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Santin A, Spatola Rossi T, Morlino MS, Gupte AP, Favaro L, Morosinotto T, Treu L, Campanaro S. Autotrophic poly-3-hydroxybutyrate accumulation in Cupriavidus necator for sustainable bioplastic production triggered by nutrient starvation. BIORESOURCE TECHNOLOGY 2024; 406:131068. [PMID: 38972429 DOI: 10.1016/j.biortech.2024.131068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 07/03/2024] [Accepted: 07/03/2024] [Indexed: 07/09/2024]
Abstract
Cupriavidus necator is a facultative chemolithoautotrophic bacterium able to convert carbon dioxide into poly-3-hydroxybutyrate. This is highly promising as the conversion process allows the production of sustainable and biodegradable plastics. Poly-3-hydroxybutyrate accumulation is known to be induced by nutrient starvation, but information regarding the optimal stress conditions controlling the process is still heterogeneous and fragmentary. This study presents a comprehensive comparison of the effects of nutrient stress conditions, namely nitrogen, hydrogen, phosphorus, oxygen, and magnesium deprivation, on poly-3-hydroxybutyrate accumulation in C. necator DSM545. Nitrogen starvation exhibited the highest poly-3-hydroxybutyrate accumulation, achieving 54% of total cell dry weight after four days of nutrient stress, and a carbon conversion efficiency of 85%. The gas consumption patterns indicated flexible physiological mechanisms underlying polymer accumulation and depolymerization. These findings provide insights into strategies for efficient carbon conversion into bioplastics, and highlight the key role of C. necator for future industrial-scale applications.
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Affiliation(s)
- Anna Santin
- Department of Biology, University of Padova, 35131 Padova, Italy.
| | | | | | - Ameya Pankaj Gupte
- Waste to Bioproducts Lab, Department of Agronomy Food Natural Resources Animals and Environment, University of Padova - Agripolis, 35020 Legnaro PD, Italy.
| | - Lorenzo Favaro
- Waste to Bioproducts Lab, Department of Agronomy Food Natural Resources Animals and Environment, University of Padova - Agripolis, 35020 Legnaro PD, Italy; Department of Microbiology, Stellenbosch University, Private Bag X1, 7602 Matieland, South Africa.
| | | | - Laura Treu
- Department of Biology, University of Padova, 35131 Padova, Italy.
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2
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Gee CW, Andersen-Ranberg J, Boynton E, Rosen RZ, Jorgens D, Grob P, Holman HYN, Niyogi KK. Implicating the red body of Nannochloropsis in forming the recalcitrant cell wall polymer algaenan. Nat Commun 2024; 15:5456. [PMID: 38937455 PMCID: PMC11211512 DOI: 10.1038/s41467-024-49277-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 05/31/2024] [Indexed: 06/29/2024] Open
Abstract
Stramenopile algae contribute significantly to global primary productivity, and one class, Eustigmatophyceae, is increasingly studied for applications in high-value lipid production. Yet much about their basic biology remains unknown, including the nature of an enigmatic, pigmented globule found in vegetative cells. Here, we present an in-depth examination of this "red body," focusing on Nannochloropsis oceanica. During the cell cycle, the red body forms adjacent to the plastid, but unexpectedly it is secreted and released with the autosporangial wall following cell division. Shed red bodies contain antioxidant ketocarotenoids, and overexpression of a beta-carotene ketolase results in enlarged red bodies. Infrared spectroscopy indicates long-chain, aliphatic lipids in shed red bodies and cell walls, and UHPLC-HRMS detects a C32 alkyl diol, a potential precursor of algaenan, a recalcitrant cell wall polymer. We propose that the red body transports algaenan precursors from plastid to apoplast to be incorporated into daughter cell walls.
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Affiliation(s)
- Christopher W Gee
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Johan Andersen-Ranberg
- University of Copenhagen, Department of Plant and Environmental Sciences, Frederiksberg, DK-1871, Denmark
| | - Ethan Boynton
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Rachel Z Rosen
- Department of Chemistry, University of California, Berkeley, CA, 94702, USA
| | - Danielle Jorgens
- Electron Microscope Laboratory, University of California, Berkeley, CA, 94720, USA
| | - Patricia Grob
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA
- California Institute of Quantitative Biosciences, University of California, Berkeley, CA, 94720, USA
| | - Hoi-Ying N Holman
- Electron Microscope Laboratory, University of California, Berkeley, CA, 94720, USA
| | - Krishna K Niyogi
- Howard Hughes Medical Institute, University of California, Berkeley, CA, 94720, USA.
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
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3
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Goswami RK, Mehariya S, Verma P. Sub-pilot scale sequential microalgal consortium-based cultivation for treatment of municipal wastewater and biomass production. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 348:123796. [PMID: 38518973 DOI: 10.1016/j.envpol.2024.123796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 03/10/2024] [Accepted: 03/13/2024] [Indexed: 03/24/2024]
Abstract
Municipal wastewater (MWW) was treated by a sequential pilot microalgal cultivation process. The cultivation was performed inside a specifically designed low-cost photobioreactor (PBR) system. A microalgal consortium 2:1 was developed using Tetraselmis indica (TS) and Picochlorum sp. (PC) in the first stage and PC:TS (2:1) in the second stage and the nutrient removal efficiency and biomass production and biomolecules production was evaluated and also compared with monoculture in a two-stage sequential cultivation system. This study also investigated the effect of seasonal variations on microalgae growth and MWW treatment. The results showed that mixed microalgal consortium (TS:PC) had higher nutrient removal efficiency, with chemical oxygen demand (COD), total phosphate (TP), and total nitrate (TN) removal efficiencies of 78.50, 84.49, and 84.20%, respectively, and produced a biomass of 2.50 g/L with lipid content of 37.36% in the first stage of cultivation under indoor conditions. In the second stage of indoor cultivation, the PC:TS consortium demonstrated maximum COD, TP, and TN removal efficiencies of 92.49, 94.24, and 94.16%, respectively. It also produced a biomass of 2.65 g/L with a lipid content of 40.67%. Among all the seasonal variations, mass flow analysis indicated that the combination of mixed consortium-based two-stage sequential process during the winter season favored maximum nutrient removal efficiency of TN i.e. 88.54% (84.12 mg/L) and TP i.e., 90.18% (43.29 mg/L), respectively. It also enhanced total biomass production of 49.10 g in 20-L medium, which includes lipid yield ∼15.68 g compared to monoculture i.e., 82.06% (78.70 mg/L) and 82.87% (40.26 mg/L) removal of TN and TP, respectively, and produced biomass 43.60 g with 11.90 g of lipids.
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Affiliation(s)
- Rahul Kumar Goswami
- Bioprocess and Bioenergy Laboratory (BPBEL), Department of Microbiology, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India
| | - Sanjeet Mehariya
- Algal Technology Program, Center for Sustainable Development, College of Arts and Sciences, Qatar University, Doha, 2713, Qatar
| | - Pradeep Verma
- Bioprocess and Bioenergy Laboratory (BPBEL), Department of Microbiology, Central University of Rajasthan, Bandarsindri, Kishangarh, Ajmer, Rajasthan, 305817, India.
