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Wang M, Ye X, Bi H, Shen Z. Microalgae biofuels: illuminating the path to a sustainable future amidst challenges and opportunities. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:10. [PMID: 38254224 PMCID: PMC10804497 DOI: 10.1186/s13068-024-02461-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 01/11/2024] [Indexed: 01/24/2024]
Abstract
The development of microalgal biofuels is of significant importance in advancing the energy transition, alleviating food pressure, preserving the natural environment, and addressing climate change. Numerous countries and regions across the globe have conducted extensive research and strategic planning on microalgal bioenergy, investing significant funds and manpower into this field. However, the microalgae biofuel industry has faced a downturn due to the constraints of high costs. In the past decade, with the development of new strains, technologies, and equipment, the feasibility of large-scale production of microalgae biofuel should be re-evaluated. Here, we have gathered research results from the past decade regarding microalgae biofuel production, providing insights into the opportunities and challenges faced by this industry from the perspectives of microalgae selection, modification, and cultivation. In this review, we suggest that highly adaptable microalgae are the preferred choice for large-scale biofuel production, especially strains that can utilize high concentrations of inorganic carbon sources and possess stress resistance. The use of omics technologies and genetic editing has greatly enhanced lipid accumulation in microalgae. However, the associated risks have constrained the feasibility of large-scale outdoor cultivation. Therefore, the relatively controllable cultivation method of photobioreactors (PBRs) has made it the mainstream approach for microalgae biofuel production. Moreover, adjusting the performance and parameters of PBRs can also enhance lipid accumulation in microalgae. In the future, given the relentless escalation in demand for sustainable energy sources, microalgae biofuels should be deemed a pivotal constituent of national energy planning, particularly in the case of China. The advancement of synthetic biology helps reduce the risks associated with genetically modified (GM) microalgae and enhances the economic viability of their biofuel production.
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Affiliation(s)
- Min Wang
- Institute of Agricultural Remote Sensing and Information, Heilongjiang Academy of Agricultural Sciences, Harbin, 150086, China.
| | - Xiaoxue Ye
- Sanya Research Institute of Chinese Academy of Tropical Agricultural Sciences, Sanya, 572025, China
| | - Hongwen Bi
- Institute of Agricultural Remote Sensing and Information, Heilongjiang Academy of Agricultural Sciences, Harbin, 150086, China
| | - Zhongbao Shen
- Grass and Science Institute of Heilongjiang Academy of Agricultural Sciences, Harbin, 150086, China.
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2
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Wang R, Miao X. Lipid turnover and SQUAMOSA promoter-binding proteins mediate variation in fatty acid desaturation under early nitrogen deprivation revealed by lipidomic and transcriptomic analyses in Chlorella pyrenoidosa. FRONTIERS IN PLANT SCIENCE 2022; 13:987354. [PMID: 36247620 PMCID: PMC9558234 DOI: 10.3389/fpls.2022.987354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 09/06/2022] [Indexed: 06/16/2023]
Abstract
Nitrogen deprivation induces variations in fatty acid desaturation in microalgae, which determines the performance of biodiesel and the nutritional value of bioproducts. However, the detailed scenario and the underlying regulatory mechanism remain unclear. In this study, we attempt to outline these scenario and mechanisms by performing biochemical, lipidomic, and transcriptomic analyses in Chlorella pyrenoidosa and functional characterization of transcription factors in Yarrowia lipolytica. We found that early nitrogen deprivation dramatically reduced fatty acid desaturation without increasing lipid content. The contents of palmitic acid (16:0) and oleic acid (18:1) dramatically increased to 2.14 and 2.87 times that of nitrogen repletion on the second day, respectively. Lipidomic analysis showed the transfer of polyunsaturated fatty acids from phospholipids and glycolipids to triacylglycerols, and an increase in lipid species with 16:0 or 18:1 under nitrogen deprivation conditions. Upregulated stearoyl-ACP desaturase and oleyl-ACP thioesterase promoted the synthesis of 18:1, but restricted acetyl-CoA supply revealed that it was the intensive lipid turnover instead of an attenuated Kennedy pathway that played an important role in the variation in fatty acid composition under early nitrogen deprivation. Finally, two differentially expressed SQUAMOSA promoter-binding proteins (SBPs) were heterologously expressed in Y. lipolytica, demonstrating their role in promoting the accumulation of total fatty acid and the reduction in fatty acid desaturation. These results revealed the crucial role of lipid turnover and SBPs in determining fatty acid desaturation under early nitrogen deprivation, opening new avenues for the metabolic engineering of fatty acid desaturation in microalgae.
