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Malcicka M, Visser B, Ellers J. An Evolutionary Perspective on Linoleic Acid Synthesis in Animals. Evol Biol 2017; 45:15-26. [PMID: 29497218 PMCID: PMC5816129 DOI: 10.1007/s11692-017-9436-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 10/16/2017] [Indexed: 01/20/2023]
Abstract
The diet of organisms generally provides a sufficient supply of energy and building materials for healthy growth and development, but should also contain essential nutrients. Species differ in their exogenous requirements, but it is not clear why some species are able to synthesize essential nutrients, while others are not. The unsaturated fatty acid, linoleic acid (LA; 18:2n-6) plays an important role in functions such as cell physiology, immunity, and reproduction, and is an essential nutrient in diverse organisms. LA is readily synthesized in bacteria, protozoa and plants, but it was long thought that all animals lacked the ability to synthesize LA de novo and thus required a dietary source of this fatty acid. Over the years, however, an increasing number of studies have shown active LA synthesis in animals, including insects, nematodes and pulmonates. Despite continued interest in LA metabolism, it has remained unclear why some organisms can synthesize LA while others cannot. Here, we review the mechanisms by which LA is synthesized and which biological functions LA supports in different organisms to answer the question why LA synthesis was lost and repeatedly gained during the evolution of distinct invertebrate groups. We propose several hypotheses and compile data from the available literature to identify which factors promote LA synthesis within a phylogenetic framework. We have not found a clear link between our proposed hypotheses and LA synthesis; therefore we suggest that LA synthesis may be facilitated through bifunctionality of desaturase enzymes or evolved through a combination of different selective pressures.
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Affiliation(s)
- Miriama Malcicka
- Department of Ecological Sciences, Section Animal Ecology, Vrije Universiteit, Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
| | - Bertanne Visser
- Evolutionary Ecology and Genetics Group, Biodiversity Research Centre, Earth and Life Institute, Université Catholique de Louvain, Croix du Sud 4-5, 1348 Louvain-la-Neuve, Belgium
| | - Jacintha Ellers
- Department of Ecological Sciences, Section Animal Ecology, Vrije Universiteit, Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands
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Effects of disrupted omega-3 desaturase gene construct on fatty acid composition and expression of four fatty acid biosynthetic genes in transgenic Chlorella vulgaris. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.07.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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53
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Banerjee A, Banerjee C, Negi S, Chang JS, Shukla P. Improvements in algal lipid production: a systems biology and gene editing approach. Crit Rev Biotechnol 2017; 38:369-385. [DOI: 10.1080/07388551.2017.1356803] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Avik Banerjee
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, India
| | - Chiranjib Banerjee
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, India
| | | | - Jo-Shu Chang
- Department of Chemical Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Pratyoosh Shukla
- Department of Microbiology, Enzyme Technology and Protein Bioinformatics Laboratory, Maharshi Dayanand University, Rohtak, India
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Beacham TA, Sweet JB, Allen MJ. Large scale cultivation of genetically modified microalgae: A new era for environmental risk assessment. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.04.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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55
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Schüler LM, Schulze PS, Pereira H, Barreira L, León R, Varela J. Trends and strategies to enhance triacylglycerols and high-value compounds in microalgae. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.05.025] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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56
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Meng Y, Cao X, Yao C, Xue S, Yang Q. Identification of the role of polar glycerolipids in lipid metabolism and their acyl attribution for TAG accumulation in Nannochloropsis oceanica. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.03.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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57
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Osada K, Maeda Y, Yoshino T, Nojima D, Bowler C, Tanaka T. Enhanced NADPH production in the pentose phosphate pathway accelerates lipid accumulation in the oleaginous diatom Fistulifera solaris. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.01.015] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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58
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Wei L, Huang X. Long-duration effect of multi-factor stresses on the cellular biochemistry, oil-yielding performance and morphology of Nannochloropsis oculata. PLoS One 2017; 12:e0174646. [PMID: 28346505 PMCID: PMC5367823 DOI: 10.1371/journal.pone.0174646] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 03/13/2017] [Indexed: 12/03/2022] Open
Abstract
Microalga Nannochloropsis oculata is a promising alternative feedstock for biodiesel. Elevating its oil-yielding capacity is conducive to cost-saving biodiesel production. However, the regulatory processes of multi-factor collaborative stresses (MFCS) on the oil-yielding performance of N. oculata are unclear. The duration effects of MFCS (high irradiation, nitrogen deficiency and elevated iron supplementation) on N. oculata were investigated in an 18-d batch culture. Despite the reduction in cell division, the biomass concentration increased, resulting from the large accumulation of the carbon/energy-reservoir. However, different storage forms were found in different cellular storage compounds, and both the protein content and pigment composition swiftly and drastically changed. The analysis of four biodiesel properties using pertinent empirical equations indicated their progressive effective improvement in lipid classes and fatty acid composition. The variation curve of neutral lipid productivity was monitored with fluorescent Nile red and was closely correlated to the results from conventional methods. In addition, a series of changes in the organelles (e.g., chloroplast, lipid body and vacuole) and cell shape, dependent on the stress duration, were observed by TEM and LSCM. These changes presumably played an important role in the acclimation of N. oculata to MFCS and accordingly improved its oil-yielding performance.