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4
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Gong Y, Wang Q, Wei L, Liang W, Wang L, Lv N, Du X, Zhang J, Shen C, Xin Y, Sun L, Xu J. Genome-wide adenine N6-methylation map reveals epigenomic regulation of lipid accumulation in Nannochloropsis. PLANT COMMUNICATIONS 2024; 5:100773. [PMID: 38007614 PMCID: PMC10943562 DOI: 10.1016/j.xplc.2023.100773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/09/2023] [Accepted: 11/23/2023] [Indexed: 11/27/2023]
Abstract
Epigenetic marks on histones and DNA, such as DNA methylation at N6-adenine (6mA), play crucial roles in gene expression and genome maintenance, but their deposition and function in microalgae remain largely uncharacterized. Here, we report a genome-wide 6mA map for the model industrial oleaginous microalga Nannochloropsis oceanica produced by single-molecule real-time sequencing. Found in 0.1% of adenines, 6mA sites are mostly enriched at the AGGYV motif, more abundant in transposons and 3' untranslated regions, and associated with active transcription. Moreover, 6mA gradually increases in abundance along the direction of gene transcription and shows special positional enrichment near splicing donor and transcription termination sites. Highly expressed genes tend to show greater 6mA abundance in the gene body than do poorly expressed genes, indicating a positive interaction between 6mA and general transcription factors. Furthermore, knockout of the putative 6mA methylase NO08G00280 by genome editing leads to changes in methylation patterns that are correlated with changes in the expression of molybdenum cofactor, sulfate transporter, glycosyl transferase, and lipase genes that underlie reductions in biomass and oil productivity. By contrast, knockout of the candidate demethylase NO06G02500 results in increased 6mA levels and reduced growth. Unraveling the epigenomic players and their roles in biomass productivity and lipid metabolism lays a foundation for epigenetic engineering of industrial microalgae.
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Affiliation(s)
- Yanhai Gong
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Qintao Wang
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Li Wei
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Wensi Liang
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Lianhong Wang
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Nana Lv
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Xuefeng Du
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Jiashun Zhang
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Chen Shen
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Yi Xin
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Luyang Sun
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
| | - Jian Xu
- Single-Cell Center, CAS Key Laboratory of Biofuels, Shandong Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China; Shandong Energy Institute, Qingdao, China; Qingdao New Energy Shandong Laboratory, Qingdao, China; University of Chinese Academy of Sciences, Beijing 100049, China; Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
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5
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Kim M, Kim J, Lee S, Khanh N, Li Z, Polle JEW, Jin E. Deciphering the β-carotene hyperaccumulation in Dunaliella by the comprehensive analysis of Dunaliella salina and Dunaliella tertiolecta under high light conditions. PLANT, CELL & ENVIRONMENT 2024; 47:213-229. [PMID: 37727131 DOI: 10.1111/pce.14724] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 09/04/2023] [Accepted: 09/10/2023] [Indexed: 09/21/2023]
Abstract
The green microalga Dunaliella salina hyperaccumulates β-carotene in the chloroplast, which turns its cells orange. This does not occur in the sister species Dunaliella tertiolecta. However, the molecular mechanisms of β-carotene hyperaccumulation were still unclear. Here, we discovered the reasons for β-carotene hyperaccumulation by comparing the morphology, physiology, genome, and transcriptome between the carotenogenic D. salina and the noncarotenogenic D. tertiolecta after transfer to high light. The differences in photosynthetic capacity, cell growth, and the concentration of stored carbon suggest that these species regulate the supply and utilization of carbon differently. The number of β-carotene-containing plastid lipid globules increased in both species, but much faster and to a greater extent in D. salina than in D. tertiolecta. Consistent with the accumulation of plastid lipid globules, the expression of the methyl-erythritol-phosphate and carotenoid biosynthetic pathways increased only in D. salina, which explains the de novo synthesis of β-carotene. In D. salina, the concomitantly upregulated expression of the carotene globule proteins suggests that hyperaccumulation of β-carotene also requires a simultaneous increase in its sink capacity. Based on genomic analysis, we propose that D. salina has genetic advantages for routing carbon from growth to carotenoid metabolism.
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Affiliation(s)
- Minjae Kim
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea
| | - Jongrae Kim
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea
| | - Sangmuk Lee
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea
| | - Nguyen Khanh
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea
| | - Zhun Li
- Biological Resource Center/Korean Collection for Type Cultures (KCTC), Korea Research Institute of Bioscience and Biotechnology, Jeongeup, Republic of Korea
| | - Juergen E W Polle
- Department of Biology, Brooklyn College of the City University of New York, New York, Brooklyn, USA
| | - EonSeon Jin
- Department of Life Science, Research Institute for Natural Sciences, Hanyang University, Seoul, Republic of Korea
- Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, Republic of Korea
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6
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Yan CX, Zhang Y, Yang WQ, Ma W, Sun XM, Huang H. Universal and unique strategies for the production of polyunsaturated fatty acids in industrial oleaginous microorganisms. Biotechnol Adv 2024; 70:108298. [PMID: 38048920 DOI: 10.1016/j.biotechadv.2023.108298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 11/21/2023] [Accepted: 12/01/2023] [Indexed: 12/06/2023]
Abstract
Polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA), are beneficial for reducing blood cholesterol and enhancing memory. Traditional PUFA production relies on extraction from plants and animals, which is unsustainable. Thus, using microorganisms as lipid-producing factories holds promise as an alternative way for PUFA production. Several oleaginous microorganisms have been successfully industrialized to date. These can be divided into universal and specialized hosts according to the products range of biosynthesis. The Yarrowia lipolytica is universal oleaginous host that has been engineered to produce a variety of fatty acids, such as γ-linolenic acid (GLA), EPA, ARA and so on. By contrast, the specialized host are used to produce only certain fatty acids, such as ARA in Mortierella alpina, EPA in Nannochloropsis, and DHA in Thraustochytrids. The metabolic engineering and fermentation strategies for improving PUFA production in universal and specialized hosts are different, which is the subject of this review. In addition, the widely applicable strategies for microbial lipid production that are not specific to individual hosts were also reviewed.
