51
|
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.
Collapse
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
| |
Collapse
|
52
|
Ma X, Yao L, Yang B, Lee YK, Chen F, Liu J. RNAi-mediated silencing of a pyruvate dehydrogenase kinase enhances triacylglycerol biosynthesis in the oleaginous marine alga Nannochloropsis salina. Sci Rep 2017; 7:11485. [PMID: 28904365 PMCID: PMC5597597 DOI: 10.1038/s41598-017-11932-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/31/2017] [Indexed: 01/01/2023] Open
Abstract
Oleaginous microalgae have been emerging as the third-generation feedstocks for biofuel production. Genetic manipulation for improving triacylglycerol (TAG) accumulation represents a promising approach towards the economics of microalgal biofuels. Acetyl-CoA, the essential carbon precursor for de novo fatty acid biosynthesis, can be derived from pyruvate catalyzed by pyruvate dehydrogenase, which is negatively regulated by pyruvate dehydrogenase kinase (PDK). In the present study, we characterized a PDK gene (NsPDK) from Nannochloropsis salina. Subcellular localization assay assisted by green fluorescence protein (GFP) fusion indicated the localization of NsPDK in mitochondria of N. salina cells. NsPDK knockdown via RNA interference strategy attenuated NsPDK expression at the mRNA level and its enzymatic activity in vivo, leading to faster TAG accumulation without compromising cell growth under high light stress conditions. Interestingly, the TAG increase was accompanied by a decline in membrane polar lipids. NsPDK knockdown also altered fatty acid profile in N. salina. Furthermore, transcriptional analysis suggested that the carbon metabolic pathways might be influenced by NsPDK knockdown leading to diverted carbon flux towards TAG synthesis. Taken together, our results demonstrate the role of NsPDK in regulating TAG accumulation and provide valuable insights into future manipulation of oleaginous microalgae for improving biofuel production.
Collapse
Affiliation(s)
- Xiaonian Ma
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China
- BIC-ESAT, College of Engineering, Peking University, Beijing, 100871, China
| | - Lina Yao
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore, Singapore
| | - Bo Yang
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Yuan Kun Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore, Singapore
| | - Feng Chen
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
- BIC-ESAT, College of Engineering, Peking University, Beijing, 100871, China.
| | - Jin Liu
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
- BIC-ESAT, College of Engineering, Peking University, Beijing, 100871, China.
| |
Collapse
|
53
|
Wang X, Hao TB, Balamurugan S, Yang WD, Liu JS, Dong HP, Li HY. A lipid droplet-associated protein involved in lipid droplet biogenesis and triacylglycerol accumulation in the oleaginous microalga Phaeodactylum tricornutum. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.07.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
54
|
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
| |
Collapse
|
55
|
Transcriptional Regulation of Cellulose Biosynthesis during the Early Phase of Nitrogen Deprivation in Nannochloropsis salina. Sci Rep 2017; 7:5264. [PMID: 28706285 PMCID: PMC5509672 DOI: 10.1038/s41598-017-05684-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 06/01/2017] [Indexed: 12/20/2022] Open
Abstract
Microalgal photosynthesis provides energy and carbon-containing precursors for the biosynthesis of storage carbohydrates such as starch, chrysolaminarin, lipids, and cell wall components. Under mild nitrogen deficiency (N−), some Nannochloropsis species accumulate lipid by augmenting cytosolic fatty acid biosynthesis with a temporary increase in laminarin. Accordingly, biosynthesis of the cellulose-rich cell wall should change in response to N− stress because this biosynthetic pathway begins with utilisation of the hexose phosphate pool supplied from photosynthesis. However, few studies have characterised microalgal cell wall metabolism, including oleaginous Nannochloropsis sp. microalgae subjected to nitrogen deficiency. Here, we investigated N-induced changes in cellulose biosynthesis in N. salina. We observed that N− induced cell wall thickening, concurrently increased the transcript levels of genes coding for UDPG pyrophosphorylase and cellulose synthases, and increased cellulose content. Nannochloropsis salina cells with thickened cell wall were more susceptible to mechanical stress such as bead-beating and sonication, implicating cellulose metabolism as a potential target for cost-effective microalgal cell disruption.
Collapse
|
56
|
Rai V, Muthuraj M, Gandhi MN, Das D, Srivastava S. Real-time iTRAQ-based proteome profiling revealed the central metabolism involved in nitrogen starvation induced lipid accumulation in microalgae. Sci Rep 2017; 7:45732. [PMID: 28378827 PMCID: PMC5381106 DOI: 10.1038/srep45732] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 03/06/2017] [Indexed: 02/06/2023] Open
Abstract
To understand the post-transcriptional molecular mechanisms attributing to oleaginousness in microalgae challenged with nitrogen starvation (N-starvation), the longitudinal proteome dynamics of Chlorella sp. FC2 IITG was investigated using multipronged quantitative proteomics and multiple reaction monitoring assays. Physiological data suggested a remarkably enhanced lipid accumulation with concomitant reduction in carbon flux towards carbohydrate, protein and chlorophyll biosynthesis. The proteomics-based investigations identified the down-regulation of enzymes involved in chlorophyll biosynthesis (porphobilinogen deaminase) and photosynthetic carbon fixation (sedoheptulose-1,7 bisphosphate and phosphoribulokinase). Profound up-regulation of hydroxyacyl-ACP dehydrogenase and enoyl-ACP reductase ascertained lipid accumulation. The carbon skeletons to be integrated into lipid precursors were regenerated by glycolysis, β-oxidation and TCA cycle. The enhanced expression of glycolysis and pentose phosphate pathway enzymes indicates heightened energy needs of FC2 cells for the sustenance of N-starvation. FC2 cells strategically reserved nitrogen by incorporating it into the TCA-cycle intermediates to form amino acids; particularly the enzymes involved in the biosynthesis of glutamate, aspartate and arginine were up-regulated. Regulation of arginine, superoxide dismutase, thioredoxin-peroxiredoxin, lipocalin, serine-hydroxymethyltransferase, cysteine synthase, and octanoyltransferase play a critical role in maintaining cellular homeostasis during N-starvation. These findings may provide a rationale for genetic engineering of microalgae, which may enable synchronized biomass and lipid synthesis.
Collapse
Affiliation(s)
- Vineeta Rai
- Department of Biosciences and Bioengineering, Wadhwani Research Center for Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India
| | - Muthusivaramapandian Muthuraj
- Department of Biosciences and Bioengineering, Centre for Energy, Indian Institute of Technology Guwahati, Assam 781039, India
| | - Mayuri N. Gandhi
- Centre for Research in Nanotechnology & Science, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Debasish Das
- Department of Biosciences and Bioengineering, Centre for Energy, Indian Institute of Technology Guwahati, Assam 781039, India
- DBT PAN IIT Centre for Bioenergy, Indian Institute of Technology Bombay, Mumbai, Powai - 400067, India
| | - Sanjeeva Srivastava
- Department of Biosciences and Bioengineering, Wadhwani Research Center for Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra, India
- DBT PAN IIT Centre for Bioenergy, Indian Institute of Technology Bombay, Mumbai, Powai - 400067, India
| |
Collapse
|
57
|
Wei L, Huang X. Long-duration effect of multi-factor stresses on the cellular biochemistry, oil-yielding performance and morphology of Nannochloropsis oculata. PLoS One 2017; 12:e0174646. [PMID: 28346505 PMCID: PMC5367823 DOI: 10.1371/journal.pone.0174646] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/13/2017] [Indexed: 12/03/2022] Open
Abstract
Microalga Nannochloropsis oculata is a promising alternative feedstock for biodiesel. Elevating its oil-yielding capacity is conducive to cost-saving biodiesel production. However, the regulatory processes of multi-factor collaborative stresses (MFCS) on the oil-yielding performance of N. oculata are unclear. The duration effects of MFCS (high irradiation, nitrogen deficiency and elevated iron supplementation) on N. oculata were investigated in an 18-d batch culture. Despite the reduction in cell division, the biomass concentration increased, resulting from the large accumulation of the carbon/energy-reservoir. However, different storage forms were found in different cellular storage compounds, and both the protein content and pigment composition swiftly and drastically changed. The analysis of four biodiesel properties using pertinent empirical equations indicated their progressive effective improvement in lipid classes and fatty acid composition. The variation curve of neutral lipid productivity was monitored with fluorescent Nile red and was closely correlated to the results from conventional methods. In addition, a series of changes in the organelles (e.g., chloroplast, lipid body and vacuole) and cell shape, dependent on the stress duration, were observed by TEM and LSCM. These changes presumably played an important role in the acclimation of N. oculata to MFCS and accordingly improved its oil-yielding performance.