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Affiliation(s)
- Likun Wei
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Xuxiong Huang
- Key Laboratory of Genetic Resources for Freshwater Aquaculture and Fisheries, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
- Shanghai Engineering Research Centre of Aquaculture, Shanghai, China
- Shanghai University Knowledge Service Platform, Shanghai Ocean University Aquatic Animal Breeding Centre (ZF1206), Shanghai, China
- * E-mail:
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59
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Roointan A, Morowvat MH. Road to the future of systems biotechnology: CRISPR-Cas-mediated metabolic engineering for recombinant protein production. Biotechnol Genet Eng Rev 2017; 32:74-91. [PMID: 28052722 DOI: 10.1080/02648725.2016.1270095] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The rising potential for CRISPR-Cas-mediated genome editing has revolutionized our strategies in basic and practical bioengineering research. It provides a predictable and precise method for genome modification in a robust and reproducible fashion. Emergence of systems biotechnology and synthetic biology approaches coupled with CRISPR-Cas technology could change the future of cell factories to possess some new features which have not been found naturally. We have discussed the possibility and versatile potentials of CRISPR-Cas technology for metabolic engineering of a recombinant host for heterologous protein production. We describe the mechanisms involved in this metabolic engineering approach and present the diverse features of its application in biotechnology and protein production.
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Affiliation(s)
- Amir Roointan
- a Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies , Shiraz , Iran.,c Department of Medical Biotechnology, School of Medicine , Fasa University of Medical Sciences , Fasa , Iran
| | - Mohammad Hossein Morowvat
- a Department of Medical Biotechnology, School of Advanced Medical Sciences and Technologies , Shiraz , Iran.,b Pharmaceutical Sciences Research Center, School of Pharmacy , Shiraz University of Medical Sciences , Shiraz , Iran
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60
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Kang NK, Kim EK, Kim YU, Lee B, Jeong WJ, Jeong BR, Chang YK. Increased lipid production by heterologous expression of AtWRI1 transcription factor in Nannochloropsis salina. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:231. [PMID: 29046718 PMCID: PMC5635583 DOI: 10.1186/s13068-017-0919-5] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/30/2017] [Indexed: 05/03/2023]
Abstract
BACKGROUND Genetic engineering of microalgae is necessary to produce economically feasible strains for biofuel production. Current efforts are focused on the manipulation of individual metabolic genes, but the outcomes are not sufficiently stable and/or efficient for large-scale production of biofuels and other materials. Transcription factors (TFs) are emerging as good alternatives for engineering of microalgae, not only to increase production of biomaterials but to enhance stress tolerance. Here, we investigated an AP2 type TF Wrinkled1 in Arabidopsis (AtWRI1) known as a key regulator of lipid biosynthesis in plants, and applied it to industrial microalgae, Nannochloropsis salina. RESULTS We expressed AtWRI1 TF heterologously in N. salina, named NsAtWRI1, in an effort to re-enact its key regulatory function of lipid accumulation. Stable integration AtWRI1 was confirmed by RESDA PCR, and its expression was confirmed by Western blotting using the