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Zhang YT, Jiang JY, Shi TQ, Sun XM, Zhao QY, Huang H, Ren LJ. Application of the CRISPR/Cas system for genome editing in microalgae. Appl Microbiol Biotechnol 2019; 103:3239-3248. [PMID: 30877356 DOI: 10.1007/s00253-019-09726-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 02/25/2019] [Accepted: 02/25/2019] [Indexed: 12/12/2022]
Abstract
Microalgae are arguably the most abundant single-celled eukaryotes and are widely distributed in oceans and freshwater lakes. Moreover, microalgae are widely used in biotechnology to produce bioenergy and high-value products such as polyunsaturated fatty acids (PUFAs), bioactive peptides, proteins, antioxidants and so on. In general, genetic editing techniques were adapted to increase the production of microalgal metabolites. The main genome editing tools available today include zinc finger nucleases (ZFNs), transcriptional activator-like effector nucleases (TALENs), and the clustered regularly interspaced short palindromic repeats (CRISPR)/Cas nuclease system. Due to its high genome editing efficiency, the CRISPR/Cas system is emerging as the most important genome editing method. In this review, we summarized the available literature on the application of CRISPR/Cas in microalgal genetic engineering, including transformation methods, strategies for the expression of Cas9 and sgRNA, the CRISPR/Cas9-mediated gene knock-in/knock-out strategies, and CRISPR interference expression modification strategies.
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Affiliation(s)
- Yu-Ting Zhang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
| | - Jia-Yi Jiang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
| | - Tian-Qiong Shi
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
| | - Xiao-Man Sun
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
| | - Quan-Yu Zhao
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
| | - He Huang
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
- School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
- State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, No. 5 Xinmofan Road, Nanjing, 210009, People's Republic of China
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Wenyuan Road, Nanjing, 210023, People's Republic of China
| | - Lu-Jing Ren
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China.
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China.
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Liang Y, Kong F, Torres-Romero I, Burlacot A, Cuine S, Légeret B, Billon E, Brotman Y, Alseekh S, Fernie AR, Beisson F, Peltier G, Li-Beisson Y. Branched-Chain Amino Acid Catabolism Impacts Triacylglycerol Homeostasis in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2019; 179:1502-1514. [PMID: 30728273 PMCID: PMC6446750 DOI: 10.1104/pp.18.01584] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/30/2019] [Indexed: 05/05/2023]
Abstract
Nitrogen (N) starvation-induced triacylglycerol (TAG) synthesis, and its complex relationship with starch metabolism in algal cells, has been intensively studied; however, few studies have examined the interaction between amino acid metabolism and TAG biosynthesis. Here, via a forward genetic screen for TAG homeostasis, we isolated a Chlamydomonas (Chlamydomonas reinhardtii) mutant (bkdE1α) that is deficient in the E1α subunit of the branched-chain ketoacid dehydrogenase (BCKDH) complex. Metabolomics analysis revealed a defect in the catabolism of branched-chain amino acids in bkdE1α Furthermore, this mutant accumulated 30% less TAG than the parental strain during N starvation and was compromised in TAG remobilization upon N resupply. Intriguingly, the rate of mitochondrial respiration was 20% to 35% lower in bkdE1α compared with the parental strains. Three additional knockout mutants of the other components of the BCKDH complex exhibited phenotypes similar to that of bkdE1α Transcriptional responses of BCKDH to different N status were consistent with its role in TAG homeostasis. Collectively, these results indicate that branched-chain amino acid catabolism contributes to TAG metabolism by providing carbon precursors and ATP, thus highlighting the complex interplay between distinct subcellular metabolisms for oil storage in green microalgae.
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Affiliation(s)
- Yuanxue Liang
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Fantao Kong
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Ismael Torres-Romero
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Adrien Burlacot
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Stéphan Cuine
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Bertrand Légeret
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Emmanuelle Billon
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Yariv Brotman
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Saleh Alseekh
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Fred Beisson
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Gilles Peltier
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Yonghua Li-Beisson
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
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Liang J, Wen F, Liu J. Transcriptomic and lipidomic analysis of an EPA-containing Nannochloropsis sp. PJ12 in response to nitrogen deprivation. Sci Rep 2019; 9:4540. [PMID: 30872742 PMCID: PMC6418175 DOI: 10.1038/s41598-019-41169-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 03/01/2019] [Indexed: 12/30/2022] Open
Abstract
To understand genes involved in neutral lipid accumulation upon nitrogen deprivation (ND) in a novel isolate of Nannochloropsis sp. PJ12, we performed comparative transcriptomic and lipidomic analyses of cells under ND and NR (nitrogen replete) conditions. Transcriptomic profiling indicated that, while enzymes involved in TCA cycle in PJ12 under ND condition were upregulated compared to that under NR condition, those involved in Calvin cycle and glycolysis under ND condition were downregulated. Furthermore, we showed that enzymes involved in fatty acid synthesis and glycerolipid synthesis were downregulated but not β-oxidation. Lipidomic profiling indicated that, while the level of neutral lipids in ND cells was increased compared to that of NR cells, level of photosynthetic membrane-lipids DGDG and PG was decreased. Taken together, our analysis indicated that TAG accumulation is attributed to the modification of membrane lipids derived primarily from “prokaryotic” pathway and secondarily from “eukaryotic” pathway based on the 16:X or 18:X fatty acid at the sn2 position of the glycerol backbone. We propose that two-phase (NR-ND) growth is ideal for biomass and biofuel production because ND reduces cell growth rate due to the loss of photosynthetic membrane and decreased quantum yield.
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Affiliation(s)
- Jibei Liang
- Ocean College, Zhejiang University, Zhoushan, ZJ316000, China
| | - Fang Wen
- Ocean College, Zhejiang University, Zhoushan, ZJ316000, China
| | - Jianhua Liu
- Ocean College, Zhejiang University, Zhoushan, ZJ316000, China. .,Ocean Research Center of Zhoushan, Zhoushan, ZJ316021, China.
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High level of reactive oxygen species inhibits triacylglycerols accumulation in Chlamydomonas reinhardtii. ALGAL RES 2019. [DOI: 10.1016/j.algal.2018.101400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Vishwakarma R, Dhar DW, Saxena S. Influence of nutrient formulations on growth, lipid yield, carbon partitioning and biodiesel quality potential of Botryococcus sp. and Chlorella sp. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:7589-7600. [PMID: 30659489 DOI: 10.1007/s11356-019-04213-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 01/09/2019] [Indexed: 06/09/2023]
Abstract
The study was conducted to analyse the influence of three nutrient formulations, namely BG-11 medium, BBM and TAP medium, on growth potential and lipid yield of two microalgal genera (Botryococcus sp. and Chlorella sp.) and to study the roles of N, P and other major nutrients. The study focussed on the general patterns of starch and lipid synthesis and storage and to further assess how photosynthetic carbon partitioning into starch and lipid is altered by conditions in growth media such as N and C presence as seen in BG11 medium which are known to induce neutral lipid production and the lack of it in BBM and TAP medium. BG-11 medium performed better as compared to BBM and TAP medium in terms of biomass productivity and lipid yield. The lipid yield was highest in Botryococcus sp. (63.03% dry wt.) and Chlorella sp. (50.27% dry wt.) at 30th day of incubation. Mean biomass productivity was highest for Botryococcus in BBM medium (6.14 mg/L/day) and for Chlorella in BG-11 medium (4.97 mg/L/day). Mean lipid productivity (50.78% and 39.36%) was highest in BG11 medium for both Botryococcus and Chlorella species, respectively. A sharp decline in sugar content was observed in the late stationary phase of growth from 30th day to 45th day. Fatty acid methyl ester (FAME) profile of the extracted lipids showed predominantly oleic acid, followed by palmitic acid and stearic acid in both the strains when grown in BG-11 medium. The other biodiesel quality parameters were in accordance with the international standards. A complex relationship was found between chemical composition and biodiesel properties. Proximity analysis indicated that the fuel properties of biodiesels are determined by a number of parameters and by the combination of different chemical compositions. The results provide an insight into organic carbon partitioning into lipid compounds and how the organism's lipid metabolism changes due to N-deplete culturing in TAP medium and inorganic carbon source availability as seen in BG-11 and BBM medium.
