined with cellular and molecular analyses of N. oceanica CCMP1779 during the transition from quiescence to autotrophy. N deprivation-induced quiescence was accompanied by a strong reorganization of the photosynthetic apparatus and changes in the lipid homeostasis, leading to accumulation of triacylglycerol. Cell cycle activation and re-establishment of photosynthetic activity observed in response to resupply of the growth medium with N were accompanied by a rapid degradation of triacylglycerol stored in lipid droplets (LDs). Besides observing LD translocation into vacuoles, we also provide evidence for direct interaction between the LD surface protein (NoLDSP) and AUTOPHAGY-RELATED8 (NoATG8) protein and show a role of microlipophagy in LD turnover in N. oceanica CCMP1779. This knowledge is crucial not only for understanding the fundamental mechanisms controlling the cellular energy homeostasis in microalgal cells but also for development of efficient strategies to achieve higher algal biomass and better microalgal lipid productivity.
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Affiliation(s)
- Agnieszka Zienkiewicz
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, Michigan 48824
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, 87-100 Toruń, Poland
| | - Krzysztof Zienkiewicz
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, 87-100 Toruń, Poland
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37073 Goettingen, Germany
| | - Eric Poliner
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Cell and Molecular Biology Program, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Jane A Pulman
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Center for Genomics-Enabled Plant Science, Michigan State University, East Lansing, Michigan 48824
| | - Zhi-Yan Du
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Giovanni Stefano
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Chia-Hong Tsai
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Patrick Horn
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37073 Goettingen, Germany
- Department of Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37073 Goettingen, Germany
- Department of Plant Biochemistry, International Center for Advanced Studies of Energy Conversion (ICASEC), University of Goettingen, 37073 Goettingen, Germany
| | - Eva M Farre
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Kevin L Childs
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Center for Genomics-Enabled Plant Science, Michigan State University, East Lansing, Michigan 48824
| | - Federica Brandizzi
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
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Burlacot A, Peltier G, Li-Beisson Y. Subcellular Energetics and Carbon Storage in Chlamydomonas. Cells 2019; 8:E1154. [PMID: 31561610 PMCID: PMC6830334 DOI: 10.3390/cells8101154] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 01/09/2023] Open
Abstract
Microalgae have emerged as a promising platform for production of carbon- and energy- rich molecules, notably starch and oil. Establishing an economically viable algal biotechnology sector requires a holistic understanding of algal photosynthesis, physiology, cell cycle and metabolism. Starch/oil productivity is a combined effect of their cellular content and cell division activities. Cell growth, starch and fatty acid synthesis all require carbon building blocks and a source of energy in the form of ATP and NADPH, but with a different requirement in ATP/NADPH ratio. Thus, several cellular mechanisms have been developed by microalgae to balance ATP and NADPH supply which are essentially produced by photosynthesis. Major energy management mechanisms include ATP production by the chloroplast-based cyclic electron flow and NADPH removal by water-water cycles. Furthermore, energetic coupling between chloroplast and other cellular compartments, mitochondria and peroxisome, is increasingly recognized as an important process involved in the chloroplast redox poise. Emerging literature suggests that alterations of energy management pathways affect not only cell fitness and survival, but also influence biomass content and composition. These emerging discoveries are important steps towards diverting algal photosynthetic energy to useful products for biotechnological applications.
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Affiliation(s)
- Adrien Burlacot
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache CEDEX, 13108 Saint Paul-Lez-Durance, France.
| | - Gilles Peltier
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache CEDEX, 13108 Saint Paul-Lez-Durance, France.
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache CEDEX, 13108 Saint Paul-Lez-Durance, France.