FLAG tag. Characterizations of transformants revealed that the neutral and total lipid contents were greater in NsAtWRI1 transformants than in WT under both normal and stress conditions from day 8. Especially, total lipid contents were 36.5 and 44.7% higher in NsAtWRI1 2-3 than in WT under normal and osmotic stress condition, respectively. FAME contents of NsAtWRI1 2-3 were also increased compared to WT. As a result, FAME yield of NsAtWRI1 2-3 was increased to 768 mg/L/day, which was 64% higher than that of WT under the normal condition. We identified candidates of AtWRI1-regulated genes by searching for the presence of the AW-box in promoter regions, among which lipid metabolic genes were further analyzed by qRT-PCR. Overall, qRT-PCR results on day 1 indicated that AtWRI1 down-regulated TAGL and DAGK, and up-regulated PPDK, LPL, LPGAT1, and PDH, resulting in enhanced lipid production in NsAtWRI1 transformants from early growth phase. CONCLUSION AtWRI1 TF regulated several genes involved in lipid synthesis in N. salina, resulting in enhancement of neutral lipid and FAME production. These findings suggest that heterologous expression of AtWRI1 TF can be utilized for efficient biofuel production in industrial microalgae.
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Affiliation(s)
- Nam Kyu Kang
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Eun Kyung Kim
- Advanced Biomass R&D Center, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Young Uk Kim
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125, Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Won-Joong Jeong
- Plant Systems Engineering Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125, Gwahak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Advanced Biomass R&D Center, 291, Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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61
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Wang Q, Lu Y, Xin Y, Wei L, Huang S, Xu J. Genome editing of model oleaginous microalgae Nannochloropsis spp. by CRISPR/Cas9. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 88:1071-1081. [PMID: 27538728 DOI: 10.1111/tpj.13307] [Citation(s) in RCA: 135] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/04/2016] [Accepted: 08/05/2016] [Indexed: 05/18/2023]
Abstract
Microalgae are promising feedstock for biofuels yet mechanistic probing of their cellular network and industrial strain development have been hindered by lack of genome-editing tools. Nannochloropsis spp. are emerging model microalgae for scalable oil production and carbon sequestration. Here we established a CRISPR/Cas9-based precise genome-editing approach for the industrial oleaginous microalga Nannochloropsis oceanica, using nitrate reductase (NR; g7988) as example. A new screening procedure that compares between restriction enzyme-digested nested PCR (nPCR) products derived from enzyme-digested and not-digested genomic DNA of transformant pools was developed to quickly, yet reliably, detect genome-engineered mutants. Deep sequencing of nPCR products directly amplified from pooled genomic DNA revealed over an 1% proportion of 5-bp deletion mutants and a lower frequency of 12-bp deletion mutants, with both types of editing precisely located at the targeted site. The isolated mutants, in which precise deletion of five bases caused a frameshift in NR translation, grow normally under NH4 Cl but fail to grow under NaNO3 , and thus represent a valuable chassis strain for transgenic-strain development. This demonstration of CRISPR/Cas9-based genome editing in industrial microalgae opens many doors for microalgae-based biotechnological applications.