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Affiliation(s)
- Rashi Vishwakarma
- Centre for Conservation and Utilisation of Blue Green Algae, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India.
| | - Dolly Wattal Dhar
- Centre for Conservation and Utilisation of Blue Green Algae, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
| | - Sudhir Saxena
- Centre for Conservation and Utilisation of Blue Green Algae, ICAR-Indian Agricultural Research Institute, New Delhi, 110012, India
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Batista AD, Rosa RM, Machado M, Magalhães AS, Shalaguti BA, Gomes PF, Covell L, Vaz MGMV, Araújo WL, Nunes-Nesi A. Increased urea availability promotes adjustments in C/N metabolism and lipid content without impacting growth in Chlamydomonas reinhardtii. Metabolomics 2019; 15:31. [PMID: 30830512 DOI: 10.1007/s11306-019-1496-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 02/21/2019] [Indexed: 01/31/2023]
Abstract
INTRODUCTION The use of urea as a nitrogen (N) source by Chlorophytes usually enhances biomass and lipid production when compared to ammonium (NH4+). However, the metabolic shifts displayed by Chlamydomonas reinhardtii growing with this organic N source are not known. OBJECTIVES This study aimed: (i) to characterize the metabolism of C. reinhardtii cultivated in media containing only urea as N source as well as combined with different NH4+ ratios; (ii) to understand how metabolism respond to urea availability. METHODS Specific quantification of metabolites using 96-well microplates, and high-performance liquid chromatography combined with non-targeted metabolite profiling by gas chromatography (GC)-time-of-flight (TOF)-mass spectrometry (MS) were used in this study. In addition, GC analysis was used to determine fatty acid profiling. RESULTS The use of urea did not alter the growth rate in comparison with NH4+. Interestingly, the cell number decreased and the cell size increased proportionally with urea availability. Furthermore, chlorophyll, protein and lipid contents increased with the amount of urea. Regarding the fatty acid profile, oleic acid (C18:1 w8) decreased with amount of urea, while linoleic acid (C18:2 w6) doubled in urea-containing medium. CONCLUSIONS These results indicate that urea promotes remarkable adjustments in metabolism, without drastic changes in biomass, promoting changes in carbohydrate and amino acid metabolism, as well as in lipids production and fatty acid profile.
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Affiliation(s)
- Aline D Batista
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Rinamara M Rosa
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Mariana Machado
- Instituto de Biociências, Universidade Federal de Goiás - Regional Jataí, Jataí, Goiás, 75801-615, Brazil
| | - Alan S Magalhães
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Bárbara A Shalaguti
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Priscilla F Gomes
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Lidiane Covell
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Marcelo G M V Vaz
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
- Max-Planck Partner Group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, Minas Gerais, 36570-900, Brazil.
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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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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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Remmers IM, D'Adamo S, Martens DE, de Vos RC, Mumm R, America AH, Cordewener JH, Bakker LV, Peters SA, Wijffels RH, Lamers PP. Orchestration of transcriptome, proteome and metabolome in the diatom Phaeodactylum tricornutum during nitrogen limitation. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.08.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Poliner E, Farré EM, Benning C. Advanced genetic tools enable synthetic biology in the oleaginous microalgae Nannochloropsis sp. PLANT CELL REPORTS 2018; 37:1383-1399. [PMID: 29511798 DOI: 10.1007/s00299-018-2270-0] [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: 12/08/2017] [Accepted: 02/26/2018] [Indexed: 05/16/2023]
Abstract
Nannochloropsis is a genus of fast-growing microalgae that are regularly used for biotechnology applications. Nannochloropsis species have a high triacylglycerol content and their polar lipids are rich in the omega-3 long-chain polyunsaturated fatty acid, eicosapentaenoic acid. Placed in the heterokont lineage, the Nannochloropsis genus has a complex evolutionary history. Genome sequences are available for several species, and a number of transcriptomic datasets have been produced, making this genus a facile model for comparative genomics. There is a growing interest in Nannochloropsis species as models for the study of microalga lipid metabolism and as a chassis for synthetic biology. Recently, techniques for gene stacking, and targeted gene disruption and repression in the Nannochloropsis genus have been developed. These tools enable gene-specific, mechanistic studies and have already allowed the engineering of improved Nannochloropsis strains with superior growth, or greater bioproduction.
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Affiliation(s)
- Eric Poliner
- Cell and Molecular Biology Program, Michigan State University, East Lansing, MI, USA
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Eva M Farré
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
| | - Christoph Benning
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA.
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA.
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA.
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Wirth R, Lakatos G, Böjti T, Maróti G, Bagi Z, Rákhely G, Kovács KL. Anaerobic gaseous biofuel production using microalgal biomass – A review. Anaerobe 2018; 52:1-8. [DOI: 10.1016/j.anaerobe.2018.05.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/16/2018] [Accepted: 05/22/2018] [Indexed: 12/17/2022]
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Takahashi K, Ide Y, Hayakawa J, Yoshimitsu Y, Fukuhara I, Abe J, Kasai Y, Harayama S. Lipid productivity in TALEN-induced starchless mutants of the unicellular green alga Coccomyxa sp. strain Obi. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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Fei Q, Puri AW, Smith H, Dowe N, Pienkos PT. Enhanced biological fixation of methane for microbial lipid production by recombinant Methylomicrobium buryatense. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:129. [PMID: 29755588 PMCID: PMC5934843 DOI: 10.1186/s13068-018-1128-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Accepted: 04/23/2018] [Indexed: 05/24/2023]
Abstract
BACKGROUND Due to the success of shale gas development in the US, the production cost of natural gas has been reduced significantly, which in turn has made methane (CH4), the major component of natural gas, a potential alternative substrate for bioconversion processes compared with other high-price raw material sources or edible feedstocks. Therefore, exploring effective ways to use CH4 for the production of biofuels is attractive. Biological fixation of CH4 by methanotrophic bacteria capable of using CH4 as their sole carbon and energy source has obtained great attention for biofuel production from this resource. RESULTS In this study, a fast-growing and lipid-rich methanotroph, Methylomicrobium buryatense 5GB1 and its glycogen-knock-out mutant (AP18) were investigated for the production of lipids derived from intracellular membranes, which are key precursors for the production of green diesel. The effects of culture conditions on cell growth and lipid production were investigated in high cell density cultivation with continuous feeding of CH4 and O2. The highest dry cell weight observed was 21.4 g/L and the maximum lipid productivity observed was 45.4 mg/L/h obtained in batch cultures, which corresponds to a 2-fold enhancement in cell density and 3-fold improvement in lipid production, compared with previous reported data from cultures of 5GB1. A 90% enhancement of lipid content was achieved by limiting the biosynthesis of glycogen in strain AP18. Increased CH4/O2 uptake and CO2 evaluation rates were observed in AP18 cultures suggesting that more carbon substrate and energy are needed for AP18 growth while producing lipids. The lipid produced by M. buryatense was estimated to have a cetane number of 75, which is 50% higher than biofuel standards requested by US and EU. CONCLUSIONS Cell growth and lipid production were significantly influenced by culture conditions for both 5GB1 and AP18. Enhanced lipid production in terms of titer, productivity, and content was achieved under high cell density culture conditions by blocking glycogen accumulation as a carbon sink in the strain AP18. Differences observed in CH4/O2 gas uptake and CO2 evolution rates as well as cell growth and glycogen accumulation between 5GB1 and AP18 suggest changes in the metabolic network between these strains. This bioconversion process provides a promising opportunity to transform CH4 into biofuel molecules and encourages further investigation to elucidate the remarkable CH4 biofixation mechanism used by these bacteria.
