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Random Mutagenesis as a Promising Tool for Microalgal Strain Improvement towards Industrial Production. Mar Drugs 2022; 20:md20070440. [PMID: 35877733 PMCID: PMC9318807 DOI: 10.3390/md20070440] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/27/2022] [Accepted: 06/27/2022] [Indexed: 02/06/2023] Open
Abstract
Microalgae have become a promising novel and sustainable feedstock for meeting the rising demand for food and feed. However, microalgae-based products are currently hindered by high production costs. One major reason for this is that commonly cultivated wildtype strains do not possess the robustness and productivity required for successful industrial production. Several strain improvement technologies have been developed towards creating more stress tolerant and productive strains. While classical methods of forward genetics have been extensively used to determine gene function of randomly generated mutants, reverse genetics has been explored to generate specific mutations and target phenotypes. Site-directed mutagenesis can be accomplished by employing different gene editing tools, which enable the generation of tailor-made genotypes. Nevertheless, strategies promoting the selection of randomly generated mutants avoid the introduction of foreign genetic material. In this paper, we review different microalgal strain improvement approaches and their applications, with a primary focus on random mutagenesis. Current challenges hampering strain improvement, selection, and commercialization will be discussed. The combination of these approaches with high-throughput technologies, such as fluorescence-activated cell sorting, as tools to select the most promising mutants, will also be discussed.
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2
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Kuo EY, Yang RY, Chin YY, Chien YL, Chen YC, Wei CY, Kao LJ, Chang YH, Li YJ, Chen TY, Lee TM. Multi-omics approaches and genetic engineering of metabolism for improved biorefinery and wastewater treatment in microalgae. Biotechnol J 2022; 17:e2100603. [PMID: 35467782 DOI: 10.1002/biot.202100603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 03/12/2022] [Accepted: 04/01/2022] [Indexed: 11/06/2022]
Abstract
Microalgae, a group of photosynthetic microorganisms rich in diverse and novel bioactive metabolites, have been explored for the production of biofuels, high value-added compounds as food and feeds, and pharmaceutical chemicals as agents with therapeutic benefits. This article reviews the development of omics resources and genetic engineering techniques including gene transformation methodologies, mutagenesis, and genome-editing tools in microalgae biorefinery and wastewater treatment. The introduction of these enlisted techniques has simplified the understanding of complex metabolic pathways undergoing microalgal cells. The multiomics approach of the integrated omics datasets, big data analysis, and machine learning for the discovery of objective traits and genes responsible for metabolic pathways was reviewed. Recent advances and limitations of multiomics analysis and genetic bioengineering technology to facilitate the improvement of microalgae as the dual role of wastewater treatment and biorefinery feedstock production are discussed. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Eva YuHua Kuo
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan.,Frontier Center for Ocean Science and Technology, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Ru-Yin Yang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Yuan Yu Chin
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Yi-Lin Chien
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan.,Frontier Center for Ocean Science and Technology, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Yu Chu Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Cheng-Yu Wei
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Li-Jung Kao
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Yi-Hua Chang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Yu-Jia Li
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Te-Yuan Chen
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
| | - Tse-Min Lee
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 804, Taiwan.,Frontier Center for Ocean Science and Technology, National Sun Yat-sen University, Kaohsiung, 804, Taiwan.,Doctoral Degree Program in Marine Biotechnology, National Sun Yat-sen University, Kaohsiung, 804, Taiwan
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3
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Sproles AE, Berndt A, Fields FJ, Mayfield SP. Improved high-throughput screening technique to rapidly isolate Chlamydomonas transformants expressing recombinant proteins. Appl Microbiol Biotechnol 2022; 106:1677-1689. [PMID: 35129657 PMCID: PMC8882119 DOI: 10.1007/s00253-022-11790-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 12/20/2022]
Abstract
Abstract
The single-celled eukaryotic green alga Chlamydomonas reinhardtii has long been a model system for developing genetic tools for algae, and is also considered a potential platform for the production of high-value recombinant proteins. Identifying transformants with high levels of recombinant protein expression has been a challenge in this organism, as random integration of transgenes into the nuclear genome leads to low frequency of cell lines with high gene expression. Here, we describe the design of an optimized vector for the expression of recombinant proteins in Chlamydomonas, that when transformed and screened using a dual antibiotic selection, followed by screening using fluorescence activated cell sorting (FACS), permits rapid identification and isolation of microalgal transformants with high expression of a recombinant protein. This process greatly reduces the time required for the screening process, and can produce large populations of recombinant algae transformants with between 60 and 100% of cells producing the recombinant protein of interest, in as little as 3 weeks, that can then be used for whole population sequencing or individual clone analysis. Utilizing this new vector and high-throughput screening (HTS) process resulted in an order of magnitude improvement over existing methods, which normally produced under 1% of algae transformants expressing the protein of interest. This process can be applied to other algal strains and recombinant proteins to enhance screening efficiency, thereby speeding up the discovery and development of algal-derived recombinant protein products. Key points • A protein expression vector using double-antibiotic resistance genes was designed • Double antibiotic selection causes fewer colonies with more positive for phenotype • Coupling the new vector with FACS improves microalgal screening efficiency > 60% Supplementary Information The online version contains supplementary material available at 10.1007/s00253-022-11790-9.
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Affiliation(s)
- Ashley E Sproles
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Anthony Berndt
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Francis J Fields
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA.,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Stephen P Mayfield
- The California Center for Algae Biotechnology, University of California, San Diego, La Jolla, CA, USA. .,Division of Biological Sciences, University of California, San Diego, La Jolla, CA, USA.
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4
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Li-Beisson Y, Kong F, Wang P, Lee Y, Kang BH. The disassembly of lipid droplets in Chlamydomonas. THE NEW PHYTOLOGIST 2021; 231:1359-1364. [PMID: 34028037 DOI: 10.1111/nph.17505] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/07/2021] [Indexed: 06/12/2023]
Abstract
Lipid droplets (LDs) are ubiquitous and specialized organelles in eukaryotic cells. Consisting of a triacylglycerol core surrounded by a monolayer of membrane lipids, LDs are decorated with proteins and have myriad functions, from carbon/energy storage to membrane lipid remodeling and signal transduction. The biogenesis and turnover of LDs are therefore tightly coordinated with cellular metabolic needs in a fluctuating environment. Lipid droplet turnover requires remodeling of the protein coat, lipolysis, autophagy and fatty acid β-oxidation. Several key components of these processes have been identified in Chlamydomonas (Chlamydomonas reinhardtii), including the major lipid droplet protein, a CXC-domain containing regulatory protein, the phosphatidylethanolamine-binding DTH1 (DELAYED IN TAG HYDROLYSIS1), two lipases and two enzymes involved in fatty acid β-oxidation. Here, we review LD turnover and discuss its physiological significance in Chlamydomonas, a major model green microalga in research on algal oil.
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Affiliation(s)
- Yonghua Li-Beisson
- CEA, CNRS, BIAM, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, Aix-Marseille Univ, Saint Paul-Lez-Durance, 13108, France
| | - Fantao Kong
- School of Bioengineering, Dalian University of Technology, Dalian, 116024, China
| | - Pengfei Wang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
| | - Youngsook Lee
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang, 37673, Korea
| | - Byung-Ho Kang
- School of Life Sciences, Centre for Cell & Developmental Biology and State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, 999077, China
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5
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Enhancing carbohydrate repartitioning into lipid and carotenoid by disruption of microalgae starch debranching enzyme. Commun Biol 2021; 4:450. [PMID: 33837247 PMCID: PMC8035404 DOI: 10.1038/s42003-021-01976-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 03/11/2021] [Indexed: 02/01/2023] Open
Abstract
Light/dark cycling is an inherent condition of outdoor microalgae cultivation, but is often unfavorable for lipid accumulation. This study aims to identify promising targets for metabolic engineering of improved lipid accumulation under outdoor conditions. Consequently, the lipid-rich mutant Chlamydomonas sp. KOR1 was developed through light/dark-conditioned screening. During dark periods with depressed CO2 fixation, KOR1 shows rapid carbohydrate degradation together with increased lipid and carotenoid contents. KOR1 was subsequently characterized with extensive mutation of the ISA1 gene encoding a starch debranching enzyme (DBE). Dynamic time-course profiling and metabolomics reveal dramatic changes in KOR1 metabolism throughout light/dark cycles. During light periods, increased flux from CO2 through glycolytic intermediates is directly observed to accompany enhanced formation of small starch-like particles, which are then efficiently repartitioned in the next dark cycle. This study demonstrates that disruption of DBE can improve biofuel production under light/dark conditions, through accelerated carbohydrate repartitioning into lipid and carotenoid.