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14
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Overexpression of malic enzyme isoform 2 in Chlamydomonas reinhardtii PTS42 increases lipid production. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.biteb.2019.100239] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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15
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Kugler A, Zorin B, Didi-Cohen S, Sibiryak M, Gorelova O, Ismagulova T, Kokabi K, Kumari P, Lukyanov A, Boussiba S, Solovchenko A, Khozin-Goldberg I. Long-Chain Polyunsaturated Fatty Acids in the Green Microalga Lobosphaera incisa Contribute to Tolerance to Abiotic Stresses. PLANT & CELL PHYSIOLOGY 2019; 60:1205-1223. [PMID: 30668793 DOI: 10.1093/pcp/pcz013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/15/2019] [Indexed: 05/16/2023]
Abstract
Lobosphaera incisa is a green microalga that accumulates high levels of the valuable omega-6 long-chain polyunsaturated fatty acids (LC-PUFA) arachidonic acid (ARA, 20:4n-6) in triacylglycerols (TAG) under nitrogen (N) starvation. LC-PUFA accumulation is a rare trait in photosynthetic microalgae with insufficiently understood physiological significance. In this study, RNAi was attempted, for the first time in L. incisa, to produce knockdown lines for the Δ5 desaturase gene. Two lines, termed modified lines, which were isolated during screening for transgenic events, demonstrated alterations in their LC-PUFA profile, ARA-biosynthesis gene expression and lipid class distribution. In line M5-78, which appeared to carry a mutation in the Δ6 elongase gene, LC-PUFA were substituted by 18:3n-6 in all glycerolipids. Line M2-35, for which the exact genetic background has not been established, displayed a dramatic reduction in 20:4n-6, concomitant with an augmented proportion of 18:1n-9, in particular in the extraplastidial membrane lipids and TAG. The physiological responses of the modified lines to stressful conditions were compared with the wild type and the Δ5 desaturase mutant. In the N-replete cells of modified lines, the frequency of lipid droplets was reduced, while a number of starch grains increased, suggesting altered partitioning of assimilated carbon into reserve products. Furthermore, both lines exhibited reduced ability to accumulate TAG under N deprivation and recover from N starvation. Both lines demonstrated lower photosynthetic pigment contents, impairments in photosynthesis under a range of stressful conditions, and less efficient functioning of photoprotection under optimal conditions. Possible implications of fatty acids modifications in the stress response of L. incisa are addressed.
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Affiliation(s)
- Amit Kugler
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Boris Zorin
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Shoshana Didi-Cohen
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Maria Sibiryak
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Olga Gorelova
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
| | - Tatiana Ismagulova
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
| | - Kamilya Kokabi
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Puja Kumari
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Alexander Lukyanov
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
| | - Sammy Boussiba
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
| | - Alexei Solovchenko
- Faculty of Biology, Department of Bioengineering, Moscow State University, GSP-1, Moscow, Russia
- Institute of Agriculture and Technology, Peoples Friendship University of Russia (RUDN University), Moscow, Russia
| | - Inna Khozin-Goldberg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology for Drylands, The J. Blaustein Institutes for Desert Research Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, Israel
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16
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Sun XM, Ren LJ, Zhao QY, Ji XJ, Huang H. Enhancement of lipid accumulation in microalgae by metabolic engineering. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:552-566. [DOI: 10.1016/j.bbalip.2018.10.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/30/2018] [Accepted: 10/05/2018] [Indexed: 01/08/2023]
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17
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Li-Beisson Y, Thelen JJ, Fedosejevs E, Harwood JL. The lipid biochemistry of eukaryotic algae. Prog Lipid Res 2019; 74:31-68. [PMID: 30703388 DOI: 10.1016/j.plipres.2019.01.003] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/06/2023]
Abstract
Algal lipid metabolism fascinates both scientists and entrepreneurs due to the large diversity of fatty acyl structures that algae produce. Algae have therefore long been studied as sources of genes for novel fatty acids; and, due to their superior biomass productivity, algae are also considered a potential feedstock for biofuels. However, a major issue in a commercially viable "algal oil-to-biofuel" industry is the high production cost, because most algal species only produce large amounts of oils after being exposed to stress conditions. Recent studies have therefore focused on the identification of factors involved in TAG metabolism, on the subcellular organization of lipid pathways, and on interactions between organelles. This has been accompanied by the development of genetic/genomic and synthetic biological tools not only for the reference green alga Chlamydomonas reinhardtii but also for Nannochloropsis spp. and Phaeodactylum tricornutum. Advances in our understanding of enzymes and regulatory proteins of acyl lipid biosynthesis and turnover are described herein with a focus on carbon and energetic aspects. We also summarize how changes in environmental factors can impact lipid metabolism and describe present and potential industrial uses of algal lipids.
