101
|
Nagappan S, Devendran S, Tsai PC, Jayaraman H, Alagarsamy V, Pugazhendhi A, Ponnusamy VK. Metabolomics integrated with transcriptomics and proteomics: Evaluation of systems reaction to nitrogen deficiency stress in microalgae. Process Biochem 2020. [DOI: 10.1016/j.procbio.2019.11.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
102
|
Bjerkelund Røkke G, Hohmann-Marriott MF, Almaas E. An adjustable algal chloroplast plug-and-play model for genome-scale metabolic models. PLoS One 2020; 15:e0229408. [PMID: 32092117 PMCID: PMC7039451 DOI: 10.1371/journal.pone.0229408] [Citation(s) in RCA: 4] [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: 09/25/2019] [Accepted: 02/05/2020] [Indexed: 01/25/2023] Open
Abstract
The chloroplast is a central part of plant cells, as this is the organelle where the photosynthesis, fixation of inorganic carbon, and other key functions related to fatty acid synthesis and amino acid synthesis occur. Since this organelle should be an integral part of any genome-scale metabolic model for a microalgae or a higher plant, it is of great interest to generate a detailed and standardized chloroplast model. Additionally, we see the need for a novel type of sub-model template, or organelle model, which could be incorporated into a larger, less specific genome-scale metabolic model, while allowing for minor differences between chloroplast-containing organisms. The result of this work is the very first standardized chloroplast model, iGR774, consisting of 788 reactions, 764 metabolites, and 774 genes. The model is currently able to run in three different modes, mimicking the chloroplast metabolism of three photosynthetic microalgae-Nannochloropsis gaditana, Chlamydomonas reinhardtii and Phaeodactylum tricornutum. In addition to developing the chloroplast metabolic network reconstruction, we have developed multiple software tools for working with this novel type of sub-model in the COBRA Toolbox for MATLAB, including tools for connecting the chloroplast model to a genome-scale metabolic reconstruction in need of a chloroplast, for switching the model between running in different organism modes, and for expanding it by introducing more reactions either related to one of the current organisms included in the model, or to a new organism.
Collapse
Affiliation(s)
- Gunvor Bjerkelund Røkke
- Department of Biotechnology and Food Science, The Norwegian University of Science and Technology, Trondheim, Norway
| | | | - Eivind Almaas
- Department of Biotechnology and Food Science, The Norwegian University of Science and Technology, Trondheim, Norway
- K. G. Jebsen Center for Genetic Epidemiology, The Norwegian University of Science and Technology, Trondheim, Norway
| |
Collapse
|
103
|
Zienkiewicz A, Zienkiewicz K, Poliner E, Pulman JA, Du ZY, Stefano G, Tsai CH, Horn P, Feussner I, Farre EM, Childs KL, Brandizzi F, Benning C. The Microalga Nannochloropsis during Transition from Quiescence to Autotrophy in Response to Nitrogen Availability. PLANT PHYSIOLOGY 2020; 182:819-839. [PMID: 31740503 PMCID: PMC6997683 DOI: 10.1104/pp.19.00854] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 11/04/2019] [Indexed: 05/03/2023]
Abstract
The marine microalgae Nannochloropsis oceanica (CCMP1779) is a prolific producer of oil and is considered a viable and sustainable resource for biofuel feedstocks. Nitrogen (N) availability has a strong impact on the physiological status and metabolism of microalgal cells, but the exact nature of this response is poorly understood. To fill this gap we performed transcriptomic profiling combined with cellular and molecular analyses of N. oceanica CCMP1779 during the transition from quiescence to autotrophy. N deprivation-induced quiescence was accompanied by a strong reorganization of the photosynthetic apparatus and changes in the lipid homeostasis, leading to accumulation of triacylglycerol. Cell cycle activation and re-establishment of photosynthetic activity observed in response to resupply of the growth medium with N were accompanied by a rapid degradation of triacylglycerol stored in lipid droplets (LDs). Besides observing LD translocation into vacuoles, we also provide evidence for direct interaction between the LD surface protein (NoLDSP) and AUTOPHAGY-RELATED8 (NoATG8) protein and show a role of microlipophagy in LD turnover in N. oceanica CCMP1779. This knowledge is crucial not only for understanding the fundamental mechanisms controlling the cellular energy homeostasis in microalgal cells but also for development of efficient strategies to achieve higher algal biomass and better microalgal lipid productivity.
Collapse
Affiliation(s)
- Agnieszka Zienkiewicz
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, Michigan 48824
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, 87-100 Toruń, Poland
| | - Krzysztof Zienkiewicz
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, 87-100 Toruń, Poland
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37073 Goettingen, Germany
| | - Eric Poliner
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Cell and Molecular Biology Program, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Jane A Pulman
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Center for Genomics-Enabled Plant Science, Michigan State University, East Lansing, Michigan 48824
| | - Zhi-Yan Du
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Giovanni Stefano
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Chia-Hong Tsai
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Patrick Horn
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Ivo Feussner
- Department of Plant Biochemistry, Albrecht-von-Haller-Institute for Plant Sciences, University of Goettingen, 37073 Goettingen, Germany
- Department of Plant Biochemistry, Goettingen Center for Molecular Biosciences (GZMB), University of Goettingen, 37073 Goettingen, Germany
- Department of Plant Biochemistry, International Center for Advanced Studies of Energy Conversion (ICASEC), University of Goettingen, 37073 Goettingen, Germany
| | - Eva M Farre
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Kevin L Childs
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Center for Genomics-Enabled Plant Science, Michigan State University, East Lansing, Michigan 48824
| | - Federica Brandizzi
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- Michigan State University-United States Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824
- Great Lakes Bioenergy Center, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
104
|
Fang L, Zhang J, Fei Z, Wan M. Astaxanthin accumulation difference between non-motile cells and akinetes of Haematococcus pluvialis was affected by pyruvate metabolism. BIORESOUR BIOPROCESS 2020. [DOI: 10.1186/s40643-019-0293-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Haematococcus pluvialis is the best source of natural astaxanthin, known as the king of antioxidants. H. pluvialis have four cell forms: spore, motile cell, non-motile cell and akinete. Spores and motile cells are susceptible to photoinhibition and would die under photoinduction conditions. Photoinduction using non-motile cells as seeds could result in a higher astaxanthin production than that using akinetes. However, the mechanism of this phenomenon has not been clarified.
Results
Transcriptome was sequenced and annotated to illustrate the mechanism of this phenomenon. All differentially expressed genes involved in astaxanthin biosynthesis were up-regulated. Particularly, chyb gene was up-regulated by 16-fold, improving the conversion of β-carotene into astaxanthin. Pyruvate was the precursor of carotenoids biosynthesis. Pyruvate kinase gene expression level was increased by 2.0-fold at the early stage of akinetes formation. More changes of gene transcription occurred at the early stage of akinetes formation, 52.7% and 51.9% of total DEGs in control group and treatment group, respectively.
Conclusions
Genes transcription network was constructed and the synthesis mechanism of astaxanthin was clarified. The results are expected to further guide the in-depth optimization of the astaxanthin production process in H. pluvialis by improving pyruvate metabolism.
Collapse
|
105
|
Bellan A, Bucci F, Perin G, Alboresi A, Morosinotto T. Photosynthesis Regulation in Response to Fluctuating Light in the Secondary Endosymbiont Alga Nannochloropsis gaditana. PLANT & CELL PHYSIOLOGY 2020; 61:41-52. [PMID: 31511895 DOI: 10.1093/pcp/pcz174] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
In nature, photosynthetic organisms are exposed to highly dynamic environmental conditions where the excitation energy and electron flow in the photosynthetic apparatus need to be continuously modulated. Fluctuations in incident light are particularly challenging because they drive oversaturation of photosynthesis with consequent oxidative stress and photoinhibition. Plants and algae have evolved several mechanisms to modulate their photosynthetic machinery to cope with light dynamics, such as thermal dissipation of excited chlorophyll states (non-photochemical quenching, NPQ) and regulation of electron transport. The regulatory mechanisms involved in the response to light dynamics have adapted during evolution, and exploring biodiversity is a valuable strategy for expanding our understanding of their biological roles. In this work, we investigated the response to fluctuating light in Nannochloropsis gaditana, a eukaryotic microalga of the phylum Heterokonta originating from a secondary endosymbiotic event. Nannochloropsis gaditana is negatively affected by light fluctuations, leading to large reductions in growth and photosynthetic electron transport. Exposure to light fluctuations specifically damages photosystem I, likely because of the ineffective regulation of electron transport in this species. The role of NPQ, also assessed using a mutant strain specifically depleted of this response, was instead found to be minor, especially in responding to the fastest light fluctuations.
Collapse
Affiliation(s)
- Alessandra Bellan
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Francesca Bucci
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Giorgio Perin
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Alessandro Alboresi
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| | - Tomas Morosinotto
- Department of Biology, University of Padova, Via U. Bassi 58/B, Padova 35121, Italy
| |
Collapse
|
106
|
Mao X, Zhang Y, Wang X, Liu J. Novel insights into salinity-induced lipogenesis and carotenogenesis in the oleaginous astaxanthin-producing alga Chromochloris zofingiensis: a multi-omics study. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:73. [PMID: 32322303 PMCID: PMC7161124 DOI: 10.1186/s13068-020-01714-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 04/09/2020] [Indexed: 05/03/2023]
Abstract
BACKGROUND Chromochloris zofingiensis, a freshwater alga capable of synthesizing both triacylglycerol (TAG) and astaxanthin, has been receiving increasing attention as a leading candidate producer. While the mechanism of oleaginousness and/or carotenogenesis has been studied under such induction conditions as nitrogen deprivation, high light and glucose feeding, it remains to be elucidated in response to salt stress, a condition critical for reducing freshwater footprint during algal production processes. RESULTS Firstly, the effect of salt concentrations on growth, lipids and carotenoids was examined for C. zofingiensis, and 0.2 M NaCl demonstrated to be the optimal salt concentration for maximizing both TAG and astaxanthin production. Then, the time-resolved lipid and carotenoid profiles and comparative transcriptomes and metabolomes were generated in response to the optimized salt concentration for congruent analysis. A global response was triggered in C. zofingiensis allowing acclimation to salt stress, including photosynthesis impairment, ROS build-up, protein turnover, starch degradation, and TAG and astaxanthin accumulation. The lipid metabolism involved a set of stimulated biological pathways that contributed to carbon precursors, energy and reductant molecules, pushing and pulling power, and storage sink for TAG accumulation. On the other hand, salt stress suppressed lutein biosynthesis, stimulated astaxanthin biosynthesis (mainly via ketolation), yet had little effect on total carotenoid flux, leading to astaxanthin accumulation at the expense of lutein. Astaxanthin was predominantly esterified and accumulated in a well-coordinated manner with TAG, pointing to the presence of common regulators and potential communication for the two compounds. Furthermore, the comparison between salt stress and nitrogen deprivation conditions revealed distinctions in TAG and astaxanthin biosynthesis as well as critical genes with engineering potential. CONCLUSIONS Our multi-omics data and integrated analysis shed light on the salt acclimation of C. zofingiensis and underlying mechanisms of TAG and astaxanthin biosynthesis, provide engineering implications into future trait improvements, and will benefit the development of this alga for production uses under saline environment, thus reducing the footprint of freshwater.