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Affiliation(s)
- Qiang Fei
- School of Chemical Engineering and Technology, Xi’an Jiaotong University, Xi’an, China
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Aaron W. Puri
- Department of Chemical Engineering, University of Washington, Seattle, WA USA
| | - Holly Smith
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Nancy Dowe
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
| | - Philip. T. Pienkos
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO USA
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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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66
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The impact of day length on cell division and efficiency of light use in a starchless mutant of Tetradesmus obliquus. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.02.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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67
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Can We Approach Theoretical Lipid Yields in Microalgae? Trends Biotechnol 2018; 36:265-276. [DOI: 10.1016/j.tibtech.2017.10.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/29/2017] [Accepted: 10/30/2017] [Indexed: 11/17/2022]
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Tsai CH, Uygun S, Roston R, Shiu SH, Benning C. Recovery from N Deprivation Is a Transcriptionally and Functionally Distinct State in Chlamydomonas. PLANT PHYSIOLOGY 2018; 176:2007-2023. [PMID: 29288234 PMCID: PMC5841715 DOI: 10.1104/pp.17.01546] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 12/26/2017] [Indexed: 05/20/2023]
Abstract
Facing adverse conditions such as nitrogen (N) deprivation, microalgae enter cellular quiescence, a reversible cell cycle arrest with drastic changes in metabolism allowing cells to remain viable. Recovering from N deprivation and quiescence is an active and orderly process as we are showing here for Chlamydomonas reinhardtii We conducted comparative transcriptomics on this alga to discern processes relevant to quiescence in the context of N deprivation and recovery following refeeding. A mutant with slow recovery from N deprivation, compromised hydrolysis of triacylglycerols7 (cht7), was included to better define the regulatory processes governing the respective transitions. We identified an ordered set of biological processes with expression patterns that showed sequential reversal following N resupply and uncovered acclimation responses specific to the recovery phase. Biochemical assays and microscopy validated selected inferences made based on the transcriptional analyses. These comprise (1) the restoration of N source preference and cellular bioenergetics during the early stage of recovery; (2) flagellum-based motility in the mid to late stage of recovery; and (3) recovery phase-specific gene groups cooperating in the rapid replenishment of chloroplast proteins. In the cht7 mutant, a large number of programmed responses failed to readjust in a timely manner. Finally, evidence is provided for the involvement of the cAMP-protein kinase A pathway in gating the recovery. We conclude that the recovery from N deprivation represents not simply a reversal of processes directly following N deprivation, but a distinct cellular state.
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Affiliation(s)
- Chia-Hong Tsai
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Sahra Uygun
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Genetics Program, Michigan State University, East Lansing, Michigan 48824
| | - Rebecca Roston
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Shin-Han Shiu
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Genetics Program, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- Department of Energy Plant Research Laboratory, 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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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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Critical steps in carbon metabolism affecting lipid accumulation and their regulation in oleaginous microorganisms. Appl Microbiol Biotechnol 2018; 102:2509-2523. [DOI: 10.1007/s00253-018-8813-z] [Citation(s) in RCA: 108] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 01/23/2018] [Accepted: 01/24/2018] [Indexed: 12/11/2022]
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71
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Du ZY, Lucker BF, Zienkiewicz K, Miller TE, Zienkiewicz A, Sears BB, Kramer DM, Benning C. Galactoglycerolipid Lipase PGD1 Is Involved in Thylakoid Membrane Remodeling in Response to Adverse Environmental Conditions in Chlamydomonas. THE PLANT CELL 2018; 30:447-465. [PMID: 29437989 PMCID: PMC5868692 DOI: 10.1105/tpc.17.00446] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 01/25/2018] [Accepted: 02/03/2018] [Indexed: 05/20/2023]
Abstract
Photosynthesis occurs in the thylakoid membrane, where the predominant lipid is monogalactosyldiacylglycerol (MGDG). As environmental conditions change, photosynthetic membranes have to adjust. In this study, we used a loss-of-function Chlamydomonas reinhardtii mutant deficient in the MGDG-specific lipase PGD1 (PLASTID GALACTOGLYCEROLIPID DEGRADATION1) to investigate the link between MGDG turnover, chloroplast ultrastructure, and the production of reactive oxygen species (ROS) in response to different adverse environmental conditions. The pgd1 mutant showed altered MGDG abundance and acyl composition and altered abundance of photosynthesis complexes, with an increased PSII/PSI ratio. Transmission electron microscopy showed hyperstacking of the thylakoid grana in the pgd1 mutant. The mutant also exhibited increased ROS production during N deprivation and high light exposure. Supplementation with bicarbonate or treatment with the photosynthetic electron transport blocker DCMU protected the cells against oxidative stress in the light and reverted chlorosis of pgd1 cells during N deprivation. Furthermore, exposure to stress conditions such as cold and high osmolarity induced the expression of PGD1, and loss of PGD1 in the mutant led to increased ROS production and inhibited cell growth. These findings suggest that PGD1 plays essential roles in maintaining appropriate thylakoid membrane composition and structure, thereby affecting growth and stress tolerance when cells are challenged under adverse conditions.
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Affiliation(s)
- Zhi-Yan Du
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Ben F Lucker
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Krzysztof Zienkiewicz
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, 37073 Goettingen, Germany
| | - Tarryn E Miller
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Agnieszka Zienkiewicz
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University, 37073 Goettingen, Germany
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824
| | - Barbara B Sears
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - David M Kramer
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- U.S. Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
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72
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Moriyama T, Toyoshima M, Saito M, Wada H, Sato N. Revisiting the Algal "Chloroplast Lipid Droplet": The Absence of an Entity That Is Unlikely to Exist. PLANT PHYSIOLOGY 2018; 176:1519-1530. [PMID: 29061905 PMCID: PMC5813570 DOI: 10.1104/pp.17.01512] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 10/19/2017] [Indexed: 05/03/2023]
Abstract
The precise localization of the lipid droplets and the metabolic pathways associated with oil production are crucial to the engineering of microalgae for biofuel production. Several studies have reported detecting lipid droplets within the chloroplast of the microalga Chlamydomonas reinhardtii, which accumulates considerable amounts of triacylglycerol and starch within the cell under nitrogen deprivation or high-light stress conditions. Starch undoubtedly accumulates within the chloroplast, but there have been debates on the localization of the lipid droplets, which are cytosolic organelles in other organisms. Although it is impossible to prove an absence, we tried to repeat experiments that previously indicated the presence of lipid droplets in chloroplasts. Here, we present microscopic results showing no evidence for the presence of lipid droplets within the chloroplast stroma, even though some lipid droplets existed in close association with the chloroplast or were largely engulfed by the chloroplasts. These lipid droplets are cytosolic structures, distinct from the plastoglobules present in the chloroplast stroma. These results not only contrast with the old ideas but also point out that what were previously thought to be chloroplast lipid droplets are likely to be embedded within chloroplast invaginations in association with the outer envelope of the chloroplast without intervention of the endoplasmic reticulum. These findings point to the intriguing possibility of a tight metabolic flow from the chloroplast to the lipid droplet through a close association rather than direct contact of both organelles.