Collapse
Affiliation(s)
- Likun Wei
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Xuxiong Huang
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- Shanghai Engineering Research Centre of Aquaculture, Shanghai, China
- Shanghai University Knowledge Service Platform, Shanghai Ocean University Aquatic Animal Breeding Centre (ZF1206), Shanghai, China
- * E-mail:
| |
Collapse
|
58
|
Garibay-Hernández A, Barkla BJ, Vera-Estrella R, Martinez A, Pantoja O. Membrane Proteomic Insights into the Physiology and Taxonomy of an Oleaginous Green Microalga. PLANT PHYSIOLOGY 2017; 173:390-416. [PMID: 27837088 PMCID: PMC5210721 DOI: 10.1104/pp.16.01240] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 11/03/2016] [Indexed: 05/22/2023]
Abstract
Ettlia oleoabundans is a nonsequenced oleaginous green microalga. Despite the significant biotechnological interest in producing value-added compounds from the acyl lipids of this microalga, a basic understanding of the physiology and biochemistry of oleaginous microalgae is lacking, especially under nitrogen deprivation conditions known to trigger lipid accumulation. Using an RNA sequencing-based proteomics approach together with manual annotation, we are able to provide, to our knowledge, the first membrane proteome of an oleaginous microalga. This approach allowed the identification of novel proteins in E. oleoabundans, including two photoprotection-related proteins, Photosystem II Subunit S and Maintenance of Photosystem II under High Light1, which were considered exclusive to higher photosynthetic organisms, as well as Retinitis Pigmentosa Type 2-Clathrin Light Chain, a membrane protein with a novel domain architecture. Free-flow zonal electrophoresis of microalgal membranes coupled to liquid chromatography-tandem mass spectrometry proved to be a useful technique for determining the intracellular location of proteins of interest. Carbon-flow compartmentalization in E. oleoabundans was modeled using this information. Molecular phylogenetic analyses of protein markers and 18S ribosomal DNA support the reclassification of E. oleoabundans within the trebouxiophycean microalgae, rather than with the Chlorophyceae class, in which it is currently classified, indicating that it may not be closely related to the model green alga Chlamydomonas reinhardtii A detailed survey of biological processes taking place in the membranes of nitrogen-deprived E. oleoabundans, including lipid metabolism, provides insights into the basic biology of this nonmodel organism.
Collapse
Affiliation(s)
- Adriana Garibay-Hernández
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210 Mexico (A.G.-H., R.V.-E., A.M., O.P.); and
- Southern Cross Plant Science, Southern Cross University, Lismore, 2480 New South Wales, Australia (B.J.B.)
| | - Bronwyn J Barkla
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210 Mexico (A.G.-H., R.V.-E., A.M., O.P.); and
- Southern Cross Plant Science, Southern Cross University, Lismore, 2480 New South Wales, Australia (B.J.B.)
| | - Rosario Vera-Estrella
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210 Mexico (A.G.-H., R.V.-E., A.M., O.P.); and
- Southern Cross Plant Science, Southern Cross University, Lismore, 2480 New South Wales, Australia (B.J.B.)
| | - Alfredo Martinez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210 Mexico (A.G.-H., R.V.-E., A.M., O.P.); and
- Southern Cross Plant Science, Southern Cross University, Lismore, 2480 New South Wales, Australia (B.J.B.)
| | - Omar Pantoja
- Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, 62210 Mexico (A.G.-H., R.V.-E., A.M., O.P.); and
- Southern Cross Plant Science, Southern Cross University, Lismore, 2480 New South Wales, Australia (B.J.B.)
| |
Collapse
|
59
|
Hong SJ, Yim N, Han MA, Yoo D, Lee CG. Effect of Nitrogen Deficiency on Cell Growth and Fatty Acids Production of Nannochloropsis oculata K-1281. ACTA ACUST UNITED AC 2016. [DOI: 10.15433/ksmb.2016.8.2.045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
60
|
Wang Q, Lu Y, Xin Y, Wei L, Huang S, Xu J. Genome editing of model oleaginous microalgae Nannochloropsis spp. by CRISPR/Cas9. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 88:1071-1081. [PMID: 27538728 DOI: 10.1111/tpj.13307] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 05/18/2023]
Abstract
Microalgae are promising feedstock for biofuels yet mechanistic probing of their cellular network and industrial strain development have been hindered by lack of genome-editing tools. Nannochloropsis spp. are emerging model microalgae for scalable oil production and carbon sequestration. Here we established a CRISPR/Cas9-based precise genome-editing approach for the industrial oleaginous microalga Nannochloropsis oceanica, using nitrate reductase (NR; g7988) as example. A new screening procedure that compares between restriction enzyme-digested nested PCR (nPCR) products derived from enzyme-digested and not-digested genomic DNA of transformant pools was developed to quickly, yet reliably, detect genome-engineered mutants. Deep sequencing of nPCR products directly amplified from pooled genomic DNA revealed over an 1% proportion of 5-bp deletion mutants and a lower frequency of 12-bp deletion mutants, with both types of editing precisely located at the targeted site. The isolated mutants, in which precise deletion of five bases caused a frameshift in NR translation, grow normally under NH4 Cl but fail to grow under NaNO3 , and thus represent a valuable chassis strain for transgenic-strain development. This demonstration of CRISPR/Cas9-based genome editing in industrial microalgae opens many doors for microalgae-based biotechnological applications.
Collapse
Affiliation(s)
- Qintao Wang
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yandu Lu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan University, 570228, Haikou, Hainan, China
| | - Yi Xin
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
| | - Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
| | - Shi Huang
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| |
Collapse
|
61
|
Garnier M, Bougaran G, Pavlovic M, Berard JB, Carrier G, Charrier A, Le Grand F, Lukomska E, Rouxel C, Schreiber N, Cadoret JP, Rogniaux H, Saint-Jean B. Use of a lipid rich strain reveals mechanisms of nitrogen limitation and carbon partitioning in the haptophyte Tisochrysis lutea. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.10.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
|
62
|
Tan KWM, Lin H, Shen H, Lee YK. Nitrogen-induced metabolic changes and molecular determinants of carbon allocation in Dunaliella tertiolecta. Sci Rep 2016; 6:37235. [PMID: 27849022 PMCID: PMC5110973 DOI: 10.1038/srep37235] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/25/2016] [Indexed: 01/06/2023] Open
Abstract
Certain species of microalgae are natural accumulators of lipids, while others are more inclined to store starch. However, what governs the preference to store lipids or starch is not well understood. In this study, the microalga Dunaliella tertiolecta was used as a model to study the global gene expression profile regulating starch accumulation in microalgae. D. tertiolecta, when depleted of nitrogen, produced only 1% of dry cell weight (DCW) in neutral lipids, while starch was rapidly accumulated up to 46% DCW. The increased in starch content was accompanied by a coordinated overexpression of genes shunting carbon towards starch synthesis, a response not seen in the oleaginous microalgae Nannochloropsis oceanica, Chlamydomonas reinhardtii or Chlorella vulgaris. Genes in the central carbon metabolism pathways, particularly those of the tricarboxylic acid cycle, were also simultaneously upregulated, indicating a robust interchange of carbon skeletons for anabolic and catabolic processes. In contrast, fatty acid and triacylglycerol synthesis genes were downregulated or unchanged, suggesting that lipids are not a preferred form of storage in these cells. This study reveals the transcriptomic influence behind storage reserve allocation in D. tertiolecta and provides valuable insights into the possible manipulation of genes for engineering microorganisms to synthesize products of interest.