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Affiliation(s)
- Yonghua Li-Beisson
- Aix-Marseille Univ, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F-13108, France.
| | - Jay J Thelen
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - Eric Fedosejevs
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
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18
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Kim J, Liu L, Hu Z, Jin E. Identification and Functional Analysis of the psaD Promoter of Chlorella vulgaris Using Heterologous Model Strains. Int J Mol Sci 2018; 19:E1969. [PMID: 29986409 PMCID: PMC6073903 DOI: 10.3390/ijms19071969] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 06/22/2018] [Accepted: 07/05/2018] [Indexed: 12/18/2022] Open
Abstract
Chlorella has great potential as a bio-factory for production of value-added compounds. To produce the desired chemicals more efficiently in Chlorella, genetic tools for modification of Chlorella need to be developed, especially an endogenous promoter. In this study, the promoter of photosystem I protein D (psaD) from Chlorella vulgaris UTEX395 was identified. Computational analysis revealed the presence of several putative cis-acting elements, including a potential core element, and light-responsive or stress-responsive elements. Gene expression analysis in heterologous expression system in Chlamydomonasreinhardtii and Nicotianabenthamiana showed that CvpsaD promoter can be used to drive the expression of genes. Functional analysis of this promoter suggested that the initiator element (Inr) is important for its function (i.e., TATA-less promoter) and that an additional factor (e.g., downstream of the transcriptional start site) might be needed for light response. We have shown that the CvpsaD promoter is functional, but not sufficiently strong, both in microalgae and higher plant.
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Affiliation(s)
- Jongrae Kim
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 04763, Korea.
| | - Linpo Liu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Zanmin Hu
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
| | - EonSeon Jin
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 04763, Korea.
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19
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McKie-Krisberg ZM, Laurens LM, Huang A, Polle JE. Comparative energetics of carbon storage molecules in green algae. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.01.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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20
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Grand Challenges in Marine Biotechnology: Overview of Recent EU-Funded Projects. GRAND CHALLENGES IN MARINE BIOTECHNOLOGY 2018. [DOI: 10.1007/978-3-319-69075-9_11] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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21
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De novo transcriptomic and metabolomic analysis of docosahexaenoic acid (DHA)-producing Crypthecodinium cohnii during fed-batch fermentation. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.07.031] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Pal-Nath D, Didi-Cohen S, Shtaida N, Nath PR, Samani T, Boussiba S, Khozin-Goldberg I. Improved productivity and oxidative stress tolerance under nitrogen starvation is associated with the ablated Δ5 desaturation in the green microalga Lobosphaera incisa. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.06.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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23
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Zorin B, Pal-Nath D, Lukyanov A, Smolskaya S, Kolusheva S, Didi-Cohen S, Boussiba S, Cohen Z, Khozin-Goldberg I, Solovchenko A. Arachidonic acid is important for efficient use of light by the microalga Lobosphaera incisa under chilling stress. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:853-868. [DOI: 10.1016/j.bbalip.2017.04.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/25/2017] [Accepted: 04/30/2017] [Indexed: 12/11/2022]
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24
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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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25
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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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26
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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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27
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Stress-induced neutral lipid biosynthesis in microalgae - Molecular, cellular and physiological insights. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1269-1281. [PMID: 26883557 DOI: 10.1016/j.bbalip.2016.02.008] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/04/2016] [Accepted: 02/07/2016] [Indexed: 01/01/2023]
Abstract
Photosynthetic microalgae have promise as biofuel feedstock. Under certain conditions, they produce substantial amounts of neutral lipids, mainly in the form of triacylglycerols (TAGs), which can be converted to fuels. Much of our current knowledge on the genetic and molecular basis of algal neutral lipid metabolism derives mainly from studies of plants, i.e. seed tissues, and to a lesser extent from direct studies of algal lipid metabolism. Thus, the knowledge of TAG synthesis and the cellular trafficking of TAG precursors in algal cells is to a large extent based on genome predictions, and most aspects of TAG metabolism have yet to be experimentally verified. The biofuel prospects of microalgae have raised the interest in mechanistic studies of algal TAG biosynthesis in recent years and resulted in an increasing number of publications on lipid metabolism in microalgae. In this review we summarize the current findings on genetic, molecular and physiological studies of TAG accumulation in microalgae. Special emphasis is on the functional analysis of key genes involved in TAG synthesis, molecular mechanisms of regulation of TAG biosynthesis, as well as on possible mechanisms of lipid droplet formation in microalgal cells. This article is part of a Special Issue entitled: Plant Lipid Biology edited by Kent D. Chapman and Ivo Feussner.