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Affiliation(s)
- Chun-Xiao Yan
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, People's Republic of China
| | - Ying Zhang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, People's Republic of China
| | - Wen-Qian Yang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, People's Republic of China
| | - Wang Ma
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, People's Republic of China
| | - Xiao-Man Sun
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, People's Republic of China.
| | - He Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, 2 Xuelin Road, Qixia District, Nanjing, People's Republic of China
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Light modulates the lipidome of the photosynthetic sea slug Elysia timida. Biochim Biophys Acta Mol Cell Biol Lipids 2023; 1868:159249. [PMID: 36336252 DOI: 10.1016/j.bbalip.2022.159249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 10/27/2022] [Accepted: 10/28/2022] [Indexed: 11/06/2022]
Abstract
Long-term kleptoplasty, the capability to retain functional stolen chloroplasts (kleptoplasts) for several weeks to months, has been shown in a handful of Sacoglossa sea slugs. One of these sea slugs is Elysia timida, endemic to the Mediterranean, which retains functional chloroplasts of the macroalga Acetabularia acetabulum. To understand how light modulates the lipidome of E. timida, sea slug specimens were subjected to two different 4-week light treatments: regular light and quasi-dark conditions. Lipidomic analyses were performed by HILIC-HR-ESI-MS and MS/MS. Quasi-dark conditions caused a reduction in the amount of essential lipids for photosynthetic membranes, such as glycolipids, indicating high level of kleptoplast degradation under sub-optimal light conditions. However, maximum photosynthetic capacities (Fv/Fm) were identical in both light treatments (≈0.75), showing similar kleptoplast functionality and suggesting that older kleptoplasts were targeted for degradation. Although more stable, the phospholipidome showed differences between light treatments: the amount of certain lipid species of phosphatidylethanolamine (PE), phosphatidylinositol (PI), and phosphatidylglycerol (PG) decreased under quasi-dark conditions, while other lipid species of phosphatidylcholine (PC), PE and lyso-PE (LPE) increased. Quasi-dark conditions promoted a decrease in the relative abundance of polyunsaturated fatty acids. These results suggest a light-driven remodelling of the lipidome according to the functions of the different lipids and highlight the plasticity of polar lipids in the photosynthetic sea slug E. timida.
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An increase in the membrane lipids recycling by PDAT overexpression stimulates the accumulation of triacylglycerol in Nannochloropsis gaditana. J Biotechnol 2022; 357:28-37. [PMID: 35931238 DOI: 10.1016/j.jbiotec.2022.07.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 07/18/2022] [Accepted: 07/30/2022] [Indexed: 11/23/2022]
Abstract
Oleaginous microalgae represent potential feedstocks for the sustainable production of lipids thanks to their ability to accumulate triacylglycerols (TAGs). TAG accumulation in several algal species is strongly induced under specific conditions such as nutrient deprivation and high light which, however, also negatively impact growth. Genetic modification of lipogenic pathways can potentially enhance TAG accumulation without negatively affecting growth, avoiding the trade-off between biomass and lipids productivity. In this study, the phospholipid: diacylglycerol acyltransferase (PDAT), an enzyme involved in membrane lipid recycling, was overexpressed in the seawater alga Nannochloropsis gaditana. PDAT overexpression induced increased TAG content in actively growing algae cultures while no effects were observed in conditions naturally stimulating strong lipid accumulation such as high light and nitrogen starvation. The increase of TAG content was confirmed also in a strain cultivated in industrially relevant conditions even though PDAT overexpression, if too strong, the gene overexpression becomes detrimental for growth in the longer term. Results overall suggest that genetic modulation of the PDAT gene represents a promising strategy to increase microalgae lipids content by minimizing negative effects on biomass productivity.
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Yang J, Liu J, Pan Y, Maréchal E, Amato A, Liu M, Gong Y, Li Y, Hu H. PDAT regulates PE as transient carbon sink alternative to triacylglycerol in Nannochloropsis. PLANT PHYSIOLOGY 2022; 189:1345-1362. [PMID: 35385114 PMCID: PMC9237688 DOI: 10.1093/plphys/kiac160] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 03/14/2022] [Indexed: 05/21/2023]
Abstract
Triacylglycerols (TAGs) are the main storage lipids in photosynthetic organisms under stress. In the oleaginous alga Nannochloropsis oceanica, while multiple acyl CoA:diacylglycerol (DAG) acyltransferases (NoDGATs) are involved in TAG production, the role of the unique phospholipid:DAG acyltransferase (NoPDAT) remains unknown. Here, we performed a functional complementation assay in TAG-deficient yeast (Saccharomyces cerevisiae) and an in vitro assay to probe the acyltransferase activity of NoPDAT. Subcellular localization, overexpression, and knockdown (KD) experiments were also conducted to elucidate the role of NoPDAT in N. oceanica. NoPDAT, residing at the outermost plastid membrane, does not phylogenetically fall into the clades of algae or plants and uses phosphatidylethanolamine (PE) and phosphatidylglycerol with 16:0, 16:1, and 18:1 at position sn-2 as acyl-donors in vivo. NoPDAT KD, not triggering any compensatory mechanism via DGATs, led to an ∼30% decrease of TAG content, accompanied by a vast accumulation of PEs rich in 16:0, 16:1, and 18:1 fatty acids (referred to as "LU-PE") that was positively associated with CO2 availability. We conclude that the NoPDAT pathway is parallel to and independent of the NoDGAT pathway for oil production. LU-PE can serve as an alternative carbon sink for photosynthetically assimilated carbon in N. oceanica when PDAT-mediated TAG biosynthesis is compromised or under stress in the presence of high CO2 levels.
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Affiliation(s)
| | | | - Yufang Pan
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG‐LPCV, 38054 Grenoble Cedex 9, France
| | - Alberto Amato
- Laboratoire de Physiologie Cellulaire Végétale, Université Grenoble Alpes, CEA, CNRS, INRA, IRIG‐LPCV, 38054 Grenoble Cedex 9, France
| | - Meijing Liu
- Laboratory for Algae Biotechnology and Innovation, College of Engineering, Peking University, Beijing 100871, China
| | - Yangmin Gong
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China
| | - Yantao Li
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science and University of Maryland Baltimore County, Baltimore, Maryland 21202, USA
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Cecchin M, Cazzaniga S, Martini F, Paltrinieri S, Bossi S, Maffei ME, Ballottari M. Astaxanthin and eicosapentaenoic acid production by S4, a new mutant strain of Nannochloropsis gaditana. Microb Cell Fact 2022; 21:117. [PMID: 35710482 PMCID: PMC9204945 DOI: 10.1186/s12934-022-01847-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 06/01/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Astaxanthin is a ketocarotenoid with high antioxidant power used in different fields as healthcare, food/feed supplementation and as pigmenting agent in aquaculture. Primary producers of astaxanthin are some species of microalgae, unicellular photosynthetic organisms, as Haematococcus lacustris. Astaxanthin production by cultivation of Haematococcus lacustris is costly due to low biomass productivity, high risk of contamination and the requirement of downstream extraction processes, causing an extremely high price on the market. Some microalgae species are also primary producers of omega-3 fatty acids, essential nutrients for humans, being related to cardiovascular wellness, and required for visual and cognitive development. One of the main well-known producers of omega-3 fatty eicosapentaenoic acid (EPA) is the marine microalga Nannochloropsis gaditana (named also Microchloropsis gaditana): this species has been already approved by the Food and Drug Administration (FDA) for human consumption and it is characterized by a fast grow phenotype. RESULTS Here we obtained by chemical mutagenesis a Nannochloropsis gaditana mutant strain, called S4, characterized by increased carotenoid to chlorophyll ratio. S4 strain showed improved photosynthetic activity, increased lipid productivity and increased ketocarotenoids accumulation, producing not only canthaxanthin but also astaxanthin, usually found only in traces in the WT strain. Ketocarotenoids produced in S4 strain were extractible in different organic solvents, with the highest efficiency observed upon microwaves pre-treatment followed by methanol extraction. By cultivation of S4 strain at different irradiances it was possible to produce up to 1.3 and 5.2 mgL-1 day-1 of ketocarotenoids and EPA respectively, in a single cultivation phase, even in absence of stressing conditions. Genome sequencing of S4 strain allowed to identify 199 single nucleotide polymorphisms (SNP): among the mutated genes, mutations in a carotenoid oxygenase gene and in a glutamate synthase gene could explain the different carotenoids content and the lower chlorophylls content, respectively. CONCLUSIONS By chemical mutagenesis and selection of strain with increased carotenoids to chlorophyll ratio it was possible to isolate a new Nannochloropsis gaditana strain, called S4 strain, characterized by increased lipids and ketocarotenoids accumulation. S4 strain can thus be considered as novel platform for ketocarotenoids and EPA production for different industrial applications.