Collapse
Affiliation(s)
- Xuemei Mao
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Yu Zhang
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Xiaofei Wang
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Jin Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| |
Collapse
|
107
|
Haslam RP, Hamilton ML, Economou CK, Smith R, Hassall KL, Napier JA, Sayanova O. Overexpression of an endogenous type 2 diacylglycerol acyltransferase in the marine diatom Phaeodactylum tricornutum enhances lipid production and omega-3 long-chain polyunsaturated fatty acid content. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:87. [PMID: 32467729 PMCID: PMC7227059 DOI: 10.1186/s13068-020-01726-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/08/2020] [Indexed: 05/03/2023]
Abstract
BACKGROUND Oleaginous microalgae represent a valuable resource for the production of high-value molecules. Considering the importance of omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs) for human health and nutrition the yields of high-value eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) require significant improvement to meet demand; however, the current cost of production remains high. A promising approach is to metabolically engineer strains with enhanced levels of triacylglycerols (TAGs) enriched in EPA and DHA. RESULTS Recently, we have engineered the marine diatom Phaeodactylum tricornutum to accumulate enhanced levels of DHA in TAG. To further improve the incorporation of omega-3 LC-PUFAs in TAG, we focused our effort on the identification of a type 2 acyl-CoA:diacylglycerol acyltransferase (DGAT) capable of improving lipid production and the incorporation of DHA in TAG. DGAT is a key enzyme in lipid synthesis. Following a diatom based in vivo screen of candidate DGATs, a native P. tricornutum DGAT2B was taken forward for detailed characterisation. Overexpression of the endogenous P. tricornutum DGAT2B was confirmed by qRT-PCR and the transgenic strain grew successfully in comparison to wildtype. PtDGAT2B has broad substrate specificity with preferences for C16 and LC-PUFAs acyl groups. Moreover, the overexpression of an endogenous DGAT2B resulted in higher lipid yields and enhanced levels of DHA in TAG. Furthermore, a combined overexpression of the endogenous DGAT2B and ectopic expression of a Δ5-elongase showed how iterative metabolic engineering can be used to increase DHA and TAG content, irrespective of nitrogen treatment. CONCLUSION This study provides further insight into lipid metabolism in P. tricornutum and suggests a metabolic engineering approach for the efficient production of EPA and DHA in microalgae.
Collapse
Affiliation(s)
- Richard P. Haslam
- Department of Plant Sciences, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Mary L. Hamilton
- Department of Plant Sciences, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
- St Albans Girls School, St Albans, Hertfordshire, AL3 6DB UK
| | - Chloe K. Economou
- Department of Plant Sciences, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS UK
| | - Richard Smith
- Department of Plant Sciences, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
- Algenuity, Eden Laboratory, Broadmead Road, Stewartby, BEDS, Bedford, MK43 9ND UK
| | - Kirsty L. Hassall
- Department of Computational and Analytical Sciences, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Johnathan A. Napier
- Department of Plant Sciences, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Olga Sayanova
- Department of Plant Sciences, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| |
Collapse
|
108
|
Ryu KH, Kim B, Heo S, Chang YK, Lee JH. Mathematical Modeling of Microalgal Internal Metabolic Behaviors under Heterotrophic Conditions and Its Application. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b05948] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kyung Hwan Ryu
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Boeun Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Seongmin Heo
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Yong-Keun Chang
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
- Advanced Biomass R&D Center, #2502 Building W1-3, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jay H. Lee
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology 291, Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| |
Collapse
|
109
|
Lipid and DHA-production in Aurantiochytrium sp. - Responses to nitrogen starvation and oxygen limitation revealed by analyses of production kinetics and global transcriptomes. Sci Rep 2019; 9:19470. [PMID: 31857635 PMCID: PMC6923395 DOI: 10.1038/s41598-019-55902-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 12/04/2019] [Indexed: 01/30/2023] Open
Abstract
Thraustochytrids of the genera Schizochytrium and Aurantiochytrium accumulate oils rich in the essential, marine n3 fatty acid docosahexaenoic acid (DHA). DHA production in Aurantiochytrium sp T66 was studied with the aim to provide more knowledge about factors that affect the DHA-productivities and the contributions of the two enzyme systems used for fatty acid synthesis in thraustochytrids, fatty acid synthetase (FAS) and PUFA-synthase. Fermentations with nitrogen starvation, which is well-known to initiate lipid accumulation in oleaginous organisms, were compared to fermentations with nitrogen in excess, obtained by oxygen limitation. The specific productivities of fatty acids originating from FAS were considerably higher under nitrogen starvation than with nitrogen in excess, while the specific productivities of DHA were the same at both conditions. Global transcriptome analysis showed significant up-regulation of FAS under N-deficient conditions, while the PUFA-synthase genes were only marginally upregulated. Neither of them was upregulated under O2-limitation where nitrogen was in excess, suggesting that N-starvation mainly affects the FAS and may be less important for the PUFA-synthase. The transcriptome analysis also revealed responses likely to be related to the generation of reducing power (NADPH) for fatty acid synthesis.
Collapse
|
110
|
López-Pacheco IY, Salinas-Salazar C, Silva-Núñez A, Rodas-Zuluaga LI, Donoso-Quezada J, Ayala-Mar S, Barceló D, Iqbal HMN, Parra-Saldívar R. Removal and biotransformation of 4-nonylphenol by Arthrospira maxima and Chlorella vulgaris consortium. ENVIRONMENTAL RESEARCH 2019; 179:108848. [PMID: 31678727 DOI: 10.1016/j.envres.2019.108848] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 10/17/2019] [Accepted: 10/19/2019] [Indexed: 02/05/2023]
Abstract
4-Nonylphenol (4-NP) is an anthropogenic contaminant found in different environmental matrices that has an effect over the biotic and abiotic factors within the environment. Bioremediation by microorganisms can be used as a potential treatment to remove this pollutant. In this work, a consortium of two microorganisms, Arthrospira maxima and Chlorella vulgaris, was employed to remove 4-NP from water. The parameters analyzed included cell growth, removal of 4-NP, and 4-NP remnant in the biomass. In addition, the metabolites produced in the process by this consortium were identified. It was found that C. vulgaris is more resistant to 4-NP than A. maxima (cell growth inhibition by 4-NP of 99%). The consortium used in this study had an IC50 greater than any strain of microalgae or cyanobacteria reported for 4-NP removal (9.29 mg/L) and reduced up to 96% of 4-NP in water in the first 48 h of culture. It was also observed that there is a bio-transformation of 4-NP, comparable with the process carried out by another bacterium, in which three similar metabolites were found (4-(1-methyl-octyl)-4-hydroxy-cyclohex-2-enone, 4-nonyl-4-hydroxy-ciclohexa-2,5-dienone and 4-nonyl-4-hydroxy- ciclohex-2-enone) and one that is similar to plant metabolism (4-nonyl-(1-methyl,6,8-metoxy)-hydroxybenzene). These results indicate that microalgae and cyanobacteria consortium can be used to remove 4-NP from water.
Collapse
Affiliation(s)
- Itzel Y López-Pacheco
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, CP 64849, Monterrey, NL., Mexico
| | - Carmen Salinas-Salazar
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, CP 64849, Monterrey, NL., Mexico
| | - Arisbe Silva-Núñez
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, CP 64849, Monterrey, NL., Mexico
| | - Laura Isabel Rodas-Zuluaga
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, CP 64849, Monterrey, NL., Mexico
| | - Javier Donoso-Quezada
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, CP 64849, Monterrey, NL., Mexico
| | - Sergio Ayala-Mar
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, CP 64849, Monterrey, NL., Mexico
| | - Damiá Barceló
- Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, Barcelona, 08034, Spain; ICRA, Catalan Institute for Water Research, University of Girona, Emili Grahit 101, Girona, 17003, Spain; Botany and Microbiology Department, College of Science, King Saud University, PO Box 2455, Riyadh, 11451, Saudi Arabia
| | - Hafiz M N Iqbal
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, CP 64849, Monterrey, NL., Mexico.
| | - Roberto Parra-Saldívar
- Tecnologico de Monterrey, School of Engineering and Sciences, Campus Monterrey, Ave. Eugenio Garza Sada 2501, CP 64849, Monterrey, NL., Mexico.
| |
Collapse
|
111
|
Wang S, Sirbu D, Thomsen L, Kuhnert N, Ullrich MS, Thomsen C. Comparative lipidomic studies of Scenedesmus sp. (Chlorophyceae) and Cylindrotheca closterium (Bacillariophyceae) reveal their differences in lipid production under nitrogen starvation. JOURNAL OF PHYCOLOGY 2019; 55:1246-1257. [PMID: 31127609 DOI: 10.1111/jpy.12887] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 05/03/2019] [Indexed: 06/09/2023]
Abstract
Microalgae are a promising resource for the highly sustainable production of various biomaterials (food and feed), high-value biochemicals, or biofuels. However, factors influencing the valued lipid production from oleaginous algae require a more detailed investigation. This study elucidates the variations in lipid metabolites between a marine diatom (Cylindrotheca closterium) and a freshwater green alga (Scenedesmus sp.) under nitrogen starvation at the molecular species level, with emphasis on triacylglycerols using liquid chromatography-electrospray ionization mass spectrometry techniques. A comprehensive analysis was carried out by comparing the changes in total lipids, growth kinetics, fatty acid compositions, and glycerolipid profiles at the molecular species level at different time points of nitrogen starvation. A total of 60 and 72 triacylglycerol molecular species, along with numerous other polar lipids, were identified in Scenedesmus sp. and C. closterium, respectively, providing the most abundant triacylglycerol profiles for these two species. During nitrogen starvation, more triacylglycerol of Scenedesmus sp. was synthesized via the "eukaryotic pathway" in the endoplasmic reticulum, whereas the increase in triacylglycerol in C. closterium was mainly a result of the "prokaryotic pathway" in the chloroplasts after 96 h of nitrogen starvation. The distinct responses of lipid synthesis to nitrogen starvation exhibited by the two species indicate different strategies of lipid accumulation, notably triacylglycerols, in green algae and diatoms. Scenedesmus sp. and Cylindrotheca closterium could serve as excellent candidates for the mass production of biofuels or polyunsaturated fatty acids for nutraceutical purposes.
Collapse
Affiliation(s)
- Song Wang
- Department of Physics and Earth Sciences, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany
| | - Diana Sirbu
- Department of Life Science and Chemistry, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany
| | - Laurenz Thomsen
- Department of Physics and Earth Sciences, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany
| | - Nikolai Kuhnert
- Department of Life Science and Chemistry, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany
| | - Matthias S Ullrich
- Department of Life Science and Chemistry, Jacobs University Bremen, Campus Ring 1, 28759, Bremen, Germany
| | | |
Collapse
|
112
|
Ran W, Wang H, Liu Y, Qi M, Xiang Q, Yao C, Zhang Y, Lan X. Storage of starch and lipids in microalgae: Biosynthesis and manipulation by nutrients. BIORESOURCE TECHNOLOGY 2019; 291:121894. [PMID: 31387839 DOI: 10.1016/j.biortech.2019.121894] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 05/28/2023]
Abstract
Microalgae accumulate starch and lipid as storage metabolites under nutrient depletion, which can be used as sustainable feedstock for biorefinery. Omics analysis coupled with enzymatic and genetic verifications uncovered a partial picture of pathways and important enzymes or regulators related to starch and lipid biosynthesis as well as the carbon partitioning between them under nutrient depletion conditions. Depletion of macronutrients (N, P, and S) resulted in considerable enhancement of starch and/or lipid content in microalgae, but the accompanying declined photosynthesis hampered the achievements of high concentrations. This review summarized the current knowledge on the pathways and the committed steps as well as their carbon allocation involved in starch and lipid biosynthesis, and focused on the manipulation of different nutrients and the alleviation of oxidative stress for enhanced storage metabolites production. The biological and engineering approaches to cope with the conflict between biomass production and storage metabolites accumulation are proposed.