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6
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Jallet D, Xing D, Hughes A, Moosburner M, Simmons MP, Allen AE, Peers G. Mitochondrial fatty acid β-oxidation is required for storage-lipid catabolism in a marine diatom. THE NEW PHYTOLOGIST 2020; 228:946-958. [PMID: 32535932 DOI: 10.1111/nph.16744] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Accepted: 05/29/2020] [Indexed: 05/21/2023]
Abstract
Photoautotrophic growth in nature requires the accumulation of energy-containing molecules via photosynthesis during daylight to fuel nighttime catabolism. Many diatoms store photosynthate as the neutral lipid triacylglycerol (TAG). While the pathways of diatom fatty acid and TAG synthesis appear to be well conserved with plants, the pathways of TAG catabolism and downstream fatty acid β-oxidation have not been characterised in diatoms. We identified a putative mitochondria-targeted, bacterial-type acyl-CoA dehydrogenase (PtMACAD1) that is present in Stramenopile and Hacrobian eukaryotes, but not found in plants, animals or fungi. Gene knockout, protein-YFP tags and physiological assays were used to determine PtMACAD1's role in the diatom Phaeodactylum tricornutum. PtMACAD1 is located in the mitochondria. Absence of PtMACAD1 led to no consumption of TAG at night and slower growth in light : dark cycles compared with wild-type. Accumulation of transcripts encoding peroxisomal-based β-oxidation did not change in response to day : night cycles or to PtMACAD1 knockout. Mutants also hyperaccumulated TAG after the amelioration of N limitation. We conclude that diatoms utilise mitochondrial β-oxidation; this is in stark contrast to the peroxisomal-based pathways observed in plants and green algae. We infer that this pattern is caused by retention of catabolic pathways from the host during plastid secondary endosymbiosis.
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Affiliation(s)
- Denis Jallet
- Department of Biology, Colorado State University, 1878 Campus Delivery, 200 West Lake Street, Fort Collins, CO, 80523, USA
- Toulouse Biotechnology Institute, CNRS, INRAE, INSA, Université de Toulouse, Toulouse, 31077, France
| | - Denghui Xing
- Department of Biology, Colorado State University, 1878 Campus Delivery, 200 West Lake Street, Fort Collins, CO, 80523, USA
| | - Alexander Hughes
- Department of Biology, Colorado State University, 1878 Campus Delivery, 200 West Lake Street, Fort Collins, CO, 80523, USA
| | - Mark Moosburner
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
- J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA, 92037, USA
| | - Mark P Simmons
- Department of Biology, Colorado State University, 1878 Campus Delivery, 200 West Lake Street, Fort Collins, CO, 80523, USA
| | - Andrew E Allen
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
- J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA, 92037, USA
| | - Graham Peers
- Department of Biology, Colorado State University, 1878 Campus Delivery, 200 West Lake Street, Fort Collins, CO, 80523, USA
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7
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Kumar G, Shekh A, Jakhu S, Sharma Y, Kapoor R, Sharma TR. Bioengineering of Microalgae: Recent Advances, Perspectives, and Regulatory Challenges for Industrial Application. Front Bioeng Biotechnol 2020; 8:914. [PMID: 33014997 PMCID: PMC7494788 DOI: 10.3389/fbioe.2020.00914] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/15/2020] [Indexed: 01/14/2023] Open
Abstract
Microalgae, due to their complex metabolic capacity, are being continuously explored for nutraceuticals, pharmaceuticals, and other industrially important bioactives. However, suboptimal yield and productivity of the bioactive of interest in local and robust wild-type strains are of perennial concerns for their industrial applications. To overcome such limitations, strain improvement through genetic engineering could play a decisive role. Though the advanced tools for genetic engineering have emerged at a greater pace, they still remain underused for microalgae as compared to other microorganisms. Pertaining to this, we reviewed the progress made so far in the development of molecular tools and techniques, and their deployment for microalgae strain improvement through genetic engineering. The recent availability of genome sequences and other omics datasets form diverse microalgae species have remarkable potential to guide strategic momentum in microalgae strain improvement program. This review focuses on the recent and significant improvements in the omics resources, mutant libraries, and high throughput screening methodologies helpful to augment research in the model and non-model microalgae. Authors have also summarized the case studies on genetically engineered microalgae and highlight the opportunities and challenges that are emerging from the current progress in the application of genome-editing to facilitate microalgal strain improvement. Toward the end, the regulatory and biosafety issues in the use of genetically engineered microalgae in commercial applications are described.
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Affiliation(s)
- Gulshan Kumar
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Ajam Shekh
- Plant Cell Biotechnology Department, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, India
| | - Sunaina Jakhu
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Yogesh Sharma
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Ritu Kapoor
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Tilak Raj Sharma
- Division of Crop Science, Indian Council of Agricultural Research, New Delhi, India
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8
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The phosphatidylethanolamine-binding protein DTH1 mediates degradation of lipid droplets in Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A 2020; 117:23131-23139. [PMID: 32868427 DOI: 10.1073/pnas.2005600117] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Lipid droplets (LDs) are intracellular organelles found in a wide range of organisms and play important roles in stress tolerance. During nitrogen (N) starvation, Chlamydomonas reinhardtii stores large amounts of triacylglycerols (TAGs) inside LDs. When N is resupplied, the LDs disappear and the TAGs are degraded, presumably providing carbon and energy for regrowth. The mechanism by which cells degrade LDs is poorly understood. Here, we isolated a mutant (dth1-1, Delayed in TAG Hydrolysis 1) in which TAG degradation during recovery from N starvation was compromised. Consequently, the dth1-1 mutant grew poorly compared to its parental line during N recovery. Two additional independent loss-of-function mutants (dth1-2 and dth1-3) also exhibited delayed TAG remobilization. DTH1 transcript levels increased sevenfold upon N resupply, and DTH1 protein was localized to LDs. DTH1 contains a putative lipid-binding domain (DTH1LBD) with alpha helices predicted to be structurally similar to those in apolipoproteins E and A-I. Recombinant DTH1LBD bound specifically to phosphatidylethanolamine (PE), a major phospholipid coating the LD surface. Overexpression of DTH1LBD in Chlamydomonas phenocopied the dth1 mutant's defective TAG degradation, suggesting that the function of DTH1 depends on its ability to bind PE. Together, our results demonstrate that the lipid-binding DTH1 plays an essential role in LD degradation and provide insight into the molecular mechanism of protein anchorage to LDs at the LD surface in photosynthetic cells.
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9
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Yaisamlee C, Sirikhachornkit A. Characterization of Chlamydomonas Very High Light-tolerant Mutants for Enhanced Lipid Production. J Oleo Sci 2020; 69:359-368. [PMID: 32249263 DOI: 10.5650/jos.ess19270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Biodiesel production from microalgae is still not commercially realized due to the high cost of production. High light-tolerance has been suggested as a desirable phenotype for efficient cultivation in large scale production systems under fluctuating outdoor conditions. Nevertheless, it has not been shown if algae with such a phenotype would have better efficiency for lipid production. To determine lipid productivity in high light-tolerant mutants, and to understand the pathways involved in high light-tolerant phenotype, two very high light-tolerant mutants of the green alga Chlamydomonas reinhardtii - CAL028_01_28 and CAL034_01_48 - were selected from eighteen high light-tolerant mutants from the CAL collection. Under high light intensity conditions, and the presence of reactive oxygen species, which are conditions constantly experienced by algae growing in open-pond environments, these strains exhibited higher photosynthetic efficiency and improved survival. The physiological characterization of these mutants revealed that the detoxification of ROS by carotenoids and antioxidant enzymes is crucial for their growth under high light conditions. Neither mutant was affected in terms of its ability to accumulate lipid under nitrogen-depleted condition. More importantly, lipid productivity under high light conditions increased twofold in these mutants compared to that of the wild-type. Taken together, very high light-tolerant mutants confer a high potential for biofuel production under outdoor conditions, and their improved ability to survive under oxidative stress is an important key for efficient growth under outdoor conditions.
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Affiliation(s)
- Chonlada Yaisamlee
- Microalgal Molecular Genetics and Functional Genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University.,Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University
| | - Anchalee Sirikhachornkit
- Microalgal Molecular Genetics and Functional Genomics Special Research Unit, Department of Genetics, Faculty of Science, Kasetsart University.,Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University
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10
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Fabris M, Abbriano RM, Pernice M, Sutherland DL, Commault AS, Hall CC, Labeeuw L, McCauley JI, Kuzhiuparambil U, Ray P, Kahlke T, Ralph PJ. Emerging Technologies in Algal Biotechnology: Toward the Establishment of a Sustainable, Algae-Based Bioeconomy. FRONTIERS IN PLANT SCIENCE 2020; 11:279. [PMID: 32256509 PMCID: PMC7090149 DOI: 10.3389/fpls.2020.00279] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Accepted: 02/24/2020] [Indexed: 05/18/2023]
Abstract
Mankind has recognized the value of land plants as renewable sources of food, medicine, and materials for millennia. Throughout human history, agricultural methods were continuously modified and improved to meet the changing needs of civilization. Today, our rapidly growing population requires further innovation to address the practical limitations and serious environmental concerns associated with current industrial and agricultural practices. Microalgae are a diverse group of unicellular photosynthetic organisms that are emerging as next-generation resources with the potential to address urgent industrial and agricultural demands. The extensive biological diversity of algae can be leveraged to produce a wealth of valuable bioproducts, either naturally or via genetic manipulation. Microalgae additionally possess a set of intrinsic advantages, such as low production costs, no requirement for arable land, and the capacity to grow rapidly in both large-scale outdoor systems and scalable, fully contained photobioreactors. Here, we review technical advancements, novel fields of application, and products in the field of algal biotechnology to illustrate how algae could present high-tech, low-cost, and environmentally friendly solutions to many current and future needs of our society. We discuss how emerging technologies such as synthetic biology, high-throughput phenomics, and the application of internet of things (IoT) automation to algal manufacturing technology can advance the understanding of algal biology and, ultimately, drive the establishment of an algal-based bioeconomy.