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Burgess SJ, Taha H, Yeoman JA, Iamshanova O, Chan KX, Boehm M, Behrends V, Bundy JG, Bialek W, Murray JW, Nixon PJ. Identification of the Elusive Pyruvate Reductase of Chlamydomonas reinhardtii Chloroplasts. PLANT & CELL PHYSIOLOGY 2016; 57:82-94. [PMID: 26574578 PMCID: PMC4722173 DOI: 10.1093/pcp/pcv167] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 10/27/2015] [Indexed: 05/19/2023]
Abstract
Under anoxic conditions the green alga Chlamydomonas reinhardtii activates various fermentation pathways leading to the creation of formate, acetate, ethanol and small amounts of other metabolites including d-lactate and hydrogen. Progress has been made in identifying the enzymes involved in these pathways and their subcellular locations; however, the identity of the enzyme involved in reducing pyruvate to d-lactate has remained unclear. Based on sequence comparisons, enzyme activity measurements, X-ray crystallography, biochemical fractionation and analysis of knock-down mutants, we conclude that pyruvate reduction in the chloroplast is catalyzed by a tetrameric NAD(+)-dependent d-lactate dehydrogenase encoded by Cre07.g324550. Its expression during aerobic growth supports a possible function as a 'lactate valve' for the export of lactate to the mitochondrion for oxidation by cytochrome-dependent d-lactate dehydrogenases and by glycolate dehydrogenase. We also present a revised spatial model of fermentation based on our immunochemical detection of the likely pyruvate decarboxylase, PDC3, in the cytoplasm.
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Affiliation(s)
- Steven J Burgess
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK These authors contributed equally to this work
| | - Hussein Taha
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK These authors contributed equally to this work Present address: Faculty of Science, Universiti Brunei Darussalam, Jalan Tungku Link, BE1410, Brunei Darussalam
| | - Justin A Yeoman
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Oksana Iamshanova
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Kher Xing Chan
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Marko Boehm
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Volker Behrends
- Department of Biomolecular Medicine, Sir Alexander Fleming Building, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Jacob G Bundy
- Department of Biomolecular Medicine, Sir Alexander Fleming Building, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Wojciech Bialek
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - James W Murray
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
| | - Peter J Nixon
- Department of Life Sciences, Sir Ernst Chain Building-Wolfson Laboratories, Imperial College London, S. Kensington Campus, London SW7 2AZ, UK
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Avidan O, Pick U. Acetyl-CoA synthetase is activated as part of the PDH-bypass in the oleaginous green alga Chlorella desiccata. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:7287-98. [PMID: 26357883 PMCID: PMC4765794 DOI: 10.1093/jxb/erv424] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
In a recent study, it has been shown that biosynthesis of triacylglycerol (TAG) in the oleaginous green alga Chlorella desiccata is preceded by a large increase in acetyl-coenzyme A (Ac-CoA) levels and by upregulation of plastidic pyruvate dehydrogenase (ptPDH). It was proposed that the capacity to accumulate high TAG critically depends on enhanced production of Ac-CoA. In this study, two alternative Ac-CoA producers-plastidic Ac-CoA synthase (ptACS) and ATP citrate lyase (ACL)-are shown to be upregulated prior to TAG accumulation under nitrogen deprivation in the oleaginous species C. desiccata, but not in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Measurements of endogenous acetate production and of radiolabelled acetate incorporation into lipids are consistent with the upregulation of ptACS, but suggest that its contribution to the overall TAG biosynthesis is negligible. Induction of ACS and production of endogenous acetate are correlated with activation of alcohol dehydrogenase, suggesting that the upregulation of ptACS is associated with activation of PDH-bypass in C. desiccata. It is proposed that activation of the PDH-bypass in C. desiccata is needed to enable a high rate of lipid biosynthesis under nitrogen deprivation by controlling the level of pyruvate reaching ptPHD and/or mtPDH. This may be an important parameter for massive TAG accumulation in microalgae.