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Affiliation(s)
- Michela Cecchin
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Stefano Cazzaniga
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Flavio Martini
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Stefania Paltrinieri
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy
| | - Simone Bossi
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135, Turin, Italy
| | - Massimo E Maffei
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135, Turin, Italy
| | - Matteo Ballottari
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134, Verona, Italy.
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11
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Poliner E, Busch AWU, Newton L, Kim YU, Clark R, Gonzalez-Martinez SC, Jeong BR, Montgomery BL, Farré EM. Aureochromes maintain polyunsaturated fatty acid content in Nannochloropsis oceanica. PLANT PHYSIOLOGY 2022; 189:906-921. [PMID: 35166829 PMCID: PMC9157131 DOI: 10.1093/plphys/kiac052] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 01/12/2022] [Indexed: 05/05/2023]
Abstract
Nannochloropsis oceanica, like other stramenopile microalgae, is rich in long-chain polyunsaturated fatty acids (LC-PUFAs) such as eicosapentaenoic acid (EPA). We observed that fatty acid desaturases (FADs) involved in LC-PUFA biosynthesis were among the strongest blue light-induced genes in N. oceanica CCMP1779. Blue light was also necessary for maintaining LC-PUFA levels in CCMP1779 cells, and growth under red light led to a reduction in EPA content. Aureochromes are stramenopile-specific proteins that contain a light-oxygen-voltage (LOV)-sensing domain that associates with a flavin mononucleotide and is able to sense blue light. These proteins also contain a basic leucine zipper DNA-binding motif and can act as blue light-regulated transcription factors by associating with an E-box like motif, which we found enriched in the promoters of blue light-induced genes. We demonstrated that, in vitro, two CCMP1779 aureochromes were able to absorb blue light. Moreover, the loss or reduction of the expression of any of the three aureochrome genes led to a decrease in the blue light-specific induction of several FADs in CCMP1779. EPA content was also significantly reduced in NoAUREO2 and NoAUREO4 mutants. Taken together, our results indicate that aureochromes mediate blue light-dependent regulation of LC-PUFA content in N. oceanica CCMP1779 cells.
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Affiliation(s)
- Eric Poliner
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
- Cell and Molecular Biology Program, Michigan State University, East Lansing, Michigan, USA
| | - Andrea W U Busch
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Linsey Newton
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
| | - Young Uk Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Rachel Clark
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
| | | | - Byeong-Ryool Jeong
- Single-Cell Center, CAS Key Laboratory of Biofuels and Shandon Key Laboratory of Energy Genetics, Shandong Institute of Energy Research, Qingdao Institute of BioEnergy and Bioprocess Technology (QiBEBT), Chinese Academy of Sciences, Qingdao, Shandong 266101, China
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Korea
| | - Beronda L Montgomery
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
| | - Eva M Farré
- Department of Plant Biology, Michigan State University, East Lansing, Michigan, USA
- Author for correspondence: (E.M.F.)
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12
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Perin G, Gambaro F, Morosinotto T. Knowledge of Regulation of Photosynthesis in Outdoor Microalgae Cultures Is Essential for the Optimization of Biomass Productivity. FRONTIERS IN PLANT SCIENCE 2022; 13:846496. [PMID: 35444673 PMCID: PMC9014180 DOI: 10.3389/fpls.2022.846496] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Microalgae represent a sustainable source of biomass that can be exploited for pharmaceutical, nutraceutical, cosmetic applications, as well as for food, feed, chemicals, and energy. To make microalgae applications economically competitive and maximize their positive environmental impact, it is however necessary to optimize productivity when cultivated at a large scale. Independently from the final product, this objective requires the optimization of biomass productivity and thus of microalgae ability to exploit light for CO2 fixation. Light is a highly variable environmental parameter, continuously changing depending on seasons, time of the day, and weather conditions. In microalgae large scale cultures, cell self-shading causes inhomogeneity in light distribution and, because of mixing, cells move between different parts of the culture, experiencing abrupt changes in light exposure. Microalgae evolved multiple regulatory mechanisms to deal with dynamic light conditions that, however, are not adapted to respond to the complex mixture of natural and artificial fluctuations found in large-scale cultures, which can thus drive to oversaturation of the photosynthetic machinery, leading to consequent oxidative stress. In this work, the present knowledge on the regulation of photosynthesis and its implications for the maximization of microalgae biomass productivity are discussed. Fast mechanisms of regulations, such as Non-Photochemical-Quenching and cyclic electron flow, are seminal to respond to sudden fluctuations of light intensity. However, they are less effective especially in the 1-100 s time range, where light fluctuations were shown to have the strongest negative impact on biomass productivity. On the longer term, microalgae modulate the composition and activity of the photosynthetic apparatus to environmental conditions, an acclimation response activated also in cultures outdoors. While regulation of photosynthesis has been investigated mainly in controlled lab-scale conditions so far, these mechanisms are highly impactful also in cultures outdoors, suggesting that the integration of detailed knowledge from microalgae large-scale cultivation is essential to drive more effective efforts to optimize biomass productivity.