Collapse
Affiliation(s)
- Kenneth Wei Min Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Huixin Lin
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Hui Shen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Yuan Kun Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| |
Collapse
|
63
|
Tran NAT, Padula MP, Evenhuis CR, Commault AS, Ralph PJ, Tamburic B. Proteomic and biophysical analyses reveal a metabolic shift in nitrogen deprived Nannochloropsis oculata. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.07.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
64
|
Rathod JP, Prakash G, Vira C, Lali AM. Trehalose phosphate synthase overexpression in Parachlorella kessleri improves growth and photosynthetic performance under high light conditions. Prep Biochem Biotechnol 2016; 46:803-809. [DOI: 10.1080/10826068.2015.1135465] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Jayant Pralhad Rathod
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai, India
| | - Gunjan Prakash
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai, India
| | - Chaitali Vira
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai, India
| | - Arvind M. Lali
- DBT-ICT Centre for Energy Biosciences, Institute of Chemical Technology, Matunga, Mumbai, India
- Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai, India
| |
Collapse
|
65
|
Metabolic pathways for lipid synthesis under nitrogen stress in Chlamydomonas and Nannochloropsis. Biotechnol Lett 2016; 39:1-11. [DOI: 10.1007/s10529-016-2216-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 09/13/2016] [Indexed: 12/13/2022]
|
66
|
Alboresi A, Perin G, Vitulo N, Diretto G, Block M, Jouhet J, Meneghesso A, Valle G, Giuliano G, Maréchal E, Morosinotto T. Light Remodels Lipid Biosynthesis in Nannochloropsis gaditana by Modulating Carbon Partitioning between Organelles. PLANT PHYSIOLOGY 2016; 171:2468-82. [PMID: 27325666 PMCID: PMC4972283 DOI: 10.1104/pp.16.00599] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2016] [Accepted: 06/20/2016] [Indexed: 05/18/2023]
Abstract
The seawater microalga Nannochloropsis gaditana is capable of accumulating a large fraction of reduced carbon as lipids. To clarify the molecular bases of this metabolic feature, we investigated light-driven lipid biosynthesis in Nannochloropsis gaditana cultures combining the analysis of photosynthetic functionality with transcriptomic, lipidomic and metabolomic approaches. Light-dependent alterations are observed in amino acid, isoprenoid, nucleic acid, and vitamin biosynthesis, suggesting a deep remodeling in the microalgal metabolism triggered by photoadaptation. In particular, high light intensity is shown to affect lipid biosynthesis, inducing the accumulation of diacylglyceryl-N,N,N-trimethylhomo-Ser and triacylglycerols, together with the up-regulation of genes involved in their biosynthesis. Chloroplast polar lipids are instead decreased. This situation correlates with the induction of genes coding for a putative cytosolic fatty acid synthase of type 1 (FAS1) and polyketide synthase (PKS) and the down-regulation of the chloroplast fatty acid synthase of type 2 (FAS2). Lipid accumulation is accompanied by the regulation of triose phosphate/inorganic phosphate transport across the chloroplast membranes, tuning the carbon metabolic allocation between cell compartments, favoring the cytoplasm, mitochondrion, and endoplasmic reticulum at the expense of the chloroplast. These results highlight the high flexibility of lipid biosynthesis in N. gaditana and lay the foundations for a hypothetical mechanism of regulation of primary carbon partitioning by controlling metabolite allocation at the subcellular level.
Collapse
Affiliation(s)
- Alessandro Alboresi
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Giorgio Perin
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Nicola Vitulo
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Gianfranco Diretto
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Maryse Block
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Juliette Jouhet
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Andrea Meneghesso
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Giorgio Valle
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Giovanni Giuliano
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Eric Maréchal
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| | - Tomas Morosinotto
- PAR-Lab_Padua Algae Research Laboratory, Department of Biology (A.A., G.P., A.M., T.M.), and Innovative Biotechnologies Interdepartmental Research Center (CRIBI; N.V., G.V.), University of Padova, 35121 Padova, Italy;Laboratoire de Biologie Cellulaire et Végétale, UMR 5168 CNRS, CEA, INRA, Université Grenoble Alpes, BIG, CEA-Grenoble, 38054 Grenoble, Cedex 9, France (M.B., J.J., E.M.);Department of Biotechnology, University of Verona, 37134 Verona, Italy (N.V.); andItalian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA), Casaccia Research Centre, 00123 Roma, Italy (G.D., G.G.)
| |
Collapse
|
67
|
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.
Collapse
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
| |
Collapse
|
68
|
Rai V, Karthikaichamy A, Das D, Noronha S, Wangikar PP, Srivastava S. Multi-omics Frontiers in Algal Research: Techniques and Progress to Explore Biofuels in the Postgenomics World. OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 20:387-99. [DOI: 10.1089/omi.2016.0065] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Vineeta Rai
- Department of Biosciences and Bioengineering, Proteomics Laboratory, Indian Institute of Technology Bombay, Mumbai, India
| | | | - Debasish Das
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati, India
- DBT PAN IIT Centre for Bioenergy, Indian Institute of Technology, Bombay, Mumbai, India
| | - Santosh Noronha
- DBT PAN IIT Centre for Bioenergy, Indian Institute of Technology, Bombay, Mumbai, India
- Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Pramod P. Wangikar
- DBT PAN IIT Centre for Bioenergy, Indian Institute of Technology, Bombay, Mumbai, India
- Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Mumbai, India
| | - Sanjeeva Srivastava
- Department of Biosciences and Bioengineering, Proteomics Laboratory, Indian Institute of Technology Bombay, Mumbai, India
- DBT PAN IIT Centre for Bioenergy, Indian Institute of Technology, Bombay, Mumbai, India
- Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Mumbai, India
| |
Collapse
|
69
|
Physiological and biochemical changes reveal stress-associated photosynthetic carbon partitioning into triacylglycerol in the oleaginous marine alga Nannochloropsis oculata. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.03.005] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
|
70
|
Proteomic analyses bring new insights into the effect of a dark stress on lipid biosynthesis in Phaeodactylum tricornutum. Sci Rep 2016; 6:25494. [PMID: 27147218 PMCID: PMC4857112 DOI: 10.1038/srep25494] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/19/2016] [Indexed: 01/24/2023] Open
Abstract
Microalgae biosynthesize high amount of lipids and show high potential for renewable biodiesel production. However, the production cost of microalgae-derived biodiesel hampers large-scale biodiesel commercialization and new strategies for increasing lipid production efficiency from algae are urgently needed. Here we submitted the marine algae Phaeodactylum tricornutum to a 4-day dark stress, a condition increasing by 2.3-fold the total lipid cell quotas, and studied the cellular mechanisms leading to lipid accumulation using a combination of physiological, proteomic (iTRAQ) and genomic (qRT-PCR) approaches. Our results show that the expression of proteins in the biochemical pathways of glycolysis and the synthesis of fatty acids were induced in the dark, potentially using excess carbon and nitrogen produced from protein breakdown. Treatment of algae in the dark, which increased algal lipid cell quotas at low cost, combined with optimal growth treatment could help optimizing biodiesel production.