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Affiliation(s)
- Rui Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai, China
- Biomass Energy Research Center, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaoling Miao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai, China
- Biomass Energy Research Center, Shanghai Jiao Tong University, Shanghai, China
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3
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Chen G, Harwood JL, Lemieux MJ, Stone SJ, Weselake RJ. Acyl-CoA:diacylglycerol acyltransferase: Properties, physiological roles, metabolic engineering and intentional control. Prog Lipid Res 2022; 88:101181. [PMID: 35820474 DOI: 10.1016/j.plipres.2022.101181] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 05/31/2022] [Accepted: 07/04/2022] [Indexed: 12/15/2022]
Abstract
Acyl-CoA:diacylglycerol acyltransferase (DGAT, EC 2.3.1.20) catalyzes the last reaction in the acyl-CoA-dependent biosynthesis of triacylglycerol (TAG). DGAT activity resides mainly in membrane-bound DGAT1 and DGAT2 in eukaryotes and bifunctional wax ester synthase-diacylglycerol acyltransferase (WSD) in bacteria, which are all membrane-bound proteins but exhibit no sequence homology to each other. Recent studies also identified other DGAT enzymes such as the soluble DGAT3 and diacylglycerol acetyltransferase (EaDAcT), as well as enzymes with DGAT activities including defective in cuticular ridges (DCR) and steryl and phytyl ester synthases (PESs). This review comprehensively discusses research advances on DGATs in prokaryotes and eukaryotes with a focus on their biochemical properties, physiological roles, and biotechnological and therapeutic applications. The review begins with a discussion of DGAT assay methods, followed by a systematic discussion of TAG biosynthesis and the properties and physiological role of DGATs. Thereafter, the review discusses the three-dimensional structure and insights into mechanism of action of human DGAT1, and the modeled DGAT1 from Brassica napus. The review then examines metabolic engineering strategies involving manipulation of DGAT, followed by a discussion of its therapeutic applications. DGAT in relation to improvement of livestock traits is also discussed along with DGATs in various other eukaryotic organisms.
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Affiliation(s)
- Guanqun Chen
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Membrane Protein Disease Research Group, Edmonton T6G 2H7, Canada
| | - Scot J Stone
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| | - Randall J Weselake
- Department of Agricultural, Food, and Nutritional Science, University of Alberta, Edmonton, Alberta T6H 2P5, Canada
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Grama SB, Liu Z, Li J. Emerging Trends in Genetic Engineering of Microalgae for Commercial Applications. Mar Drugs 2022; 20:285. [PMID: 35621936 PMCID: PMC9143385 DOI: 10.3390/md20050285] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/15/2022] [Accepted: 04/19/2022] [Indexed: 02/04/2023] Open
Abstract
Recently, microalgal biotechnology has received increasing interests in producing valuable, sustainable and environmentally friendly bioproducts. The development of economically viable production processes entails resolving certain limitations of microalgal biotechnology, and fast evolving genetic engineering technologies have emerged as new tools to overcome these limitations. This review provides a synopsis of recent progress, current trends and emerging approaches of genetic engineering of microalgae for commercial applications, including production of pharmaceutical protein, lipid, carotenoids and biohydrogen, etc. Photochemistry improvement in microalgae and CO2 sequestration by microalgae via genetic engineering were also discussed since these subjects are closely entangled with commercial production of the above mentioned products. Although genetic engineering of microalgae is proved to be very effective in boosting performance of production in laboratory conditions, only limited success was achieved to be applicable to industry so far. With genetic engineering technologies advancing rapidly and intensive investigations going on, more bioproducts are expected to be produced by genetically modified microalgae and even much more to be prospected.
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Affiliation(s)
- Samir B. Grama
- Laboratory of Natural Substances, Biomolecules and Biotechnological Applications, University of Oum El Bouaghi, Oum El Bouaghi 04000, Algeria;
| | - Zhiyuan Liu
- College of Marine Sciences, Hainan University, Haikou 570228, China;
| | - Jian Li
- College of Agricultural Sciences, Panzhihua University, Panzhihua 617000, China
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Kang NK, Baek K, Koh HG, Atkinson CA, Ort DR, Jin YS. Microalgal metabolic engineering strategies for the production of fuels and chemicals. BIORESOURCE TECHNOLOGY 2022; 345:126529. [PMID: 34896527 DOI: 10.1016/j.biortech.2021.126529] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 06/14/2023]
Abstract
Microalgae are promising sustainable resources because of their ability to convert CO2 into biofuels and chemicals directly. However, the industrial production and economic feasibility of microalgal bioproducts are still limited. As such, metabolic engineering approaches have been undertaken to enhance the productivities of microalgal bioproducts. In the last decade, impressive advances in microalgae metabolic engineering have been made by developing genetic engineering tools and multi-omics analysis. This review presents comprehensive microalgal metabolic pathways and metabolic engineering strategies for producing lipids, long chain-polyunsaturated fatty acids, terpenoids, and carotenoids. Additionally, promising metabolic engineering approaches specific to target products are summarized. Finally, this review discusses current challenges and provides future perspectives for the effective production of chemicals and fuels via microalgal metabolic engineering.
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Affiliation(s)
- Nam Kyu Kang
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Kwangryul Baek
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Hyun Gi Koh
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Christine Anne Atkinson
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Donald R Ort
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Global Change and Photosynthesis Research Unit, Agricultural Research Service, United States Department of Agriculture, Urbana, IL, USA; Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Plant Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Yong-Su Jin
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA; DOE Center for Advanced Bioenergy and Bioproducts Innovation, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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6
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Metabolic engineering of the oleaginous alga Nannochloropsis for enriching eicosapentaenoic acid in triacylglycerol by combined pulling and pushing strategies. Metab Eng 2021; 69:163-174. [PMID: 34864212 DOI: 10.1016/j.ymben.2021.11.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 11/20/2021] [Accepted: 11/30/2021] [Indexed: 11/23/2022]
Abstract
The marine alga Nannochloropsis oceanica has been considered as a promising photosynthetic cell factory for synthesizing eicosapentaenoic acid (EPA), yet the accumulation of EPA in triacylglycerol (TAG) is restricted to an extreme low level. Poor channeling of EPA to TAG was observed in N. oceanica under TAG induction conditions, likely due to the weak activity of endogenous diacylglycerol acyltransferases (DGATs) on EPA-CoA. Screening over thirty algal DGATs revealed potent enzymes acting on EPA-CoA. Whilst overexpressing endogenous DGATs had no or slight effect on EPA abundance in TAG, introducing selected DGATs with strong activity on EPA-CoA, particularly the Chlamydomonas-derived CrDGTT1, which resided at the outermost membrane of the chloroplast and provided a strong pulling power to divert EPA to TAG for storage and protection, led to drastic increases in EPA abundance in TAG and TAG-derived EPA level in N. oceanica. They were further promoted by additional overexpression of an elongase gene involved in EPA biosynthesis, reaching 5.9- and 12.3-fold greater than the control strain, respectively. Our results together demonstrate the concept of applying combined pulling and pushing strategies to enrich EPA in algal TAG and provide clues for the enrichment of other desired fatty acids in TAG as well.