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Affiliation(s)
- Takashi Moriyama
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
- CREST, Japan Science and Technology Agency, Tokyo 102-0076, Japan
| | - Masakazu Toyoshima
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
- CREST, Japan Science and Technology Agency, Tokyo 102-0076, Japan
| | - Masakazu Saito
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
- CREST, Japan Science and Technology Agency, Tokyo 102-0076, Japan
| | - Hajime Wada
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
- CREST, Japan Science and Technology Agency, Tokyo 102-0076, Japan
| | - Naoki Sato
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan
- CREST, Japan Science and Technology Agency, Tokyo 102-0076, Japan
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73
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Tailored carbon partitioning for phototrophic production of (E)-α-bisabolene from the green microalga Chlamydomonas reinhardtii. Metab Eng 2018; 45:211-222. [DOI: 10.1016/j.ymben.2017.12.010] [Citation(s) in RCA: 99] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 11/27/2017] [Accepted: 12/11/2017] [Indexed: 12/20/2022]
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74
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Hao X, Luo L, Jouhet J, Rébeillé F, Maréchal E, Hu H, Pan Y, Tan X, Chen Z, You L, Chen H, Wei F, Gong Y. Enhanced triacylglycerol production in the diatom Phaeodactylum tricornutum by inactivation of a Hotdog-fold thioesterase gene using TALEN-based targeted mutagenesis. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:312. [PMID: 30455741 PMCID: PMC6231261 DOI: 10.1186/s13068-018-1309-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 10/30/2018] [Indexed: 05/18/2023]
Abstract
BACKGROUND In photosynthetic oleaginous microalgae, acyl-CoA molecules are used as substrates for the biosynthesis of membrane glycerolipids, triacylglycerol (TAG) and other acylated molecules. Acyl-CoA can also be directed to beta-oxidative catabolism. They can be utilized by a number of lipid metabolic enzymes including endogenous thioesterases, which catalyze their hydrolysis to release free fatty acids. Acyl-CoA availability thus plays fundamental roles in determining the quantity and composition of membrane lipids and storage lipids. RESULTS Here, we have engineered the model diatom Phaeodactylum tricornutum to produce significantly increased TAGs by disruption of the gene encoding a Hotdog-fold thioesterase involved in acyl-CoA hydrolysis (ptTES1). This plastidial thioesterase can hydrolyze both medium- and long-chain fatty acyl-CoAs, but has the highest activity toward long-chain saturated and monounsaturated fatty acyl-CoAs. The maximum rate was found with oleoyl-CoA, which is hydrolyzed at 50 nmol/min/mg protein. The stable and targeted interruption of acyl-CoA thioesterase gene was achieved using a genome editing technique, transcription activator-like effector nucleases (TALENs). Disruption of native ptTES1 gene resulted in a 1.7-fold increase in TAG content when algal strains were grown in nitrogen-replete media for 8 days, whereas the content of other lipid classes, including phosphoglycerolipids and galactoglycerolipids, remained almost unchanged. The engineered algal strain also exhibited a marked change in fatty acid profile, including a remarkable increase in 16:0 and 16:1 and a decrease in 20:5. Nitrogen deprivation for 72 h further increased TAG content and titer of the engineered strain, reaching 478 μg/109 cells and 4.8 mg/L, respectively. Quantitative determination of in vivo acyl-CoAs showed that the total acyl-CoA pool size was significantly higher in the engineered algal strain than that in the wild type. CONCLUSIONS This study supports the role of ptTES1 in free fatty acid homeostasis in the plastid of Phaeodactylum and demonstrates the potential of TALEN-based genome editing technique to generate an enhanced lipid-producing algal strain through blocking acyl-CoA catabolism.
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Affiliation(s)
- Xiahui Hao
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, No. 2 Xudong Second Road, Wuhan, 430062 People’s Republic of China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Ling Luo
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, No. 2 Xudong Second Road, Wuhan, 430062 People’s Republic of China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale, Centre National de la Recherche Scientifique, Commissariat à l’Energie Atomique et aux Energies Alternatives, Institut National de la Recherche Agronomique, Université Grenoble Alpes, UMR 5168, 38041 Grenoble, France
| | - Fabrice Rébeillé
- Laboratoire de Physiologie Cellulaire et Végétale, Centre National de la Recherche Scientifique, Commissariat à l’Energie Atomique et aux Energies Alternatives, Institut National de la Recherche Agronomique, Université Grenoble Alpes, UMR 5168, 38041 Grenoble, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, Centre National de la Recherche Scientifique, Commissariat à l’Energie Atomique et aux Energies Alternatives, Institut National de la Recherche Agronomique, Université Grenoble Alpes, UMR 5168, 38041 Grenoble, France
| | - 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
| | - Xiaoming Tan
- Hubei Collaborative Innovation Center for Green Transformation of Bioresources, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Zhuo Chen
- Shandong Provincial Key Laboratory of Plant Stress, College of Life Science, Shandong Normal University, Jinan, 250014 China
| | - Lingjie You
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, No. 2 Xudong Second Road, Wuhan, 430062 People’s Republic of China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Hong Chen
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, No. 2 Xudong Second Road, Wuhan, 430062 People’s Republic of China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Fang Wei
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, No. 2 Xudong Second Road, Wuhan, 430062 People’s Republic of China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
| | - Yangmin Gong
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, No. 2 Xudong Second Road, Wuhan, 430062 People’s Republic of China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062 China
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Karpagam R, Jawaharraj K, Ashokkumar B, Sridhar J, Varalakshmi P. Unraveling the lipid and pigment biosynthesis in Coelastrella sp. M-60: Genomics-enabled transcript profiling. ALGAL RES 2018. [DOI: 10.1016/j.algal.2017.11.031] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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76
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Russo DA, Beckerman AP, Pandhal J. Competitive growth experiments with a high-lipid Chlamydomonas reinhardtii mutant strain and its wild-type to predict industrial and ecological risks. AMB Express 2017; 7:10. [PMID: 28050851 PMCID: PMC5209313 DOI: 10.1186/s13568-016-0305-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/11/2016] [Indexed: 11/10/2022] Open
Abstract
Key microalgal species are currently being exploited as biomanufacturing platforms using mass cultivation systems. The opportunities to enhance productivity levels or produce non-native compounds are increasing as genetic manipulation and metabolic engineering tools are rapidly advancing. Regardless of the end product, there are both environmental and industrial risks associated to open pond cultivation of mutant microalgal strains. A mutant escape could be detrimental to local biodiversity and increase the risk of algal blooms. Similarly, if the cultivation pond is invaded by a wild-type (WT) microalgae or the mutant reverts to WT phenotypes, productivity could be impacted. To investigate these potential risks, a response surface methodology was applied to determine the competitive outcome of two Chlamydomonas reinhardtii strains, a WT (CC-124) and a high-lipid accumulating mutant (CC-4333), grown in mixotrophic conditions, with differing levels of nitrogen and initial WT to mutant ratios. Results of the growth experiments show that mutant cells have double the exponential growth rate of the WT in monoculture. However, due to a slower transition from lag phase to exponential phase, mutant cells are outcompeted by the WT in every co-culture treatment. This suggests that, under the conditions tested, outdoor cultivation of the C. reinhardtii cell wall-deficient mutant strains does not carry a significant environmental risk to its WT in an escape scenario. Furthermore, lipid results show the mutant strain accumulates over 200% more TAGs per cell, at 50 mg L-1 NH4Cl, compared to the WT, therefore, the fragility of the mutant strain could impact on overall industrial productivity.
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Wang Y, Ho SH, Yen HW, Nagarajan D, Ren NQ, Li S, Hu Z, Lee DJ, Kondo A, Chang JS. Current advances on fermentative biobutanol production using third generation feedstock. Biotechnol Adv 2017; 35:1049-1059. [DOI: 10.1016/j.biotechadv.2017.06.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/08/2017] [Accepted: 06/01/2017] [Indexed: 12/23/2022]
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78
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Pick U, Avidan O. Triacylglycerol is produced from starch and polar lipids in the green alga Dunaliella tertiolecta. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4939-4950. [PMID: 28992231 PMCID: PMC5853294 DOI: 10.1093/jxb/erx280] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The halotolerant green alga Dunaliella tertiolecta accumulates starch and triacylglycerol (TAG) amounting to 70% and 10-15% of total cellular carbon, respectively, when exposed to nitrogen (N) deprivation. The purpose of this study was to clarify the inter-relationships between the biosynthesis of TAG, starch, and polar lipids (PLs) in this alga. Pulse labeling with [14C]bicarbonate was utilized to label starch and [14C]palmitic acid (PlA) to label lipids. Transfer of 14C into TAG was measured and used to calculate rates of synthesis. About two-thirds of the carbon in TAG originates from starch, and one-third is made de novo by direct CO2 assimilation. The level made from degradation of pre-formed PLs is estimated to be very small. Most of the de novo synthesis involves fatty acid transfer through PLs made during the first day of N deprivation. The results suggest that starch made by photosynthetic carbon assimilation at the early stages of N deprivation is utilized for synthesis of TAG. Trans-acylation from PLs is the second major contributor to TAG biosynthesis. The utilization of starch for TAG biosynthesis may have biotechnological applications to optimize TAG biosynthesis in algae.