Collapse
|
71
|
Temporal Succession of Ancient Phytoplankton Community in Qinghai Lake and Implication for Paleo-environmental Change. Sci Rep 2016; 6:19769. [PMID: 26805936 PMCID: PMC4726407 DOI: 10.1038/srep19769] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 11/10/2015] [Indexed: 11/24/2022] Open
Abstract
Tibetan lake sediments in NW China are sensitive recorders of climate change. However, many important plankton members do not leave any microscopic features in sedimentary records. Here we used ancient DNA preserved in Qinghai Lake sediments to reconstruct the temporal succession of plankton communities in the past 18,500 years. Our results showed that seven classes and sixteen genera of phytoplankton in the lake underwent major temporal changes, in correlation with known climatic events. Trebouxiophyceae and Eustigmatophyceae were predominant during the cold periods, whereas Chlorophyceae, Phaeophyceae, Xanthophyceae, Bacillariophyceae, and Cyanophyceae were abundant during the warm periods. The inferred changes in temperature, nutrients, precipitation, and salinity, as driven by the Westerlies and summer Monsoon strength, likely contributed to these observed temporal changes. Based on these correlations, we propose the phytoplankton index as a proxy to reconstruct the stadial versus interstadial climate change history in Qinghai Lake. This taxon-specific index is free of terrestrial contamination, sensitive to short-term climatic oscillations, and continuous in recording all climatic events in the lake. The validity of this index and its applicability to other lakes is demonstrated by its good correlations with multiple climate records of Qinghai Lake and another lake on the Tibetan Plateau, Kusai Lake.
Collapse
|
72
|
Kirchner L, Wirshing A, Kurt L, Reinard T, Glick J, Cram EJ, Jacobsen HJ, Lee-Parsons CW. Identification, characterization, and expression of diacylgylcerol acyltransferase type-1 from Chlorella vulgaris. ALGAL RES 2016. [DOI: 10.1016/j.algal.2015.10.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
73
|
Fakhry EM, El Maghraby DM. Lipid accumulation in response to nitrogen limitation and variation of temperature in Nannochloropsis salina. BOTANICAL STUDIES 2015; 56:6. [PMID: 28510815 PMCID: PMC5432932 DOI: 10.1186/s40529-015-0085-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 03/05/2015] [Indexed: 05/18/2023]
Abstract
BACKGROUND This batch study deals with the relation between lipid as well as triglyceride contents in Nannochloropsis salina and variation in culture conditions such as nitrogen concentration and temperature. RESULTS The tested parameters caused reduction in growth expressed as cell count, optical density and dry weight, as well strongly involved in lipids and triglycerides accumulation and significantly affected the lipid productivity. At the beginning of the work, the concentration of nitrogen in the medium was reduced to three quarter, half and quarter of the original f2 medium while the temperature kept constant. After that, the optimal nitrogen concentration (quarter of the original media) giving high lipid yield was tested with different temperature degrees from 15 to 35°C with five degree intervals. Although the growth was insignificantly influenced, a considerable increase in lipid and triglyceride (56.1 and 15.1% of dry weight respectively) was observed when the concentration of nitrogen in the medium was reduced to the quarter. Moreover, 59.3% lipid and 17.1% triglyceride on the basis of dry weight were obtained by the combination of 25% nitrogen concentration and 30°C. Simple regressions recommended that the interaction effect of nitrogen limitation and temperature on lipid and triglyceride accumulation was not as fundamental as for nitrogen limitation stress. CONCLUSION The degree of nitrogen availability in the combination of temperature effect has been identified as the critical determinant for the maximal production of lipid in N. salina. Nevertheless, major advances in this field can be considered by studying more stresses techniques and genetic strategies.
Collapse
Affiliation(s)
- Eman M Fakhry
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, 21511 Egypt
| | - Dahlia M El Maghraby
- Department of Botany and Microbiology, Faculty of Science, Alexandria University, Alexandria, 21511 Egypt
| |
Collapse
|
74
|
|
75
|
Zhang YJ, Zhang SF, He ZP, Lin L, Wang DZ. Proteomic analysis provides new insights into the adaptive response of a dinoflagellate Prorocentrum donghaiense to changing ambient nitrogen. PLANT, CELL & ENVIRONMENT 2015; 38:2128-2142. [PMID: 25789726 DOI: 10.1111/pce.12538] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 03/05/2015] [Indexed: 06/04/2023]
Abstract
Nitrogen (N) is the major nutrient limiting phytoplankton growth and productivity over large ocean areas. Dinoflagellates are important primary producers and major causative agents of harmful algal blooms in the ocean. However, very little is known about their adaptive response to changing ambient N. Here, we compared the protein profiles of a marine dinoflagellate Prorocentrum donghaiense grown in inorganic N-replete, N-deplete and N-resupplied conditions using 2-D fluorescence differential gel electrophoresis. The results showed that cell density, chlorophyll a and particulate organic N contents presented low levels in N-deplete cells, while particulate organic carbon content and glutamine synthetase (GS) activity maintained high levels. Comparison of the protein profiles of N-replete, N-deplete and N-resupplied cells indicated that proteins involved in photosynthesis, carbon fixation, protein and lipid synthesis were down-regulated, while proteins participating in N reallocation and transport activity were up-regulated in N-deplete cells. High expressions of GS and 60 kDa chaperonin as well as high GS activity in N-deplete cells indicated their central role in N stress adaptation. Overall, in contrast with other photosynthetic eukaryotic algae, P. donghaiense possessed a specific ability to regulate intracellular carbon and N metabolism in response to extreme ambient N deficiency.
Collapse
Affiliation(s)
- Ying-Jiao Zhang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, China
- Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China
| | - Shu-Fei Zhang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, China
| | - Zhi-Ping He
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, China
| | - Lin Lin
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, China
| | - Da-Zhi Wang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, 361102, China
| |
Collapse
|
76
|
Xiao Y, Zhang J, Cui J, Yao X, Sun Z, Feng Y, Cui Q. Simultaneous accumulation of neutral lipids and biomass in Nannochloropsis oceanica IMET1 under high light intensity and nitrogen replete conditions. ALGAL RES 2015. [DOI: 10.1016/j.algal.2015.05.019] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
77
|
Kaye Y, Grundman O, Leu S, Zarka A, Zorin B, Didi-Cohen S, Khozin-Goldberg I, Boussiba S. Metabolic engineering toward enhanced LC-PUFA biosynthesis in Nannochloropsis oceanica : Overexpression of endogenous Δ12 desaturase driven by stress-inducible promoter leads to enhanced deposition of polyunsaturated fatty acids in TAG. ALGAL RES 2015. [DOI: 10.1016/j.algal.2015.05.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
78
|
Zhao Y, Wang Y, Quigg A. The 24 hour recovery kinetics from n starvation in Phaeodactylum tricornutum and Emiliania huxleyi. JOURNAL OF PHYCOLOGY 2015; 51:726-738. [PMID: 26986793 DOI: 10.1111/jpy.12314] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 04/27/2015] [Indexed: 06/05/2023]
Abstract
The response of N (nitrate) starved cells of the diatom Phaeodactylum tricornutum and the coccolithophore Emiliania huxleyi to a pulse of new N were measured to investigate rapid cellular and photosynthetic recovery kinetics. The changes of multiple parameters were followed over 24 h. In P. tricornutum, the recovery of Fv /Fm (the maximum quantum yield of PS II) and σPSII (the functional absorption cross-section for PSII) started within the first hour, much earlier than other parameters. Cellular pigments did not recover during the 24 h but the chlorophyll (chl) a/carotenoid ratios increased to levels measured in the controls. Cell division was independent of the recovery of chl a. In E. huxleyi, the recovery of Fv /Fm and σPSII started after an hour, synchronous with the increase in cellular organic N and chl a with pigments fully recovered within 14 h. P. tricornutum prioritized the recovery of its photosynthetic functions and cell divisions while E. huxleyi did not follow this pattern. We hypothesize that the different recovery strategies between the two species allow P. tricornutum to be more competitive when N pulses are introduced into N-limited water while E. huxleyi is adapted to N scarce waters where such pulses are infrequent. These findings are consistent with successional patterns observed in coastal environments. This is one of only a few studies exploring recovery kinetics of cellular functions and photosynthesis after nitrogen stress in phytoplankton. Our results can be used to enhance ecological models linking phytoplankton traits to species diversity and community structure.