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Affiliation(s)
- Omri Avidan
- Department of Biological Chemistry, The Weizmann institute of Science, Rehovot 76100, Israel
| | - Uri Pick
- Department of Biological Chemistry, The Weizmann institute of Science, Rehovot 76100, Israel
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Shtaida N, Khozin-Goldberg I, Boussiba S. The role of pyruvate hub enzymes in supplying carbon precursors for fatty acid synthesis in photosynthetic microalgae. PHOTOSYNTHESIS RESEARCH 2015; 125:407-22. [PMID: 25846135 DOI: 10.1007/s11120-015-0136-7] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Accepted: 03/27/2015] [Indexed: 05/15/2023]
Abstract
Photosynthetic microalgae are currently the focus of basic and applied research due to an ever-growing interest in renewable energy resources. This review discusses the role of carbon-unit supply for the production of acetyl-CoA, a direct precursor of fatty acid biosynthesis and the primary building block of the growing acyl chains for the purpose of triacylglycerol (TAG) production in photosynthetic microalgae under stressful conditions. It underscores the importance of intraplastidic acetyl-CoA generation for storage lipid accumulation. The main focus is placed on two enzymatic steps linking the central carbon metabolism and fatty acid synthesis, namely the reactions catalyzed by the plastidic isoform of pyruvate kinase and the chloroplastic pyruvate dehydrogenase complex. Alternative routes for plastidic acetyl-CoA synthesis are also reviewed. A separate section is devoted to recent advances in functional genomics studies related to fatty acid and TAG biosynthesis.
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Affiliation(s)
- Nastassia Shtaida
- Microalgal Biotechnology Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, J. Blaustein Institutes of Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Midreshet Ben-Gurion, Israel
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Solovchenko AE. Recent breakthroughs in the biology of astaxanthin accumulation by microalgal cell. PHOTOSYNTHESIS RESEARCH 2015; 125:437-49. [PMID: 25975708 DOI: 10.1007/s11120-015-0156-3] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 05/06/2015] [Indexed: 05/09/2023]
Abstract
Massive accumulation of the secondary ketokarotenoid astaxanthin is a characteristic stress response of certain microalgal species with Haematococcus pluvialis as an illustrious example. The carotenogenic response confers these organisms a remarkable ability to survive in extremely unfavorable environments and makes them the richest source of natural astaxanthin. Exerting a plethora of beneficial effects on human and animal health, astaxanthin is among the most important bioproducts from microalgae. Though our understanding of astaxanthin biosynthesis, induction, and regulation is far from complete, this gap is filling rapidly with new knowledge generated predominantly by application of advanced "omics" approaches. This review focuses on the most recent progress in the biology of astaxanthin accumulation in microalgae including the genomic, proteomic, and metabolomics insights into the induction and regulation of secondary carotenogenesis and its role in stress tolerance of the photosynthetic microorganisms. Special attention is paid to the coupling of the carotenoid and lipid biosynthesis as well as deposition of astaxanthin in the algal cell. The place of the carotenogenic response among the stress tolerance mechanisms is revisited, and possible implications of the new findings for biotechnological production of astaxanthin from microalgae are considered. The potential use of the carotenogenic microalgae as a source not only of value-added carotenoids, but also of biofuel precursors is discussed.