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Affiliation(s)
- Michele Fabris
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
- CSIRO Synthetic Biology Future Science Platform, Brisbane, QLD, Australia
| | - Raffaela M. Abbriano
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Mathieu Pernice
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Donna L. Sutherland
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Audrey S. Commault
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Christopher C. Hall
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Leen Labeeuw
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Janice I. McCauley
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | | | - Parijat Ray
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Tim Kahlke
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
| | - Peter J. Ralph
- Climate Change Cluster (C3), University of Technology Sydney, Ultimo, NSW, Australia
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11
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Sung YJ, Patel AK, Yu BS, Choi HI, Kim J, Jin E, Sim SJ. Sedimentation rate-based screening of oleaginous microalgae for utilization as a direct combustion fuel. BIORESOURCE TECHNOLOGY 2019; 293:122045. [PMID: 31470230 DOI: 10.1016/j.biortech.2019.122045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 08/17/2019] [Accepted: 08/20/2019] [Indexed: 06/10/2023]
Abstract
The co-combustion of microalgae biomass with coal has the potential to significantly reduce CO2 emissions by eliminating expensive and carbon-emitting downstream processes. In this study, the utilization of microalgal biomass as a direct combustion fuel in co-firing industries and the screening of potential oleaginous strains of high calorific value was investigated. High-lipid accumulating mutants were selected from mutant mixtures based on cell density using differential sedimentation rates. Of the mutant strains obtained in the top phase of the separation medium, 72% showed a higher lipid content than the wild-type strain. One mutant strain exhibited a 57.3% enhanced lipid content and a 9.3% lower heating value (LHV), both indicators of direct combustion fuel performance, compared to the wild-type strain. Our findings indicate that sedimentation rate-based strain selection allows for the easy and rapid screening of high-lipid content algal strains for the use of microalgae as direct combustion fuels.
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Affiliation(s)
- Young Joon Sung
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Anil Kumar Patel
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Byung Sun Yu
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Hong Il Choi
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Jongrae Kim
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea
| | - EonSeon Jin
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea
| | - Sang Jun Sim
- Department of Chemical and Biological Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
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12
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Torres-Romero I, Kong F, Légeret B, Beisson F, Peltier G, Li-Beisson Y. Chlamydomonas cell cycle mutant crcdc5 over-accumulates starch and oil. Biochimie 2019; 169:54-61. [PMID: 31563539 DOI: 10.1016/j.biochi.2019.09.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 09/23/2019] [Indexed: 10/25/2022]
Abstract
The use of algal biomass for biofuel production requires improvements in both biomass productivity and its energy density. Green microalgae store starch and oil as two major forms of carbon reserves. Current strategies to increase the amount of carbon reserves often compromise algal growth. To better understand the cellular mechanisms connecting cell division to carbon storage, we examined starch and oil accumulation in two Chlamydomonas mutants deficient in a gene encoding a homolog of the Arabidopsis Cell Division Cycle 5 (CDC5), a MYB DNA binding protein known to be involved in cell cycle in higher plants. The two crcdc5 mutants (crcdc5-1 and crcdc5-2) were found to accumulate significantly higher amount of starch and oil than their corresponding parental lines. Flow cytometry analysis on synchronized cultures cultivated in a diurnal light/dark cycle revealed an abnormal division of the two mutants, characterized by a prolonged S/M phase, therefore demonstrating its implication in cell cycle in Chlamydomonas. Taken together, these results suggest that the energy saved by a slowdown in cell division is used for the synthesis of reserve compounds. This work highlights the importance in understanding the interplay between cell cycle and starch/oil homeostasis, which should have a critical impact on improving lipid/starch productivity.
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Affiliation(s)
- Ismael Torres-Romero
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Fantao Kong
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Bertrand Légeret
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Fred Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Gilles Peltier
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France
| | - Yonghua Li-Beisson
- Aix Marseille Univ, CEA, CNRS, Institut de Biosciences et Biotechnologies Aix-Marseille, CEA Cadarache, 13108, Saint Paul-Lez-Durance, France.
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Osorio H, Jara C, Fuenzalida K, Rey-Jurado E, Vásquez M. High-efficiency nuclear transformation of the microalgae Nannochloropsis oceanica using Tn5 Transposome for the generation of altered lipid accumulation phenotypes. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:134. [PMID: 31168324 PMCID: PMC6545213 DOI: 10.1186/s13068-019-1475-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/23/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND One of the major problems in the production of lipids for biotechnological purposes using microalgae is maintaining a high productivity of these molecules without reducing cellular biomass. High production rates are usually obtained by cultivating microalgae under different stress conditions. However, many of these changes usually result in lower biomass productivity. Therefore, the optimization of the culture conditions and genetic modification techniques in these organisms is needed to generate robust new strains for profitable economic use. RESULTS In this work, we describe a new strategy for random mutation of genomic DNA in the microalgae Nannochloropsis oceanica by insertion of a Transposome complex Tn5. This complex contains an antibiotic-resistance cassette commanded by a CMV viral promoter that allows high efficiency of transformation and the generation of mutants. This strategy, complemented with a large-scale identification and selection system for mutants, such as flow cytometry with cell selection, allowed us to obtain clonal cultures of mutants with altered phenotypes in the accumulation of intracellular lipids. The characterization of some of these mutants uncovered new genes that are likely to be involved in the regulation of lipid synthesis, revealing possible cellular responses that influence the intracellular homeostasis of lipids. CONCLUSION The strategies proposed here are easy to implement in different types of microalgae and provide a promising scenario for improving biotechnological applications.
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Affiliation(s)
- Hector Osorio
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Carol Jara
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Karen Fuenzalida
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Emma Rey-Jurado
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Mónica Vásquez
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
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14
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Kong F, Yamaoka Y, Ohama T, Lee Y, Li-Beisson Y. Molecular Genetic Tools and Emerging Synthetic Biology Strategies to Increase Cellular Oil Content in Chlamydomonas reinhardtii. PLANT & CELL PHYSIOLOGY 2019; 60:1184-1196. [PMID: 30715500 DOI: 10.1093/pcp/pcz022] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Accepted: 01/18/2019] [Indexed: 05/26/2023]
Abstract
Microalgae constitute a highly diverse group of eukaryotic and photosynthetic microorganisms that have developed extremely efficient systems for harvesting and transforming solar energy into energy-rich molecules such as lipids. Although microalgae are considered to be one of the most promising platforms for the sustainable production of liquid oil, the oil content of these organisms is naturally low, and algal oil production is currently not economically viable. Chlamydomonas reinhardtii (Chlamydomonas) is an established algal model due to its fast growth, high transformation efficiency, and well-understood physiology and to the availability of detailed genome information and versatile molecular tools for this organism. In this review, we summarize recent advances in the development of genetic manipulation tools for Chlamydomonas, from gene delivery methods to state-of-the-art genome-editing technologies and fluorescent dye-based high-throughput mutant screening approaches. Furthermore, we discuss practical strategies and toolkits that enhance transgene expression, such as choice of expression vector and background strain. We then provide examples of how advanced genetic tools have been used to increase oil content in Chlamydomonas. Collectively, the current literature indicates that microalgal oil content can be increased by overexpressing key enzymes that catalyze lipid biosynthesis, blocking lipid degradation, silencing metabolic pathways that compete with lipid biosynthesis and modulating redox state. The tools and knowledge generated through metabolic engineering studies should pave the way for developing a synthetic biological approach to enhance lipid productivity in microalgae.
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Affiliation(s)
- Fantao Kong
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, China
| | - Yasuyo Yamaoka
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea
| | - Takeshi Ohama
- School of Environmental Science and Engineering, Kochi University of Technology (KUT), Tosayamada, Kochi, Japan
| | - Youngsook Lee
- Department of Integrative Bioscience & Biotechnology, Pohang University of Science and Technology, Pohang, Korea
- Department of Life Science, Pohang University of Science and Technology, Pohang, Korea
| | - Yonghua Li-Beisson
- Aix-Marseille Univ., CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F, France
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15
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Liang Y, Kong F, Torres-Romero I, Burlacot A, Cuine S, Légeret B, Billon E, Brotman Y, Alseekh S, Fernie AR, Beisson F, Peltier G, Li-Beisson Y. Branched-Chain Amino Acid Catabolism Impacts Triacylglycerol Homeostasis in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2019; 179:1502-1514. [PMID: 30728273 PMCID: PMC6446750 DOI: 10.1104/pp.18.01584] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 01/30/2019] [Indexed: 05/05/2023]
Abstract
Nitrogen (N) starvation-induced triacylglycerol (TAG) synthesis, and its complex relationship with starch metabolism in algal cells, has been intensively studied; however, few studies have examined the interaction between amino acid metabolism and TAG biosynthesis. Here, via a forward genetic screen for TAG homeostasis, we isolated a Chlamydomonas (Chlamydomonas reinhardtii) mutant (bkdE1α) that is deficient in the E1α subunit of the branched-chain ketoacid dehydrogenase (BCKDH) complex. Metabolomics analysis revealed a defect in the catabolism of branched-chain amino acids in bkdE1α Furthermore, this mutant accumulated 30% less TAG than the parental strain during N starvation and was compromised in TAG remobilization upon N resupply. Intriguingly, the rate of mitochondrial respiration was 20% to 35% lower in bkdE1α compared with the parental strains. Three additional knockout mutants of the other components of the BCKDH complex exhibited phenotypes similar to that of bkdE1α Transcriptional responses of BCKDH to different N status were consistent with its role in TAG homeostasis. Collectively, these results indicate that branched-chain amino acid catabolism contributes to TAG metabolism by providing carbon precursors and ATP, thus highlighting the complex interplay between distinct subcellular metabolisms for oil storage in green microalgae.