Collapse
Affiliation(s)
- Yan Zhao
- Department of Oceanography, Texas A&M University, College Station, Texas, 77843, USA
- Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China
| | - You Wang
- Department of Marine Ecology, Ocean University of China, Qingdao, 266003, China
| | - Antonietta Quigg
- Department of Oceanography, Texas A&M University, College Station, Texas, 77843, USA
- Department of Marine Biology, Texas A&M University, Galveston, Texas, 77553, USA
| |
Collapse
|
79
|
Abstract
Micro-algae synthesize high levels of lipids, carbohydrates and proteins photoautotrophically, thus attracting considerable interest for the biotechnological production of fuels, environmental remediation, functional foods and nutraceuticals. Currently, only a few micro-algae species are grown commercially at large-scale, primarily for “health-foods” and pigments. For a range of potential products (fuel to pharma), high lipid productivity strains are required to mitigate the economic costs of mass culture. Here we present a screen concentrating on marine micro-algal strains, which if suitable for scale-up would minimise competition with agriculture for water. Mass-Spectrophotometric analysis (MS) of nitrogen (N) and carbon (C) was subsequently validated by measurement of total fatty acids (TFA) by Gas-Chromatography (GC). This identified a rapid and accurate screening strategy based on elemental analysis. The screen identified Nannochloropsis oceanica CCAP 849/10 and a marine isolate of Chlorella vulgaris CCAP 211/21A as the best lipid producers. Analysis of C, N, protein, carbohydrate and Fatty Acid (FA) composition identified a suite of strains for further biotechnological applications e.g. Dunaliella polymorpha CCAP 19/14, significantly the most productive for carbohydrates, and Cyclotella cryptica CCAP 1070/2, with utility for EPA production and N-assimilation.
Collapse
|
80
|
Shene C, Monsalve MT, Vergara D, Lienqueo ME, Rubilar M. High pressure homogenization ofNannochloropsis oculatafor the extraction of intracellular components: Effect of process conditions and culture age. EUR J LIPID SCI TECH 2015. [DOI: 10.1002/ejlt.201500011] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Carolina Shene
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN; Universidad de La Frontera; Temuco Chile
- Centre for Biotechnology and Bioengineering (CeBiB); Universidad de La Frontera; Temuco Chile
| | - María Teresa Monsalve
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN; Universidad de La Frontera; Temuco Chile
| | - Daniela Vergara
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN; Universidad de La Frontera; Temuco Chile
| | - María Elena Lienqueo
- Department of Chemical Engineering and Biotechnology; Centre for Biotechnology and Bioengineering (CeBiB), University of Chile; Santiago Chile
| | - Mónica Rubilar
- Department of Chemical Engineering, Center of Food Biotechnology and Bioseparations, BIOREN; Universidad de La Frontera; Temuco Chile
| |
Collapse
|
81
|
|
82
|
Sarkar D, Shimizu K. An overview on biofuel and biochemical production by photosynthetic microorganisms with understanding of the metabolism and by metabolic engineering together with efficient cultivation and downstream processing. BIORESOUR BIOPROCESS 2015. [DOI: 10.1186/s40643-015-0045-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
|
83
|
Juergens MT, Deshpande RR, Lucker BF, Park JJ, Wang H, Gargouri M, Holguin FO, Disbrow B, Schaub T, Skepper JN, Kramer DM, Gang DR, Hicks LM, Shachar-Hill Y. The regulation of photosynthetic structure and function during nitrogen deprivation in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2015; 167:558-73. [PMID: 25489023 PMCID: PMC4326741 DOI: 10.1104/pp.114.250530] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 12/01/2014] [Indexed: 05/19/2023]
Abstract
The accumulation of carbon storage compounds by many unicellular algae after nutrient deprivation occurs despite declines in their photosynthetic apparatus. To understand the regulation and roles of photosynthesis during this potentially bioenergetically valuable process, we analyzed photosynthetic structure and function after nitrogen deprivation in the model alga Chlamydomonas reinhardtii. Transcriptomic, proteomic, metabolite, and lipid profiling and microscopic time course data were combined with multiple measures of photosynthetic function. Levels of transcripts and proteins of photosystems I and II and most antenna genes fell with differing trajectories; thylakoid membrane lipid levels decreased, while their proportions remained similar and thylakoid membrane organization appeared to be preserved. Cellular chlorophyll (Chl) content decreased more than 2-fold within 24 h, and we conclude from transcript protein and (13)C labeling rates that Chl synthesis was down-regulated both pre- and posttranslationally and that Chl levels fell because of a rapid cessation in synthesis and dilution by cellular growth rather than because of degradation. Photosynthetically driven oxygen production and the efficiency of photosystem II as well as P700(+) reduction and electrochromic shift kinetics all decreased over the time course, without evidence of substantial energy overflow. The results also indicate that linear electron flow fell approximately 15% more than cyclic flow over the first 24 h. Comparing Calvin-Benson cycle transcript and enzyme levels with changes in photosynthetic (13)CO2 incorporation rates also pointed to a coordinated multilevel down-regulation of photosynthetic fluxes during starch synthesis before the induction of high triacylglycerol accumulation rates.
Collapse
Affiliation(s)
- Matthew T Juergens
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Rahul R Deshpande
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Ben F Lucker
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Jeong-Jin Park
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Hongxia Wang
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Mahmoud Gargouri
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - F Omar Holguin
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Bradley Disbrow
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Tanner Schaub
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Jeremy N Skepper
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - David M Kramer
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - David R Gang
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Leslie M Hicks
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| | - Yair Shachar-Hill
- Department of Plant Biology (M.T.J., R.R.D., B.D., Y.S.-H.) and Plant Research Laboratory (M.T.J., B.F.L., D.M.K.), Michigan State University, East Lansing, Michigan 48824;Institute of Biological Chemistry, Washington State University, Pullman, Washington 99164 (J.-J.P., M.G., D.R.G.);Donald Danforth Plant Science Center, St. Louis, Missouri 63132 (H.W., L.M.H.);National Center of Biomedical Analysis, Beijing 100850, China (H.W.);College of Agricultural, Consumer, and Environmental Sciences, New Mexico State University, Las Cruces, New Mexico 88003 (F.O.H., T.S.);Department of Physiology, Cambridge Advanced Imaging Centre, Cambridge CB2 3DY, United Kingdom (J.N.S.); andDepartment of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599 (L.M.H.)
| |
Collapse
|
84
|
Wang HT, Meng YY, Cao XP, Ai JN, Zhou JN, Xue S, Wang WL. Coordinated response of photosynthesis, carbon assimilation, and triacylglycerol accumulation to nitrogen starvation in the marine microalgae Isochrysis zhangjiangensis (Haptophyta). BIORESOURCE TECHNOLOGY 2015; 177:282-8. [PMID: 25496949 DOI: 10.1016/j.biortech.2014.11.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 11/07/2014] [Accepted: 11/09/2014] [Indexed: 05/26/2023]
Abstract
The photosynthetic performance, carbon assimilation, and triacylglycerol accumulation of Isochrysis zhangjiangensis under nitrogen-deplete conditions were studied to understand the intrinsic correlations between them. The nitrogen-deplete period was divided into two stages based on the photosynthetic parameters. During the first stage, carbon assimilation was not reduced compared with that under favorable conditions. The marked increase in triacylglycerols and the variation in the fatty acid profile suggested that triacylglycerols were mainly derived from de novo synthesized acyl groups. In the second stage, the triacylglycerol content continued increasing while the carbohydrate content decreased from 44.0% to 26.3%. These results indicated that the intracellular conversion of carbohydrates to triacylglycerols occurred. Thus, we propose that sustainable carbon assimilation and incremental triacylglycerol production can be achieved by supplying appropriate amounts of nitrogen in medium to protect the photosynthetic process from severe damage using the photosynthetic parameters as indicators.