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Affiliation(s)
- Uri Pick
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
- Correspondence:
| | - Omri Avidan
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
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79
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Kim HS, Hsu S, Han S, Thapa HR, Guzman AR, Browne DR, Tatli M, Devarenne TP, Stern DB, Han A. High-throughput droplet microfluidics screening platform for selecting fast-growing and high lipid-producing microalgae from a mutant library. PLANT DIRECT 2017; 1:e00011. [PMID: 31245660 PMCID: PMC6508572 DOI: 10.1002/pld3.11] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 06/13/2017] [Accepted: 06/29/2017] [Indexed: 05/21/2023]
Abstract
Biofuels derived from microalgal lipids have demonstrated a promising potential as future renewable bioenergy. However, the production costs for microalgae-based biofuels are not economically competitive, and one strategy to overcome this limitation is to develop better-performing microalgal strains that have faster growth and higher lipid content through genetic screening and metabolic engineering. In this work, we present a high-throughput droplet microfluidics-based screening platform capable of analyzing growth and lipid content in populations derived from single cells of a randomly mutated microalgal library to identify and sort variants that exhibit the desired traits such as higher growth rate and increased lipid content. By encapsulating single cells into water-in-oil emulsion droplets, each variant was separately cultured inside an individual droplet that functioned as an independent bioreactor. In conjunction with an on-chip fluorescent lipid staining process within droplets, microalgal growth and lipid content were characterized by measuring chlorophyll and BODIPY fluorescence intensities through an integrated optical detection system in a flow-through manner. Droplets containing cells with higher growth and lipid content were selectively retrieved and further analyzed off-chip. The growth and lipid content screening capabilities of the developed platform were successfully demonstrated by first carrying out proof-of-concept screening using known Chlamydomonas reinhardtii mutants. The platform was then utilized to screen an ethyl methanesulfonate (EMS)-mutated C. reinhardtii population, where eight potential mutants showing faster growth and higher lipid content were selected from 200,000 examined samples, demonstrating the capability of the platform as a high-throughput screening tool for microalgal biofuel development.
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Affiliation(s)
- Hyun Soo Kim
- Department of Electrical and Computer EngineeringTexas A&M UniversityCollege StationTXUSA
- Korea Institute of Machinery and MaterialsDaegu Research Center for Medical Devices and RehabilitationDaeguSouth Korea
| | | | - Song‐I Han
- Department of Electrical and Computer EngineeringTexas A&M UniversityCollege StationTXUSA
| | - Hem R. Thapa
- Department of Biochemistry and BiophysicsTexas A&M UniversityCollege StationTXUSA
| | - Adrian R. Guzman
- Department of Electrical and Computer EngineeringTexas A&M UniversityCollege StationTXUSA
| | - Daniel R. Browne
- Department of Biochemistry and BiophysicsTexas A&M UniversityCollege StationTXUSA
| | - Mehmet Tatli
- Department of Biochemistry and BiophysicsTexas A&M UniversityCollege StationTXUSA
| | - Timothy P. Devarenne
- Department of Biochemistry and BiophysicsTexas A&M UniversityCollege StationTXUSA
| | | | - Arum Han
- Department of Electrical and Computer EngineeringTexas A&M UniversityCollege StationTXUSA
- Department of Biomedical EngineeringTexas A&M UniversityCollege StationTXUSA
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80
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Bayro-Kaiser V, Nelson N. Microalgal hydrogen production: prospects of an essential technology for a clean and sustainable energy economy. PHOTOSYNTHESIS RESEARCH 2017; 133:49-62. [PMID: 28239761 PMCID: PMC5500669 DOI: 10.1007/s11120-017-0350-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/06/2017] [Indexed: 05/17/2023]
Abstract
Modern energy production is required to undergo a dramatic transformation. It will have to replace fossil fuel use by a sustainable and clean energy economy while meeting the growing world energy needs. This review analyzes the current energy sector, available energy sources, and energy conversion technologies. Solar energy is the only energy source with the potential to fully replace fossil fuels, and hydrogen is a crucial energy carrier for ensuring energy availability across the globe. The importance of photosynthetic hydrogen production for a solar-powered hydrogen economy is highlighted and the development and potential of this technology are discussed. Much successful research for improved photosynthetic hydrogen production under laboratory conditions has been reported, and attempts are underway to develop upscale systems. We suggest that a process of integrating these achievements into one system to strive for efficient sustainable energy conversion is already justified. Pursuing this goal may lead to a mature technology for industrial deployment.
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Affiliation(s)
- Vinzenz Bayro-Kaiser
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978, Tel Aviv, Israel.
| | - Nathan Nelson
- Department of Biochemistry and Molecular Biology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, 69978, Tel Aviv, Israel
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81
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Banerjee A, Banerjee C, Negi S, Chang JS, Shukla P. Improvements in algal lipid production: a systems biology and gene editing approach. Crit Rev Biotechnol 2017; 38:369-385. [DOI: 10.1080/07388551.2017.1356803] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Avik Banerjee
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, India
| | - Chiranjib Banerjee
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, India
| | | | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Pratyoosh Shukla
- Department of Microbiology, Enzyme Technology and Protein Bioinformatics Laboratory, Maharshi Dayanand University, Rohtak, India
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82
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Sierra LS, Dixon CK, Wilken LR. Enzymatic cell disruption of the microalgae Chlamydomonas reinhardtii for lipid and protein extraction. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.04.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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83
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León-Saiki GM, Remmers IM, Martens DE, Lamers PP, Wijffels RH, van der Veen D. The role of starch as transient energy buffer in synchronized microalgal growth in Acutodesmus obliquus. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.05.018] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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84
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Morales-Sánchez D, Kim Y, Terng EL, Peterson L, Cerutti H. A multidomain enzyme, with glycerol-3-phosphate dehydrogenase and phosphatase activities, is involved in a chloroplastic pathway for glycerol synthesis in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:1079-1092. [PMID: 28273364 DOI: 10.1111/tpj.13530] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 02/06/2017] [Accepted: 02/28/2017] [Indexed: 05/20/2023]
Abstract
Understanding the unique features of algal metabolism may be necessary to realize the full potential of algae as feedstock for the production of biofuels and biomaterials. Under nitrogen deprivation, the green alga C. reinhardtii showed substantial triacylglycerol (TAG) accumulation and up-regulation of a gene, GPD2, encoding a multidomain enzyme with a putative phosphoserine phosphatase (PSP) motif fused to glycerol-3-phosphate dehydrogenase (GPD) domains. Canonical GPD enzymes catalyze the synthesis of glycerol-3-phosphate (G3P) by reduction of dihydroxyacetone phosphate (DHAP). G3P forms the backbone of TAGs and membrane glycerolipids and it can be dephosphorylated to yield glycerol, an osmotic stabilizer and compatible solute under hypertonic stress. Recombinant Chlamydomonas GPD2 showed both reductase and phosphatase activities in vitro and it can work as a bifunctional enzyme capable of synthesizing glycerol directly from DHAP. In addition, GPD2 and a gene encoding glycerol kinase were up-regulated in Chlamydomonas cells exposed to high salinity. RNA-mediated silencing of GPD2 revealed that the multidomain enzyme was required for TAG accumulation under nitrogen deprivation and for glycerol synthesis under high salinity. Moreover, a GPD2-mCherry fusion protein was found to localize to the chloroplast, supporting the existence of a GPD2-dependent plastid pathway for the rapid synthesis of glycerol in response to hyperosmotic stress. We hypothesize that the reductase and phosphatase activities of PSP-GPD multidomain enzymes may be modulated by post-translational modifications/mechanisms, allowing them to synthesize primarily G3P or glycerol depending on environmental conditions and/or metabolic demands in algal species of the core Chlorophytes.