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Affiliation(s)
- Yuanxue Liang
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Fantao Kong
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Ismael Torres-Romero
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Adrien Burlacot
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Stéphan Cuine
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Bertrand Légeret
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Emmanuelle Billon
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Yariv Brotman
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Saleh Alseekh
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Fred Beisson
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Gilles Peltier
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
| | - Yonghua Li-Beisson
- Aix-Marseille University, Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique, Bioscience and Biotechnology Institute of Aix-Marseille (BIAM), Commissariat à l'Energie Atomique Cadarache, Saint-Paul-lez Durance F-13108, France
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16
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High level of reactive oxygen species inhibits triacylglycerols accumulation in Chlamydomonas reinhardtii. ALGAL RES 2019. [DOI: 10.1016/j.algal.2018.101400] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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17
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Li-Beisson Y, Thelen JJ, Fedosejevs E, Harwood JL. The lipid biochemistry of eukaryotic algae. Prog Lipid Res 2019; 74:31-68. [PMID: 30703388 DOI: 10.1016/j.plipres.2019.01.003] [Citation(s) in RCA: 162] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/06/2023]
Abstract
Algal lipid metabolism fascinates both scientists and entrepreneurs due to the large diversity of fatty acyl structures that algae produce. Algae have therefore long been studied as sources of genes for novel fatty acids; and, due to their superior biomass productivity, algae are also considered a potential feedstock for biofuels. However, a major issue in a commercially viable "algal oil-to-biofuel" industry is the high production cost, because most algal species only produce large amounts of oils after being exposed to stress conditions. Recent studies have therefore focused on the identification of factors involved in TAG metabolism, on the subcellular organization of lipid pathways, and on interactions between organelles. This has been accompanied by the development of genetic/genomic and synthetic biological tools not only for the reference green alga Chlamydomonas reinhardtii but also for Nannochloropsis spp. and Phaeodactylum tricornutum. Advances in our understanding of enzymes and regulatory proteins of acyl lipid biosynthesis and turnover are described herein with a focus on carbon and energetic aspects. We also summarize how changes in environmental factors can impact lipid metabolism and describe present and potential industrial uses of algal lipids.
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Affiliation(s)
- Yonghua Li-Beisson
- Aix-Marseille Univ, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F-13108, France.
| | - Jay J Thelen
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - Eric Fedosejevs
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
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18
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Kong F, Burlacot A, Liang Y, Légeret B, Alseekh S, Brotman Y, Fernie AR, Krieger-Liszkay A, Beisson F, Peltier G, Li-Beisson Y. Interorganelle Communication: Peroxisomal MALATE DEHYDROGENASE2 Connects Lipid Catabolism to Photosynthesis through Redox Coupling in Chlamydomonas. THE PLANT CELL 2018; 30:1824-1847. [PMID: 29997239 PMCID: PMC6139685 DOI: 10.1105/tpc.18.00361] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/12/2018] [Accepted: 07/10/2018] [Indexed: 05/17/2023]
Abstract
Plants and algae must tightly coordinate photosynthetic electron transport and metabolic activities given that they often face fluctuating light and nutrient conditions. The exchange of metabolites and signaling molecules between organelles is thought to be central to this regulation but evidence for this is still fragmentary. Here, we show that knocking out the peroxisome-located MALATE DEHYDROGENASE2 (MDH2) of Chlamydomonas reinhardtii results in dramatic alterations not only in peroxisomal fatty acid breakdown but also in chloroplast starch metabolism and photosynthesis. mdh2 mutants accumulated 50% more storage lipid and 2-fold more starch than the wild type during nitrogen deprivation. In parallel, mdh2 showed increased photosystem II yield and photosynthetic CO2 fixation. Metabolite analyses revealed a >60% reduction in malate, together with increased levels of NADPH and H2O2 in mdh2 Similar phenotypes were found upon high light exposure. Furthermore, based on the lack of starch accumulation in a knockout mutant of the H2O2-producing peroxisomal ACYL-COA OXIDASE2 and on the effects of H2O2 supplementation, we propose that peroxisome-derived H2O2 acts as a regulator of chloroplast metabolism. We conclude that peroxisomal MDH2 helps photoautotrophs cope with nitrogen scarcity and high light by transmitting the redox state of the peroxisome to the chloroplast by means of malate shuttle- and H2O2-based redox signaling.
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Affiliation(s)
- Fantao Kong
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Adrien Burlacot
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Yuanxue Liang
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Bertrand Légeret
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Saleh Alseekh
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Center of Plant System Biology and Biotechnology, 4000 Plovdiv, Bulgaria
| | - Yariv Brotman
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Alisdair R Fernie
- Max Planck Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
- Center of Plant System Biology and Biotechnology, 4000 Plovdiv, Bulgaria
| | - Anja Krieger-Liszkay
- Institute for Integrative Biology of the Cell, CEA Saclay, CNRS, University Paris-Sud, University Paris-Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - Fred Beisson
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Gilles Peltier
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
| | - Yonghua Li-Beisson
- Aix Marseille University, CEA, CNRS, BIAM, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, F-13108 Saint Paul-Lez-Durance, France
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19
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Rengel R, Smith RT, Haslam RP, Sayanova O, Vila M, León R. Overexpression of acetyl-CoA synthetase (ACS) enhances the biosynthesis of neutral lipids and starch in the green microalga Chlamydomonas reinhardtii. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.02.009] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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20
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Can We Approach Theoretical Lipid Yields in Microalgae? Trends Biotechnol 2018; 36:265-276. [DOI: 10.1016/j.tibtech.2017.10.020] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 10/29/2017] [Accepted: 10/30/2017] [Indexed: 11/17/2022]
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21
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Kong F, Li-Beisson Y. Identification of Insertion Site by RESDA-PCR in Chlamydomonas Mutants Generated by AphVIII Random Insertional Mutagenesis. Bio Protoc 2018; 8:e2718. [PMID: 34179256 DOI: 10.21769/bioprotoc.2718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Revised: 01/16/2018] [Accepted: 01/18/2018] [Indexed: 11/02/2022] Open
Abstract
Chlamydomonas reinhardtii is frequently used as a model organism to study fundamental processes in photosynthesis, metabolism, and flagellar biology. Versatile tool boxes have been developed for this alga ( Fuhrmann et al., 1999 ; Schroda et al., 2000 ; Schroda, 2006). Among them, forward genetic approach has been intensively used, mostly because of the high efficiency in the generation of hundreds of thousands of mutants by random insertional mutagenesis and the haploid nature therefore phenotypic analysis can be done in the first generation ( Cagnon et al., 2013 ; Tunçay et al., 2013 ). A major bottleneck in the application of high throughput methods in a forward genetic approach is the identification of the genetic lesion(s) responsible for the observed phenotype. In this protocol, we describe in detail an improved version of the restriction enzyme site-directed amplification PCR (RESDA-PCR) originally reported in (González- Ballester et al., 2005 ). The improvement includes optimization of primer combination, the choice of DNA polymerase, optimization of PCR cycle parameters, and application of direct sequencing of the PCR products. These modifications make it easier to get specific PCR products as well as speeding up subcloning steps to obtain sequencing data faster.