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7
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Genetic engineering of microalgae for enhanced lipid production. Biotechnol Adv 2021; 52:107836. [PMID: 34534633 DOI: 10.1016/j.biotechadv.2021.107836] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 09/09/2021] [Accepted: 09/09/2021] [Indexed: 12/24/2022]
Abstract
Microalgae have the potential to become microbial cell factories for lipid production. Their ability to convert sunlight and CO2 into valuable lipid compounds has attracted interest from cosmetic, biofuel, food and feed industries. In order to make microalgae-derived products cost-effective and commercially competitive, enhanced growth rates and lipid productivities are needed, which require optimization of cultivation systems and strain improvement. Advances in genetic tool development and omics technologies have increased our understanding of lipid metabolism, which has opened up possibilities for targeted metabolic engineering. In this review we provide a comprehensive overview on the developments made to genetically engineer microalgal strains over the last 30 years. We focus on the strategies that lead to an increased lipid content and altered fatty acid profile. These include the genetic engineering of the fatty acid synthesis pathway, Kennedy pathway, polyunsaturated fatty acid and triacylglycerol metabolisms and fatty acid catabolism. Moreover, genetic engineering of specific transcription factors, NADPH generation and central carbon metabolism, which lead to increase of lipid accumulation are also reviewed.
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8
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Pancha I, Takaya K, Tanaka K, Imamura S. The Unicellular Red Alga Cyanidioschyzon merolae, an Excellent Model Organism for Elucidating Fundamental Molecular Mechanisms and Their Applications in Biofuel Production. PLANTS 2021; 10:plants10061218. [PMID: 34203949 PMCID: PMC8232737 DOI: 10.3390/plants10061218] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/11/2021] [Accepted: 06/11/2021] [Indexed: 11/16/2022]
Abstract
Microalgae are considered one of the best resources for the production of biofuels and industrially important compounds. Various models have been developed to understand the fundamental mechanism underlying the accumulation of triacylglycerols (TAGs)/starch and to enhance its content in cells. Among various algae, the red alga Cyanidioschyzonmerolae has been considered an excellent model system to understand the fundamental mechanisms behind the accumulation of TAG/starch in the microalga, as it has a smaller genome size and various biotechnological methods are available for it. Furthermore, C. merolae can grow and survive under high temperature (40 °C) and low pH (2–3) conditions, where most other organisms would die, thus making it a choice alga for large-scale production. Investigations using this alga has revealed that the target of rapamycin (TOR) kinase is involved in the accumulation of carbon-reserved molecules, TAGs, and starch. Furthermore, detailed molecular mechanisms of the role of TOR in controlling the accumulation of TAGs and starch were uncovered via omics analyses. Based on these findings, genetic engineering of the key gene and proteins resulted in a drastic increment of the amount of TAGs and starch. In addition to these studies, other trials that attempted to achieve the TAG increment in C. merolae have been summarized in this article.
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Affiliation(s)
- Imran Pancha
- Department of Biological Sciences, SRM University-AP, Amaravati, Andhra Pradesh 522502, India
- Correspondence: (I.P.); (S.I.); Tel.: +81-422-59-6179 (S.I.)
| | - Kazuhiro Takaya
- NTT Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, 3-9-11 Midori-cho, Musashino-shi, Tokyo 180-8585, Japan;
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259-R1-29 Nagatsuta, Midori-ku, Yokohama-shi, Kanagawa 226-8503, Japan;
| | - Sousuke Imamura
- NTT Space Environment and Energy Laboratories, Nippon Telegraph and Telephone Corporation, 3-9-11 Midori-cho, Musashino-shi, Tokyo 180-8585, Japan;
- Correspondence: (I.P.); (S.I.); Tel.: +81-422-59-6179 (S.I.)
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9
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Zhang Y, Ye Y, Bai F, Liu J. The oleaginous astaxanthin-producing alga Chromochloris zofingiensis: potential from production to an emerging model for studying lipid metabolism and carotenogenesis. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:119. [PMID: 33992124 PMCID: PMC8126118 DOI: 10.1186/s13068-021-01969-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 05/07/2021] [Indexed: 05/05/2023]
Abstract
The algal lipids-based biodiesel, albeit having advantages over plant oils, still remains high in the production cost. Co-production of value-added products with lipids has the potential to add benefits and is thus believed to be a promising strategy to improve the production economics of algal biodiesel. Chromochloris zofingiensis, a unicellular green alga, has been considered as a promising feedstock for biodiesel production because of its robust growth and ability of accumulating high levels of triacylglycerol under multiple trophic conditions. This alga is also able to synthesize high-value keto-carotenoids and has been cited as a candidate producer of astaxanthin, the strongest antioxidant found in nature. The concurrent accumulation of triacylglycerol and astaxanthin enables C. zofingiensis an ideal cell factory for integrated production of the two compounds and has potential to improve algae-based production economics. Furthermore, with the advent of chromosome-level whole genome sequence and genetic tools, C. zofingiensis becomes an emerging model for studying lipid metabolism and carotenogenesis. In this review, we summarize recent progress on the production of triacylglycerol and astaxanthin by C. zofingiensis. We also update our understanding in the distinctive molecular mechanisms underlying lipid metabolism and carotenogenesis, with an emphasis on triacylglycerol and astaxanthin biosynthesis and crosstalk between the two pathways. Furthermore, strategies for trait improvements are discussed regarding triacylglycerol and astaxanthin synthesis in C. zofingiensis.