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Affiliation(s)
- Daniela Morales-Sánchez
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Yeongho Kim
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Ee Leng Terng
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Laura Peterson
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - Heriberto Cerutti
- School of Biological Sciences and Center for Plant Science Innovation, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
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85
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Souza LDS, Simioni C, Bouzon ZL, Schneider RDCDS, Gressler P, Miotto MC, Rossi MJ, Rörig LR. Morphological and ultrastructural characterization of the acidophilic and lipid-producer strain Chlamydomonas acidophila LAFIC-004 (Chlorophyta) under different culture conditions. PROTOPLASMA 2017; 254:1385-1398. [PMID: 27696020 DOI: 10.1007/s00709-016-1030-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 09/20/2016] [Indexed: 05/18/2023]
Abstract
Chlamydomonas acidophila LAFIC-004 is an acidophilic strain of green microalgae isolated from coal mining drainage. In the present work, this strain was cultivated in acidic medium (pH 3.6) under phototrophic, mixotrophic, and heterotrophic regimes to determine the best condition for growth and lipid production, simultaneously assessing possible morphological and ultrastructural alterations in the cells. For heterotrophic and mixotrophic treatments, two organic carbon sources were tested: 1 % glucose and 1 % sodium acetate. Lipid content and fatty acid profiles were only determined in phototrophic condition. The higher growth rates were achieved in phototrophic conditions, varying from 0.18 to 0.82 day-1. Glucose did not result in significant growth increase in either mixotrophic or heterotrophic conditions, and acetate proved to be toxic to the strain in both conditions. Oil content under phototrophic condition was 15.9 % at exponential growth phase and increased to 54.63 % at stationary phase. Based on cell morphology (flow cytometry and light microscopy) and ultrastructure (transmission electron microscopy), similar characteristics were observed between phototrophic and mixotrophic conditions with glucose evidencing many lipid bodies, starch granules, and intense fluorescence. Under the tested conditions, mixotrophic and heterotrophic modes did not result in increased neutral lipid fluorescence. It can be concluded that the strain is a promising lipid producer when grown until stationary phase in acidic medium and under a phototrophic regime, presenting a fatty acid profile suitable for biodiesel production. The ability to grow this strain in acidic mining residues suggests a potential for bioremediation with production of useful biomass.
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Affiliation(s)
- Luana Dos S Souza
- Post Graduate Program in Biotechnology and Biosciences, Federal University of Santa Catarina, 88049-900, CP 476, Florianópolis, SC, Brazil.
| | - Carmen Simioni
- Postdoctoral Research of Post-Graduate Program in Cell Biology and Development, Department of Cell Biology, Embryology and Genetics, Federal University of Santa Catarina, 88049-900, CP 476, Florianópolis, SC, Brazil
| | - Zenilda L Bouzon
- Central Laboratory of Electron Microscopy, Federal University of Santa Catarina, 88049-900, CP 476, Florianópolis, SC, Brazil
| | - Rosana de Cassia da S Schneider
- Department of Chemistry and Physics, Graduate Program in Environmental Technology, University of Santa Cruz do Sul, 96815-900, Santa Cruz do Sul, RS, Brazil
| | - Pablo Gressler
- Post Graduate Program in Biotechnology and Biosciences, Federal University of Santa Catarina, 88049-900, CP 476, Florianópolis, SC, Brazil
| | - Maria Cecília Miotto
- Post Graduate Program in Biotechnology and Biosciences, Federal University of Santa Catarina, 88049-900, CP 476, Florianópolis, SC, Brazil
| | - Marcio J Rossi
- Bioprocess Laboratory, Department of Microbiology and Parasitology, Federal University of Santa Catarina, 88049-900, CP 476, Florianópolis, SC, Brazil
| | - Leonardo R Rörig
- Phycology Laboratory, Botany Department, Federal University of Santa Catarina, 88049-900, CP 476, Florianópolis, SC, Brazil
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86
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Song H, Lavoie M, Fan X, Tan H, Liu G, Xu P, Fu Z, Paerl HW, Qian H. Allelopathic interactions of linoleic acid and nitric oxide increase the competitive ability of Microcystis aeruginosa. ISME JOURNAL 2017; 11:1865-1876. [PMID: 28398349 PMCID: PMC5520033 DOI: 10.1038/ismej.2017.45] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 01/15/2017] [Accepted: 02/16/2017] [Indexed: 12/02/2022]
Abstract
The frequency and intensity of cyanobacterial blooms are increasing worldwide with major societal and economic costs. Interactions between toxic cyanobacteria and eukaryotic algal competitors can affect toxic bloom formation, but the exact mechanisms of interspecies interactions remain unknown. Using metabolomic and proteomic profiling of co-cultures of the toxic cyanobacterium Microcystis aeruginosa with a green alga as well as of microorganisms collected in a Microcystis spp. bloom in Lake Taihu (China), we disentangle novel interspecies allelopathic interactions. We describe an interspecies molecular network in which M. aeruginosa inhibits growth of Chlorella vulgaris, a model green algal competitor, via the release of linoleic acid. In addition, we demonstrate how M. aeruginosa takes advantage of the cell signaling compound nitric oxide produced by C. vulgaris, which stimulates a positive feedback mechanism of linoleic acid release by M. aeruginosa and its toxicity. Our high-throughput system-biology approach highlights the importance of previously unrecognized allelopathic interactions between a broadly distributed toxic cyanobacterial bloom former and one of its algal competitors.
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Affiliation(s)
- Hao Song
- College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Michel Lavoie
- Quebec-Ocean and Takuvik Joint International Research Unit, Université Laval, Lavel, QC, Canada
| | - Xiaoji Fan
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Hana Tan
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Guangfu Liu
- College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Pengfei Xu
- College of Environment, Zhejiang University of Technology, Hangzhou, China
| | - Zhengwei Fu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Hans W Paerl
- Institute of Marine Sciences, University of North Carolina at Chapel Hill, Morehead City, NC, USA.,College of Environment, Hohai University, Nanjing, China
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou, China.,Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Chinese Academy of Sciences, Urumqi, China
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87
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Effects of chrysolaminarin synthase knockdown in the diatom Thalassiosira pseudonana: Implications of reduced carbohydrate storage relative to green algae. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.01.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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88
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Kim HS, Waqued SC, Nodurft DT, Devarenne TP, Yakovlev VV, Han A. Raman spectroscopy compatible PDMS droplet microfluidic culture and analysis platform towards on-chip lipidomics. Analyst 2017; 142:1054-1060. [PMID: 28294227 DOI: 10.1039/c6an02221a] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Lipids produced by microalgae are viewed as a potential renewable alternative to fossil fuels, however, significant improvements in productivity are required for microalgal biofuels to become economically feasible. Here we present a method that allows for the use of Raman spectroscopy with poly(dimethylsiloxane) (PDMS) droplet microfluidic devices, which not only overcomes the high Raman background of PDMS, but also achieves pairing of the high-throughput single-cell resolution advantages of droplet microfluidics with the direct, chemically specific, label-free, and non-destructive nature of Raman spectroscopy. The platform was successfully utilized for in situ characterization of microalgal lipid production over time within droplets, paving the way towards high-throughput microalgal lipidomics assays.
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Affiliation(s)
- Hyun Soo Kim
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas, USA.