Collapse
Affiliation(s)
- Wenyi Ran
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Haitao Wang
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, China
| | - Yinghui Liu
- Information Management Center of Sichuan University, Chengdu, Sichuan 610065, China
| | - Man Qi
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Qi Xiang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Changhong Yao
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China.
| | - Yongkui Zhang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Xianqiu Lan
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| |
Collapse
|
113
|
Park S, Nguyen THT, Jin E. Improving lipid production by strain development in microalgae: Strategies, challenges and perspectives. BIORESOURCE TECHNOLOGY 2019; 292:121953. [PMID: 31405625 DOI: 10.1016/j.biortech.2019.121953] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 05/16/2023]
Abstract
Over the past decade, the number of original articles and reviews presenting microalgae as a promising feedstock for biodiesel has increased tremendously. Many improvements of microalgae have been achieved through selection and strain development for industrial applications. However, the large-scale production of lipids for commercialization is not yet realistic because the production is still much more expensive than that of agricultural products. This review summarizes recent research on the induction of lipid biosynthesis in microalgae and the various strategies of genetic and metabolic engineering for enhancing lipid production. Strain engineering targets are proposed based on these strategies. To address current limitations of strain engineering for lipid production, this review provides insights on recent engineering strategies based on molecular tools and methods, and also discusses further perspectives.
Collapse
Affiliation(s)
- Seunghye Park
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea
| | - Thu Ha Thi Nguyen
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea
| | - EonSeon Jin
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea.
| |
Collapse
|
114
|
Mishra A, Medhi K, Malaviya P, Thakur IS. Omics approaches for microalgal applications: Prospects and challenges. BIORESOURCE TECHNOLOGY 2019; 291:121890. [PMID: 31378447 DOI: 10.1016/j.biortech.2019.121890] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 07/23/2019] [Accepted: 07/24/2019] [Indexed: 06/10/2023]
Abstract
In recent impetus of phycological research, microalgae have emerged as a potential candidate for various arena of application-driven research. Omics-based tactics are used for disentangling the regulation and network integration for biosynthesis/degradation of metabolic precursors, intermediates, end products, and identifying the networks that regulate the metabolic flux. Multi-omics coupled with data analytics have facilitated understanding of biological processes and allow ample access to diverse metabolic pathways utilized for genetic manipulations making microalgal factories more efficient. The present review discusses state-of-art "Algomics" and the prospect of microalgae and their role in symbiotic association by using omics approaches including genomics, transcriptomics, proteomics and metabolomics. Microalgal based uni- and multi-omics approaches are critically analyzed in wastewater treatment, metal toxicity and remediation, biofuel production, and therapeutics to provide an imminent outlook for an array of environmentally sustainable and economically viable microalgal applications.
Collapse
Affiliation(s)
- Arti Mishra
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Kristina Medhi
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Piyush Malaviya
- Department of Environmental Science, University of Jammu, Jammu (J&K), India
| | - Indu Shekhar Thakur
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India.
| |
Collapse
|
115
|
Otaki R, Oishi Y, Abe S, Fujiwara S, Sato N. Regulatory carbon metabolism underlying seawater-based promotion of triacylglycerol accumulation in Chlorella kessleri. BIORESOURCE TECHNOLOGY 2019; 289:121686. [PMID: 31238290 DOI: 10.1016/j.biortech.2019.121686] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/03/2019] [Accepted: 06/18/2019] [Indexed: 06/09/2023]
Abstract
Chlorella kessleri accumulates triacylglycerol usable for biodiesel-fuel production to >20% dry cell weight in three days when cultured in three-fold diluted seawater, which imposes the combinatory stress of hyperosmosis and nutrients limitation. The quantitative behavior of major C-compounds, and related-gene expression patterns were investigated in Chlorella cells stressed with hyperosmosis, nutrients limitation, or their combination, to elucidate the C-metabolism for economical seawater-based triacylglycerol accumulation. Combinatory-stress cells showed repressed protein synthesis with initially accumulated starch being degraded later, the C-metabolic flow thereby being diverted to fatty acid and subsequent triacylglycerol accumulation. This C-flow diversion was induced by cooperative actions of nutrients-limitation and hyperosmosis. Semi-quantitative PCR analysis implied positive rewiring of the diverted C-flow into triacylglycerol in combinatory-stress cells through upregulation of gene expression concerning fatty acid and triacylglycerol synthesis, and starch synthesis and degradation. The information of regulatory C-metabolism will help reinforce the seawater-based triacylglycerol accumulation ability in algae including Chlorella.
Collapse
Affiliation(s)
- Rie Otaki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Yutaro Oishi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Seiya Abe
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Shoko Fujiwara
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Norihiro Sato
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
| |
Collapse
|
116
|
Liang J, Iqbal S, Wen F, Tong M, Liu J. Phosphorus-Induced Lipid Class Alteration Revealed by Lipidomic and Transcriptomic Profiling in Oleaginous Microalga Nannochloropsis sp. PJ12. Mar Drugs 2019; 17:md17090519. [PMID: 31484443 PMCID: PMC6780086 DOI: 10.3390/md17090519] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Revised: 08/29/2019] [Accepted: 09/02/2019] [Indexed: 12/22/2022] Open
Abstract
Phytoplankton are primary producers in the marine ecosystem, where phosphorus is often a limiting factor of their growth. Hence, they have evolved strategies to recycle phosphorus by replacing membrane phospholipids with phosphorus-free lipids. However, mechanisms for replacement of lipid classes remain poorly understood. To improve our understanding, we performed the lipidomic and transcriptomic profiling analyses of an oleaginous marine microalga Nannochloropsis sp. PJ12 in response to phosphorus depletion (PD) and replenishing. In this study, by using (liquid chromatography couple with tandem mass spectrometry) LC-MS/MS-based lipidomic analysis, we show that membrane phospholipid levels are significantly reduced upon PD, while phosphorus-free betaine lipid levels are increased. However, levels of phosphorus-free photosynthetic galactolipid and sulfolipid are not increased upon PD, consistent with the reduced photosynthetic activity. RNA-seq-based transcriptomic analysis indicates that enzymes involved in phospholipid recycling and phosphorus-free lipid synthesis are upregulated, supporting the lipidomic analysis. Furthermore, enzymes involved in FASII (type II fatty acid synthesis) elongation cycle upon PD are transcriptionally downregulated. EPA (eicosapentaenoic acid) level decrease upon PD is revealed by both GC-MS (gas chromatography coupled with mass spectrometry) and LC-MS/MS-based lipidomic analyses. PD-induced alteration is reversed after phosphorus replenishing. Taken together, our results suggest that the alteration of lipid classes upon environmental change of phosphorus is a result of remodeling rather than de novo synthesis in Nannochloropsis sp. PJ12.
Collapse
Affiliation(s)
- Jibei Liang
- Ocean College, Zhejiang University, Zhoushan 316000, China.
- School of Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316022, China.
| | - Sunya Iqbal
- Ocean College, Zhejiang University, Zhoushan 316000, China.
| | - Fang Wen
- Ocean College, Zhejiang University, Zhoushan 316000, China.
| | - Mengmeng Tong
- Ocean College, Zhejiang University, Zhoushan 316000, China.
| | - Jianhua Liu
- School of Marine Science and Technology, Zhejiang Ocean University, Zhoushan 316022, China.
| |
Collapse
|
117
|
Abstract
Some species belonging to the Rhodococcus genus, such as Rhodococcus opacus, R. jostii, and R. wratislaviensis, are known to be oleaginous microorganisms, since they are able to accumulate triacylglycerols (TAG) at more than 20% of their weight (dry weight). Oleaginous rhodococci are promising microbial cell factories for the production of lipids to be used as fuels and chemicals. Cells could be engineered to create strains capable of producing high quantities of oils from industrial wastes and a variety of high-value lipids. The comprehensive understanding of carbon metabolism and its regulation will contribute to the design of a reliable process for bacterial oil production. Bacterial oleagenicity requires an integral configuration of metabolism and regulatory processes rather than the sole existence of an efficient lipid biosynthesis pathway. In recent years, several studies have been focused on basic aspects of TAG biosynthesis and accumulation using R. opacus PD630 and R. jostii RHA1 strains as models of oleaginous bacteria. The combination of results obtained in these studies allows us to propose a metabolic landscape for oleaginous rhodococci. In this context, this article provides a comprehensive and integrative view of different metabolic and regulatory attributes and innovations that explain the extraordinary ability of these bacteria to synthesize and accumulate TAG. We hope that the accessibility to such information in an integrated way will help researchers to rationally select new targets for further studies in the field.
Collapse
|
118
|
Wu T, Mao X, Kou Y, Li Y, Sun H, He Y, Chen F. Characterization of Microalgal Acetyl-CoA Synthetases with High Catalytic Efficiency Reveals Their Regulatory Mechanism and Lipid Engineering Potential. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:9569-9578. [PMID: 31385495 DOI: 10.1021/acs.jafc.9b03370] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Acetyl-CoA synthetase (ACS) plays a key role in microalgal lipid biosynthesis and acetyl-CoA industrial production. In the present study, two ACSs were cloned and characterized from the oleaginous microalga Chromochloris zofingiensis. In vitro kinetic analysis showed that the Km values of CzACS1 and CzACS2 for potassium acetate were 0.99 and 0.81 mM, respectively. Moreover, CzACS1 and CzACS2 had outstanding catalytic efficiencies (kcat/Km), which were 70.67 and 79.98 s-1 mM-1, respectively, and these values were higher than that of other reported ACSs. CzACS1 and CzACS2 exhibited differential expression patterns at the transcriptional level under various conditions. Screening a recombinant library of 52 transcription factors (TFs) constructed in the present study via yeast one-hybrid assay pointed to seven TFs with potential involvement in the regulation of the two ACS genes. Expression correlation analysis implied that GATA20 was likely an important regulator of CzACS2 and that ERF9 could regulate two CzACSs simultaneously.
Collapse
Affiliation(s)
| | | | | | | | - Han Sun
- Institute for Advanced Study , Shenzhen University , Shenzhen 518060 , China
| | | | - Feng Chen
- Institute for Advanced Study , Shenzhen University , Shenzhen 518060 , China
| |
Collapse
|
119
|
Vingiani GM, De Luca P, Ianora A, Dobson ADW, Lauritano C. Microalgal Enzymes with Biotechnological Applications. Mar Drugs 2019; 17:md17080459. [PMID: 31387272 PMCID: PMC6723882 DOI: 10.3390/md17080459] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/26/2022] Open
Abstract
Enzymes are essential components of biological reactions and play important roles in the scaling and optimization of many industrial processes. Due to the growing commercial demand for new and more efficient enzymes to help further optimize these processes, many studies are now focusing their attention on more renewable and environmentally sustainable sources for the production of these enzymes. Microalgae are very promising from this perspective since they can be cultivated in photobioreactors, allowing the production of high biomass levels in a cost-efficient manner. This is reflected in the increased number of publications in this area, especially in the use of microalgae as a source of novel enzymes. In particular, various microalgal enzymes with different industrial applications (e.g., lipids and biofuel production, healthcare, and bioremediation) have been studied to date, and the modification of enzymatic sequences involved in lipid and carotenoid production has resulted in promising results. However, the entire biosynthetic pathways/systems leading to synthesis of potentially important bioactive compounds have in many cases yet to be fully characterized (e.g., for the synthesis of polyketides). Nonetheless, with recent advances in microalgal genomics and transcriptomic approaches, it is becoming easier to identify sequences encoding targeted enzymes, increasing the likelihood of the identification, heterologous expression, and characterization of these enzymes of interest. This review provides an overview of the state of the art in marine and freshwater microalgal enzymes with potential biotechnological applications and provides future perspectives for this field.