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Affiliation(s)
- Fantao Kong
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et Biotechnologie, CEA Cadarache, Saint-Paul-lez-Durance, France.,Centre National de la Recherche Scientifique, UMR7265, Saint-Paul-lez-Durance, France.,Aix-Marseille Université, UMR7265, Marseille, France
| | - Yonghua Li-Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Institut de Biologie Environnementale et Biotechnologie, CEA Cadarache, Saint-Paul-lez-Durance, France.,Centre National de la Recherche Scientifique, UMR7265, Saint-Paul-lez-Durance, France.,Aix-Marseille Université, UMR7265, Marseille, France
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22
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Prioretti L, Avilan L, Carrière F, Montané MH, Field B, Grégori G, Menand B, Gontero B. The inhibition of TOR in the model diatom Phaeodactylum tricornutum promotes a get-fat growth regime. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.08.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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23
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Lázaro B, Villa JA, Santín O, Cabezas M, Milagre CDF, de la Cruz F, Moncalián G. Heterologous expression of a thermophilic diacylglycerol acyltransferase triggers triglyceride accumulation in Escherichia coli. PLoS One 2017; 12:e0176520. [PMID: 28448543 PMCID: PMC5407786 DOI: 10.1371/journal.pone.0176520] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 04/12/2017] [Indexed: 01/05/2023] Open
Abstract
Triglycerides (TAGs), the major storage molecules of metabolic energy and source of fatty acids, are produced as single cell oil by some oleogenic microorganisms. However, these microorganisms require strict culture conditions, show low carbon source flexibilities, lack efficient genetic modification tools and in some cases pose safety concerns. TAGs have essential applications such as behaving as a source for added-value fatty acids or giving rise to the production of biodiesel. Hence, new alternative methods are urgently required for obtaining these oils. In this work we describe TAG accumulation in the industrially appropriate microorganism Escherichia coli expressing the heterologous enzyme tDGAT, a wax ester synthase/triacylglycerol:acylCoA acyltranferase (WS/DGAT). With this purpose, we introduce a codon-optimized gene from the thermophilic actinomycete Thermomonospora curvata coding for a WS/DGAT into different E. coli strains, describe the metabolic effects associated to the expression of this protein and evaluate neutral lipid accumulation. We observe a direct relation between the expression of this WS/DGAT and TAG production within a wide range of culture conditions. More than 30% TAGs were detected within the bacterial neutral lipids in 90 minutes after induction. TAGs were observed to be associated with the hydrophobic enzyme while forming round intracytoplasmic bodies, which could represent a bottleneck for lipid accumulation in E. coli. We detected an increase of almost 3-fold in the monounsaturated fatty acids (MUFA) occurring in the recombinant strains. These MUFA were predominant in the accumulated TAGs achieving 46% of the TAG fatty acids. These results set the basis for further research on the achievement of a suitable method towards the sustainable production of these neutral lipids.
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Affiliation(s)
- Beatriz Lázaro
- Departamento de Biología Molecular, Universidad de Cantabria and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas - Universidad de Cantabria, C/ Albert Einstein, Santander, Cantabria, Spain
- Department of Organic Chemistry, Institute of Chemistry, Universidade Estadual Paulista (UNESP), Rua Prof. Francisco Degni, Araraquara, São Paulo, Brazil
| | - Juan A. Villa
- Departamento de Biología Molecular, Universidad de Cantabria and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas - Universidad de Cantabria, C/ Albert Einstein, Santander, Cantabria, Spain
| | - Omar Santín
- Departamento de Biología Molecular, Universidad de Cantabria and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas - Universidad de Cantabria, C/ Albert Einstein, Santander, Cantabria, Spain
| | - Matilde Cabezas
- Departamento de Biología Molecular, Universidad de Cantabria and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas - Universidad de Cantabria, C/ Albert Einstein, Santander, Cantabria, Spain
| | - Cintia D. F. Milagre
- Department of Organic Chemistry, Institute of Chemistry, Universidade Estadual Paulista (UNESP), Rua Prof. Francisco Degni, Araraquara, São Paulo, Brazil
| | - Fernando de la Cruz
- Departamento de Biología Molecular, Universidad de Cantabria and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas - Universidad de Cantabria, C/ Albert Einstein, Santander, Cantabria, Spain
| | - Gabriel Moncalián
- Departamento de Biología Molecular, Universidad de Cantabria and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Consejo Superior de Investigaciones Científicas - Universidad de Cantabria, C/ Albert Einstein, Santander, Cantabria, Spain
- * E-mail:
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24
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Kong F, Liang Y, Légeret B, Beyly-Adriano A, Blangy S, Haslam RP, Napier JA, Beisson F, Peltier G, Li-Beisson Y. Chlamydomonas carries out fatty acid β-oxidation in ancestral peroxisomes using a bona fide acyl-CoA oxidase. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 90:358-371. [PMID: 28142200 DOI: 10.1111/tpj.13498] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 01/25/2017] [Accepted: 01/27/2017] [Indexed: 05/03/2023]
Abstract
Peroxisomes are thought to have played a key role in the evolution of metabolic networks of photosynthetic organisms by connecting oxidative and biosynthetic routes operating in different compartments. While the various oxidative pathways operating in the peroxisomes of higher plants are fairly well characterized, the reactions present in the primitive peroxisomes (microbodies) of algae are poorly understood. Screening of a Chlamydomonas insertional mutant library identified a strain strongly impaired in oil remobilization and defective in Cre05.g232002 (CrACX2), a gene encoding a member of the acyl-CoA oxidase/dehydrogenase superfamily. The purified recombinant CrACX2 expressed in Escherichia coli catalyzed the oxidation of fatty acyl-CoAs into trans-2-enoyl-CoA and produced H2 O2 . This result demonstrated that CrACX2 is a genuine acyl-CoA oxidase, which is responsible for the first step of the peroxisomal fatty acid (FA) β-oxidation spiral. A fluorescent protein-tagging study pointed to a peroxisomal location of CrACX2. The importance of peroxisomal FA β-oxidation in algal physiology was shown by the impact of the mutation on FA turnover during day/night cycles. Moreover, under nitrogen depletion the mutant accumulated 20% more oil than the wild type, illustrating the potential of β-oxidation mutants for algal biotechnology. This study provides experimental evidence that a plant-type FA β-oxidation involving H2 O2 -producing acyl-CoA oxidation activity has already evolved in the microbodies of the unicellular green alga Chlamydomonas reinhardtii.
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Affiliation(s)
- Fantao Kong
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Yuanxue Liang
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Bertrand Légeret
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Audrey Beyly-Adriano
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Stéphanie Blangy
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Richard P Haslam
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, UK
| | - Johnathan A Napier
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, UK
| | - Fred Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Gilles Peltier
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
| | - Yonghua Li-Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives, CNRS, Aix Marseille Université, UMR7265, Institut de Biosciences et Biotechnologies Aix Marseille, 13108, Cadarache, France
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25
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Seed CE, Tomkins JL. Flow Cytometric Methods for Indirect Analysis and Quantification of Gametogenesis in Chlamydomonas reinhardtii (Chlorophyceae). PLoS One 2016; 11:e0161453. [PMID: 27676075 PMCID: PMC5038954 DOI: 10.1371/journal.pone.0161453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 08/06/2016] [Indexed: 11/30/2022] Open
Abstract
Induction of sexual reproduction in the facultatively sexual Chlamydomonas reinhardtii is cued by depletion of nitrogen. We explore the capacity for indirect monitoring of population variation in the gametogenic process using flow cytometry. We describe a high-throughput method capable of identifying fluorescence, ploidy and scatter profiles that track vegetative cells entering and undergoing gametogenesis. We demonstrate for the first time, that very early and late growth phases reduce the capacity to distinguish putative gametes from vegetative cells based on scatter and fluorescence profiles, and that early/mid-logarithmic cultures show the optimal distinction between vegetative cells and gamete scatter profiles. We argue that early/mid logarithmic cultures are valuable in such high throughput comparative approaches when investigating optimisation or quantification of gametogenesis based on scatter and fluorescence profiles. This approach provides new insights into the impact of culture conditions on gametogenesis, while documenting novel scatter and fluorescence profile shifts which typify the process. This method has potential applications to; enabling quick high-throughput monitoring, uses in increasing efficiency in the quantification of gametogenesis, as a method of comparing the switch between vegetative and gametic states across treatments, and as criteria for enrichment of gametic phenotypes in cell sorting assays.
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Affiliation(s)
- Catherine E. Seed
- Centre for Evolutionary Biology, School of Animal Biology (M092), The University of Western Australia, Crawley, Australia
- * E-mail:
| | - Joseph L. Tomkins
- Centre for Evolutionary Biology, School of Animal Biology (M092), The University of Western Australia, Crawley, Australia
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26
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Goncalves EC, Wilkie AC, Kirst M, Rathinasabapathi B. Metabolic regulation of triacylglycerol accumulation in the green algae: identification of potential targets for engineering to improve oil yield. PLANT BIOTECHNOLOGY JOURNAL 2016; 14:1649-60. [PMID: 26801206 PMCID: PMC5066758 DOI: 10.1111/pbi.12523] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 11/13/2015] [Accepted: 11/25/2015] [Indexed: 05/03/2023]
Abstract
The great need for more sustainable alternatives to fossil fuels has increased our research interests in algal biofuels. Microalgal cells, characterized by high photosynthetic efficiency and rapid cell division, are an excellent source of neutral lipids as potential fuel stocks. Various stress factors, especially nutrient-starvation conditions, induce an increased formation of lipid bodies filled with triacylglycerol in these cells. Here we review our knowledge base on glycerolipid synthesis in the green algae with an emphasis on recent studies on carbon flux, redistribution of lipids under nutrient-limiting conditions and its regulation. We discuss the contributions and limitations of classical and novel approaches used to elucidate the algal triacylglycerol biosynthetic pathway and its regulatory network in green algae. Also discussed are gaps in knowledge and suggestions for much needed research both on the biology of triacylglycerol accumulation and possible avenues to engineer improved algal strains.