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13
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Sun Y, Liu Q, Shang S, Chen J, Lu P, Zang Y, Tang X. Physiological Responses and Metabonomics Analysis of Male and Female Sargassum thunbergii Macroalgae Exposed to Ultraviolet-B Stress. FRONTIERS IN PLANT SCIENCE 2022; 13:778602. [PMID: 35481140 PMCID: PMC9037290 DOI: 10.3389/fpls.2022.778602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 03/10/2022] [Indexed: 06/14/2023]
Abstract
Ultraviolet-B (UV-B) radiation is a major environmental stress that suppresses or activates defense responses in organisms. UV-B radiation affecting growth and development in intertidal species have been researched for a long time, but a series of unknown knowledge remain in the male and female macroalgae comparison. To compare the different responses of male and female Sargassum thunbergii macroalgae under UV-B radiation, PSII photochemical efficiency determination, metabolomic analysis, and main carbon-based metabolites (including soluble sugar, total amino acid, and lipid) content measuring have been performed in our experiments. Results showed that males have significantly superiority performance in the chlorophyll fluorescence parameters of F v/F m, Y(II), and Y(NO) either low or high UV-B radiation treatments. Metabolomics analysis revealed that carbon and nitrogen metabolism pathways in male and female S. thunbergii were significant components responding to enhanced UV-B radiation. Based on measuring, female S. thunbergii lipid content expressed higher than males without any stimulation. Additionally, under low UV-B radiation stimulation, females total amino acid content shown significantly higher than control group and their lipid content also significantly higher than males. Under high UV-B radiation, males soluble sugar, total amino acid, and lipid content significantly varied from females, which meant that enhancing UV-B stress might altered mainly carbon-based metabolites flowing directions. The present study elucidated the potential role of enhanced UV-B radiation in regulating macroalgae physiological responses, metabolites changing, and reflecting differences between male and female S. thunbergii, contributing to understanding of brown-macroalgae diecious adopting mechanisms in defending intertidal UV-B stresses.
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Affiliation(s)
- Yan Sun
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Qian Liu
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Shuai Shang
- College of Biological and Environmental Engineering, Binzhou University, Binzhou, China
| | - Jun Chen
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Peiyao Lu
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
| | - Yu Zang
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, China
| | - Xuexi Tang
- College of Marine Life Sciences, Ocean University of China, Qingdao, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
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14
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Heredia V, Marchal L, Gonçalves O, Pruvost J. Optimization of continuous TAG production by Nannochloropsis gaditana in solar-nitrogen-limited culture. Biotechnol Bioeng 2022; 119:1808-1819. [PMID: 35377482 DOI: 10.1002/bit.28097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 03/22/2022] [Accepted: 03/25/2022] [Indexed: 11/08/2022]
Abstract
Nitrogen limitation and changing solar conditions are both known to affect triacylglycerol (TAG) production in microalgae. This work investigates the optimization of TAG production with a continuous nitrogen-limited culture of Nannochloropsis gaditana in simulated day-night cycles. The effect of day-night cycles was firstly investigated in nitrogen-deprived condition (i.e. batch culture), emphasizing a significant change in mechanical resistance of the strain during the night. The concept of Released TAG, which shows how much of the TAG produced is actually recovered in the downstream stages, i.e. after cell disruption, was shown here of interest. For a maximum released TAG, the optimum harvesting time was suggested as being 4 hours into the night period, which minimizes the losses due to a too great cell mechanical resistance. The protocol for continuous nitrogen-limited culture was then optimized, and a continuous nitrogen addition was compared to a pulsed-addition. For the latter, nitrogen was supplied in a single pulse at the beginning of the light periods, while the bulk medium was supplied separately at a slow but constant dilution rate of 0.005 h - 1 . The pulse dose was calculated after the study of nitrogen consumption and TAG production/consumption during the day-night cycles. The estimated released TAG for the pulsed-addition of 1.4 ⋅ 1 0 - 3 kg/m 2 ⋅ d was found significantly higher than the one achieved in batch culture (0.3 ⋅ 1 0 - 3 kg/m 2 ⋅ d) but lower than for continuous nitrogen addition which obtained the highest released TAG of 3 ⋅ 1 0 - 3 kg/m 2 ⋅ d. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Vladimir Heredia
- Université de Nantes, Oniris, GEPEA, UMR 6144 F-44600, Saint-Nazaire, France
| | - Luc Marchal
- Université de Nantes, Oniris, GEPEA, UMR 6144 F-44600, Saint-Nazaire, France
| | - Olivier Gonçalves
- Université de Nantes, Oniris, GEPEA, UMR 6144 F-44600, Saint-Nazaire, France
| | - Jeremy Pruvost
- Université de Nantes, Oniris, GEPEA, UMR 6144 F-44600, Saint-Nazaire, France
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15
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Bright as day and dark as night: light-dependant energy for lipid biosynthesis and production in microalgae. World J Microbiol Biotechnol 2022; 38:70. [PMID: 35257233 DOI: 10.1007/s11274-022-03245-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 02/08/2022] [Indexed: 10/18/2022]
Abstract
Microalgae are photosynthetic organisms functioning as the green bio-factories for various pharmaceutical and biofuel products. To date, numerous attempts have been carried out to manipulate culture conditions to maximize the production of the desired metabolites. Because light is the energy source of microalgae for their growth and metabolites biosynthesis, it has been one of the most investigated variables emphasized on the deep understanding of how microalgae respond towards light changes as an external stimulus. This review discusses the effects of different light sources, light intensities, light wavelengths and length of photoperiod on various microalgae species, especially in terms of biomass and lipid productivity. Additionally, the relationship between photoregulation processes and lipid productivity of microalgae are also deliberated. The current available approaches of microalgae mass cultivation, including different types of open and closed systems are recapitulated with the intention to highlight the significant insights for the design of future photoreactors.
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16
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Rey F, Melo T, Lopes D, Couto D, Marques F, Domingues MDRM. Applications of lipidomics in marine organisms: Progresses, challenges and future perspectives. Mol Omics 2022; 18:357-386. [DOI: 10.1039/d2mo00012a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Marine ecosystems comprise a high diversity of life forms, such as algae, invertebrates, and vertebrates. These organisms have adapted their physiology according to the conditions of the environments in which...
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17
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Ben-Sheleg A, Khozin-Godberg I, Yaakov B, Vonshak A. Characterization of Nannochloropsis oceanica Rose Bengal Mutants Sheds Light on Acclimation Mechanisms to High Light When Grown in Low Temperature. PLANT & CELL PHYSIOLOGY 2021; 62:1478-1493. [PMID: 34180533 PMCID: PMC8600018 DOI: 10.1093/pcp/pcab094] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 06/23/2021] [Accepted: 06/27/2021] [Indexed: 06/13/2023]
Abstract
A barrier to realizing Nannochloropsis oceanica's potential for omega-3 eicosapentaenoic acid (EPA) production is the disparity between conditions that are optimal for growth and those that are optimal for EPA biomass content. A case in point is temperature: higher content of polyunsaturated fatty acid, and especially EPA, is observed in low-temperature (LT) environments, where growth rates are often inhibited. We hypothesized that mutant strains of N. oceanica resistant to the singlet-oxygen photosensitizer Rose Bengal (RB) would withstand the oxidative stress conditions that prevail in the combined stressful environment of high light (HL; 250 μmol photons m-2 s-1) and LT (18°C). This growth environment caused the wild-type (WT) strain to experience a spike in lipid peroxidation and an inability to proliferate, whereas growth and homeostatic reactive oxygen species levels were observed in the mutant strains. We suggest that the mutant strains' success in this environment can be attributed to their truncated photosystem II antennas and their increased ability to diffuse energy in those antennas as heat (non-photosynthetic quenching). As a result, the mutant strains produced upward of four times more EPA than the WT strain in this HL-LT environment. The major plastidial lipid monogalactosyldiacylglycerol was a likely target for oxidative damage, contributing to the photosynthetic inhibition of the WT strain. A mutation in the NO10G01010.1 gene, causing a subunit of the 2-oxoisovalerate dehydrogenase E1 protein to become non-functional, was determined to be the likely source of tolerance in the RB113 mutant strain.