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Affiliation(s)
- Yu Zhang
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Ying Ye
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Fan Bai
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China
| | - Jin Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing, 100871, China.
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Identification of Transcription Factors and the Regulatory Genes Involved in Triacylglycerol Accumulation in the Unicellular Red Alga Cyanidioschyzon merolae. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10050971. [PMID: 34068121 PMCID: PMC8152781 DOI: 10.3390/plants10050971] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 05/10/2021] [Accepted: 05/10/2021] [Indexed: 12/30/2022]
Abstract
Microalgal triacylglycerols (TAGs) are a good feedstock for liquid biofuel production. Improving the expression and/or function of transcription factors (TFs) involved in TAG accumulation may increase TAG content; however, information on microalgae is still lacking. In this study, 14 TFs in the unicellular red alga Cyanidioschyzon merolae were identified as candidate TFs regulating TAG accumulation using available transcriptome and phosphoproteome data under conditions driving TAG accumulation. To investigate the roles of these TFs, we constructed TF-overexpression strains and analyzed lipid droplet (LD) formation and TAG contents in the cells grown under standard conditions. Based on the results, we identified four TFs involved in LD and TAG accumulation. RNA-Seq analyses were performed to identify genes regulated by the four TFs using each overexpression strain. Among the TAG biosynthesis-related genes, only the gene encoding the endoplasmic reticulum-localized lysophosphatidic acid acyltransferase 1 (LPAT1) was notably increased among the overexpression strains. In the LPAT1 overexpression strain, TAG accumulation was significantly increased compared with the control strain under normal growth conditions. These results indicate that the four TFs positively regulate TAG accumulation by changing their target gene expression in C. merolae.
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Chakdar H, Hasan M, Pabbi S, Nevalainen H, Shukla P. High-throughput proteomics and metabolomic studies guide re-engineering of metabolic pathways in eukaryotic microalgae: A review. BIORESOURCE TECHNOLOGY 2021; 321:124495. [PMID: 33307484 DOI: 10.1016/j.biortech.2020.124495] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 11/24/2020] [Accepted: 11/28/2020] [Indexed: 06/12/2023]
Abstract
Eukaryotic microalgae are a rich source of commercially important metabolites including lipids, pigments, sugars, amino acids and enzymes. However, their inherent genetic potential is usually not enough to support high level production of metabolites of interest. In order to move on from the traditional approach of improving product yields by modification of the cultivation conditions, understanding the metabolic pathways leading to the synthesis of the bioproducts of interest is crucial. Identification of new targets for strain engineering has been greatly facilitated by the rapid development of high-throughput sequencing and spectroscopic techniques discussed in this review. Despite the availability of high throughput analytical tools, examples of gathering and application of proteomic and metabolomic data for metabolic engineering of microalgae are few and mainly limited to lipid production. The present review highlights the application of contemporary proteomic and metabolomic techniques in eukaryotic microalgae for redesigning pathways for enhanced production of algal metabolites.
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Affiliation(s)
- Hillol Chakdar
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Maunath Bhanjan, Uttar Pradesh 275103, India
| | - Mafruha Hasan
- School of Life and Environmental Sciences, University of Sydney, NSW 2006, Australia
| | - Sunil Pabbi
- Centre for Conservation and Utilisation of Blue Green Algae (CCUBGA), Division of Microbiology, ICAR - Indian Agricultural Research Institute, New Delhi 110 012
| | - Helena Nevalainen
- Department of Molecular Sciences, Macquarie University, NSW 2109, Australia; Biomolecular Discovery and Design Research Centre, Macquarie University, Sydney, NSW 2109, Australia
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University, Rohtak 124001, Haryana, India; School of Biotechnology, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
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12
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Cui H, Xu W, Zhu X, Zhao C, Cui Y, Ji C, Zhang C, Xue J, Qin S, Jia X, Li R. Characterization of a Haematococcus pluvialis Diacylglycerol Acyltransferase 1 and Its Potential in Unsaturated Fatty Acid-Rich Triacylglycerol Production. FRONTIERS IN PLANT SCIENCE 2021; 12:771300. [PMID: 34950166 PMCID: PMC8688921 DOI: 10.3389/fpls.2021.771300] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 11/08/2021] [Indexed: 05/17/2023]
Abstract
The unicellular green alga Haematococcus pluvialis has been recognized as an industry strain to produce simultaneously esterified astaxanthin (EAST) and triacylglycerol (TAG) under stress induction. It is necessary to identify the key enzymes involving in synergistic accumulation of EAST and TAG in H. pluvialis. In this study, a novel diacylglycerol acyltransferase 1 was systematically characterized by in vivo and in silico assays. The upregulated expression of HpDGAT1 gene was positively associated with the significant increase of TAG and EAST contents under stress conditions. Functional complementation by overexpressing HpDGAT1 in a TAG-deficient yeast strain H1246 revealed that HpDGAT1 could restore TAG biosynthesis and exhibited a high substrate preference for monounsaturated fatty acyl-CoAs (MUFAs) and polyunsaturated fatty acyl-CoAs (PUFAs). Notably, heterogeneous expression of HpDGAT1 in Chlamydomonas reinhardtii and Arabidopsis thaliana resulted in a significant enhancement of total oils and concurrently a high accumulation of MUFAs- and PUFAs-rich TAGs. Furthermore, molecular docking analysis indicated that HpDGAT1 contained AST-binding sites. These findings evidence a possible dual-function role for HpDGAT1 involving in TAG and EAST synthesis, demonstrating that it is a potential target gene to enrich AST accumulation in this alga and to design oil production in both commercial algae and oil crops.