Collapse
Affiliation(s)
- Hai-Tao Wang
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ying-Ying Meng
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China; School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China
| | - Xu-Peng Cao
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Jiang-Ning Ai
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Jian-Nan Zhou
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China
| | - Song Xue
- Marine Bioengineering Group, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
| | - Wei-liang Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
| |
Collapse
|
85
|
Johnson MD. Inducible Mixotrophy in the Dinoflagellate Prorocentrum minimum. J Eukaryot Microbiol 2015; 62:431-43. [DOI: 10.1111/jeu.12198] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 11/12/2014] [Accepted: 11/12/2014] [Indexed: 10/24/2022]
Affiliation(s)
- Matthew D. Johnson
- Woods Hole Oceanographic Institution; 266 Woods Hole Road Woods Hole Massachusetts 02543
| |
Collapse
|
86
|
Chi Y, Chen F, Takiguchi Y. Effect of Nitrogen Source on Biomass and Lipid Production of a Marine Microalga, <i>Nannochloropsis oceanica</i> IMET1. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/gsc.2015.52013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
87
|
Jia J, Han D, Gerken HG, Li Y, Sommerfeld M, Hu Q, Xu J. Molecular mechanisms for photosynthetic carbon partitioning into storage neutral lipids in Nannochloropsis oceanica under nitrogen-depletion conditions. ALGAL RES 2015. [DOI: 10.1016/j.algal.2014.11.005] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
88
|
Kang NK, Jeon S, Kwon S, Koh HG, Shin SE, Lee B, Choi GG, Yang JW, Jeong BR, Chang YK. Effects of overexpression of a bHLH transcription factor on biomass and lipid production in Nannochloropsis salina. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:200. [PMID: 26628914 PMCID: PMC4666162 DOI: 10.1186/s13068-015-0386-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/16/2015] [Indexed: 05/02/2023]
Abstract
BACKGROUND Microalgae are considered promising alternative energy sources because they consume CO2 and accumulate large amounts of lipids that can be used as biofuel. Nannochloropsis is a particularly promising microalga due to its high growth rate and lipid content, and the availability of genomic information. Transcription factors (TFs) are global regulators of biological pathways by up- or down-regulation of related genes. Among these, basic helix-loop-helix (bHLH) TFs regulate growth, development, and stress responses in plants and animals, and have been identified in microalgae. We identified two bHLH TFs in the genome of N. salina CCMP1776, NsbHLH1, and NsbHLH2, and characterized functions of NsbHLH2 that may be involved in growth and nutrient uptake. RESULTS We obtained NsbHLH2 overexpressing transformants of N. salina CCMP1776 by particle bombardment and confirmed that these were stable transformants. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting using antibodies against the FLAG tag that was attached at the end of the coding sequence confirmed the expression of the NsbHLH2 protein under various culture conditions. The qRT-PCR results also indicated that the endogenous and transgenic expression of NsbHLH2 was reduced under stressed conditions. Overexpression of NsbHLH2 led to increased growth rate in the early growth period, and concomitantly higher nutrient uptake, than wild type (WT). These enhanced growth and nutrient uptake resulted in increased productivities of biomass and FAME. For example, one of the transformants, NsbHLH2 3-6, showed increased biomass productivity by 36 % under the normal condition, and FAME productivity by 33 % under nitrogen limitation condition. Conclusively, the improved growth in the transformants can be associated with the enhanced nutrient uptake. We are currently assessing their potential for scale-up cultivation with positive outcomes. CONCLUSION Overexpression of NsbHLH2 led to enhanced growth rate and nutrient uptake during the early growth phase, and increased biomass and FAME productivity, especially in the later period under normal and stressed conditions. Based on these results, we postulate that NsbHLH2 can be employed for the industrial production of biodiesel from N. salina.
Collapse
Affiliation(s)
- Nam Kyu Kang
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Seungjib Jeon
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Sohee Kwon
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Hyun Gi Koh
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Sung-Eun Shin
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Bongsoo Lee
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Gang-Guk Choi
- />Advanced Biomass R&D Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Ji-Won Yang
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Byeong-ryool Jeong
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Yong Keun Chang
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
- />Advanced Biomass R&D Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| |
Collapse
|
89
|
Coordinated rearrangements of assimilatory and storage cell compartments in a nitrogen-starving symbiotic chlorophyte cultivated under high light. Arch Microbiol 2014; 197:181-95. [PMID: 25239707 DOI: 10.1007/s00203-014-1036-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2014] [Revised: 09/01/2014] [Accepted: 09/06/2014] [Indexed: 12/28/2022]
Abstract
A quantitative micromorphometric study of the cell compartment rearrangements was performed in a symbiotic chlorophyte Desmodesmus sp. 3Dp86E-1 grown on nitrogen (N) replete or N-free medium under 480 μmol PAR quanta m(-2) s(-1). The changes in the chloroplast, intraplastidial, and cytoplasmic inclusions induced by high light (HL) and N starvation were similar to those characteristic of free-living chlorophytes. The N-sufficient culture responded to HL by a transient swelling of the thylakoid lumen and a decline in photosynthetic efficiency followed by its recovery. In the N-starving cells, a more rapid expansion and thylakoid swelling occurred along with the irreversible decline in the photosynthetic efficiency. Differential induction of starch grains, oil bodies, and cell wall polysaccharides depending on the stress exposure and type was recorded. Tight relationships between the changes in the assimilatory and storage compartments in the stressed Desmodesmus sp. cells were revealed.
Collapse
|
90
|
Ultrastructure and composition of the Nannochloropsis gaditana cell wall. EUKARYOTIC CELL 2014; 13:1450-64. [PMID: 25239976 DOI: 10.1128/ec.00183-14] [Citation(s) in RCA: 199] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Marine algae of the genus Nannochloropsis are promising producers of biofuel precursors and nutraceuticals and are also harvested commercially for aquaculture feed. We have used quick-freeze, deep-etch electron microscopy, Fourier transform infrared spectroscopy, and carbohydrate analyses to characterize the architecture of the Nannochloropsis gaditana (strain CCMP 526) cell wall, whose recalcitrance presents a significant barrier to biocommodity extraction. The data indicate a bilayer structure consisting of a cellulosic inner wall (~75% of the mass balance) protected by an outer hydrophobic algaenan layer. Cellulase treatment of walls purified after cell lysis generates highly enriched algaenan preparations without using the harsh chemical treatments typically used in algaenan isolation and characterization. Nannochloropsis algaenan was determined to comprise long, straight-chain, saturated aliphatics with ether cross-links, which closely resembles the cutan of vascular plants. Chemical identification of >85% of the isolated cell wall mass is detailed, and genome analysis is used to identify candidate biosynthetic enzymes.