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89
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A Mathematical Model of Neutral Lipid Content in terms of Initial Nitrogen Concentration and Validation in Coelastrum sp. HA-1 and Application in Chlorella sorokiniana. BIOMED RESEARCH INTERNATIONAL 2017; 2017:9253020. [PMID: 28194424 PMCID: PMC5286495 DOI: 10.1155/2017/9253020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 11/06/2016] [Accepted: 12/19/2016] [Indexed: 11/17/2022]
Abstract
Microalgae are considered to be a potential major biomass feedstock for biofuel due to their high lipid content. However, no correlation equations as a function of initial nitrogen concentration for lipid accumulation have been developed for simplicity to predict lipid production and optimize the lipid production process. In this study, a lipid accumulation model was developed with simple parameters based on the assumption protein synthesis shift to lipid synthesis by a linear function of nitrogen quota. The model predictions fitted well for the growth, lipid content, and nitrogen consumption of Coelastrum sp. HA-1 under various initial nitrogen concentrations. Then the model was applied successfully in Chlorella sorokiniana to predict the lipid content with different light intensities. The quantitative relationship between initial nitrogen concentrations and the final lipid content with sensitivity analysis of the model were also discussed. Based on the model results, the conversion efficiency from protein synthesis to lipid synthesis is higher and higher in microalgae metabolism process as nitrogen decreases; however, the carbohydrate composition content remains basically unchanged neither in HA-1 nor in C. sorokiniana.
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90
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Gardner JJ, Boyle NR. The use of genome-scale metabolic network reconstruction to predict fluxes and equilibrium composition of N-fixing versus C-fixing cells in a diazotrophic cyanobacterium, Trichodesmium erythraeum. BMC SYSTEMS BIOLOGY 2017; 11:4. [PMID: 28103880 PMCID: PMC5244712 DOI: 10.1186/s12918-016-0383-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 12/21/2016] [Indexed: 01/08/2023]
Abstract
Background Computational, genome based predictions of organism phenotypes has enhanced the ability to investigate the biological phenomena that help organisms survive and respond to their environments. In this study, we have created the first genome-scale metabolic network reconstruction of the nitrogen fixing cyanobacterium T. erythraeum and used genome-scale modeling approaches to investigate carbon and nitrogen fluxes as well as growth and equilibrium population composition. Results We created a genome-scale reconstruction of T. erythraeum with 971 reactions, 986 metabolites, and 647 unique genes. We then used data from previous studies as well as our own laboratory data to establish a biomass equation and two distinct submodels that correspond to the two cell types formed by T. erythraeum. We then use flux balance analysis and flux variability analysis to generate predictions for how metabolism is distributed to account for the unique productivity of T. erythraeum. Finally, we used in situ data to constrain the model, infer time dependent population compositions and metabolite production using dynamic Flux Balance Analysis. We find that our model predicts equilibrium compositions similar to laboratory measurements, approximately 15.5% diazotrophs for our model versus 10-20% diazotrophs reported in literature. We also found that equilibrium was the most efficient mode of growth and that equilibrium was stoichiometrically mediated. Moreover, the model predicts that nitrogen leakage is an essential condition of optimality for T. erythraeum; cells leak approximately 29.4% total fixed nitrogen when growing at the optimal growth rate, which agrees with values observed in situ. Conclusion The genome-metabolic network reconstruction allows us to use constraints based modeling approaches to predict growth and optimal cellular composition in T. erythraeum colonies. Our predictions match both in situ and laboratory data, indicating that stoichiometry of metabolic reactions plays a large role in the differentiation and composition of different cell types. In order to realize the full potential of the model, advance modeling techniques which account for interactions between colonies, the environment and surrounding species need to be developed. Electronic supplementary material The online version of this article (doi:10.1186/s12918-016-0383-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Joseph J Gardner
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, 80401, USA
| | - Nanette R Boyle
- Department of Chemical and Biological Engineering, Colorado School of Mines, Golden, CO, 80401, USA.
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91
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Shin SE, Koh HG, Kang NK, Suh WI, Jeong BR, Lee B, Chang YK. Isolation, phenotypic characterization and genome wide analysis of a Chlamydomonas reinhardtii strain naturally modified under laboratory conditions: towards enhanced microalgal biomass and lipid production for biofuels. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:308. [PMID: 29296121 PMCID: PMC5740574 DOI: 10.1186/s13068-017-1000-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/14/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Microalgal strain development through genetic engineering has received much attention as a way to improve the traits of microalgae suitable for biofuel production. However, there are still some limitations in application of genetically modified organisms. In this regard, there has been recent interest in the isolation and characterization of superior strains naturally modified and/or adapted under a certain condition and on the interpretation of phenotypic changes through the whole genome sequencing. RESULTS In this study, we isolated and characterized a novel derivative of C. reinhardtii, whose phenotypic traits diverged significantly from its ancestral strain, C. reinhardtii CC-124. This strain, designated as CC-124H, displayed cell population containing increased numbers of larger cells, which resulted in an increased biomass productivity compared to its ancestor CC-124. CC-124H was further compared with the CC-124 wild-type strain which underwent long-term storage under low light condition, designated as CC-124L. In an effort to evaluate the potential of CC-124H for biofuel production, we also found that CC-124H accumulated 116 and 66% greater lipids than that of the CC-124L, after 4 days under nitrogen and sulfur depleted conditions, respectively. Taken together, our results revealed that CC-124H had significantly increased fatty acid methyl ester (FAME) yields that were 2.66 and 1.98 times higher than that of the CC-124L at 4 days after the onset of cultivation under N and S depleted conditions, respectively, and these higher FAME yields were still maintained by day 8. We next analyzed single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) based on the whole genome sequencing. The result revealed that of the 44 CDS region alterations, 34 resulted in non-synonymous substitutions within 33 genes which may mostly be involved in cell cycle, division or proliferation. CONCLUSION Our phenotypic analysis, which emphasized lipid productivity, clearly revealed that CC-124H had a dramatically enhanced biomass and lipid content compared to the CC-124L. Moreover, SNPs and indels analysis enabled us to identify 34 of non-synonymous substitutions which may result in phenotypic changes of CC-124H. All of these results suggest that the concept of adaptive evolution combined with genome wide analysis can be applied to microalgal strain development for biofuel production.
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Affiliation(s)
- Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: LG Chem, 188 Munji-ro, Yuseong-gu, Daejeon, 34122 Republic of Korea
| | - Hyun Gi Koh
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Nam Kyu Kang
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - William I. Suh
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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92
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Dong HP, Dong YL, Cui L, Balamurugan S, Gao J, Lu SH, Jiang T. High light stress triggers distinct proteomic responses in the marine diatom Thalassiosira pseudonana. BMC Genomics 2016; 17:994. [PMID: 27919227 PMCID: PMC5139114 DOI: 10.1186/s12864-016-3335-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 11/17/2016] [Indexed: 11/16/2022] Open
Abstract
Background Diatoms are able to acclimate to frequent and large light fluctuations in the surface ocean waters. However, the molecular mechanisms underlying these acclimation responses of diaotms remain elusive. Results In this study, we investigated the mechanism of high light protection in marine diatom Thalassiosira pseudonana using comparative proteomics in combination with biochemical analyses. Cells treated under high light (800 μmol photons m−2s−1) for 10 h were subjected to proteomic analysis. We observed that 143 proteins were differentially expressed under high light treatment. Light-harvesting complex proteins, ROS scavenging systems, photorespiration, lipid metabolism and some specific proteins might be involved in light protection and acclimation of diatoms. Non-photochemical quenching (NPQ) and relative electron transport rate could respond rapidly to varying light intensities. High-light treatment also resulted in increased diadinoxanthin + diatoxanthin content, decreased Fv/Fm, increased triacylglycerol and altered fatty acid composition. Under HL stress, levels of C14:0 and C16:0 increased while C20:5ω3 decreased. Conclusions We demonstrate that T. pseudonana has efficient photoprotective mechanisms to deal with HL stress. De novo synthesis of Ddx/Dtx and lipid accumulation contribute to utilization of the excess energy. Our data will provide new clues for in-depth study of photoprotective mechanisms in diatoms. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3335-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hong-Po Dong
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.,School of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, 524088, China
| | - Yue-Lei Dong
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
| | - Lei Cui
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
| | - Srinivasan Balamurugan
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
| | - Jian Gao
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
| | - Song-Hui Lu
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China.