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Affiliation(s)
- Hongli Cui
- College of Agriculture, Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, China
| | - Wenxin Xu
- College of Agriculture, Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, China
| | - Xiaoli Zhu
- College of Plant Protection, Shanxi Agricultural University, Taigu, China
| | - Chunchao Zhao
- College of Agriculture, Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, China
| | - Yulin Cui
- Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Chunli Ji
- College of Agriculture, Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, China
| | - Chunhui Zhang
- College of Agriculture, Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, China
| | - Jinai Xue
- College of Agriculture, Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, China
| | - Song Qin
- Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, China
| | - Xiaoyun Jia
- College of Life Sciences, Shanxi Agricultural University, Taigu, China
| | - Runzhi Li
- College of Agriculture, Institute of Molecular Agriculture and Bioenergy, Shanxi Agricultural University, Taigu, China
- *Correspondence: Runzhi Li,
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Shaikh KM, Kumar P, Nesamma AA, Abdin MZ, Jutur PP. Hybrid genome assembly and functional annotation reveals insights on lipid biosynthesis of oleaginous native isolate Parachlorella kessleri, a potential industrial strain for production of biofuel precursors. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.102118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Chungjatupornchai W, Fa-Aroonsawat S. Enhanced triacylglycerol production in oleaginous microalga Neochloris oleoabundans by co-overexpression of lipogenic genes: Plastidial LPAAT1 and ER-located DGAT2. J Biosci Bioeng 2020; 131:124-130. [PMID: 33069576 DOI: 10.1016/j.jbiosc.2020.09.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/18/2020] [Accepted: 09/18/2020] [Indexed: 12/29/2022]
Abstract
Microalgae accumulate lipid triacylglycerol (TAG), a promising feedstock for production of natural edible oils and biofuels. To make products derived from microalgal TAG economically viable, increasing TAG content and productivity are of high importance. To increase TAG content, two endogenous key enzymes of TAG biosynthesis: plastidial lysophosphatidic acid acyltransferase (NeoLPAAT1) and endoplasmic reticulum-located diacylglycerol acyltransferase 2 (NeoDGAT2) were co-overexpressed in oleaginous microalga Neochloris oleoabundans. The neutral lipid content in NeoLPAAT1-NeoDGAT2 co-overexpressing transformant detected by Nile red staining increased 2-fold without compromising cell growth. The transcriptional levels of NeoLPAAT1 and NeoDGAT2 levels were 1.9-fold higher in the transformant than wild type. Considerably higher lipid accumulation was found in the transformant than wild type: total lipid content (73.72 ± 4.17 % DCW) increased 1.6-fold, TAG content (50.63 ± 6.15 % DCW) increased 2.1-fold, total lipid productivity (16.84 ± 0.66 mg/L/day) increased 1.9-fold, and TAG productivity (11.68 ± 0.90 mg/L/day) increased 2.1-fold. Fatty acid composition was slightly altered in the transformant compared to wild type; saturated fatty acid C16:0 increased to 26% from 20%, whereas C18:0 was reduced to 7% from 14%. Long-term stability of NeoLPAAT1-NeoDGAT2 co-overexpression was observed in the transformant continuously maintained on solid medium in a period of 4 years. The results suggested that targeted engineering of genes in pathway located at different organelles should be possible in microalgal lipid metabolism.
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Affiliation(s)
- Wipa Chungjatupornchai
- Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakhon Pathom 73170, Thailand.
| | - Sirirat Fa-Aroonsawat
- Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Nakhon Pathom 73170, Thailand.
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Yan C, Guo H, Ding Q, Shao Y, Kang D, Yu T, Li C, Huang H, Du Y, Wang H, Hu K, Xie L, Wang G, Liang Y. Multiomics Profiling Reveals Protective Function of Schisandra Lignans against Acetaminophen-Induced Hepatotoxicity. Drug Metab Dispos 2020; 48:1092-1103. [PMID: 32719086 DOI: 10.1124/dmd.120.000083] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/30/2020] [Indexed: 12/13/2022] Open
Abstract
The action principles of traditional Chinese medicines (TCMs) feature multiactive components, multitarget sites, and weak combination with action targets. In the present study, we performed an integrated analysis of metabonomics, proteomics, and lipidomics to establish a scientific research system on the underlying mechanism of TCMs, and Schisandra lignan extract (SLE) was selected as a model TCM. In metabonomics, several metabolic pathways were found to mediate the liver injury induced by acetaminophen (APAP), and SLE could regulate the disorder of lipid metabolism. The proteomic study further proved that the hepatoprotective effect of SLE was closely related to the regulation of lipid metabolism. Indeed, the results of lipidomics demonstrated that SLE dosing has an obvious callback effect on APAP-induced lipidic profile shift. The contents of 25 diglycerides (DAGs) and 21 triglycerides (TAGs) were enhanced significantly by APAP-induced liver injury, which could further induce liver injury and inflammatory response by upregulating protein kinase C (PKCβ, PKCγ, PKCδ, and PKCθ). The upregulated lipids and PKCs could be reversed to the normal level by SLE dosing. More importantly, phosphatidic acid phosphatase, fatty acid transport protein 5, and diacylglycerol acyltransferase 2 were proved to be positively associated with the regulation of DAGs and TAGs. SIGNIFICANCE STATEMENT: Integrated multiomics was first used to reveal the mechanism of APAP-induced acute liver failure (ALF) and the hepatoprotective role of SLE. The results showed that the ALF caused by APAP was closely related to lipid regulation and that SLE dosing could exert a hepatoprotective role by reducing intrahepatic diglyceride and triglyceride levels. Our research can not only promote the application of multicomponent technology in the study of the mechanism of traditional Chinese medicines but also provide an effective approach for the prevention and treatment of ALF.