Collapse
|
91
|
Palenik B. Molecular mechanisms by which marine phytoplankton respond to their dynamic chemical environment. ANNUAL REVIEW OF MARINE SCIENCE 2014; 7:325-340. [PMID: 25195866 DOI: 10.1146/annurev-marine-010814-015639] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Marine scientists have long been interested in the interactions of marine phytoplankton with their chemical environments. Nutrient availability clearly controls carbon fixation on a global scale, but the interactions between phytoplankton and nutrients are complex and include both short-term responses (seconds to minutes) and longer-term evolutionary adaptations. This review outlines how genomics and functional genomics approaches are providing a better understanding of these complex interactions, especially for cyanobacteria and diatoms, for which the genome sequences of multiple model organisms are available. Transporters and related genes are emerging as the most likely candidates for biomarkers in stress-specific studies, but other genes are also possible candidates. One surprise has been the important role of horizontal gene transfer in mediating chemical-biological interactions.
Collapse
Affiliation(s)
- Brian Palenik
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093-0202;
| |
Collapse
|
92
|
Kiyota H, Hirai MY, Ikeuchi M. NblA1/A2-Dependent Homeostasis of Amino Acid Pools during Nitrogen Starvation in Synechocystis sp. PCC 6803. Metabolites 2014; 4:517-31. [PMID: 24983765 PMCID: PMC4192677 DOI: 10.3390/metabo4030517] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 06/14/2014] [Accepted: 06/23/2014] [Indexed: 01/21/2023] Open
Abstract
Nutrient balance is important for photosynthetic growth and biomass production in microalgae. Here, we investigated and compared metabolic responses of amino acid pools to nitrogen and sulfur starvation in a unicellular model cyanobacterium, Synechocystis sp. PCC 6803, and its mutant nblA1/A2. It is known that NblA1/A2-dependent and -independent breakdown of abundant photosynthetic phycobiliproteins and other cellular proteins supply nutrients to the organism. However, the contribution of the NblA1/A2-dependent nutrient supply to amino acid pool homeostasis has not been studied. Our study demonstrates that changes in the pool size of many amino acids during nitrogen starvation can be categorized as NblA1/A2-dependent (Gln, Glu, glutathione, Gly, Ile, Leu, Met, Phe, Pro, Ser, Thr, Tyr and Val) and NblA1/A2-independent (Ala, Asn, Lys, and Trp). We also report unique changes in amino acid pool sizes during sulfur starvation in wild type and the mutant and found a generally marked increase in the Lys pool in cyanobacteria during nutrient starvation. In conclusion, the NblA1/A2-dependent protein turnover contributes to the maintenance of many amino acid pools during nitrogen starvation.
Collapse
Affiliation(s)
- Hiroshi Kiyota
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Masami Yokota Hirai
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan.
| | - Masahiko Ikeuchi
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| |
Collapse
|
93
|
Li J, Han D, Wang D, Ning K, Jia J, Wei L, Jing X, Huang S, Chen J, Li Y, Hu Q, Xu J. Choreography of Transcriptomes and Lipidomes of Nannochloropsis Reveals the Mechanisms of Oil Synthesis in Microalgae. THE PLANT CELL 2014; 26:1645-1665. [PMID: 24692423 PMCID: PMC4036577 DOI: 10.1105/tpc.113.121418] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Revised: 02/16/2014] [Accepted: 03/11/2014] [Indexed: 05/17/2023]
Abstract
To reveal the molecular mechanisms of oleaginousness in microalgae, transcriptomic and lipidomic dynamics of the oleaginous microalga Nannochloropsis oceanica IMET1 under nitrogen-replete (N+) and N-depleted (N-) conditions were simultaneously tracked. At the transcript level, enhanced triacylglycerol (TAG) synthesis under N- conditions primarily involved upregulation of seven putative diacylglycerol acyltransferase (DGAT) genes and downregulation of six other DGAT genes, with a simultaneous elevation of the other Kennedy pathway genes. Under N- conditions, despite downregulation of most de novo fatty acid synthesis genes, the pathways that shunt carbon precursors from protein and carbohydrate metabolic pathways into glycerolipid synthesis were stimulated at the transcript level. In particular, the genes involved in supplying carbon precursors and energy for de novo fatty acid synthesis, including those encoding components of the pyruvate dehydrogenase complex (PDHC), glycolysis, and PDHC bypass, and suites of specific transporters, were substantially upregulated under N- conditions, resulting in increased overall TAG production. Moreover, genes involved in the citric acid cycle and β-oxidation in mitochondria were greatly enhanced to utilize the carbon skeletons derived from membrane lipids and proteins to produce additional TAG or its precursors. This temporal and spatial regulation model of oil accumulation in microalgae provides a basis for improving our understanding of TAG synthesis in microalgae and will also enable more rational genetic engineering of TAG production.
Collapse
Affiliation(s)
- Jing Li
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China University of Chinese Academy of Sciences, Beijing 100049, China
| | - Danxiang Han
- Laboratory for Algae Research and Biotechnology, Department of Applied Biological Sciences, Arizona State University, Mesa, Arizona 85212
| | - Dongmei Wang
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Kang Ning
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Jing Jia
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoyan Jing
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Shi Huang
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jie Chen
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Yantao Li
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science and University of Maryland Baltimore County, Baltimore, Maryland 21202
| | - Qiang Hu
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| |
Collapse
|
94
|
Garnier M, Carrier G, Rogniaux H, Nicolau E, Bougaran G, Saint-Jean B, Cadoret JP. Comparative proteomics reveals proteins impacted by nitrogen deprivation in wild-type and high lipid-accumulating mutant strains of Tisochrysis lutea. J Proteomics 2014; 105:107-20. [PMID: 24583506 DOI: 10.1016/j.jprot.2014.02.022] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 01/24/2014] [Accepted: 02/19/2014] [Indexed: 11/30/2022]
Abstract
UNLABELLED Understanding microalgal lipid accumulation under nitrogen starvation is of major interest for biomass feedstock, food and biofuel production. Using a domesticated oleaginous algae Tisochrysis lutea, we performed the first comparative proteomic analysis on the wild type strain and a selected lipid over-accumulating mutant. 2-DE analysis was made on these strains cultured in two metabolic conditions, with and without nitrogen deprivation, which revealed significant differences in proteomes according to both strain and nitrogen availability. Mass spectrometry allowed us to identify 37 proteins that were differentially expressed between the two strains, and 17 proteins regulated by nitrogen starvation concomitantly with lipid accumulation. The proteins identified are known to be involved in various metabolic pathways including lipid, carbohydrate, amino acid, energy and pigment metabolisms, photosynthesis, protein translation, stress response and cell division. Four candidates were selected for possible implication in the over-accumulation of lipids during nitrogen starvation. These include the plastid beta-ketoacyl-ACP reductase protein, the coccolith scale associated protein and two glycoside hydrolases involved in biosynthesis of fatty acids, carbon homeostasis and carbohydrate catabolism, respectively. This proteomic study confirms the impact of nitrogen starvation on overall metabolism and provides new perspectives to study the lipid over-accumulation in the prymnesiophyte haptophyte T. lutea. BIOLOGICAL SIGNIFICANCE This paper study consists of the first proteomic analysis on Tisochrysis lutea, a non-model marine microalga of interest for aquaculture and lipids production. Comparative proteomics revealed proteins putatively involved in the up-accumulation of neutral lipids in a mutant strain during nitrogen starvation. The results are of great importance for future works to improve lipid accumulation in microalgae of biotechnological interest for biofuel production. This article is part of a Special Issue entitled: Proteomics of non-model organisms.