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Affiliation(s)
- Qintao Wang
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yandu Lu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan University, 570228, Haikou, Hainan, China
| | - Yi Xin
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
| | - Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
| | - Shi Huang
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandong Key Laboratory of Energy Genetics, Qingdao Institute of BioEnergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, Shandong, 266101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
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Lauersen KJ, Baier T, Wichmann J, Wördenweber R, Mussgnug JH, Hübner W, Huser T, Kruse O. Efficient phototrophic production of a high-value sesquiterpenoid from the eukaryotic microalga Chlamydomonas reinhardtii. Metab Eng 2016; 38:331-343. [DOI: 10.1016/j.ymben.2016.07.013] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 06/17/2016] [Accepted: 07/26/2016] [Indexed: 02/07/2023]
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63
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Fernandes T, Fernandes I, Andrade CA, Cordeiro N. Changes in fatty acid biosynthesis in marine microalgae as a response to medium nutrient availability. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.07.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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64
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Current advances in molecular, biochemical, and computational modeling analysis of microalgal triacylglycerol biosynthesis. Biotechnol Adv 2016; 34:1046-1063. [DOI: 10.1016/j.biotechadv.2016.06.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 06/08/2016] [Accepted: 06/12/2016] [Indexed: 12/12/2022]
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65
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Mallick N, Bagchi SK, Koley S, Singh AK. Progress and Challenges in Microalgal Biodiesel Production. Front Microbiol 2016; 7:1019. [PMID: 27446055 PMCID: PMC4927567 DOI: 10.3389/fmicb.2016.01019] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 06/15/2016] [Indexed: 11/13/2022] Open
Abstract
The last decade has witnessed a tremendous impetus on biofuel research due to the irreversible diminution of fossil fuel reserves for enormous demands of transportation vis-a-vis escalating emissions of green house gasses (GHGs) into the atmosphere. With an imperative need of CO2 reduction and considering the declining status of crude oil, governments in various countries have not only diverted substantial funds for biofuel projects but also have introduced incentives to vendors that produce biofuels. Currently, biodiesel production from microalgal biomass has drawn an immense importance with the potential to exclude high-quality agricultural land use and food safe-keeping issues. Moreover, microalgae can grow in seawater or wastewater and microalgal oil can exceed 50–60% (dry cell weight) as compared with some best agricultural oil crops of only 5–10% oil content. Globally, microalgae are the highest biomass producers and neutral lipid accumulators contending any other terrestrial oil crops. However, there remain many hurdles in each and every step, starting from strain selection and lipid accumulation/yield, algae mass cultivation followed by the downstream processes such as harvesting, drying, oil extraction, and biodiesel conversion (transesterification), and overall, the cost of production. Isolation and screening of oleaginous microalgae is one pivotal important upstream factor which should be addressed according to the need of freshwater or marine algae with a consideration that wild-type indigenous isolate can be the best suited for the laboratory to large scale exploitation. Nowadays, a large number of literature on microalgal biodiesel production are available, but none of those illustrate a detailed step-wise description with the pros and cons of the upstream and downstream processes of biodiesel production from microalgae. Specifically, harvesting and drying constitute more than 50% of the total production costs; however, there are quite a less number of detailed study reports available. In this review, a pragmatic and critical analysis was tried to put forward with the on-going researches on isolation and screening of oleaginous microalgae, microalgal large scale cultivation, biomass harvesting, drying, lipid extraction and finally biodiesel production.
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Affiliation(s)
- Nirupama Mallick
- Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur India
| | - Sourav K Bagchi
- Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur India
| | - Shankha Koley
- Agricultural and Food Engineering Department, Indian Institute of Technology Kharagpur, Kharagpur India
| | - Akhilesh K Singh
- Amity Institute of Biotechnology, Amity University at Lucknow, Lucknow India
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66
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Banerjee C, Dubey KK, Shukla P. Metabolic Engineering of Microalgal Based Biofuel Production: Prospects and Challenges. Front Microbiol 2016; 7:432. [PMID: 27065986 PMCID: PMC4815533 DOI: 10.3389/fmicb.2016.00432] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 03/17/2016] [Indexed: 12/14/2022] Open
Abstract
The current scenario in renewable energy is focused on development of alternate and sustainable energy sources, amongst which microalgae stands as one of the promising feedstock for biofuel production. It is well known that microalgae generate much larger amounts of biofuels in a shorter time than other sources based on plant seeds. However, the greatest challenge in a transition to algae-based biofuel production is the various other complications involved in microalgal cultivation, its harvesting, concentration, drying and lipid extraction. Several green microalgae accumulate lipids, especially triacylglycerols (TAGs), which are main precursors in the production of lipid. The various aspects on metabolic pathway analysis of an oleaginous microalgae i.e., Chlamydomonas reinhardtii have elucidated some novel metabolically important genes and this enhances the lipid production in this microalgae. Adding to it, various other aspects in metabolic engineering using OptFlux and effectual bioprocess design also gives an interactive snapshot of enhancing lipid production which ultimately improvises the oil yield. This article reviews the current status of microalgal based technologies for biofuel production, bioreactor process design, flux analysis and it also provides various strategies to increase lipids accumulation via metabolic engineering.