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Affiliation(s)
- Caixia Yan
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Huimin Guo
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Qingqing Ding
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Yuhao Shao
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Dian Kang
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Tengjie Yu
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Changjian Li
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Haoran Huang
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Yisha Du
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - He Wang
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Kangrui Hu
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Lin Xie
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Guangji Wang
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
| | - Yan Liang
- Key Laboratory of Drug Metabolism & Pharmacokinetics, State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, P.R. China (C.Y., H.G., Y.S., D.K., T.Y., C.L., H.H., Y.D., H.W., K.H., L.X., G.W., Y.L.) and Department of Geriatric Oncology, First Affiliated Hospital of Nanjing Medical University (Jiangsu People's Hospital), Nanjing, P.R. China (Q.D.)
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16
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Khan S, Fu P. Biotechnological perspectives on algae: a viable option for next generation biofuels. Curr Opin Biotechnol 2020; 62:146-152. [DOI: 10.1016/j.copbio.2019.09.020] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/23/2019] [Accepted: 09/25/2019] [Indexed: 10/25/2022]
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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.
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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.
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18
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Sun XM, Ren LJ, Zhao QY, Ji XJ, Huang H. Enhancement of lipid accumulation in microalgae by metabolic engineering. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:552-566. [DOI: 10.1016/j.bbalip.2018.10.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/30/2018] [Accepted: 10/05/2018] [Indexed: 01/08/2023]
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19
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Chungjatupornchai W, Areerat K, Fa-Aroonsawat S. Increased triacylglycerol production in oleaginous microalga Neochloris oleoabundans by overexpression of plastidial lysophosphatidic acid acyltransferase. Microb Cell Fact 2019; 18:53. [PMID: 30866936 PMCID: PMC6415348 DOI: 10.1186/s12934-019-1104-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 03/08/2019] [Indexed: 11/17/2022] Open
Abstract
Background Microalgae are promising sources of lipid triacylglycerol (TAG) for sustainable production of natural edible oils and biofuels. Nevertheless, products derived from microalgal TAG are not yet economically feasible; increasing TAG content via targeted genetic engineering of genes in TAG biosynthesis pathway are important to achieve economic viability. To increase TAG content, oleaginous microalga Neochloris oleoabundans was genetically engineered with the endogenous enzyme lysophosphatidic acid acyltransferase (NeoLPAAT1) responsible for plastidial TAG biosynthesis Results NeoLPAAT1 was found to contain all canonical motifs attributed to LPAAT proteins, two hypothetical membrane-spanning domains and a putative chloroplast transit peptide, indicating as a member of plastidial LPAAT type 1 subfamily. The NeoLPAAT1-expression cassette integrated in N. oleoabundans transformant was confirmed by PCR. The neutral lipid content in the transformant detected by Nile red staining was 1.6-fold higher than in wild type. The NeoLPAAT1 transcript was twofold higher in the transformant than wild type. Considerably higher lipid quantity was found in the transformant than wild type: total lipid content increased 1.8- to 1.9-fold up to 78.99 ± 1.75% dry cell weight (DCW) and total lipid productivity increased 1.8- to 2.4-fold up to 16.06 ± 2.68 mg/L/day; while TAG content increased 2.1- to 2.2-fold up to 55.40 ± 5.56% DCW and TAG productivity increased 1.9- to 2.8-fold up to 10.67 ± 2.37 mg/L/day. A slightly altered fatty acid composition was detected in the transformant compared to wild type; polyunsaturated fatty acid (C18:2) increased to 19% from 11%. NeoLPAAT1-overexpression stability was observed in the transformant continuously maintained in solid medium over 150 generations in a period of about 6 years. Conclusions Our results demonstrate the considerably increased TAG content and productivity in N. oleoabundans by overexpression of plastidial NeoLPAAT1 that are important for products derived from microalgal TAG to achieve economic viability. Plastidial LPAAT1 can be a candidate for target genetic manipulation to increase TAG content in other microalgal species with desired characteristics for production of natural edible oils and biofuels.