| | - Tao Jiang
- Research Center for Harmful Algae and Marine Biology, Key Laboratory of Eutrophication and Red Tide Prevention of Guangdong Higher Education Institutes, Jinan University, Guangzhou, 510632, China
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93
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Song H, Fan X, Liu G, Xu J, Li X, Tan Y, Qian H. Inhibitory effects of tributyl phosphate on algal growth, photosynthesis, and fatty acid synthesis in the marine diatom Phaeodactylum tricornutum. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:24009-24018. [PMID: 27638802 DOI: 10.1007/s11356-016-7531-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 08/26/2016] [Indexed: 06/06/2023]
Abstract
The widely used solvent extractant, tributyl phosphate (TBP), primarily used as a solvent for the conventional processing of nuclear fuel, has come under scrutiny recently due to concerns surrounding potential environmental contamination and toxicity. In this study, we found that, in Phaeodactylum tricornutum, administration of TBP severely inhibited algal cell growth by reducing photosynthetic efficiency and inducing oxidative stress. We further explored the effect of TBP by examining the gene expression of the photosynthetic electron transport chain and its contribution to reactive oxygen species (ROS) burst. Our data revealed that TBP affected both fatty acid content and profile by regulating the transcription of genes related to glycolysis, fatty acid biosynthesis, and β-oxidation. These results demonstrated that TBP did in fact trigger the synthesis of ROS, disrupting the subcellular membrane structure of this aquatic organism. Our study brings new insight into the fundamental mechanism of toxicity exerted by TBP on the marine alga P. tricornutum.
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Affiliation(s)
- Hao Song
- Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Xiaoji Fan
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Guangfu Liu
- Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Jiahui Xu
- Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Xingxing Li
- Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Yuzhu Tan
- Department of Food Science and Technology, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou, 310032, People's Republic of China.
- Xinjiang Key Laboratory of Environmental Pollution and Bioremediation, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China.
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94
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Caballero MA, Jallet D, Shi L, Rithner C, Zhang Y, Peers G. Quantification of chrysolaminarin from the model diatom Phaeodactylum tricornutum. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.10.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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95
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Sachdeva N, Gupta RP, Mathur AS, Tuli DK. Enhanced lipid production in thermo-tolerant mutants of Chlorella pyrenoidosa NCIM 2738. BIORESOURCE TECHNOLOGY 2016; 221:576-587. [PMID: 27689351 DOI: 10.1016/j.biortech.2016.09.049] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 09/07/2016] [Accepted: 09/11/2016] [Indexed: 06/06/2023]
Abstract
The present study aimed to develop thermo-tolerant mutants of Chlorella pyrenoidosa NCIM 2738 for high lipids production. For this, ethyl methane sulfonate was used, which generated two effective thermo-tolerant mutants, M18 and M24 of Chlorella pyrenoidosa NCIM 2738, capable of surviving at temperature up to 47°C and showing improved lipid and biomass yields. They showed 59.62% and 50.75% increase, respectively in lipid content compared to wild type at 30°C, which could not grow at temperature above 35°C. The novelty of this study lied in incorporation of PAM Flurometry with mutagenesis to generate thermo-tolerant mutants of C. pyrenoidosa and investigating the reasons for increased yields of mutants at cellular and photosynthetic levels with the aim to use them for commercial biodiesel production.
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Affiliation(s)
- Neha Sachdeva
- DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad 121007, India
| | | | | | - Deepak Kumar Tuli
- DBT-IOC Centre for Advanced Bioenergy Research, Research & Development Centre, Indian Oil Corporation Limited, Sector-13, Faridabad 121007, India
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96
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Couso I, Evans BS, Li J, Liu Y, Ma F, Diamond S, Allen DK, Umen JG. Synergism between Inositol Polyphosphates and TOR Kinase Signaling in Nutrient Sensing, Growth Control, and Lipid Metabolism in Chlamydomonas. THE PLANT CELL 2016; 28:2026-2042. [PMID: 27600537 PMCID: PMC5059802 DOI: 10.1105/tpc.16.00351] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 08/19/2016] [Accepted: 09/02/2016] [Indexed: 05/17/2023]
Abstract
The networks that govern carbon metabolism and control intracellular carbon partitioning in photosynthetic cells are poorly understood. Target of Rapamycin (TOR) kinase is a conserved growth regulator that integrates nutrient signals and modulates cell growth in eukaryotes, though the TOR signaling pathway in plants and algae has yet to be completely elucidated. We screened the unicellular green alga Chlamydomonas reinhardtii using insertional mutagenesis to find mutants that conferred hypersensitivity to the TOR inhibitor rapamycin. We characterized one mutant, vip1-1, that is predicted to encode a conserved inositol hexakisphosphate kinase from the VIP family that pyrophosphorylates phytic acid (InsP6) to produce the low abundance signaling molecules InsP7 and InsP8 Unexpectedly, the rapamycin hypersensitive growth arrest of vip1-1 cells was dependent on the presence of external acetate, which normally has a growth-stimulatory effect on Chlamydomonas. vip1-1 mutants also constitutively overaccumulated triacylglycerols (TAGs) in a manner that was synergistic with other TAG inducing stimuli such as starvation. vip1-1 cells had reduced InsP7 and InsP8, both of which are dynamically modulated in wild-type cells by TOR kinase activity and the presence of acetate. Our data uncover an interaction between the TOR kinase and inositol polyphosphate signaling systems that we propose governs carbon metabolism and intracellular pathways that lead to storage lipid accumulation.
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Affiliation(s)
| | - Bradley S Evans
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Jia Li
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Yu Liu
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Fangfang Ma
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| | - Spencer Diamond
- Earth and Planetary Science, University of California, Berkeley, California 94720
| | - Doug K Allen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
- Agricultural Research Service, U.S. Department of Agriculture, St. Louis, Missouri 63132
| | - James G Umen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
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97
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Regulation of starch, lipids and amino acids upon nitrogen sensing in Chlamydomonas reinhardtii. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.05.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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98
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Goncalves EC, Wilkie AC, Kirst M, Rathinasabapathi B. Metabolic regulation of triacylglycerol accumulation in the green algae: identification of potential targets for engineering to improve oil yield. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:1649-60. [PMID: 26801206 PMCID: PMC5066758 DOI: 10.1111/pbi.12523] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 11/13/2015] [Accepted: 11/25/2015] [Indexed: 05/03/2023]
Abstract
The great need for more sustainable alternatives to fossil fuels has increased our research interests in algal biofuels. Microalgal cells, characterized by high photosynthetic efficiency and rapid cell division, are an excellent source of neutral lipids as potential fuel stocks. Various stress factors, especially nutrient-starvation conditions, induce an increased formation of lipid bodies filled with triacylglycerol in these cells. Here we review our knowledge base on glycerolipid synthesis in the green algae with an emphasis on recent studies on carbon flux, redistribution of lipids under nutrient-limiting conditions and its regulation. We discuss the contributions and limitations of classical and novel approaches used to elucidate the algal triacylglycerol biosynthetic pathway and its regulatory network in green algae. Also discussed are gaps in knowledge and suggestions for much needed research both on the biology of triacylglycerol accumulation and possible avenues to engineer improved algal strains.
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Affiliation(s)
- Elton C Goncalves
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Ann C Wilkie
- Soil and Water Science Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Matias Kirst
- School of Forestry, University of Florida, Gainesville, FL, USA
| | - Bala Rathinasabapathi
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
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99
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He Y, Chen L, Zhou Y, Chen H, Zhou X, Cai F, Huang J, Wang M, Chen B, Guo Z. Analysis and model delineation of marine microalgae growth and lipid accumulation in flat-plate photobioreactor. Biochem Eng J 2016. [DOI: 10.1016/j.bej.2016.03.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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100
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Palacios OA, Choix FJ, Bashan Y, de-Bashan LE. Influence of tryptophan and indole-3-acetic acid on starch accumulation in the synthetic mutualistic Chlorella sorokiniana – Azospirillum brasilense system under heterotrophic conditions. Res Microbiol 2016; 167:367-79. [DOI: 10.1016/j.resmic.2016.02.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 09/07/2015] [Accepted: 02/15/2016] [Indexed: 01/08/2023]
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