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Affiliation(s)
- Elton C Goncalves
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Ann C Wilkie
- Soil and Water Science Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
| | - Matias Kirst
- School of Forestry, University of Florida, Gainesville, FL, USA
| | - Bala Rathinasabapathi
- Plant Molecular and Cellular Biology Program, Horticultural Sciences Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, USA
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27
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Goold HD, Cuiné S, Légeret B, Liang Y, Brugière S, Auroy P, Javot H, Tardif M, Jones B, Beisson F, Peltier G, Li-Beisson Y. Saturating Light Induces Sustained Accumulation of Oil in Plastidal Lipid Droplets in Chlamydomonas reinhardtii. PLANT PHYSIOLOGY 2016; 171:2406-17. [PMID: 27297678 PMCID: PMC4972293 DOI: 10.1104/pp.16.00718] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 06/10/2016] [Indexed: 05/02/2023]
Abstract
Enriching algal biomass in energy density is an important goal in algal biotechnology. Nitrogen (N) starvation is considered the most potent trigger of oil accumulation in microalgae and has been thoroughly investigated. However, N starvation causes the slow down and eventually the arrest of biomass growth. In this study, we show that exposing a Chlamydomonas reinhardtii culture to saturating light (SL) under a nonlimiting CO2 concentration in turbidostatic photobioreactors induces a sustained accumulation of lipid droplets (LDs) without compromising growth, which results in much higher oil productivity than N starvation. We also show that the polar membrane lipid fraction of SL-induced LDs is rich in plastidial lipids (approximately 70%), in contrast to N starvation-induced LDs, which contain approximately 60% lipids of endoplasmic reticulum origin. Proteomic analysis of LDs isolated from SL-exposed cells identified more than 200 proteins, including known proteins of lipid metabolism, as well as 74 proteins uniquely present in SL-induced LDs. LDs induced by SL and N depletion thus differ in protein and lipid contents. Taken together, lipidomic and proteomic data thus show that a large part of the sustained oil accumulation occurring under SL is likely due to the formation of plastidial LDs. We discuss our data in relation to the different metabolic routes used by microalgae to accumulate oil reserves depending on cultivation conditions. Finally, we propose a model in which oil accumulation is governed by an imbalance between photosynthesis and growth, which can be achieved by impairing growth or by boosting photosynthetic carbon fixation, with the latter resulting in higher oil productivity.
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Affiliation(s)
- Hugh Douglas Goold
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Stéphan Cuiné
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Bertrand Légeret
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Yuanxue Liang
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Sabine Brugière
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Pascaline Auroy
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Hélène Javot
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Marianne Tardif
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Brian Jones
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Fred Beisson
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Gilles Peltier
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
| | - Yonghua Li-Beisson
- Commissariat à l'Energie Atomique, Centre National de la Recherche Scientifique Aix Marseille Université, Unité Mixte de Recherche 7265, Institut de Biosciences et Biotechnologies, Cadarache 13108, France (H.D.G., S.C., B.L., Y.L., P.A., H.J., F.B., G.P., Y.L.-B.);Faculty of Agriculture and the Environment, University of Sydney, Sydney, New South Wales 2006, Australia (H.D.G., B.J.); andCommissariat à l'Energie Atomique, INSERM, Université Grenoble Alpes, Institut de Biosciences et Biotechnologies de Grenoble, Grenoble 38000, France (S.B., M.T.)
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28
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Goold HD, Nguyen HM, Kong F, Beyly-Adriano A, Légeret B, Billon E, Cuiné S, Beisson F, Peltier G, Li-Beisson Y. Whole Genome Re-Sequencing Identifies a Quantitative Trait Locus Repressing Carbon Reserve Accumulation during Optimal Growth in Chlamydomonas reinhardtii. Sci Rep 2016; 6:25209. [PMID: 27141848 PMCID: PMC4855234 DOI: 10.1038/srep25209] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 04/13/2016] [Indexed: 02/08/2023] Open
Abstract
Microalgae have emerged as a promising source for biofuel production. Massive oil and starch accumulation in microalgae is possible, but occurs mostly when biomass growth is impaired. The molecular networks underlying the negative correlation between growth and reserve formation are not known. Thus isolation of strains capable of accumulating carbon reserves during optimal growth would be highly desirable. To this end, we screened an insertional mutant library of Chlamydomonas reinhardtii for alterations in oil content. A mutant accumulating five times more oil and twice more starch than wild-type during optimal growth was isolated and named constitutive oil accumulator 1 (coa1). Growth in photobioreactors under highly controlled conditions revealed that the increase in oil and starch content in coa1 was dependent on light intensity. Genetic analysis and DNA hybridization pointed to a single insertional event responsible for the phenotype. Whole genome re-sequencing identified in coa1 a >200 kb deletion on chromosome 14 containing 41 genes. This study demonstrates that, 1), the generation of algal strains accumulating higher reserve amount without compromising biomass accumulation is feasible; 2), light is an important parameter in phenotypic analysis; and 3), a chromosomal region (Quantitative Trait Locus) acts as suppressor of carbon reserve accumulation during optimal growth.
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Affiliation(s)
- Hugh Douglas Goold
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France.,Faculty of Agriculture and the Environment, University of Sydney, Australia
| | - Hoa Mai Nguyen
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Fantao Kong
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Audrey Beyly-Adriano
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Bertrand Légeret
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Emmanuelle Billon
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Stéphan Cuiné
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Fred Beisson
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Gilles Peltier
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
| | - Yonghua Li-Beisson
- CEA, BIAM, Lab Bioenerget Biotechnol Bacteries &Microalgues, Saint-Paul-lez-Durance, 13108, France.,CNRS, UMR 7265 Biol Veget &Microbiol Environ, Saint-Paul-lez-Durance, 13108, France.,Aix Marseille Université, BVME UMR7265, Marseille, 13284, France
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29
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Li-Beisson Y, Nakamura Y, Harwood J. Lipids: From Chemical Structures, Biosynthesis, and Analyses to Industrial Applications. Subcell Biochem 2016; 86:1-18. [PMID: 27023229 DOI: 10.1007/978-3-319-25979-6_1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Lipids are one of the major subcellular components, and play numerous essential functions. As well as their physiological roles, oils stored in biomass are useful commodities for a variety of biotechnological applications including food, chemical feedstocks, and fuel. Due to their agronomic as well as economic and societal importance, lipids have historically been subjected to intensive studies. Major current efforts are to increase the energy density of cell biomass, and/or create designer oils suitable for specific applications. This chapter covers some basic aspects of what one needs to know about lipids: definition, structure, function, metabolism and focus is also given on the development of modern lipid analytical tools and major current engineering approaches for biotechnological applications. This introductory chapter is intended to serve as a primer for all subsequent chapters in this book outlining current development in specific areas of lipids and their metabolism.
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Affiliation(s)
- Yonghua Li-Beisson
- Institut de Biologie Environnementale et Biotechnologie, UMR 7265 CEA - CNRS - Université Aix Marseille, CEA Cadarache, Saint-Paul-lez-Durance, 13108, France.
| | - Yuki Nakamura
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - John Harwood
- School of Biosciences, Cardiff University, Cardiff, CF10 3AX, UK
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30
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Bajhaiya AK, Dean AP, Driver T, Trivedi DK, Rattray NJW, Allwood JW, Goodacre R, Pittman JK. High-throughput metabolic screening of microalgae genetic variation in response to nutrient limitation. Metabolomics 2016; 12:9. [PMID: 26594136 PMCID: PMC4644200 DOI: 10.1007/s11306-015-0878-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/29/2015] [Indexed: 11/26/2022]
Abstract
Microalgae produce metabolites that could be useful for applications in food, biofuel or fine chemical production. The identification and development of suitable strains require analytical methods that are accurate and allow rapid screening of strains or cultivation conditions. We demonstrate the use of Fourier transform infrared (FT-IR) spectroscopy to screen mutant strains of Chlamydomonas reinhardtii. These mutants have knockdowns for one or more nutrient starvation response genes, namely PSR1, SNRK2.1 and SNRK2.2. Limitation of nutrients including nitrogen and phosphorus can induce metabolic changes in microalgae, including the accumulation of glycerolipids and starch. By performing multivariate statistical analysis of FT-IR spectra, metabolic variation between different nutrient limitation and non-stressed conditions could be differentiated. A number of mutant strains with similar genetic backgrounds could be distinguished from wild type when grown under specific nutrient limited and replete conditions, demonstrating the sensitivity of FT-IR spectroscopy to detect specific genetic traits. Changes in lipid and carbohydrate between strains and specific nutrient stress treatments were validated by other analytical methods, including liquid chromatography-mass spectrometry for lipidomics. These results demonstrate that the PSR1 gene is an important determinant of lipid and starch accumulation in response to phosphorus starvation but not nitrogen starvation. However, the SNRK2.1 and SNRK2.2 genes are not as important for determining the metabolic response to either nutrient stress. We conclude that FT-IR spectroscopy and chemometric approaches provide a robust method for microalgae screening.