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Affiliation(s)
- Wipa Chungjatupornchai
- Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Phutthamonthon, Nakhon Pathom, 73170, Thailand.
| | - Kanchanaporn Areerat
- Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Phutthamonthon, Nakhon Pathom, 73170, Thailand
| | - Sirirat Fa-Aroonsawat
- Institute of Molecular Biosciences, Mahidol University, Salaya Campus, Phutthamonthon, Nakhon Pathom, 73170, Thailand
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20
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Bt Md Nasir NAN, Islam AKMA, Anuar N, Yaakob Z. Genetic Improvement and Challenges for Cultivation of Microalgae for Biodiesel: A Review. MINI-REV ORG CHEM 2019. [DOI: 10.2174/1570193x15666180627115502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Microalgae are a viable alternative for biofuel production to replace the world dependency on
fossil fuel. It has a wide range of application for the sustainable production of biomaterials. Microalgae
can convert solar energy into important natural components by utilizing marginal nutrients, wastewater
and exhaust CO2 without sharing expensive crop field. Microalgae also have the potentiality to generate
several promising components such as Polyunsaturated Fatty Acids (PUFAs), organic pigments and
pharmaceutically important hydrocarbons. Cultivation and production of microalgae biomass have multifaceted
challenges due to the requirement of large volume of water for the algae growth, high processing
cost and contamination by pathogens. Genetic improvement and modifications are essential to
construct superior microalgae for manufacturing industries using various methods such as selection of
novel strain, stress tolerance, resistance to pathogens, product development and metabolic pathways and
cellular contents. In addition, technologies related to cultivation, harvesting, extraction and processing
are essential to develop for the growth of novel microalgae strains.
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Affiliation(s)
- Nor-Anis N. Bt Md Nasir
- Department of Plant Science, Kulliyyah of Science, International Islamic University Malaysia, Kuantan Kampus, 25710, Kuantan, Pahang Darul Makmur, Malaysia
| | - A. K. M. Aminul Islam
- Department of Genetics and Plant Breeding, Faculty of Agriculture, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur 1706, Bangladesh
| | - Nurina Anuar
- Department of Chemical and Process Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia (UKM), Bangi, Selangor, 43600, Malaysia
| | - Zahira Yaakob
- Department of Chemical and Process Engineering, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia (UKM), Bangi, Selangor, 43600, Malaysia
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21
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Yang F, Xiang W, Li T, Long L. Transcriptome analysis for phosphorus starvation-induced lipid accumulation in Scenedesmus sp. Sci Rep 2018; 8:16420. [PMID: 30401886 PMCID: PMC6219579 DOI: 10.1038/s41598-018-34650-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/15/2018] [Indexed: 12/31/2022] Open
Abstract
Phosphorus stress was applied to enhance the lipid production in Scenedesmus sp. The highest lipid production (350 mg L−1) and lipid content (approximately 41.0% of dry weight) were obtained by addition of 2 mg L−1 NaH2PO4·2H2O every 2 days, which were higher than those in replete phosphorus. Correspondingly, carbohydrate content decreased significantly. We speculated that phosphorus limitation could block starch biosynthesis, and photosynthate flow tended to fatty acid biosynthesis to cope with stress. To investigate the mechanism that phosphorus stress triggers the carbon fixation to lipid biosynthesis, the transcriptome analysis was carried out by the Illumina RNA-seq platform. A total of 2897 genes were identified as differentially expressed genes. The observed overexpression of lipid production under phosphorus stress was bolstered by up-regulation of genes encoding for DGAT and pyruvate kinase, activation of carbohydrate metabolism pathway and fatty acid biosynthesis, and repression of carbohydrate synthesis-presumably to shunt the carbon flux toward TAG biosynthesis. The transcriptome will be useful to understand the lipid metabolism pathway and obtain the engineering economic algae species aimed at biodiesel production.
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Affiliation(s)
- Fangfang Yang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Wenzhou Xiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Tao Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Lijuan Long
- Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
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22
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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.
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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
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Accelerated triacylglycerol production without growth inhibition by overexpression of a glycerol-3-phosphate acyltransferase in the unicellular red alga Cyanidioschyzon merolae. Sci Rep 2018; 8:12410. [PMID: 30120352 PMCID: PMC6098107 DOI: 10.1038/s41598-018-30809-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Accepted: 08/04/2018] [Indexed: 12/14/2022] Open
Abstract
Microalgae accumulate triacylglycerols (TAGs), a promising feedstock for biodiesel production, under unfavorable environmental or stress conditions for their growth. Our previous analyses revealed that only transcripts of CmGPAT1 and CmGPAT2, both encoding glycerol-3-phosphate acyltransferase, were increased among fatty acid and TAG synthesis genes under TAG accumulation conditions in the red alga Cyanidioschyzon merolae. In this study, to investigate the role of these proteins in TAG accumulation in C. merolae, we constructed FLAG-fused CmGPAT1 and CmGPAT2 overexpression strains. We found that CmGPAT1 overexpression resulted in marked accumulation of TAG even under normal growth conditions, with the maximum TAG productivity increased 56.1-fold compared with the control strain, without a negative impact on algal growth. The relative fatty acid composition of 18:2 in the TAGs and the sn-1/sn-3 positions were significantly increased compared with the control strain, suggesting that CmGPAT1 had a substrate preference for 18:2. Immunoblot analysis after cell fractionation and immunostaining analysis demonstrated that CmGPAT1 localizes in the endoplasmic reticulum (ER). These results indicate that the reaction catalyzed by the ER-localized CmGPAT1 is a rate-limiting step for TAG synthesis in C. merolae, and would be a potential target for improvement of TAG productivity in microalgae.