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Affiliation(s)
- Alexei E Solovchenko
- Department of Bioengineering, Faculty of Biology, Lomonosov Moscow State University, Moscow, 119234, Russia,
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Kim BJ, Richter LV, Hatter N, Tung CK, Ahner BA, Wu M. An array microhabitat system for high throughput studies of microalgal growth under controlled nutrient gradients. LAB ON A CHIP 2015; 15:3687-3694. [PMID: 26248065 DOI: 10.1039/c5lc00727e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Microalgae have been increasingly recognized in the fields of environmental and biomedical engineering because of its use as base materials for biofuels or biomedical products, and also the urgent needs to control harmful algal blooms protecting water resources worldwide. Central to the theme is the growth rate of microalgae under the influences of various environmental cues including nutrients, pH, oxygen tension and light intensity. Current microalgal culture systems, e.g. raceway ponds or chemostats, are not designed for system parameter optimizations of cell growth. In this article, we present the development of an array microfluidic system for high throughput studies of microalgal growth under well defined environmental conditions. The microfluidic platform consists of an array of microhabitats flanked by two parallel side channels, all of which are patterned in a thin agarose gel membrane. The unique feature of the device is that each microhabitat is physically confined suitable for both motile and non-motile cell culture, and at the same time, the device is transparent and can be perfused through the two side channels amendable for precise environmental control of photosynthetic microorganisms. This microfluidic system is used to study the growth kinetics of a model microalgal strain, Chlamydomonas reinhardtii (C. reinhardtii), under ammonium (NH4Cl) concentration gradients. Experimental results show that C. reinhardtii follows Monod growth kinetics with a half-saturation constant of 1.2 ± 0.3 μM. This microfluidic platform provides a fast (~50 fold speed increase), cost effective (less reagents and human intervention) and quantitative technique for microalgal growth studies, in contrast to the current chemostat or batch cell culture system. It can be easily extended to investigate growth kinetics of other microorganisms under either single or co-culture setting.
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Affiliation(s)
- Beum Jun Kim
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY, USA.
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Avidan O, Brandis A, Rogachev I, Pick U. Enhanced acetyl-CoA production is associated with increased triglyceride accumulation in the green alga Chlorella desiccata. JOURNAL OF EXPERIMENTAL BOTANY 2015; 66:3725-35. [PMID: 25922486 PMCID: PMC4473976 DOI: 10.1093/jxb/erv166] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Triglycerides (TAGs) from microalgae can be utilized as food supplements and for biodiesel production, but little is known about the regulation of their biosynthesis. This work aimed to test the relationship between acetyl-CoA (Ac-CoA) levels and TAG biosynthesis in green algae under nitrogen deprivation. A novel, highly sensitive liquid chromatography mass spectrometry (LC-MS/MS) technique enabled us to determine the levels of Ac-CoA, malonyl-CoA, and unacetylated (free) CoA in green microalgae. A comparative study of three algal species that differ in TAG accumulation levels shows that during N starvation, Ac-CoA levels rapidly rise, preceding TAG accumulation in all tested species. The levels of Ac-CoA in the high TAG accumulator Chlorella desiccata exceed the levels in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Similarly, malonyl-CoA and free CoA levels also increase, but to lower extents. Calculated cellular concentrations of Ac-CoA are far lower than reported K mAc-CoA values of plastidic Ac-CoA carboxylase (ptACCase) in plants. Transcript level analysis of plastidic pyruvate dehydrogenase (ptPDH), the major chloroplastic Ac-CoA producer, revealed rapid induction in parallel with Ac-CoA accumulation in C. desiccata, but not in D. tertiolecta or C. reinhardtii. It is proposed that the capacity to accumulate high TAG levels in green algae critically depends on their ability to divert carbon flow towards Ac-CoA. This requires elevation of the chloroplastic CoA pool level and enhancement of Ac-CoA biosynthesis. These conclusions may have important implications for future genetic manipulation to enhance TAG biosynthesis in green algae.
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Affiliation(s)
- Omri Avidan
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alexander Brandis
- Biological Services Unit, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ilana Rogachev
- Department of Plant and Environmental Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Uri Pick
- Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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