Collapse
Affiliation(s)
- Giorgio Maria Vingiani
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, CAP80121 (NA) Villa Comunale, Italy
| | - Pasquale De Luca
- Research Infrastructure for Marine Biological Resources Department, Stazione Zoologica Anton Dohrn, CAP80121 (NA) Villa Comunale, Italy
| | - Adrianna Ianora
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, CAP80121 (NA) Villa Comunale, Italy
| | - Alan D W Dobson
- School of Microbiology, University College Cork, College Road, T12 YN60 Cork, Ireland
- Environmental Research Institute, University College Cork, Lee Road, T23XE10 Cork, Ireland
| | - Chiara Lauritano
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, CAP80121 (NA) Villa Comunale, Italy.
| |
Collapse
|
120
|
Balzano S, Villanueva L, de Bar M, Sahonero Canavesi DX, Yildiz C, Engelmann JC, Marechal E, Lupette J, Sinninghe Damst� JS, Schouten S. Biosynthesis of Long Chain Alkyl Diols and Long Chain Alkenols in Nannochloropsis spp. (Eustigmatophyceae). PLANT & CELL PHYSIOLOGY 2019; 60:1666-1682. [PMID: 31058972 PMCID: PMC6872974 DOI: 10.1093/pcp/pcz078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/26/2019] [Indexed: 05/05/2023]
Abstract
We investigated potential biosynthetic pathways of long chain alkenols (LCAs), long chain alkyl diols (LCDs), and long chain hydroxy fatty acids (LCHFAs) in Nannochloropsis oceanica and Nannochloropsis gaditana, by combining culturing experiments with genomic and transcriptomic analyses. Incubation of Nannochloropsis spp. in the dark for 1 week led to significant increases in the cellular concentrations of LCAs and LCDs in both species. Consistently, 13C-labelled substrate experiments confirmed that both LCA and LCD were actively produced in the dark from C14-18 fatty acids by either condensation or elongation/hydroxylation, although no enzymatic evidence was found for the former pathway. Nannochloropsis spp. did, however, contain (i) multiple polyketide synthases (PKSs) including one type (PKS-Clade II) that might catalyze incomplete fatty acid elongations leading to the formation of 3-OH-fatty acids, (ii) 3-hydroxyacyl dehydratases (HADs), which can possibly form Δ2/Δ3 monounsaturated fatty acids, and (iii) fatty acid elongases (FAEs) that could elongate 3-OH-fatty acids and Δ2/Δ3 monounsaturated fatty acids to longer products. The enzymes responsible for reduction of the long chain fatty acids to LCDs and LCAs are, however, unclear. A putative wax ester synthase/acyl coenzyme A (acyl-CoA): diacylglycerol acyltransferase is likely to be involved in the esterification of LCAs and LCDs in the cell wall. Our data thus provide useful insights in predicting the biosynthetic pathways of LCAs and LCDs in phytoplankton suggesting a key role of FAE and PKS enzymes.
Collapse
Affiliation(s)
- Sergio Balzano
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Corresponding author: E-mail, ; Fax, +39 081 7641355. Present address: Stazione Zoologica Anton Dohrn, Istituto Nazionale di Biologia Ecologia e Biotecnologie Marine, Villa Comunale, Napoli, Italy
| | - Laura Villanueva
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Marijke de Bar
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Diana X Sahonero Canavesi
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Caglar Yildiz
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Julia C Engelmann
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Eric Marechal
- Laboratoire de Physiologie Cellulaire et V�g�tale, Unit� mixte de recherche CNRS, CEA, INRA, Universit� Grenoble Alpes, CEA Grenoble, 17 Avenue des Martyrs, Grenoble, France
| | - Josselin Lupette
- Laboratoire de Physiologie Cellulaire et V�g�tale, Unit� mixte de recherche CNRS, CEA, INRA, Universit� Grenoble Alpes, CEA Grenoble, 17 Avenue des Martyrs, Grenoble, France
- Present address: MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Jaap S Sinninghe Damst�
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Stefan Schouten
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| |
Collapse
|
121
|
Salama ES, Govindwar SP, Khandare RV, Roh HS, Jeon BH, Li X. Can Omics Approaches Improve Microalgal Biofuels under Abiotic Stress? TRENDS IN PLANT SCIENCE 2019; 24:611-624. [PMID: 31085124 DOI: 10.1016/j.tplants.2019.04.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 03/27/2019] [Accepted: 04/11/2019] [Indexed: 06/09/2023]
Abstract
Microalgae hold the promise of an inexpensive and sustainable source of biofuels. The existing microalgal cultivation technologies need significant improvement to outcompete other biofuel sources such as terrestrial plants. Application of 'algomics' approaches under different abiotic stress conditions could be an effective strategy for optimization of microalgal growth and production of high-quality biofuels. In this review, we discuss the roles of omics in understanding genome structure and biocomponents metabolism in various microalgal species to optimize sustainable biofuel production. Application of individual and integrated omics revealed that genes and metabolic pathways of microalgae have been altered under multiple stress conditions, resulting in an increase in biocomponents, providing a research platform for expansion of genetic engineering studies in microalgal strains.
Collapse
Affiliation(s)
- El-Sayed Salama
- MOE, Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, 730000, Gansu Province, PR China; Department of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou 730000, Gansu Province, PR China
| | - Sanjay P Govindwar
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, South Korea
| | - Rahul V Khandare
- Amity Institute of Biotechnology, Amity University, Mumbai, 410206, India
| | - Hyun-Seog Roh
- Department of Environmental Engineering, Yonsei University, Wonju, Gangwon-do 220-710, South Korea
| | - Byong-Hun Jeon
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, South Korea.
| | - Xiangkai Li
- MOE, Key Laboratory of Cell Activities and Stress Adaptations, Lanzhou University, Lanzhou, 730000, Gansu Province, PR China.
| |
Collapse
|
122
|
Knockdown of carbonate anhydrase elevates Nannochloropsis productivity at high CO2 level. Metab Eng 2019; 54:96-108. [DOI: 10.1016/j.ymben.2019.03.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/13/2019] [Accepted: 03/14/2019] [Indexed: 01/07/2023]
|
123
|
Liu J, Sun Z, Mao X, Gerken H, Wang X, Yang W. Multiomics analysis reveals a distinct mechanism of oleaginousness in the emerging model alga Chromochloris zofingiensis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:1060-1077. [PMID: 30828893 DOI: 10.1111/tpj.14302] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Revised: 02/15/2019] [Accepted: 02/19/2019] [Indexed: 06/09/2023]
Abstract
Chromochloris zofingiensis, featured due to its capability to simultaneously synthesize triacylglycerol (TAG) and astaxanthin, is emerging as a leading candidate alga for production uses. To better understand the oleaginous mechanism of this alga, we conducted a multiomics analysis by systematically integrating time-resolved transcriptomes, lipidomes and metabolomes in response to nitrogen deprivation. The data analysis unraveled the distinct mechanism of TAG accumulation, which involved coordinated stimulation of multiple biological processes including supply of energy and reductants, carbon reallocation from protein and starch, and 'pushing' and 'pulling' carbon to TAG synthesis. Unlike the model alga Chlamydomonas, de novo fatty acid synthesis in C. zofingiensis was promoted, together with enhanced turnover of both glycolipids and phospholipids, supporting the drastic need of acyls for TAG assembly. Moreover, genomewide analysis identified many key functional enzymes and transcription factors that had engineering potential for TAG modulation. Two genes encoding glycerol-3-phosphate acyltransferase (GPAT), the first committed enzyme for TAG assembly, were found in the C. zofingiensis genome; in vivo functional characterization revealed that extrachloroplastic GPAT instead of chloroplastic GPAT played a central role in TAG synthesis. These findings illuminate distinct oleaginousness mechanisms in C. zofingiensis and pave the way towards rational manipulation of this alga to becone an emerging model for trait improvements.
Collapse
Affiliation(s)
- Jin Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Zheng Sun
- International Research Center for Marine Biosciences, Ministry of Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Xuemei Mao
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Henri Gerken
- School of Sustainable Engineering and the Built Environment, Arizona State University Polytechnic campus, Mesa, AZ, 85212, USA
| | - Xiaofei Wang
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Wenqiang Yang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| |
Collapse
|
124
|
Nobusawa T, Yamakawa-Ayukawa K, Saito F, Nomura S, Takami A, Ohta H. A homolog of Arabidopsis SDP1 lipase in Nannochloropsis is involved in degradation of de novo-synthesized triacylglycerols in the endoplasmic reticulum. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1185-1193. [PMID: 31152796 DOI: 10.1016/j.bbalip.2019.05.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/26/2019] [Accepted: 05/25/2019] [Indexed: 01/22/2023]
Abstract
Organisms of the microalgal genus Nannochloropsis produce high levels of triacylglycerols (TAGs), an efficient raw material for biofuels. A complete understanding of the TAG-breakdown pathway is critical for improving the productivity of TAGs to meet future needs. Among a number of lipases annotated as TAG lipase in the genomes of every organism, Arabidopsis SUGAR-DEPENDENT 1 (AtSDP1) lipases are characterized as a type of crucial TAG lipase in plants, similar to ScTgl3-5 in Saccharomyces cerevisiae. Homologs of the AtSDP1 TAG lipases are universally found in the genomes of plants, fungi, and algae. Here we identified two homologs of AtSDP1 TAG lipases in the oleaginous microalga species Nannochloropsis oceanica, NoTGL1 and NoTGL2. We generated single- and double-knockout strains for these lipases by homologous recombination. Whereas overall TAG content in the NoTGL2 single-knockout mutant was identical to that of wild type, the NoTGL1 knockout showed a two-fold increase in TAG content per cell in early log phase under nutrient-sufficient conditions without affecting growth. Homologs of AtSDP1 in S. cerevisiae are localized to the surface of lipid droplets, and AtSDP1 is transported from peroxisomes to the surface of lipid droplets. In contrast, NoTGL1 localized to the endoplasmic reticulum in both Nannochloropsis and yeast. We suggest that homologs of AtSDP1 lipases in Nannochloropsis modulate de novo TAG biosynthesis in the endoplasmic reticulum, unlike the roles of these lipases in other organisms. These results provide important insights into the mechanisms of TAG metabolism catalyzed by homologs of AtSDP1 lipase, which are highly conserved across species.