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Affiliation(s)
- Chiranjib Banerjee
- Department of Environmental Science and Engineering, Indian School of Mines Dhanbad, India
| | - Kashyap K Dubey
- Department of Biotechnology, University Institute of Engineering and Technology, Maharshi Dayanand University Rohtak, India
| | - Pratyoosh Shukla
- Enzyme Technology and Protein Bioinformatics Laboratory, Department of Microbiology, Maharshi Dayanand University Rohtak, India
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Guihéneuf F, Khan A, Tran LSP. Genetic Engineering: A Promising Tool to Engender Physiological, Biochemical, and Molecular Stress Resilience in Green Microalgae. FRONTIERS IN PLANT SCIENCE 2016; 7:400. [PMID: 27066043 PMCID: PMC4815356 DOI: 10.3389/fpls.2016.00400] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Accepted: 03/14/2016] [Indexed: 05/03/2023]
Abstract
As we march into the 21st century, the prevailing scenario of depleting energy resources, global warming and ever increasing issues of human health and food security will quadruple. In this context, genetic and metabolic engineering of green microalgae complete the quest toward a continuum of environmentally clean fuel and food production. Evolutionarily related, but unlike land plants, microalgae need nominal land or water, and are best described as unicellular autotrophs using light energy to fix atmospheric carbon dioxide (CO2) into algal biomass, mitigating fossil CO2 pollution in the process. Remarkably, a feature innate to most microalgae is synthesis and accumulation of lipids (60-65% of dry weight), carbohydrates and secondary metabolites like pigments and vitamins, especially when grown under abiotic stress conditions. Particularly fruitful, such an application of abiotic stress factors such as nitrogen starvation, salinity, heat shock, etc., can be used in a biorefinery concept for production of multiple valuable products. The focus of this mini-review underlies metabolic reorientation practices and tolerance mechanisms as applied to green microalgae under specific stress stimuli for a sustainable pollution-free future. Moreover, we entail current progress on genetic engineering as a promising tool to grasp adaptive processes for improving strains with potential biotechnological interests.
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Affiliation(s)
- Freddy Guihéneuf
- Botany and Plant Science, School of Natural Sciences, Ryan Institute, National University of Ireland GalwayGalway, Ireland
| | - Asif Khan
- Research Group Germline Biology, Centre for Organismal Studies (COS), Heidelberg UniversityHeidelberg, Germany
| | - Lam-Son P. Tran
- Plant Abiotic Stress Research Group & Faculty of Applied Sciences, Ton Duc Thang UniversityHo Chi Minh City, Vietnam
- Signaling Pathway Research Unit, RIKEN Center for Sustainable Resource ScienceTsurumi, Japan
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68
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Ma XN, Chen TP, Yang B, Liu J, Chen F. Lipid Production from Nannochloropsis. Mar Drugs 2016; 14:md14040061. [PMID: 27023568 PMCID: PMC4849066 DOI: 10.3390/md14040061] [Citation(s) in RCA: 144] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Revised: 03/01/2016] [Accepted: 03/11/2016] [Indexed: 12/18/2022] Open
Abstract
Microalgae are sunlight-driven green cell factories for the production of potential bioactive products and biofuels. Nannochloropsis represents a genus of marine microalgae with high photosynthetic efficiency and can convert carbon dioxide to storage lipids mainly in the form of triacylglycerols and to the ω-3 long-chain polyunsaturated fatty acid eicosapentaenoic acid (EPA). Recently, Nannochloropsis has received ever-increasing interests of both research and public communities. This review aims to provide an overview of biology and biotechnological potential of Nannochloropsis, with the emphasis on lipid production. The path forward for the further exploration of Nannochloropsis for lipid production with respect to both challenges and opportunities is also discussed.