Collapse
Affiliation(s)
- M Garnier
- Laboratoire BRM-PBA Ifremer, Nantes, France.
| | - G Carrier
- Laboratoire BRM-PBA Ifremer, Nantes, France
| | - H Rogniaux
- INRA, UR1268 Biopolymers Interactions Assemblies, F-44316 Nantes, France
| | - E Nicolau
- Laboratoire BRM-PBA Ifremer, Nantes, France
| | - G Bougaran
- Laboratoire BRM-PBA Ifremer, Nantes, France
| | | | | |
Collapse
|
95
|
Nannochloropsis genomes reveal evolution of microalgal oleaginous traits. PLoS Genet 2014; 10:e1004094. [PMID: 24415958 PMCID: PMC3886936 DOI: 10.1371/journal.pgen.1004094] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 11/20/2013] [Indexed: 01/28/2023] Open
Abstract
Oleaginous microalgae are promising feedstock for biofuels, yet the genetic diversity, origin and evolution of oleaginous traits remain largely unknown. Here we present a detailed phylogenomic analysis of five oleaginous Nannochloropsis species (a total of six strains) and one time-series transcriptome dataset for triacylglycerol (TAG) synthesis on one representative strain. Despite small genome sizes, high coding potential and relative paucity of mobile elements, the genomes feature small cores of ca. 2,700 protein-coding genes and a large pan-genome of >38,000 genes. The six genomes share key oleaginous traits, such as the enrichment of selected lipid biosynthesis genes and certain glycoside hydrolase genes that potentially shift carbon flux from chrysolaminaran to TAG synthesis. The eleven type II diacylglycerol acyltransferase genes (DGAT-2) in every strain, each expressed during TAG synthesis, likely originated from three ancient genomes, including the secondary endosymbiosis host and the engulfed green and red algae. Horizontal gene transfers were inferred in most lipid synthesis nodes with expanded gene doses and many glycoside hydrolase genes. Thus multiple genome pooling and horizontal genetic exchange, together with selective inheritance of lipid synthesis genes and species-specific gene loss, have led to the enormous genetic apparatus for oleaginousness and the wide genomic divergence among present-day Nannochloropsis. These findings have important implications in the screening and genetic engineering of microalgae for biofuels.
Collapse
|
96
|
Lu Y, Zhou W, Wei L, Li J, Jia J, Li F, Smith SM, Xu J. Regulation of the cholesterol biosynthetic pathway and its integration with fatty acid biosynthesis in the oleaginous microalga Nannochloropsis oceanica. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:81. [PMID: 24920959 PMCID: PMC4052811 DOI: 10.1186/1754-6834-7-81] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 05/01/2014] [Indexed: 05/08/2023]
Abstract
BACKGROUND Sterols are vital structural and regulatory components in eukaryotic cells; however, their biosynthetic pathways and functional roles in microalgae remain poorly understood. RESULTS In the oleaginous microalga Nannochloropsis oceanica, the sterol biosynthetic pathway produces phytosterols as minor products and cholesterol as the major product. The evidence together with their deduced biosynthetic pathways suggests that N. oceanica exhibits features of both higher plants and mammals. Temporal tracking of sterol profiles and sterol-biosynthetic transcripts in response to changes in light intensity and nitrogen supply reveal that sterols play roles in cell proliferation, chloroplast differentiation, and photosynthesis. Furthermore, the dynamics of fatty acid (FA) and FA-biosynthetic transcripts upon chemical inhibitor-induced sterol depletion reveal possible co-regulation of sterol production and FA synthesis, in that the squalene epoxidase inhibitor terbinafine reduces sterol content yet significantly elevates free FA production. Thus, a feedback regulation of sterol and FA homeostasis is proposed, with the 1-deoxy-D-xylulose 5-phosphate synthase (DXS, the committed enzyme in isoprenoid and sterol biosynthesis) gene potentially subject to feedback regulation by sterols. CONCLUSION These findings reveal features of sterol function and biosynthesis in microalgae and suggest new genetic engineering or chemical biology approaches for enhanced oil production in microalgae.
Collapse
Affiliation(s)
- Yandu Lu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Wenxu Zhou
- Australian Research Council, Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Jing Li
- Australian Research Council, Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Jing Jia
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Fei Li
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Steven M Smith
- Australian Research Council, Centre of Excellence in Plant Energy Biology, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| |
Collapse
|
97
|
Breuer G, de Jaeger L, Artus VPG, Martens DE, Springer J, Draaisma RB, Eggink G, Wijffels RH, Lamers PP. Superior triacylglycerol (TAG) accumulation in starchless mutants of Scenedesmus obliquus: (II) evaluation of TAG yield and productivity in controlled photobioreactors. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:70. [PMID: 24883102 PMCID: PMC4026393 DOI: 10.1186/1754-6834-7-70] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 04/14/2014] [Indexed: 05/09/2023]
Abstract
BACKGROUND Many microalgae accumulate carbohydrates simultaneously with triacylglycerol (TAG) upon nitrogen starvation, and these products compete for photosynthetic products and metabolites from the central carbon metabolism. As shown for starchless mutants of the non-oleaginous model alga Chlamydomonas reinhardtii, reduced carbohydrate synthesis can enhance TAG production. However, these mutants still have a lower TAG productivity than wild-type oleaginous microalgae. Recently, several starchless mutants of the oleaginous microalga Scenedesmus obliquus were obtained which showed improved TAG content and productivity. RESULTS The most promising mutant, slm1, is compared in detail to wild-type S. obliquus in controlled photobioreactors. In the slm1 mutant, the maximum TAG content increased to 57 ± 0.2% of dry weight versus 45 ± 1% in the wild type. In the wild type, TAG and starch were accumulated simultaneously during initial nitrogen starvation, and starch was subsequently degraded and likely converted into TAG. The starchless mutant did not produce starch and the liberated photosynthetic capacity was directed towards TAG synthesis. This increased the maximum yield of TAG on light by 51%, from 0.144 ± 0.004 in the wild type to 0.217 ± 0.011 g TAG/mol photon in the slm1 mutant. No differences in photosynthetic efficiency between the slm1 mutant and the wild type were observed, indicating that the mutation specifically altered carbon partitioning while leaving the photosynthetic capacity unaffected. CONCLUSIONS The yield of TAG on light can be improved by 51% by using the slm1 starchless mutant of S. obliquus, and a similar improvement seems realistic for the areal productivity in outdoor cultivation. The photosynthetic performance is not negatively affected in the slm1 and the main difference with the wild type is an improved carbon partitioning towards TAG.
Collapse
Affiliation(s)
- Guido Breuer
- Bioprocess Engineering & AlgaePARC, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, Netherlands
| | - Lenny de Jaeger
- Bioprocess Engineering & AlgaePARC, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, Netherlands
- Food and Biobased Research & AlgaePARC, Wageningen University and Research Centre, P.O. Box 17, 6700 AA Wageningen, Netherlands
| | - Valentin P G Artus
- Bioprocess Engineering & AlgaePARC, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, Netherlands
| | - Dirk E Martens
- Bioprocess Engineering & AlgaePARC, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, Netherlands
| | - Jan Springer
- Food and Biobased Research & AlgaePARC, Wageningen University and Research Centre, P.O. Box 17, 6700 AA Wageningen, Netherlands
| | - René B Draaisma
- Unilever Research and Development Vlaardingen, Olivier van Noortlaan 120, 3133 AT Vlaardingen, Netherlands
| | - Gerrit Eggink
- Bioprocess Engineering & AlgaePARC, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, Netherlands
- Food and Biobased Research & AlgaePARC, Wageningen University and Research Centre, P.O. Box 17, 6700 AA Wageningen, Netherlands
| | - René H Wijffels
- Bioprocess Engineering & AlgaePARC, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, Netherlands
| | - Packo P Lamers
- Bioprocess Engineering & AlgaePARC, Wageningen University and Research Centre, P.O. Box 8129, 6700 EV Wageningen, Netherlands
| |
Collapse
|