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Affiliation(s)
- Avraham Ben-Sheleg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion 8499000, Israel
| | - Inna Khozin-Godberg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion 8499000, Israel
| | - Beery Yaakov
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion 8499000, Israel
| | - Avigad Vonshak
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, Jacob Blaustein Institute for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion 8499000, Israel
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18
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Fattore N, Bellan A, Pedroletti L, Vitulo N, Morosinotto T. Acclimation of photosynthesis and lipids biosynthesis to prolonged nitrogen and phosphorus limitation in Nannochloropsis gaditana. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102368] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Wu T, Yu L, Zhang Y, Liu J. Characterization of fatty acid desaturases reveals stress-induced synthesis of C18 unsaturated fatty acids enriched in triacylglycerol in the oleaginous alga Chromochloris zofingiensis. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:184. [PMID: 34535156 PMCID: PMC8447527 DOI: 10.1186/s13068-021-02037-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 09/07/2021] [Indexed: 05/16/2023]
Abstract
BACKGROUND The green microalga Chromochloris zofingiensis is capable of producing high levels of triacylglycerol rich in C18 unsaturated fatty acids (UFAs). FA desaturation degree is regulated by FA desaturases (FADs). Nevertheless, it remains largely unknown regarding what FADs are involved in FA desaturations and how these FADs collaborate to contribute to the high abundance of C18 UFAs in triacylglycerol in C. zofingiensis. RESULTS To address these issues, we firstly determined the transcription start sites of 11 putative membrane-bound FAD-coding genes (CzFADs) and updated their gene models. Functional validation of these CzFADs in yeast and cyanobacterial cells revealed that seven are bona fide FAD enzymes with distinct substrates. Combining the validated functions and predicted subcellular compartments of CzFADs and the FA profiles of C. zofingiensis, the FA desaturation pathways in this alga were reconstructed. Furthermore, a multifaceted lipidomic analysis by systematically integrating thin-layer chromatography, gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry techniques was conducted, unraveling profiles of polar membrane lipids in C. zofingiensis and major desaturation steps occurring in these lipids. By correlating transcriptional patterns of CzFAD genes and changes of lipids upon abiotic stress conditions, our results highlighted collaboration of CzFADs for C18 UFA synthesis and supported that both de novo FA synthesis and membrane lipid remodeling contributed C18 UFAs to triacylglycerol for storage. CONCLUSIONS Taken together, our study for the first time elucidated the pathways of C18 FA desaturations and comprehensive profiles of polar membrane lipids in C. zofingiensis and shed light on collaboration of CzFADs for the synthesis and enrichment of C18 UFAs in triacylglycerol.
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Affiliation(s)
- Tao Wu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Lihua Yu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Yu Zhang
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
| | - Jin Liu
- Laboratory for Algae Biotechnology & Innovation, College of Engineering, Peking University, Beijing, 100871 China
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20
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Carneiro M, Chini Zittelli G, Cicchi B, Touloupakis E, Faraloni C, Maia IB, Pereira H, Santos T, Malcata FX, Otero A, Varela J, Torzillo G. In situ monitoring of chlorophyll a fluorescence in Nannochloropsis oceanica cultures to assess photochemical changes and the onset of lipid accumulation during nitrogen deprivation. Biotechnol Bioeng 2021; 118:4375-4388. [PMID: 34319592 DOI: 10.1002/bit.27906] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/13/2021] [Accepted: 07/17/2021] [Indexed: 01/28/2023]
Abstract
In situ chlorophyll a fluorescence measurements were applied to monitor changes in the photochemical variables of Nannochloropsis oceanica cultures under nitrogen-deplete and nitrogen-replete (control) conditions. In addition, growth, lipid, fatty acid, and pigment contents were also followed. In the control culture, growth was promoted along with pigment content, electron transport rate (ETR), and polyunsaturated fatty acids, while total lipid content and fatty acid saturation level diminished. Under nitrogen-deplete conditions, the culture showed a higher de-epoxidation state of the xanthophyll cycle pigments. Fast transients revealed a poor processing efficiency for electron transfer beyond QA , which was in line with the low ETR due to nitrogen depletion. Lipid content and the de-epoxidation state were the first biochemical variables triggered by the change in nutrient status, which coincided with a 20% drop in the in situ effective quantum yield of PSII (ΔF'/Fm '), and a raise in the Vj measurements. A good correlation was found between the changes in ΔF'/Fm ' and lipid content (r = -0.96, p < 0.01). The results confirm the reliability and applicability of in situ fluorescence measurements to monitor lipid induction in N. oceanica.