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Metabolic engineering using iterative self-cloning to improve lipid productivity in Coccomyxa. Sci Rep 2018; 8:11742. [PMID: 30082815 PMCID: PMC6078956 DOI: 10.1038/s41598-018-30254-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 07/26/2018] [Indexed: 12/17/2022] Open
Abstract
We previously developed a self-cloning system that introduces cDNA of the uridine monophosphate synthase gene (cUMPS) of Coccomyxa sp. strain Obi as a selectable marker into uracil-auxotrophic mutants (Ura−) of the same alga. Here, we developed a Cre/loxP-based system for the removal of cUMPS flanked by directly repeated loxP sites from the Coccomyxa genome using the intracellular delivery of purified Cre recombinase to generate an Ura− strain that was used as a host for second-round transformation using cUMPS as the selection marker. Employing this marker–gene-recycling system, Coccomyxa strains devoid of foreign DNA except the 34-bp loxP sequence, which overexpressed an acyl-(acyl-carrier-protein) thioesterase gene, and a type-2 diacylglycerol acyltransferase gene, were constructed by the sequential introduction of two expression cassettes for the respective genes. One of the resulting strains showed 1.4-fold higher lipid productivity than the wild-type strain. This method will be applicable to other eukaryotic microalgae to create marker-free transgenic strains.
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Hoyer J, Cotta F, Diete A, Großmann J. Bioenergy from Microalgae - Vision or Reality? CHEMBIOENG REVIEWS 2018. [DOI: 10.1002/cben.201800007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Jan Hoyer
- GICON - Großmann Ingenieur Consult GmbH; Tiergartenstrasse 48 01219 Dresden Germany
| | - Fritz Cotta
- GICON - Großmann Ingenieur Consult GmbH; Tiergartenstrasse 48 01219 Dresden Germany
| | - Anja Diete
- GICON - Großmann Ingenieur Consult GmbH; Tiergartenstrasse 48 01219 Dresden Germany
| | - Jochen Großmann
- GICON - Großmann Ingenieur Consult GmbH; Tiergartenstrasse 48 01219 Dresden Germany
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Hoyer J, Cotta F, Diete A, Großmann J. Bioenergie aus Mikroalgen - Vision oder Wirklichkeit? CHEM-ING-TECH 2017. [DOI: 10.1002/cite.201700085] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Jan Hoyer
- GICON - Großmann Ingenieur Consult GmbH; Greppiner Straße 6 06766 Bitterfeld-Wolfen Deutschland
| | - Fritz Cotta
- GICON - Großmann Ingenieur Consult GmbH; Greppiner Straße 6 06766 Bitterfeld-Wolfen Deutschland
| | - Anja Diete
- GICON - Großmann Ingenieur Consult GmbH; Greppiner Straße 6 06766 Bitterfeld-Wolfen Deutschland
| | - Jochen Großmann
- GICON - Großmann Ingenieur Consult GmbH; Tiergartenstraße 48 01219 Dresden Deutschland
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Xin Y, Lu Y, Lee YY, Wei L, Jia J, Wang Q, Wang D, Bai F, Hu H, Hu Q, Liu J, Li Y, Xu J. Producing Designer Oils in Industrial Microalgae by Rational Modulation of Co-evolving Type-2 Diacylglycerol Acyltransferases. MOLECULAR PLANT 2017; 10:1523-1539. [PMID: 29107033 DOI: 10.1016/j.molp.2017.10.011] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/17/2017] [Accepted: 10/21/2017] [Indexed: 05/03/2023]
Abstract
Microalgal oils, depending on their degree of unsaturation, can be utilized as either nutritional supplements or fuels; thus, a feedstock with genetically designed and tunable degree of unsaturation is desirable to maximize process efficiency and product versatility. Systematic profiling of ex vivo (in yeast), in vitro, and in vivo activities of type-2 diacylglycerol acyltransferases in Nannochloropsis oceanica (NoDGAT2s or NoDGTTs), via reverse genetics, revealed that NoDGAT2A prefers saturated fatty acids (SFAs), NoDGAT2D prefers monounsaturated fatty acids (MUFAs), and NoDGAT2C exhibits the strongest activity toward polyunsaturated fatty acids (PUFAs). As NoDGAT2A, 2C, and 2D originated from the green alga, red alga, and eukaryotic host ancestral participants of secondary endosymbiosis, respectively, a mechanistic model of oleaginousness was unveiled, in which the indigenous and adopted NoDGAT2s formulated functional complementarity and specific transcript abundance ratio that underlie a rigid SFA:MUFA:PUFA hierarchy in triacylglycerol (TAG). By rationally modulating the ratio of NoDGAT2A:2C:2D transcripts, a bank of N. oceanica strains optimized for nutritional supplement or fuel production with a wide range of degree of unsaturation were created, in which proportion of SFAs, MUFAs, and PUFAs in TAG varied by 1.3-, 3.7-, and 11.2-fold, respectively. This established a novel strategy to simultaneously improve productivity and quality of oils from industrial microalgae.
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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; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yandu Lu
- 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; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi-Ying Lee
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science and University of Maryland, Baltimore County, Baltimore, MD 21202, USA
| | - 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; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jing Jia
- 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; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qintao Wang
- 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; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dongmei Wang
- 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; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fali Bai
- Core Laboratory, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong 266101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hanhua Hu
- Diatom Biology Group, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiang Hu
- Center for Microalgal Biotechnology and Biofuels, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jin Liu
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science and University of Maryland, Baltimore County, Baltimore, MD 21202, USA; Institute for Food and Bioresource Engineering and Department of Energy and Resource Engineering, College of Engineering, Peking University, Beijing 100871, China.
| | - Yantao Li
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science and University of Maryland, Baltimore County, Baltimore, MD 21202, USA.
| | - 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; University of Chinese Academy of Sciences, Beijing 100049, China.
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