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Affiliation(s)
- Amit K. Bajhaiya
- />Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT UK
| | - Andrew P. Dean
- />Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT UK
- />Department of Geography, University of Sheffield, Sheffield, S10 2TN UK
| | - Thomas Driver
- />Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT UK
| | - Drupad K. Trivedi
- />School of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M1 7DN UK
| | - Nicholas J. W. Rattray
- />School of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M1 7DN UK
| | - J. William Allwood
- />School of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M1 7DN UK
- />Environmental & Biochemical Sciences Group, The James Hutton Institute, Invergowrie, Dundee, DD2 5DA Scotland, UK
| | - Royston Goodacre
- />School of Chemistry, Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester, M1 7DN UK
| | - Jon K. Pittman
- />Faculty of Life Sciences, The University of Manchester, Michael Smith Building, Oxford Road, Manchester, M13 9PT UK
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31
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Li X, Jonikas MC. High-Throughput Genetics Strategies for Identifying New Components of Lipid Metabolism in the Green Alga Chlamydomonas reinhardtii. Subcell Biochem 2016; 86:223-247. [PMID: 27023238 DOI: 10.1007/978-3-319-25979-6_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Microalgal lipid metabolism is of broad interest because microalgae accumulate large amounts of triacylglycerols (TAGs) that can be used for biodiesel production (Durrett et al Plant J 54(4):593-607, 2008; Hu et al Plant J 54(4):621-639, 2008). Additionally, green algae are close relatives of land plants and serve as models to understand conserved lipid metabolism pathways in the green lineage. The green alga Chlamydomonas reinhardtii (Chlamydomonas hereafter) is a powerful model organism for understanding algal lipid metabolism. Various methods have been used to screen Chlamydomonas mutants for lipid amount or composition, and for identification of the mutated loci in mutants of interest. In this chapter, we summarize the advantages and caveats for each of these methods with a focus on screens for mutants with perturbed TAG content. We also discuss technical opportunities and new tools that are becoming available for screens of mutants altered in TAG content or perturbed in other processes in Chlamydomonas.
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Affiliation(s)
- Xiaobo Li
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA
| | - Martin C Jonikas
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA, 94305, USA.
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Ngan CY, Wong CH, Choi C, Yoshinaga Y, Louie K, Jia J, Chen C, Bowen B, Cheng H, Leonelli L, Kuo R, Baran R, García-Cerdán JG, Pratap A, Wang M, Lim J, Tice H, Daum C, Xu J, Northen T, Visel A, Bristow J, Niyogi KK, Wei CL. Lineage-specific chromatin signatures reveal a regulator of lipid metabolism in microalgae. NATURE PLANTS 2015; 1:15107. [PMID: 27250540 DOI: 10.1038/nplants.2015.107] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 06/22/2015] [Indexed: 05/09/2023]
Abstract
Alga-derived lipids represent an attractive potential source of biofuels. However, lipid accumulation in algae is a stress response tightly coupled to growth arrest, thereby imposing a major limitation on productivity. To identify transcriptional regulators of lipid accumulation, we performed an integrative chromatin signature and transcriptomic analysis to decipher the regulation of lipid biosynthesis in the alga Chlamydomonas reinhardtii. Genome-wide histone modification profiling revealed remarkable differences in functional chromatin states between the algae and higher eukaryotes and uncovered regulatory components at the core of lipid accumulation pathways. We identified the transcription factor, PSR1, as a pivotal switch that triggers cytosolic lipid accumulation. Dissection of the PSR1-induced lipid profiles corroborates its role in coordinating multiple lipid-inducing stress responses. The comprehensive maps of functional chromatin signatures in a major clade of eukaryotic life and the discovery of a transcriptional regulator of algal lipid metabolism will facilitate targeted engineering strategies to mediate high lipid production in microalgae.
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Affiliation(s)
- Chew Yee Ngan
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Chee-Hong Wong
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Cindy Choi
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Yuko Yoshinaga
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Katherine Louie
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
- School of Natural Sciences, University of California, Merced, California 95343, USA
| | - Jing Jia
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Cindy Chen
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Benjamin Bowen
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
- School of Natural Sciences, University of California, Merced, California 95343, USA
| | - Haoyu Cheng
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Lauriebeth Leonelli
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Rita Kuo
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Richard Baran
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
- School of Natural Sciences, University of California, Merced, California 95343, USA
| | - José G García-Cerdán
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Abhishek Pratap
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Mei Wang
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Joanne Lim
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Hope Tice
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Chris Daum
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Jian Xu
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Trent Northen
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
- School of Natural Sciences, University of California, Merced, California 95343, USA
| | - Axel Visel
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
- 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
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, California 94720, USA
| | - James Bristow
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
| | - Krishna K Niyogi
- School of Natural Sciences, University of California, Merced, California 95343, USA
- Genomics Division, MS 84-171, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Chia-Lin Wei
- US Department of Energy Joint Genome Institute, Walnut Creek, California 94598, USA
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D'Andrea S. Lipid droplet mobilization: The different ways to loosen the purse strings. Biochimie 2015; 120:17-27. [PMID: 26187474 DOI: 10.1016/j.biochi.2015.07.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 07/11/2015] [Indexed: 01/25/2023]
Abstract
Cytosolic lipid droplets are dynamic lipid-storage organelles that play a crucial role as reservoirs of metabolic energy and membrane precursors. These organelles are present in virtually all cell types, from unicellular to pluricellular organisms. Despite similar structural organization, lipid droplets are heterogeneous in morphology, distribution and composition. The protein repertoire associated to lipid droplet controls the organelle dynamics. Distinct structural lipid droplet proteins are associated to specific lipolytic pathways. The role of these structural lipid droplet-associated proteins in the control of lipid droplet degradation and lipid store mobilization is discussed. The control of the strictly-regulated lipolysis in lipid-storing tissues is compared between mammals and plants. Differences in the cellular regulation of lipolysis between lipid-storing tissues and other cell types are also discussed.
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Affiliation(s)
- Sabine D'Andrea
- INRA, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France; AgroParisTech, Institut Jean-Pierre Bourgin, UMR 1318, ERL CNRS 3559, Saclay Plant Sciences, RD10, F-78026 Versailles, France.
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Li-Beisson Y, Beisson F, Riekhof W. Metabolism of acyl-lipids in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:504-522. [PMID: 25660108 DOI: 10.1111/tpj.12787] [Citation(s) in RCA: 156] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 01/24/2015] [Accepted: 02/02/2015] [Indexed: 05/03/2023]
Abstract
Microalgae are emerging platforms for production of a suite of compounds targeting several markets, including food, nutraceuticals, green chemicals, and biofuels. Many of these products, such as biodiesel or polyunsaturated fatty acids (PUFAs), derive from lipid metabolism. A general picture of lipid metabolism in microalgae has been deduced from well characterized pathways of fungi and land plants, but recent advances in molecular and genetic analyses of microalgae have uncovered unique features, pointing out the necessity to study lipid metabolism in microalgae themselves. In the past 10 years, in addition to its traditional role as a model for photosynthetic and flagellar motility processes, Chlamydomonas reinhardtii has emerged as a model organism to study lipid metabolism in green microalgae. Here, after summarizing data on total fatty acid composition, distribution of acyl-lipid classes, and major acyl-lipid molecular species found in C. reinhardtii, we review the current knowledge on the known or putative steps for fatty acid synthesis, glycerolipid desaturation and assembly, membrane lipid turnover, and oil remobilization. A list of characterized or putative enzymes for the major steps of acyl-lipid metabolism in C. reinhardtii is included, and subcellular localizations and phenotypes of associated mutants are discussed. Biogenesis and composition of Chlamydomonas lipid droplets and the potential importance of lipolytic processes in increasing cellular oil content are also highlighted.
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Affiliation(s)
- Yonghua Li-Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut de Biologie Environnementale et Biotechnologie, CEA Cadarache, 13108, Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique (CNRS), 13108, Saint-Paul-lez-Durance, France
- Aix-Marseille Université, UMR 7265, 13284, Marseille, France
| | - Fred Beisson
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Institut de Biologie Environnementale et Biotechnologie, CEA Cadarache, 13108, Saint-Paul-lez-Durance, France
- Centre National de la Recherche Scientifique (CNRS), 13108, Saint-Paul-lez-Durance, France
- Aix-Marseille Université, UMR 7265, 13284, Marseille, France
| | - Wayne Riekhof
- School of Biological Sciences and Center for Biological Chemistry, University of Nebraska - Lincoln, Lincoln, NE, 68588, USA
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Transgressive, reiterative selection by continuous buoyant density gradient centrifugation of Dunaliella salina results in enhanced lipid and starch content. ALGAL RES 2015. [DOI: 10.1016/j.algal.2015.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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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
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Goold H, Beisson F, Peltier G, Li-Beisson Y. Microalgal lipid droplets: composition, diversity, biogenesis and functions. PLANT CELL REPORTS 2015; 34:545-55. [PMID: 25433857 DOI: 10.1007/s00299-014-1711-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 11/12/2014] [Accepted: 11/19/2014] [Indexed: 05/03/2023]
Abstract
Lipid droplet is the major site of neutral lipid storage in eukaryotic cells, and increasing evidence show its involvement in numerous cellular processes such as lipid homeostasis, signaling, trafficking and inter-organelle communications. Although the biogenesis, structure, and functions of lipid droplets have been well documented for seeds of vascular plants, mammalian adipose tissues, insects and yeasts, relative little is known about lipid droplets in microalgae. Over the past 5 years, the growing interest of microalgae as a platform for biofuel, green chemicals or value-added polyunsaturated fatty acid production has brought algal lipid droplets into spotlight. Studies conducted on the green microalga Chlamydomonas reinhardtii and other model microalgae such as Haematococcus and Nannochloropsis species have led to the identification of proteins associated with lipid droplets, which include putative structural proteins different from plant oleosins and animal perilipins, as well as candidate proteins for lipid biosynthesis, mobilization, trafficking and homeostasis. Biochemical and microscopy studies have also started to shed light on the role of chloroplasts in the biogenesis of lipid droplets in Chlamydomonas.