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Affiliation(s)
- Mariana Carneiro
- LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering of the University of Porto, Porto, Portugal
| | | | - Bernardo Cicchi
- CNR-IBE-Consiglio Nazionale delle Ricerche-Istituto per la BioEconomia, Florence, Italy
| | - Eleftherios Touloupakis
- CNR-IRET - Consiglio Nazionale delle Ricerche-Istituto di Ricerca sugli Ecosistemi Terrestri, Florence, Italy
| | - Cecilia Faraloni
- CNR-IBE-Consiglio Nazionale delle Ricerche-Istituto per la BioEconomia, Florence, Italy
| | - Inês B Maia
- CCMAR-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Hugo Pereira
- Green Colab-Associação Oceano Verde, University of Algarve, Campus de Gambelas, Faro, Portugal
| | - Tamára Santos
- CCMAR-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Francisco X Malcata
- LEPABE-Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering of the University of Porto, Porto, Portugal
| | - Ana Otero
- USC-Instituto de Acuicultura and Departamento de Microbiología y Parasitología, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - João Varela
- CCMAR-Centre of Marine Sciences, University of Algarve, Faro, Portugal
| | - Giuseppe Torzillo
- CNR-IBE-Consiglio Nazionale delle Ricerche-Istituto per la BioEconomia, Florence, Italy.,CIMAR-Centro de Investigación en Ciencias del Mar y Limnología, Universidad de Costa Rica, San José, Costa Rica
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21
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Bo DD, Magneschi L, Bedhomme M, Billey E, Deragon E, Storti M, Menneteau M, Richard C, Rak C, Lapeyre M, Lembrouk M, Conte M, Gros V, Tourcier G, Giustini C, Falconet D, Curien G, Allorent G, Petroutsos D, Laeuffer F, Fourage L, Jouhet J, Maréchal E, Finazzi G, Collin S. Consequences of Mixotrophy on Cell Energetic Metabolism in Microchloropsis gaditana Revealed by Genetic Engineering and Metabolic Approaches. FRONTIERS IN PLANT SCIENCE 2021; 12:628684. [PMID: 34113360 PMCID: PMC8185151 DOI: 10.3389/fpls.2021.628684] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 03/31/2021] [Indexed: 06/12/2023]
Abstract
Algae belonging to the Microchloropsis genus are promising organisms for biotech purposes, being able to accumulate large amounts of lipid reserves. These organisms adapt to different trophic conditions, thriving in strict photoautotrophic conditions, as well as in the concomitant presence of light plus reduced external carbon as energy sources (mixotrophy). In this work, we investigated the mixotrophic responses of Microchloropsis gaditana (formerly Nannochloropsis gaditana). Using the Biolog growth test, in which cells are loaded into multiwell plates coated with different organic compounds, we could not find a suitable substrate for Microchloropsis mixotrophy. By contrast, addition of the Lysogeny broth (LB) to the inorganic growth medium had a benefit on growth, enhancing respiratory activity at the expense of photosynthetic performances. To further dissect the role of respiration in Microchloropsis mixotrophy, we focused on the mitochondrial alternative oxidase (AOX), a protein involved in energy management in other algae prospering in mixotrophy. Knocking-out the AOX1 gene by transcription activator-like effector nuclease (TALE-N) led to the loss of capacity to implement growth upon addition of LB supporting the hypothesis that the effect of this medium was related to a provision of reduced carbon. We conclude that mixotrophic growth in Microchloropsis is dominated by respiratory rather than by photosynthetic energetic metabolism and discuss the possible reasons for this behavior in relationship with fatty acid breakdown via β-oxidation in this oleaginous alga.
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Affiliation(s)
- Davide Dal Bo
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Leonardo Magneschi
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Mariette Bedhomme
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Elodie Billey
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
- Total Refining Chemicals, Tour Coupole, Paris La Défense, France
| | - Etienne Deragon
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Mattia Storti
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Mathilde Menneteau
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Christelle Richard
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Camille Rak
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Morgane Lapeyre
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Mehdi Lembrouk
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Melissa Conte
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Valérie Gros
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Guillaume Tourcier
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Cécile Giustini
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Denis Falconet
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Gilles Curien
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Guillaume Allorent
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Dimitris Petroutsos
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | | | - Laurent Fourage
- Total Refining Chemicals, Tour Coupole, Paris La Défense, France
| | - Juliette Jouhet
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Eric Maréchal
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Giovanni Finazzi
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
| | - Séverine Collin
- Université Grenoble Alpes (UGA), Centre National Recherche Scientifique (CNRS), Commissariat Energie Atomique, Energies Alternatives (CEA), Institut National Recherche Agriculture, Alimentation, Environnement (INRAE), Interdisciplinary Research Institute of Grenoble, IRIG-Laboratoire de Physiologie Cellulaire et Végétale, Grenoble, France
- Total Refining Chemicals, Tour Coupole, Paris La Défense, France
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22
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High-throughput insertional mutagenesis reveals novel targets for enhancing lipid accumulation in Nannochloropsis oceanica. Metab Eng 2021; 66:239-258. [PMID: 33971293 DOI: 10.1016/j.ymben.2021.04.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/07/2021] [Accepted: 04/18/2021] [Indexed: 12/17/2022]
Abstract
The microalga Nannochloropsis oceanica is considered a promising platform for the sustainable production of high-value lipids and biofuel feedstocks. However, current lipid yields of N. oceanica are too low for economic feasibility. Gaining fundamental insights into the lipid metabolism of N. oceanica could open up various possibilities for the optimization of this species through genetic engineering. Therefore, the aim of this study was to discover novel genes associated with an elevated neutral lipid content. We constructed an insertional mutagenesis library of N. oceanica, selected high lipid mutants by five rounds of fluorescence-activated cell sorting, and identified disrupted genes using a novel implementation of a rapid genotyping procedure. One particularly promising mutant (HLM23) was disrupted in a putative APETALA2-like transcription factor gene. HLM23 showed a 40%-increased neutral lipid content, increased photosynthetic performance, and no growth impairment. Furthermore, transcriptome analysis revealed an upregulation of genes related to plastidial fatty acid biosynthesis, glycolysis and the Calvin-Benson-Bassham cycle in HLM23. Insights gained in this work can be used in future genetic engineering strategies for increased lipid productivity of Nannochloropsis.
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23
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Guéguen N, Le Moigne D, Amato A, Salvaing J, Maréchal E. Lipid Droplets in Unicellular Photosynthetic Stramenopiles. FRONTIERS IN PLANT SCIENCE 2021; 12:639276. [PMID: 33968100 PMCID: PMC8100218 DOI: 10.3389/fpls.2021.639276] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/17/2021] [Indexed: 06/12/2023]
Abstract
The Heterokonta or Stramenopile phylum comprises clades of unicellular photosynthetic species, which are promising for a broad range of biotechnological applications, based on their capacity to capture atmospheric CO2 via photosynthesis and produce biomolecules of interest. These molecules include triacylglycerol (TAG) loaded inside specific cytosolic bodies, called the lipid droplets (LDs). Understanding TAG production and LD biogenesis and function in photosynthetic stramenopiles is therefore essential, and is mostly based on the study of a few emerging models, such as the pennate diatom Phaeodactylum tricornutum and eustigmatophytes, such as Nannochloropsis and Microchloropsis species. The biogenesis of cytosolic LD usually occurs at the level of the endoplasmic reticulum. However, stramenopile cells contain a complex plastid deriving from a secondary endosymbiosis, limited by four membranes, the outermost one being connected to the endomembrane system. Recent cell imaging and proteomic studies suggest that at least some cytosolic LDs might be associated to the surface of the complex plastid, via still uncharacterized contact sites. The carbon length and number of double bonds of the acyl groups contained in the TAG molecules depend on their origin. De novo synthesis produces long-chain saturated or monounsaturated fatty acids (SFA, MUFA), whereas subsequent maturation processes lead to very long-chain polyunsaturated FA (VLC-PUFA). TAG composition in SFA, MUFA, and VLC-PUFA reflects therefore the metabolic context that gave rise to the formation of the LD, either via an early partitioning of carbon following FA de novo synthesis and/or a recycling of FA from membrane lipids, e.g., plastid galactolipids or endomembrane phosphor- or betaine lipids. In this review, we address the relationship between cytosolic LDs and the complex membrane compartmentalization within stramenopile cells, the metabolic routes leading to TAG accumulation, and the physiological conditions that trigger LD production, in response to various environmental factors.