Collapse
Affiliation(s)
- Takashi Nobusawa
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan; Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-3, Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Kaoru Yamakawa-Ayukawa
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Fumihiko Saito
- Technical Research Center, Mazda Motor Corporation, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima, 730-8670, Japan
| | - Seiji Nomura
- Technical Research Center, Mazda Motor Corporation, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima, 730-8670, Japan
| | - Akihide Takami
- Technical Research Center, Mazda Motor Corporation, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima, 730-8670, Japan
| | - Hiroyuki Ohta
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
| |
Collapse
|
125
|
Castro JC, Maddox JD, Estela SL, Rodríguez HN, Casuso MZ, Paredes JD, Cobos M. Caracterización <i>in silico</i> y análisis de la expresión de la subunidad alfa de la acetil-coenzima a carboxilasa heteromérica de dos microalgas. ACTA BIOLÓGICA COLOMBIANA 2019. [DOI: 10.15446/abc.v24n2.74727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Las microalgas son microorganismos fotosintéticos con gran potencial para abastecer las demandas energéticas mundiales. Sin embargo, los limitados conocimientos que se tienen de estos organismos, en particular a nivel molecular de los procesos metabólicos, han limitado su uso con estos propósitos. En esta investigación se ha realizado el análisis in silico de la subunidad alfa de la acetil-Coenzima A carboxilasa heteromérica (αACCasa), una enzima clave en la biosíntesis de lípidos de las microalgas Chlorella sp. y Scenedesmus sp. Asimismo, se ha medido la expresión de este gen en ambas especies cultivadas en medios deficientes de nitrógeno. Los resultados indican que la αACCasa muestra conservación estructural y funcional en ambas especies de microalgas y su mayor similitud genética con otras especies de microalgas. Asimismo, se ha mostrado que el nivel de expresión del gen se incrementa significativamente cuando las microalgas son cultivadas en ausencia de nitrógeno, lo cual se relaciona a su vez con una mayor acumulación de lípidos microalgales. En conclusión, el análisis in silico de la αACCasa de Chlorella sp. y Scenedesmus sp. presentan características estructurales, funcionales y evolutivas muy similares con otras especies de microalgas y plantas. Asimismo, el estudio revela que en ambas especies el gen se sobreexpresa cuando las microalgas son sometidas a estrés por deficiencia de nitrógeno, el cual se relaciona significativamente con la acumulación de lípidos totales en estas células.
Collapse
|
126
|
Xin Y, Shen C, She Y, Chen H, Wang C, Wei L, Yoon K, Han D, Hu Q, Xu J. Biosynthesis of Triacylglycerol Molecules with a Tailored PUFA Profile in Industrial Microalgae. MOLECULAR PLANT 2019; 12:474-488. [PMID: 30580039 DOI: 10.1016/j.molp.2018.12.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 11/29/2018] [Accepted: 12/13/2018] [Indexed: 05/06/2023]
Abstract
The composition of polyunsaturated fatty acids (PUFAs) in triacylglycerols (TAGs) is key to health benefits and for oil applications, yet the underlying genetic mechanism remains poorly understood. In this study, by in silico, ex vivo, and in vivo profiling of type-2 diacylglycerol acyltransferases (DGAT2s) in Nannochloropsis oceanica we revealed two novel PUFA-preferring enzymes that discriminate individual PUFA species in TAG assembly, with NoDGAT2J for linoleic acid (LA) and NoDGAT2K for eicosapentaenoic acid (EPA). The LA and EPA composition of TAG molecules is mediated in vivo via the functional partitioning between NoDGAT2J and 2K, both of which are localized in the chloroplast envelope. By modulating transcript abundance of the DGAT2s, an N. oceanica strain bank was created, where proportions of LA and EPA in TAG vary by 18.7-fold (between 0.21% and 3.92% dry weight) and 34.7-fold (between 0.09% and 3.12% dry weight), respectively. These findings lay the foundation for producing designer TAG molecules with tailored health benefits or for biofuel applications in industrial microalgae and higher-plant crops.
Collapse
Affiliation(s)
- Yi Xin
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Chen Shen
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yiting She
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong Chen
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Cong Wang
- Core Laboratory, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China
| | - Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Kangsup Yoon
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Danxiang Han
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China
| | - Qiang Hu
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, Shandong 266237, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
127
|
Sun XM, Ren LJ, Zhao QY, Ji XJ, Huang H. Enhancement of lipid accumulation in microalgae by metabolic engineering. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:552-566. [DOI: 10.1016/j.bbalip.2018.10.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/30/2018] [Accepted: 10/05/2018] [Indexed: 01/08/2023]
|
128
|
Liang J, Wen F, Liu J. Transcriptomic and lipidomic analysis of an EPA-containing Nannochloropsis sp. PJ12 in response to nitrogen deprivation. Sci Rep 2019; 9:4540. [PMID: 30872742 PMCID: PMC6418175 DOI: 10.1038/s41598-019-41169-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 03/01/2019] [Indexed: 12/30/2022] Open
Abstract
To understand genes involved in neutral lipid accumulation upon nitrogen deprivation (ND) in a novel isolate of Nannochloropsis sp. PJ12, we performed comparative transcriptomic and lipidomic analyses of cells under ND and NR (nitrogen replete) conditions. Transcriptomic profiling indicated that, while enzymes involved in TCA cycle in PJ12 under ND condition were upregulated compared to that under NR condition, those involved in Calvin cycle and glycolysis under ND condition were downregulated. Furthermore, we showed that enzymes involved in fatty acid synthesis and glycerolipid synthesis were downregulated but not β-oxidation. Lipidomic profiling indicated that, while the level of neutral lipids in ND cells was increased compared to that of NR cells, level of photosynthetic membrane-lipids DGDG and PG was decreased. Taken together, our analysis indicated that TAG accumulation is attributed to the modification of membrane lipids derived primarily from “prokaryotic” pathway and secondarily from “eukaryotic” pathway based on the 16:X or 18:X fatty acid at the sn2 position of the glycerol backbone. We propose that two-phase (NR-ND) growth is ideal for biomass and biofuel production because ND reduces cell growth rate due to the loss of photosynthetic membrane and decreased quantum yield.
Collapse
Affiliation(s)
- Jibei Liang
- Ocean College, Zhejiang University, Zhoushan, ZJ316000, China
| | - Fang Wen
- Ocean College, Zhejiang University, Zhoushan, ZJ316000, China
| | - Jianhua Liu
- Ocean College, Zhejiang University, Zhoushan, ZJ316000, China. .,Ocean Research Center of Zhoushan, Zhoushan, ZJ316021, China.
| |
Collapse
|
129
|
Chen C, Harst A, You W, Xu J, Ning K, Poetsch A. Proteomic study uncovers molecular principles of single-cell-level phenotypic heterogeneity in lipid storage of Nannochloropsis oceanica. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:21. [PMID: 30740142 PMCID: PMC6360718 DOI: 10.1186/s13068-019-1361-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 01/25/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND Nannochloropsis oceanica belongs to a large group of photoautotrophic eukaryotic organisms that play important roles in fixation and cycling of atmospheric CO2. Its capability of storing solar energy and carbon dioxide in the form of triacylglycerol (TAG) of up to 60% of total weight under nitrogen deprivation stress sparked interest in its use for biofuel production. Phenotypes varying in lipid accumulation among an N. oceanica population can be disclosed by single-cell analysis/sorting using fluorescence-activated cell sorting (FACS); yet the phenomenon of single cell heterogeneity in an algae population remains to be fully understood at the molecular level. In this study, combination of FACS and proteomics was used for identification, quantification and differentiation of these heterogeneities on the molecular level. RESULTS For N. oceanica cultivated under nitrogen deplete (-N) and replete (+N) conditions, two groups differing in lipid content were distinguished. These differentiations could be recognized on the population as well as the single-cell levels; proteomics uncovered alterations in carbon fixation and flux, photosynthetic machinery, lipid storage and turnover in the populations. Although heterogeneity patterns have been affected by nitrogen supply and cultivation conditions of the N. oceanica populations, differentiation itself seems to be very robust against these factors: cultivation under +N, -N, in shaker bottles, and in a photo-bioreactor all split into two subpopulations. Intriguingly, population heterogeneity resumed after subpopulations were separately recultivated for a second round, refuting the possible development of genetic heterogeneity in the course of sorting and cultivation. CONCLUSIONS This work illustrates for the first time the feasibility of combining FACS and (prote)-omics for mechanistic understanding of phenotypic heterogeneity in lipid-producing microalgae. Such combinatorial method can facilitate molecular breeding and design of bioprocesses.
Collapse
Affiliation(s)
- Chaoyun Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Hubei Key Laboratory of Bioinformatics and Molecular-imaging, Department of Bioinformatics and Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 Hubei China
| | - Andreas Harst
- Plant Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany
| | - Wuxin You
- Plant Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany
- 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, 266101 Shandong China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong China
| | - Kang Ning
- Key Laboratory of Molecular Biophysics of the Ministry of Education, Hubei Key Laboratory of Bioinformatics and Molecular-imaging, Department of Bioinformatics and Systems Biology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 Hubei China
| | - Ansgar Poetsch
- Plant Biochemistry, Ruhr University Bochum, 44801 Bochum, Germany
- School of Biomedical and Healthcare Sciences, Plymouth University, Plymouth, PL4 8AA UK
| |
Collapse
|
130
|
Wei L, El Hajjami M, Shen C, You W, Lu Y, Li J, Jing X, Hu Q, Zhou W, Poetsch A, Xu J. Transcriptomic and proteomic responses to very low CO 2 suggest multiple carbon concentrating mechanisms in Nannochloropsis oceanica. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:168. [PMID: 31297156 PMCID: PMC6599299 DOI: 10.1186/s13068-019-1506-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 06/18/2019] [Indexed: 05/20/2023]
Abstract
BACKGROUND In industrial oleaginous microalgae such as Nannochloropsis spp., the key components of the carbon concentration mechanism (CCM) machineries are poorly defined, and how they are mobilized to facilitate cellular utilization of inorganic carbon remains elusive. RESULTS For Nannochloropsis oceanica, to unravel genes specifically induced by CO2 depletion which are thus potentially underpinning its CCMs, transcriptome, proteome and metabolome profiles were tracked over 0 h, 3 h, 6 h, 12 h and 24 h during cellular response from high CO2 level (HC; 50,000 ppm) to very low CO2 (VLC; 100 ppm). The activity of a biophysical CCM is evidenced based on induction of transcripts encoding a bicarbonate transporter and two carbonic anhydrases under VLC. Moreover, the presence of a potential biochemical CCM is supported by the upregulation of a number of key C4-like pathway enzymes in both protein abundance and enzymatic activity under VLC, consistent with a mitochondria-implicated C4-based CCM. Furthermore, a basal CCM underpinned by VLC-induced upregulation of photorespiration and downregulation of ornithine-citrulline shuttle and the ornithine urea cycles is likely present, which may be responsible for efficient recycling of mitochondrial CO2 for chloroplastic carbon fixation. CONCLUSIONS Nannochloropsis oceanica appears to mobilize a comprehensive set of CCMs in response to very low CO2. Its genes induced by the stress are quite distinct from those of Chlamydomonas reinhardtii and Phaeodactylum tricornutum, suggesting tightly regulated yet rather unique CCMs. These findings can serve the first step toward rational engineering of the CCMs for enhanced carbon fixation and biomass productivity in industrial microalgae.