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Affiliation(s)
- Xiao-Nian Ma
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China.
| | - Tian-Peng Chen
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China.
| | - Bo Yang
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China.
| | - Jin Liu
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China.
| | - Feng Chen
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing 100871, China.
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Abstract
Microalgae present a huge and still insufficiently tapped resource of very long-chain omega-3 and omega-6 polyunsaturated fatty acids (VLC-PUFA) for human nutrition and medicinal applications. This chapter describes the diversity of unicellular eukaryotic microalgae in respect to VLC-PUFA biosynthesis. Then, we outline the major biosynthetic pathways mediating the formation of VLC-PUFA by sequential desaturation and elongation of C18-PUFA acyl groups. We address the aspects of spatial localization of those pathways and elaborate on the role for VLC-PUFA in microalgal cells. Recent progress in microalgal genetic transformation and molecular engineering has opened the way to increased production efficiencies for VLC-PUFA. The perspectives of photobiotechnology and metabolic engineering of microalgae for altered or enhanced VLC-PUFA production are also discussed.
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Affiliation(s)
- Inna Khozin-Goldberg
- Microalgal Biotechnology Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel.
| | - Stefan Leu
- Microalgal Biotechnology Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel
| | - Sammy Boussiba
- Microalgal Biotechnology Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel
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Kang NK, Jeon S, Kwon S, Koh HG, Shin SE, Lee B, Choi GG, Yang JW, Jeong BR, Chang YK. Effects of overexpression of a bHLH transcription factor on biomass and lipid production in Nannochloropsis salina. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:200. [PMID: 26628914 PMCID: PMC4666162 DOI: 10.1186/s13068-015-0386-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/16/2015] [Indexed: 05/02/2023]
Abstract
BACKGROUND Microalgae are considered promising alternative energy sources because they consume CO2 and accumulate large amounts of lipids that can be used as biofuel. Nannochloropsis is a particularly promising microalga due to its high growth rate and lipid content, and the availability of genomic information. Transcription factors (TFs) are global regulators of biological pathways by up- or down-regulation of related genes. Among these, basic helix-loop-helix (bHLH) TFs regulate growth, development, and stress responses in plants and animals, and have been identified in microalgae. We identified two bHLH TFs in the genome of N. salina CCMP1776, NsbHLH1, and NsbHLH2, and characterized functions of NsbHLH2 that may be involved in growth and nutrient uptake. RESULTS We obtained NsbHLH2 overexpressing transformants of N. salina CCMP1776 by particle bombardment and confirmed that these were stable transformants. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting using antibodies against the FLAG tag that was attached at the end of the coding sequence confirmed the expression of the NsbHLH2 protein under various culture conditions. The qRT-PCR results also indicated that the endogenous and transgenic expression of NsbHLH2 was reduced under stressed conditions. Overexpression of NsbHLH2 led to increased growth rate in the early growth period, and concomitantly higher nutrient uptake, than wild type (WT). These enhanced growth and nutrient uptake resulted in increased productivities of biomass and FAME. For example, one of the transformants, NsbHLH2 3-6, showed increased biomass productivity by 36 % under the normal condition, and FAME productivity by 33 % under nitrogen limitation condition. Conclusively, the improved growth in the transformants can be associated with the enhanced nutrient uptake. We are currently assessing their potential for scale-up cultivation with positive outcomes. CONCLUSION Overexpression of NsbHLH2 led to enhanced growth rate and nutrient uptake during the early growth phase, and increased biomass and FAME productivity, especially in the later period under normal and stressed conditions. Based on these results, we postulate that NsbHLH2 can be employed for the industrial production of biodiesel from N. salina.
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Affiliation(s)
- Nam Kyu Kang
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Seungjib Jeon
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Sohee Kwon
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Hyun Gi Koh
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Sung-Eun Shin
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Bongsoo Lee
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Gang-Guk Choi
- />Advanced Biomass R&D Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Ji-Won Yang
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Byeong-ryool Jeong
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
| | - Yong Keun Chang
- />Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
- />Advanced Biomass R&D Center, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 Republic of Korea
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