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Affiliation(s)
- Hugh Goold
- CEA, IBEB, Lab Bioenerget Biotechnol Bacteries and Microalgues, Saint-Paul-lez-Durance, 13108, France
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Terashima M, Freeman ES, Jinkerson RE, Jonikas MC. A fluorescence-activated cell sorting-based strategy for rapid isolation of high-lipid Chlamydomonas mutants. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 81:147-59. [PMID: 25267488 PMCID: PMC4280329 DOI: 10.1111/tpj.12682] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 08/22/2014] [Accepted: 09/19/2014] [Indexed: 05/22/2023]
Abstract
There is significant interest in farming algae for the direct production of biofuels and valuable lipids. Chlamydomonas reinhardtii is the leading model system for studying lipid metabolism in green algae, but current methods for isolating mutants of this organism with a perturbed lipid content are slow and tedious. Here, we present the Chlamydomonas high-lipid sorting (CHiLiS) strategy, which enables enrichment of high-lipid mutants by fluorescence-activated cell sorting (FACS) of pooled mutants stained with the lipid-sensitive dye Nile Red. This method only takes 5 weeks from mutagenesis to mutant isolation. We developed a staining protocol that allows quantification of lipid content while preserving cell viability. We improved separation of high-lipid mutants from the wild type by using each cell's chlorophyll fluorescence as an internal control. We initially demonstrated 20-fold enrichment of the known high-lipid mutant sta1 from a mixture of sta1 and wild-type cells. We then applied CHiLiS to sort thousands of high-lipid cells from a pool of about 60,000 mutants. Flow cytometry analysis of 24 individual mutants isolated by this approach revealed that about 50% showed a reproducible high-lipid phenotype. We further characterized nine of the mutants with the highest lipid content by flame ionization detection and mass spectrometry lipidomics. All mutants analyzed had a higher triacylglycerol content and perturbed whole-cell fatty acid composition. One arbitrarily chosen mutant was evaluated by microscopy, revealing larger lipid droplets than the wild type. The unprecedented throughput of CHiLiS opens the door to a systems-level understanding of green algal lipid biology by enabling genome-saturating isolation of mutants in key genes.
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Affiliation(s)
- Mia Terashima
- Department of Plant Biology, Carnegie Institution for Science260 Panama Street, Stanford, CA, 94305, USA
| | - Elizabeth S Freeman
- Department of Plant Biology, Carnegie Institution for Science260 Panama Street, Stanford, CA, 94305, USA
- Department of Biology, Stanford UniversityStanford, CA, 94305, USA
| | - Robert E Jinkerson
- Department of Plant Biology, Carnegie Institution for Science260 Panama Street, Stanford, CA, 94305, USA
| | - Martin C Jonikas
- Department of Plant Biology, Carnegie Institution for Science260 Panama Street, Stanford, CA, 94305, USA
- *For correspondence (e-mail )
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Xie B, Stessman D, Hart JH, Dong H, Wang Y, Wright DA, Nikolau BJ, Spalding MH, Halverson LJ. High-throughput fluorescence-activated cell sorting for lipid hyperaccumulating Chlamydomonas reinhardtii mutants. PLANT BIOTECHNOLOGY JOURNAL 2014; 12:872-82. [PMID: 24702864 DOI: 10.1111/pbi.12190] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 01/03/2014] [Accepted: 02/26/2014] [Indexed: 05/16/2023]
Abstract
The genetically tractable microalga Chlamydomonas reinhardtii has many advantages as a model for renewable bioproducts and/or biofuels production. However, one limitation of C. reinhardtii is its relatively low-lipid content compared with some other algal species. To overcome this limitation, we combined ethane methyl sulfonate mutagenesis with fluorescence-activated cell sorting (FACS) of cells stained with the lipophilic stain Nile Red to isolate lipid hyperaccumulating mutants of C. reinhardtii. By manipulating the FACS gates, we sorted mutagenized cells with extremely high Nile Red fluorescence signals that were rarely detected in nonmutagenized populations. This strategy successfully isolated several putative lipid hyperaccumulating mutants exhibiting 23% to 58% (dry weight basis) higher fatty acid contents than their progenitor strains. Significantly, for most mutants, nitrogen starvation was not required to attain high-lipid content nor was there a requirement for a deficiency in starch accumulation. Microscopy of Nile Red stained cells revealed that some mutants exhibit an increase in the number of lipid bodies, which correlated with TLC analysis of triacyglycerol content. Increased lipid content could also arise through increased biomass production. Collectively, our findings highlight the ability to enhance intracellular lipid accumulation in algae using random mutagenesis in conjunction with a robust FACS and lipid yield verification regime. Our lipid hyperaccumulating mutants could serve as a genetic resource for stacking additional desirable traits to further increase lipid production and for identifying genes contributing to lipid hyperaccumulation, without lengthy lipid-induction periods.
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Affiliation(s)
- Bo Xie
- Department of Plant Pathology & Microbiology, Iowa State University, Ames, IA, USA
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Huang J, Xia J, Yang Z, Guan F, Cui D, Guan G, Jiang W, Li Y. Improved production of a recombinant Rhizomucor miehei lipase expressed in Pichia pastoris and its application for conversion of microalgae oil to biodiesel. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:111. [PMID: 25788976 PMCID: PMC4364654 DOI: 10.1186/1754-6834-7-111] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 07/09/2014] [Indexed: 05/04/2023]
Abstract
BACKGROUND We previously cloned a 1,3-specific lipase gene from the fungus Rhizomucor miehei and expressed it in methylotrophic yeast Pichia pastoris strain GS115. The enzyme produced (termed RML) was able to catalyze methanolysis of soybean oil and showed strong position specificity. However, the enzyme activity and amount of enzyme produced were not adequate for industrial application. Our goal in the present study was to improve the enzyme properties of RML in order to apply it for the conversion of microalgae oil to biofuel. RESULTS Several new expression plasmids were constructed by adding the propeptide of the target gene, optimizing the signal peptide, and varying the number of target gene copies. Each plasmid was transformed separately into P. pastoris strain X-33. Screening by flask culture showed maximal (21.4-fold increased) enzyme activity for the recombinant strain with two copies of the target gene; the enzyme was termed Lipase GH2. The expressed protein with the propeptide (pRML) was a stable glycosylated protein, because of glycosylation sites in the propeptide. Quantitative real-time RT-PCR analysis revealed two major reasons for the increase in enzyme activity: (1) the modified recombinant expression system gave an increased transcription level of the target gene (rml), and (2) the enzyme was suitable for expression in host cells without causing endoplasmic reticulum (ER) stress. The modified enzyme had improved thermostability and methanol or ethanol tolerance, and was applicable directly as free lipase (fermentation supernatant) in the catalytic esterification and transesterification reaction. After reaction for 24 hours at 30°C, the conversion rate of microalgae oil to biofuel was above 90%. CONCLUSIONS Our experimental results show that signal peptide optimization in the expression plasmid, addition of the gene propeptide, and proper gene dosage significantly increased RML expression level and enhanced the enzymatic properties. The target enzyme was the major component of fermentation supernatant and was stable for over six months at 4°C. The modified free lipase is potentially applicable for industrial-scale conversion of microalgae oil to biodiesel.
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Affiliation(s)
- Jinjin Huang
- />State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, 2#,Yuanmingyuan West Road, Beijing, 100193 China
| | - Ji Xia
- />State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, 2#,Yuanmingyuan West Road, Beijing, 100193 China
| | - Zhen Yang
- />State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, 2#,Yuanmingyuan West Road, Beijing, 100193 China
| | - Feifei Guan
- />Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences & Comparative Medical Center, Peking Union Medical College, 5#, Panjiayuannanli Street, Beijing, 100021 China
| | - Di Cui
- />State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, 2#,Yuanmingyuan West Road, Beijing, 100193 China
| | - Guohua Guan
- />State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, 2#,Yuanmingyuan West Road, Beijing, 100193 China
| | - Wei Jiang
- />State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, 2#,Yuanmingyuan West Road, Beijing, 100193 China
| | - Ying Li
- />State Key Laboratories for Agro-biotechnology and College of Biological Sciences, China Agricultural University, 2#,Yuanmingyuan West Road, Beijing, 100193 China
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