Collapse
Affiliation(s)
- Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong China
- University of Chinese Academy of Science, Beijing, China
| | - Mohamed El Hajjami
- Department of Plant Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Chen Shen
- 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 China
- University of Chinese Academy of Science, Beijing, China
| | - Wuxin You
- 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 China
- Department of Plant Biochemistry, Ruhr University Bochum, Bochum, Germany
| | - Yandu Lu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong China
- University of Chinese Academy of Science, Beijing, China
| | - Jing Li
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong China
- University of Chinese Academy of Science, Beijing, China
| | - Xiaoyan Jing
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong China
- University of Chinese Academy of Science, Beijing, China
| | - Qiang Hu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei China
- University of Chinese Academy of Science, Beijing, China
| | - Wenxu Zhou
- Department of Chemistry and Biochemistry, Center for Chemical Biology, Texas Tech University, Lubbock, TX USA
| | - Ansgar Poetsch
- 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 China
- Department of Plant Biochemistry, Ruhr University Bochum, Bochum, Germany
- School of Biomedical and Healthcare Sciences, University of Plymouth, Plymouth, UK
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong China
- University of Chinese Academy of Science, Beijing, China
| |
Collapse
|
131
|
Zhang Y, Shi M, Mao X, Kou Y, Liu J. Time-resolved carotenoid profiling and transcriptomic analysis reveal mechanism of carotenogenesis for astaxanthin synthesis in the oleaginous green alga Chromochloris zofingiensis. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:287. [PMID: 31890015 PMCID: PMC6913025 DOI: 10.1186/s13068-019-1626-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 12/04/2019] [Indexed: 05/03/2023]
Abstract
BACKGROUND Chromochloris zofingiensis is emerging as an industrially relevant alga given its robust growth for the production of lipids and astaxanthin, a value-added carotenoid with broad applications. Nevertheless, poor understanding of astaxanthin synthesis has limited engineering of this alga for rational improvements. RESULTS To reveal the molecular mechanism underlying astaxanthin accumulation in C. zofingiensis, here we conducted an integrated analysis by combining the time-resolved transcriptomes and carotenoid profiling in response to nitrogen deprivation (ND). A global response was triggered for C. zofingiensis to cope with the ND stress. Albeit the little variation in total carotenoid content, individual carotenoids responded differentially to ND: the primary carotenoids particularly lutein and β-carotene decreased, while the secondary carotenoids increased considerably, with astaxanthin and canthaxanthin being the most increased ones. The carotenogenesis pathways were reconstructed: ND had little effect on the carbon flux to carotenoid precursors, but stimulated astaxanthin biosynthesis while repressing lutein biosynthesis, thereby diverting the carotenoid flux from primary carotenoids to secondary carotenoids particularly astaxanthin. Comparison between C. zofingiensis and Haematococcus pluvialis revealed the distinctive mechanism of astaxanthin synthesis in C. zofingiensis. Furthermore, potential bottlenecks in astaxanthin synthesis were identified and possible engineering strategies were proposed for the alga. CONCLUSIONS Collectively, these findings shed light on distinctive mechanism of carotenogenesis for astaxanthin biosynthesis in C. zofingiensis, identify key functional enzymes and regulators with engineering potential and will benefit rational manipulation of this alga for improving nutritional traits.
Collapse
Affiliation(s)
- Yu Zhang
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Meicheng Shi
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Xuemei Mao
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Yaping Kou
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Jin Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| |
Collapse
|
132
|
Naghshbandi MP, Tabatabaei M, Aghbashlo M, Aftab MN, Iqbal I. Metabolic Engineering of Microalgae for Biofuel Production. Methods Mol Biol 2019; 1980:153-172. [PMID: 30666564 DOI: 10.1007/7651_2018_205] [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] [Indexed: 12/02/2022]
Abstract
Microalgae are considered as promising cell factories for the production of various types of biofuels, including bioethanol, biodiesel, and biohydrogen by using carbon dioxide and sunlight. In spite of unique advantages of these microorganisms, the commercialization of microalgal biofuels has been hindered by poor economic features. Metabolic engineering is among the most promising strategies put forth to overcome this challenge. In this chapter, metabolic pathways involved in lipid and hydrogen production by microalgae are reviewed and discussed. Moreover, metabolic and genetic engineering approaches investigated for improving the rate of lipid (as a feedstock for biodiesel production) and biohydrogen synthesis are presented. Finally, genetic engineering tools and approaches employed for engineering microalgal metabolic pathways are elaborated. A thorough step-by-step protocol for reconstructing the metabolic pathway of various microorganisms including microalgae is also presented.
Collapse
Affiliation(s)
- Mohammad Pooya Naghshbandi
- Department of Microbial Biotechnology, School of Biology, College of Science, University of Tehran, Tehran, Iran
| | - Meisam Tabatabaei
- Microbial Biotechnology Department, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education, and Extension Organization (AREEO), Karaj, Iran. .,Biofuel Research Team (BRTeam), Karaj, Iran.
| | - Mortaza Aghbashlo
- Department of Mechanical Engineering of Agricultural Machinery, Faculty of Agricultural Engineering and Technology, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
| | - Muhammad Nauman Aftab
- Institute of Industrial Biotechnology, Government College University, Lahore, Pakistan
| | - Irfana Iqbal
- Department of Zoology, Lahore College for Women University, Lahore, Pakistan
| |
Collapse
|
133
|
Wang H, Zhang Y, Zhou W, Noppol L, Liu T. Mechanism and enhancement of lipid accumulation in filamentous oleaginous microalgae Tribonema minus under heterotrophic condition. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:328. [PMID: 30559837 PMCID: PMC6290495 DOI: 10.1186/s13068-018-1329-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 12/03/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND The filamentous microalgae Tribonema minus accumulates large amounts of lipids under photoautotrophic condition, while under heterotrophic condition, the lipid content decreased dramatically. Determination of the differences in metabolic pathways between photoautotrophic and heterotrophic growth will provide targets and strategies for improvement of lipid accumulation in heterotrophic cells. METHODS The metabolic differences between photoautotrophically and heterotrophically cultivated T. minus cells were studied by comparing the growth, biochemical compositions and transcriptomic and metabolomic profiles of the cells. Based on comparative transcriptomic and metabolomic studies, we generated a global model of the changes in central carbon metabolism and lipid biosynthetic pathways that occur under photoautotrophic and heterotrophic growth conditions. Moreover, the specific effects of supplementation with exogenous key metabolic intermediates on the lipid accumulation in heterotrophic culture were analyzed. RESULTS Compared to photoautotrophic cultures, heterotrophic cultures exhibited enhanced biomass levels and carbohydrate content, but decreased lipid accumulation. These effects were accompanied by low expression levels of genes involved in glycolysis, de novo fatty acids biosynthesis and lipid biosynthesis, and high levels of genes involved in gluconeogenesis. In addition, the levels of key metabolites involved in glycolysis/gluconeogenesis were elevated in abundance, whereas those of certain fatty acids and citric acid were decreased in heterotrophic cultures. Upon supplementation with exogenous potassium palmitate, the lipid content increased dramatically in heterotrophically cultivated T. minus. CONCLUSION An insufficient supply of carbon precursors caused the low levels of lipid accumulation during heterotrophic cultivation. Appropriate carbon metabolite supplementation based on the metabolomic data was shown to promote lipid accumulation. Moreover, gene regulatory metabolic targets were also identified via omics analysis.
Collapse
Affiliation(s)
- Hui Wang
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong People’s Republic of China
| | - Yan Zhang
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong People’s Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049 People’s Republic of China
| | - Wenjun Zhou
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong People’s Republic of China
- University of Chinese Academy of Sciences, Beijing, 100049 People’s Republic of China
| | - Leksawasdi Noppol
- Bioprocess Research Cluster, School of Agro-Industry, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai, 50200 Thailand
| | - Tianzhong Liu
- Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101 Shandong People’s Republic of China
| |
Collapse
|
134
|
Liang MH, Wang L, Wang Q, Zhu J, Jiang JG. High-value bioproducts from microalgae: Strategies and progress. Crit Rev Food Sci Nutr 2018; 59:2423-2441. [PMID: 29676930 DOI: 10.1080/10408398.2018.1455030] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Microalgae have been considered as alternative sustainable resources for high-value bioproducts such as lipids (especially triacylglycerides [TAGs]), polyunsaturated fatty acids (PUFAs), and carotenoids, due to their relatively high photosynthetic efficiency, no arable land requirement, and ease of scale-up. It is of great significance to exploit microalgae for the production of high-value bioproducts. How to improve the content or productivity of specific bioproducts has become one of the most urgent challenges. In this review, we will describe high-value bioproducts from microalgae and their biosynthetic pathways (mainly for lipids, PUFAs, and carotenoids). Recent progress and strategies for the enhanced production of bioproducts from microalgae are also described in detail, and these strategies take advantages of optimized cultivation conditions with abiotic stress, chemical stress (addition of metabolic precursors, phytohormones, chemical inhibitors, and chemicals inducing oxidative stress response), and molecular approaches such as metabolic engineering, transcriptional engineering, and gene disruption strategies (mainly RNAi, antisense RNA, miRNA-based knockdown, and CRISPR/Cas9).
Collapse
Affiliation(s)
- Ming-Hua Liang
- a College of Food Science and Engineering, South China University of Technology , Guangzhou , China
| | - Ling Wang
- b School of Biotechnology, Jiangsu University of Science and Technology , Zhenjiang , China
| | - Qiming Wang
- c College of Bioscience and Biotechnology, Hunan Agricultural University , Changsha , China
| | - Jianhua Zhu
- b School of Biotechnology, Jiangsu University of Science and Technology , Zhenjiang , China.,c College of Bioscience and Biotechnology, Hunan Agricultural University , Changsha , China.,d Department of Plant Science and Landscape Architecture, University of Maryland , College Park , Maryland , USA
| | - Jian-Guo Jiang
- a College of Food Science and Engineering, South China University of Technology , Guangzhou , China
| |
Collapse
|
135
|
Adelfi MG, Vitale RM, d'Ippolito G, Nuzzo G, Gallo C, Amodeo P, Manzo E, Pagano D, Landi S, Picariello G, Ferrante MI, Fontana A. Patatin-like lipolytic acyl hydrolases and galactolipid metabolism in marine diatoms of the genus Pseudo-nitzschia. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1864:181-190. [PMID: 30521937 DOI: 10.1016/j.bbalip.2018.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 08/18/2018] [Accepted: 11/28/2018] [Indexed: 02/07/2023]
Abstract
Diatoms are eukaryotic microalgae that play a pivotal role in biological and geochemical marine cycles. These microorganisms are at the basis of the trophic chain and their lipids are essential components (e.g. eicosapentaenoic acid, EPA) of aquatic food webs. Galactolipids are the primary lipid components of plastid membranes and form the largest lipid family of diatoms. As source of polyunsaturated fatty acids (PUFAs), these compounds are also involved in the synthesis of lipoxygenase (LOX) products such as non-volatile oxylipins and polyunsaturated aldehydes. Here, we report the first identification of two genes, namely PmLAH1 and PaLAH1, coding for lipolytic enzymes in two diatoms of the genus Pseudo-nitzschia. Functional and modeling studies evidence a patatin-like domain endowed with galactolipase and phospholipase activity at the C-terminus of both proteins. Homologues of Pseudo-nitzschia LAH1 genes were retrieved in other diatom species so far sequenced in agreement with conservation of the functional role of these proteins within the lineage.
Collapse
Affiliation(s)
- Maria Grazia Adelfi
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy; Stazione Zoologica Anton Dohrn, Villa Comunale 1, 80121 Naples, Italy
| | - Rosa Maria Vitale
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Giuliana d'Ippolito
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Genoveffa Nuzzo
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Carmela Gallo
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Pietro Amodeo
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Emiliano Manzo
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Dario Pagano
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Simone Landi
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy
| | - Gianluca Picariello
- CNR-Istituto di Scienze dell'Alimentazione, Via Roma, 52, 83100 Avellino, Italy
| | | | - Angelo Fontana
- CNR-Istituto di Chimica Biomolecolare, Via Campi Flegrei 34, 80078, Pozzuoli, Naples, Italy.
| |
Collapse
|
136
|
Shene C, Asenjo JA, Chisti Y. Metabolic modelling and simulation of the light and dark metabolism of Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 96:1076-1088. [PMID: 30168220 DOI: 10.1111/tpj.14078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 08/15/2018] [Accepted: 08/20/2018] [Indexed: 05/10/2023]
Abstract
A metabolic network model of the green microalga Chlamydomonas reinhardtii was used to characterize photoautotrophic and heterotrophic (i.e. growth on stored compounds) growth under light and dark, respectively. The metabolic network comprised 2514 reactions distributed among nine intracellular compartments and the extracellular space. The metabolic network included all the key biochemical pathways for synthesis and metabolism of starch and triacylglycerols (TAGs). Under light and nitrogen limitation, the model simulated the accumulation of the energy-rich compounds (TAGs and starch) in the cell. In the dark, the model could simulate cell growth and maintenance on stored compounds. The model-predicted consumption rates of storage compounds (starch or TAGs) to enable growth in the dark, were found to be greater than the rates of synthesis under light. This implied utilization of the storage compounds for cell maintenance in the dark. Under constant illumination, the simulations of cell growth and intracellular starch content agreed closely with independent experimental data. In other simulations, compared with the case without photorespiration, light uptake rate increased 1.04-fold when the ratio of the rates of oxygenation and carboxylation (Rubisco) was 0.1. Although extensive experimental work exists on culture and physiology of microalgae, it does not allow quantitative predictions of the influence of dark metabolism on the productivity of metabolites to be made. This limitation is overcome using the present model. A metabolic network model of Chlamydomonas reinhardtii is shown to simulate growth and synthesis of energy-rich compounds (triacylglycerols and starch) under light. The same model also simulates dark growth and maintenance through consumption of the stored energy-rich compounds.
Collapse
Affiliation(s)
- Carolina Shene
- Department of Chemical Engineering and Center of Food Biotechnology and Bioseparations, BIOREN, Universidad de La Frontera, Casilla 54-D, Temuco, Chile
- Centre for Biotechnology and Bioengineering (CeBiB), Universidad de La Frontera, Temuco, Chile
| | - Juan A Asenjo
- Centre for Biotechnology and Bioengineering (CeBiB), Department of Chemical Engineering and Biotechnology, Universidad de Chile, Beauchef 851, Santiago, Chile
| | - Yusuf Chisti
- School of Engineering, Massey University, Private Bag 11 222, Palmerston North, New Zealand
| |
Collapse
|
137
|
Sun XM, Ren LJ, Bi ZQ, Ji XJ, Zhao QY, Huang H. Adaptive evolution of microalgae Schizochytrium sp. under high salinity stress to alleviate oxidative damage and improve lipid biosynthesis. BIORESOURCE TECHNOLOGY 2018; 267:438-444. [PMID: 30032058 DOI: 10.1016/j.biortech.2018.07.079] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/13/2018] [Accepted: 07/14/2018] [Indexed: 05/09/2023]
Abstract
Lipid accumulation of Schizochytrium sp. can be induced by stress condition, but this stress-induction usually reduce cell growth and cause oxidative damage, which can eventually lower the lipid yield. Here, adaptive laboratory evolution (ALE) combined high salinity was performed to enhance the antioxidant system and lipid accumulation. The final strain ALE150, which was obtained after 150 days, showed a maximal cell dry weight (CDW) of 134.5 g/L and lipid yield of 80.14 g/L, representing a 32.7 and 53.31% increase over the starting strain, respectively. Moreover, ALE150 exhibited an overall higher total antioxidant capacity (T-AOC) and lower reactive oxygen species (ROS) levels than the starting strain. Furthermore, the regulatory mechanisms responsible for the improved performance of ALE150 were analyzed by transcriptomic analysis. Genes related to the antioxidant enzymes and central carbon metabolism were up-regulation. Moreover, the metabolic fluxes towards the fatty acid synthase (FAS) and polyketide synthase (PKS) pathways were also changed.
Collapse
Affiliation(s)
- Xiao-Man Sun
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - Lu-Jing Ren
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), People's Republic of China.
| | - Zhi-Qian Bi
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - Xiao-Jun Ji
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), People's Republic of China
| | - Quan-Yu Zhao
- School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China
| | - He Huang
- School of Pharmaceutical Sciences, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing 211816, People's Republic of China; State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, No. 5 Xinmofan Road, Nanjing 210009, People's Republic of China; Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), People's Republic of China
| |
Collapse
|
138
|
Poliner E, Farré EM, Benning C. Advanced genetic tools enable synthetic biology in the oleaginous microalgae Nannochloropsis sp. PLANT CELL REPORTS 2018; 37:1383-1399. [PMID: 29511798 DOI: 10.1007/s00299-018-2270-0] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 02/26/2018] [Indexed: 05/16/2023]
Abstract
Nannochloropsis is a genus of fast-growing microalgae that are regularly used for biotechnology applications. Nannochloropsis species have a high triacylglycerol content and their polar lipids are rich in the omega-3 long-chain polyunsaturated fatty acid, eicosapentaenoic acid. Placed in the heterokont lineage, the Nannochloropsis genus has a complex evolutionary history. Genome sequences are available for several species, and a number of transcriptomic datasets have been produced, making this genus a facile model for comparative genomics. There is a growing interest in Nannochloropsis species as models for the study of microalga lipid metabolism and as a chassis for synthetic biology. Recently, techniques for gene stacking, and targeted gene disruption and repression in the Nannochloropsis genus have been developed. These tools enable gene-specific, mechanistic studies and have already allowed the engineering of improved Nannochloropsis strains with superior growth, or greater bioproduction.
Collapse
Affiliation(s)
- Eric Poliner
- Cell and Molecular Biology Program, Michigan State University, East Lansing, MI, USA
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Eva M Farré
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
| | - Christoph Benning
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA.
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA.
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA.
| |
Collapse
|
139
|
Xu Y, Caldo KMP, Pal-Nath D, Ozga J, Lemieux MJ, Weselake RJ, Chen G. Properties and Biotechnological Applications of Acyl-CoA:diacylglycerol Acyltransferase and Phospholipid:diacylglycerol Acyltransferase from Terrestrial Plants and Microalgae. Lipids 2018; 53:663-688. [PMID: 30252128 DOI: 10.1002/lipd.12081] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/23/2018] [Accepted: 07/24/2018] [Indexed: 12/14/2022]
Abstract
Triacylglycerol (TAG) is the major storage lipid in most terrestrial plants and microalgae, and has great nutritional and industrial value. Since the demand for vegetable oil is consistently increasing, numerous studies have been focused on improving the TAG content and modifying the fatty-acid compositions of plant seed oils. In addition, there is a strong research interest in establishing plant vegetative tissues and microalgae as platforms for lipid production. In higher plants and microalgae, TAG biosynthesis occurs via acyl-CoA-dependent or acyl-CoA-independent pathways. Diacylglycerol acyltransferase (DGAT) catalyzes the last and committed step in the acyl-CoA-dependent biosynthesis of TAG, which appears to represent a bottleneck in oil accumulation in some oilseed species. Membrane-bound and soluble forms of DGAT have been identified with very different amino-acid sequences and biochemical properties. Alternatively, TAG can be formed through acyl-CoA-independent pathways via the catalytic action of membrane-bound phospholipid:diacylglycerol acyltransferase (PDAT). As the enzymes catalyzing the terminal steps of TAG formation, DGAT and PDAT play crucial roles in determining the flux of carbon into seed TAG and thus have been considered as the key targets for engineering oil production. Here, we summarize the most recent knowledge on DGAT and PDAT in higher plants and microalgae, with the emphasis on their physiological roles, structural features, and regulation. The development of various metabolic engineering strategies to enhance the TAG content and alter the fatty-acid composition of TAG is also discussed.
Collapse
Affiliation(s)
- Yang Xu
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
| | - Kristian Mark P Caldo
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
- Department of Biochemistry, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2H7, Canada
| | - Dipasmita Pal-Nath
- French Associates Institute for Agriculture and Biotechnology of Drylands, The Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, Midreshet Ben-Gurion, 8499000, Israel
| | - Jocelyn Ozga
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2H7, Canada
| | - Randall J Weselake
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
| | - Guanqun Chen
- Department of Agricultural, Food and Nutritional Science, University of Alberta, 116 Street and 85 Avenue, Edmonton, Alberta, T6G 2P5, Canada
| |
Collapse
|
140
|
He Q, Yang Y, Yang S, Donohoe BS, Van Wychen S, Zhang M, Himmel ME, Knoshaug EP. Oleaginicity of the yeast strain Saccharomyces cerevisiae D5A. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:258. [PMID: 30258492 PMCID: PMC6151946 DOI: 10.1186/s13068-018-1256-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 09/10/2018] [Indexed: 05/28/2023]
Abstract
BACKGROUND The model yeast, Saccharomyces cerevisiae, is not known to be oleaginous. However, an industrial wild-type strain, D5A, was shown to accumulate over 20% storage lipids from glucose when growth is nitrogen-limited compared to no more than 7% lipid accumulation without nitrogen stress. METHODS AND RESULTS To elucidate the mechanisms of S. cerevisiae D5A oleaginicity, we compared physiological and metabolic changes; as well as the transcriptional profiles of the oleaginous industrial strain, D5A, and a non-oleaginous laboratory strain, BY4741, under normal and nitrogen-limited conditions using analytic techniques and next-generation sequencing-based RNA-Seq transcriptomics. Transcriptional levels for genes associated with fatty acid biosynthesis, nitrogen metabolism, amino acid catabolism, as well as the pentose phosphate pathway and ethanol oxidation in central carbon (C) metabolism, were up-regulated in D5A during nitrogen deprivation. Despite increased carbon flux to lipids, most gene-encoding enzymes involved in triacylglycerol (TAG) assembly were expressed at similar levels regardless of the varying nitrogen concentrations in the growth media and strain backgrounds. Phospholipid turnover also contributed to TAG accumulation through increased precursor production with the down-regulation of subsequent phospholipid synthesis steps. Our results also demonstrated that nitrogen assimilation via the glutamate-glutamine pathway and amino acid metabolism, as well as the fluxes of carbon and reductants from central C metabolism, are integral to the general oleaginicity of D5A, which resulted in the enhanced lipid storage during nitrogen deprivation. CONCLUSION This work demonstrated the disequilibrium and rebalance of carbon and nitrogen contribution to the accumulation of lipids in the oleaginous yeast S. cerevisiae D5A. Rather than TAG assembly from acyl groups, the major switches for the enhanced lipid accumulation of D5A (i.e., fatty acid biosynthesis) are the increases of cytosolic pools of acetyl-CoA and NADPH, as well as alternative nitrogen assimilation.
Collapse
Affiliation(s)
- Qiaoning He
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Yongfu Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, 430062 China
| | - Shihui Yang
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-resources, Environmental Microbial Technology Center of Hubei Province, Hubei Key Laboratory of Industrial Biotechnology, College of Life Sciences, Hubei University, Wuhan, 430062 China
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, 80401 USA
| | - Bryon S. Donohoe
- Biosciences Center, National Renewable Energy Laboratory, Golden, 80401 USA
| | | | - Min Zhang
- Biosciences Center, National Renewable Energy Laboratory, Golden, 80401 USA
| | - Michael E. Himmel
- Biosciences Center, National Renewable Energy Laboratory, Golden, 80401 USA
| | - Eric P. Knoshaug
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, 80401 USA
| |
Collapse
|
141
|
Sun XM, Ren LJ, Ji XJ, Huang H. Enhancing biomass and lipid accumulation in the microalgae Schizochytrium sp. by addition of fulvic acid and EDTA. AMB Express 2018; 8:150. [PMID: 30242564 PMCID: PMC6150865 DOI: 10.1186/s13568-018-0681-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 09/18/2018] [Indexed: 12/11/2022] Open
Abstract
Enhancing lipid productivity and reducing oxidative damage is essential for lipid overproduction in microalgae. In this study, addition of 20 mg/L fulvic acid (FA) resulted a 34.4% increase of lipid yield in Schizochytrium sp. Furthermore, the cooperative effect of FA and EDTA on cell growth and lipid production was investigated. The combined addition of 20 mg/L FA and 1.0 g/L EDTA yielded a maximal cell dry weight of 130.7 g/L and lipid productivity of 1.16 g/L/h, representing 36.4% and threefold increase over the non-supplemented group, respectively. Moreover, compared with the non-supplemented group, the combined addition strategy exhibited overall lower levels of reactive oxygen species and malondialdehyde, which accompanied with 66.7% and 81.9% higher superoxide dismutase and catalase activity, respectively. Furthermore, a 24.1–37.1% increase of malic enzyme and 19.4–25.2% decrease of phosphoenolpyruvate carboxylase activity was observed during the entire fermentation stage (0–108 h). Results suggested that the combined addition strategy not only enhanced lipid accumulation, but also prevented the lipid peroxidation.
Collapse
|
142
|
Liang Y, Liu Y, Tang J, Ma J, Cheng JJ, Daroch M. Transcriptomic Profiling and Gene Disruption Revealed that Two Genes Related to PUFAs/DHA Biosynthesis May be Essential for Cell Growth of Aurantiochytrium sp. Mar Drugs 2018; 16:md16090310. [PMID: 30200435 PMCID: PMC6164183 DOI: 10.3390/md16090310] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Revised: 08/20/2018] [Accepted: 08/29/2018] [Indexed: 12/25/2022] Open
Abstract
Aurantiochytrium sp. PKU#SW7 is a thraustochytrid strain that was found to exhibit high potential for docosahexaenoic acid (DHA, C22:6n-3) production. In this work, the transcriptome of Aurantiochytrium sp. PKU#SW7 was analyzed for the study of genes involved in basic metabolic functions and especially in the mechanisms of DHA biosynthesis. Sequence annotation and functional analysis revealed that the strain contains components of fatty acid synthesis (FAS) and polyketide synthase (PKS) pathways. Fatty acid desaturases and elongases were identified as components of FAS pathway, whilst key components of PKS pathway were also found in the cDNA library. The relative contribution of the two pathways to the synthesis of DHA was unknown, as both pathways appeared to be lacking full complement of genes for standalone synthesis of DHA. Further analysis of two putative genes encoding the very-long-chain (3R)-3-hydroxyacyl-CoA dehydratase and dehydrase/isomerase involved in FAS and PKS pathways, respectively, revealed that under various salinity conditions, their relative expression levels changed corresponding to the variation of DHA content in Aurantiochytrium sp. Independent knock outs of these genes in Aurantiochytrium sp. resulted in poor cell growth, probably due to little or no intracellular DHA accumulation. Hence, it can be speculated that both genes are engaged in DHA biosynthesis and DHA in Aurantiochytrium sp. could be produced by jointed actions of both FAS and PKS systems.
Collapse
Affiliation(s)
- Yuanmei Liang
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
| | - Ying Liu
- Guangdong Engineering Research Centre for Marine Algal Biotechnology, Shenzhen Key Laboratory of Marine Bioresource and Eco-environmental Science, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
| | - Jie Tang
- School of Pharmacy and Bioengineering, Chengdu University, Chengdu 610106, China.
| | - Jiong Ma
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
| | - Jay J Cheng
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
- Department of Biological and Agricultural Engineering, North Carolina State University, Raleigh, NC 27695, USA.
| | - Maurycy Daroch
- School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
| |
Collapse
|
143
|
Ryu KH, Sung M, Kim B, Heo S, Chang YK, Lee JH. A mathematical model of intracellular behavior of microalgae for predicting growth and intracellular components syntheses under nutrient‐replete and ‐deplete conditions. Biotechnol Bioeng 2018; 115:2441-2455. [DOI: 10.1002/bit.26744] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 05/13/2018] [Accepted: 06/05/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Kyung Hwan Ryu
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Min‐Gyu Sung
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Boeun Kim
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Seongmin Heo
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
- Advanced Biomass R&D Center, Korea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| | - Jay H. Lee
- Department of Chemical and Biomolecular EngineeringKorea Advanced Institute of Science and TechnologyDeajeon Republic of Korea
| |
Collapse
|
144
|
Xing G, Yuan H, Yang J, Li J, Gao Q, Li W, Wang E. Integrated analyses of transcriptome, proteome and fatty acid profilings of the oleaginous microalga Auxenochlorella protothecoides UTEX 2341 reveal differential reprogramming of fatty acid metabolism in response to low and high temperatures. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.04.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
145
|
Sturme MH, Gong Y, Heinrich JM, Klok AJ, Eggink G, Wang D, Xu J, Wijffels RH. Transcriptome analysis reveals the genetic foundation for the dynamics of starch and lipid production in Ettlia oleoabundans. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.05.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
|
146
|
Systems-level analysis of metabolic mechanism following nitrogen limitation in benthic dinoflagellate Prorocentrum lima. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.06.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
147
|
Wei L, Xu J. Optimized methods of chromatin immunoprecipitation for profiling histone modifications in industrial microalgae Nannochloropsis spp. JOURNAL OF PHYCOLOGY 2018; 54:358-367. [PMID: 29444334 DOI: 10.1111/jpy.12623] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 01/11/2018] [Indexed: 06/08/2023]
Abstract
Epigenetic factors such as histone modifications play integral roles in plant development and stress response, yet their implications in algae remain poorly understood. In the industrial oleaginous microalgae Nannochloropsis spp., the lack of an efficient methodology for chromatin immunoprecipitation (ChIP), which determines the specific genomic location of various histone modifications, has hindered probing the epigenetic basis of their photosynthetic carbon conversion and storage as oil. Here, a detailed ChIP protocol was developed for Nannochloropsis oceanica, which represents a reliable approach for the analysis of histone modifications, chromatin state, and transcription factor-binding sites at the epigenetic level. Using ChIP-qPCR, genes related to photosynthetic carbon fixation in this microalga were systematically assessed. Furthermore, a ChIP-Seq protocol was established and optimized, which generated a genome-wide profile of histone modification events, using histone mark H3K9Ac as an example. These results are the first step for appreciation of the chromatin landscape in industrial oleaginous microalgae and for epigenetics-based microalgal feedstock development.
Collapse
Affiliation(s)
- Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| |
Collapse
|
148
|
Murakami H, Nobusawa T, Hori K, Shimojima M, Ohta H. Betaine Lipid Is Crucial for Adapting to Low Temperature and Phosphate Deficiency in Nannochloropsis. PLANT PHYSIOLOGY 2018; 177:181-193. [PMID: 29555786 PMCID: PMC5933114 DOI: 10.1104/pp.17.01573] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 02/21/2018] [Indexed: 05/12/2023]
Abstract
Diacylglyceryl-N,N,N-trimethylhomo-Ser (DGTS) is a nonphosphorous, polar glycerolipid that is regarded as analogous to the phosphatidylcholine in bacteria, fungi, algae, and basal land plants. In some species of algae, including the stramenopile microalga Nannochloropsis oceanica, DGTS contains an abundance of eicosapentaenoic acid (EPA), which is relatively scarce in phosphatidylcholine, implying that DGTS has a unique physiological role. In this study, we addressed the role of DGTS in N. oceanica We identified two DGTS biosynthetic enzymes that have distinct domain configurations compared to previously identified DGTS synthases. Mutants lacking DGTS showed growth retardation under phosphate starvation, demonstrating a pivotal role for DGTS in the adaptation to this condition. Under normal conditions, DGTS deficiency led to an increase in the relative amount of monogalactosyldiacylglycerol, a major plastid membrane lipid with high EPA content, whereas excessive production of DGTS induced by gene overexpression led to a decrease in monogalactosyldiacylglycerol. Meanwhile, lipid analysis of partial phospholipid-deficient mutants revealed a role for phosphatidylcholine and phosphatidylethanolamine in EPA biosynthesis. These results suggest that DGTS and monogalactosyldiacylglycerol may constitute the two major pools of EPA in extraplastidic and plastidic membranes, partially competing to acquire EPA or its precursors derived from phospholipids. The mutant lacking DGTS also displayed impaired growth and a lower proportion of EPA in extraplastidic compartments at low temperatures. Our results indicate that DGTS is involved in the adaptation to low temperatures through a mechanism that is distinct from the DGTS-dependent adaptation to phosphate starvation in N. oceanica.
Collapse
Affiliation(s)
- Hiroki Murakami
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Takashi Nobusawa
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Koichi Hori
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Mie Shimojima
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Hiroyuki Ohta
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| |
Collapse
|
149
|
Molecular basis of autotrophic vs mixotrophic growth in Chlorella sorokiniana. Sci Rep 2018; 8:6465. [PMID: 29691462 PMCID: PMC5915390 DOI: 10.1038/s41598-018-24979-8] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 04/13/2018] [Indexed: 11/24/2022] Open
Abstract
In this work, we investigated the molecular basis of autotrophic vs. mixotrophic growth of Chlorella sorokiniana, one of the most productive microalgae species with high potential to produce biofuels, food and high value compounds. To increase biomass accumulation, photosynthetic microalgae are commonly cultivated in mixotrophic conditions, adding reduced carbon sources to the growth media. In the case of C. sorokiniana, the presence of acetate enhanced biomass, proteins, lipids and starch productivity when compared to autotrophic conditions. Despite decreased chlorophyll content, photosynthetic properties were essentially unaffected while differential gene expression profile revealed transcriptional regulation of several genes mainly involved in control of carbon flux. Interestingly, acetate assimilation caused upregulation of phosphoenolpyruvate carboxylase enzyme, enabling potential recovery of carbon atoms lost by acetate oxidation. The obtained results allowed to associate the increased productivity observed in mixotrophy in C. sorokiniana with a different gene regulation leading to a fine regulation of cell metabolism.
Collapse
|
150
|
Arora N, Pienkos PT, Pruthi V, Poluri KM, Guarnieri MT. Leveraging algal omics to reveal potential targets for augmenting TAG accumulation. Biotechnol Adv 2018; 36:1274-1292. [PMID: 29678388 DOI: 10.1016/j.biotechadv.2018.04.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 04/11/2018] [Accepted: 04/15/2018] [Indexed: 02/08/2023]
Abstract
Ongoing global efforts to commercialize microalgal biofuels have expedited the use of multi-omics techniques to gain insights into lipid biosynthetic pathways. Functional genomics analyses have recently been employed to complement existing sequence-level omics studies, shedding light on the dynamics of lipid synthesis and its interplay with other cellular metabolic pathways, thus revealing possible targets for metabolic engineering. Here, we review the current status of algal omics studies to reveal potential targets to augment TAG accumulation in various microalgae. This review specifically aims to examine and catalog systems level data related to stress-induced TAG accumulation in oleaginous microalgae and inform future metabolic engineering strategies to develop strains with enhanced bioproductivity, which could pave a path for sustainable green energy.
Collapse
Affiliation(s)
- Neha Arora
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand 247667, India
| | - Philip T Pienkos
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Vikas Pruthi
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand 247667, India
| | - Krishna Mohan Poluri
- Department of Biotechnology, Indian Institute of Technology Roorkee, Uttarakhand 247667, India
| | - Michael T Guarnieri
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO 80401, USA.
| |
Collapse
|