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24
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Billey E, Magneschi L, Leterme S, Bedhomme M, Andres-Robin A, Poulet L, Michaud M, Finazzi G, Dumas R, Crouzy S, Laueffer F, Fourage L, Rébeillé F, Amato A, Collin S, Jouhet J, Maréchal E. Characterization of the Bubblegum acyl-CoA synthetase of Microchloropsis gaditana. PLANT PHYSIOLOGY 2021; 185:815-835. [PMID: 33793914 PMCID: PMC8133546 DOI: 10.1093/plphys/kiaa110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 12/15/2020] [Indexed: 05/15/2023]
Abstract
The metabolic pathways of glycerolipids are well described in cells containing chloroplasts limited by a two-membrane envelope but not in cells containing plastids limited by four membranes, including heterokonts. Fatty acids (FAs) produced in the plastid, palmitic and palmitoleic acids (16:0 and 16:1), are used in the cytosol for the synthesis of glycerolipids via various routes, requiring multiple acyl-Coenzyme A (CoA) synthetases (ACS). Here, we characterized an ACS of the Bubblegum subfamily in the photosynthetic eukaryote Microchloropsis gaditana, an oleaginous heterokont used for the production of lipids for multiple applications. Genome engineering with TALE-N allowed the generation of MgACSBG point mutations, but no knockout was obtained. Point mutations triggered an overall decrease of 16:1 in lipids, a specific increase of unsaturated 18-carbon acyls in phosphatidylcholine and decrease of 20-carbon acyls in the betaine lipid diacylglyceryl-trimethyl-homoserine. The profile of acyl-CoAs highlighted a decrease in 16:1-CoA and 18:3-CoA. Structural modeling supported that mutations affect accessibility of FA to the MgACSBG reaction site. Expression in yeast defective in acyl-CoA biosynthesis further confirmed that point mutations affect ACSBG activity. Altogether, this study supports a critical role of heterokont MgACSBG in the production of 16:1-CoA and 18:3-CoA. In M. gaditana mutants, the excess saturated and monounsaturated FAs were diverted to triacylglycerol, thus suggesting strategies to improve the oil content in this microalga.
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Affiliation(s)
- Elodie Billey
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
- Total Raffinage-Chimie, Tour Coupole, 2 Place Jean Millier, 92078 Paris La Défense, France
| | - Leonardo Magneschi
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Sébastien Leterme
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Mariette Bedhomme
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
- Total Raffinage-Chimie, Tour Coupole, 2 Place Jean Millier, 92078 Paris La Défense, France
| | - Amélie Andres-Robin
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Laurent Poulet
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Morgane Michaud
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Giovanni Finazzi
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Renaud Dumas
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Serge Crouzy
- Laboratoire de Chimie et Biologie des Métaux, Unité mixte de Recherche 5249 CNRS–CEA–Univ. Grenoble Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Frédéric Laueffer
- Total Raffinage-Chimie, Tour Coupole, 2 Place Jean Millier, 92078 Paris La Défense, France
| | - Laurent Fourage
- Total Raffinage-Chimie, Tour Coupole, 2 Place Jean Millier, 92078 Paris La Défense, France
| | - Fabrice Rébeillé
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Alberto Amato
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Séverine Collin
- Total Raffinage-Chimie, Tour Coupole, 2 Place Jean Millier, 92078 Paris La Défense, France
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixte de Recherche 5168 CNRS–CEA–INRA–Univ. Grenoble-Alpes, IRIG, CEA Grenoble, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France
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25
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Lu Y, Gan Q, Iwai M, Alboresi A, Burlacot A, Dautermann O, Takahashi H, Crisanto T, Peltier G, Morosinotto T, Melis A, Niyogi KK. Role of an ancient light-harvesting protein of PSI in light absorption and photoprotection. Nat Commun 2021; 12:679. [PMID: 33514722 PMCID: PMC7846763 DOI: 10.1038/s41467-021-20967-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 01/05/2021] [Indexed: 12/18/2022] Open
Abstract
Diverse algae of the red lineage possess chlorophyll a-binding proteins termed LHCR, comprising the PSI light-harvesting system, which represent an ancient antenna form that evolved in red algae and was acquired through secondary endosymbiosis. However, the function and regulation of LHCR complexes remain obscure. Here we describe isolation of a Nannochloropsis oceanica LHCR mutant, named hlr1, which exhibits a greater tolerance to high-light (HL) stress compared to the wild type. We show that increased tolerance to HL of the mutant can be attributed to alterations in PSI, making it less prone to ROS production, thereby limiting oxidative damage and favoring growth in HL. HLR1 deficiency attenuates PSI light-harvesting capacity and growth of the mutant under light-limiting conditions. We conclude that HLR1, a member of a conserved and broadly distributed clade of LHCR proteins, plays a pivotal role in a dynamic balancing act between photoprotection and efficient light harvesting for photosynthesis. LHCR proteins are ancient chlorophyll a-binding antennas that evolved in diverse algae of the red lineage. Here Lu et al. characterize a red lineage LHCR mutant and show reduced oxidative damage in high light but attenuated growth under low light, thus demonstrating how LHCR proteins impact the balance between photoprotection and light harvesting.
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Affiliation(s)
- Yandu Lu
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan University, Haikou, Hainan, China. .,Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.
| | - Qinhua Gan
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan University, Haikou, Hainan, China
| | - Masakazu Iwai
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Adrien Burlacot
- CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix-Marseille, UMR 7265, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, Saint-Paul-lezDurance, France
| | - Oliver Dautermann
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Hiroko Takahashi
- Department of Biochemistry and Molecular Biology, Graduate school of Science and Engineering, Saitama University, Saitama, Japan
| | - Thien Crisanto
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Gilles Peltier
- CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix-Marseille, UMR 7265, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, Saint-Paul-lezDurance, France
| | | | - Anastasios Melis
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Krishna K Niyogi
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA. .,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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26
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Azaman SNA, Wong DCJ, Tan SW, Yusoff FM, Nagao N, Yeap SK. De novo transcriptome analysis of Chlorella sorokiniana: effect of glucose assimilation, and moderate light intensity. Sci Rep 2020; 10:17331. [PMID: 33060668 PMCID: PMC7562877 DOI: 10.1038/s41598-020-74410-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 10/01/2020] [Indexed: 02/01/2023] Open
Abstract
Chlorella can produce an unusually wide range of metabolites under various nutrient availability, carbon source, and light availability. Glucose, an essential molecule for the growth of microorganisms, also contributes significantly to the metabolism of various metabolic compounds produced by Chlorella. In addition, manipulation of light intensity also induces the formation of secondary metabolites such as pigments, and carotenoids in Chlorella. This study will focus on the effect of glucose addition, and moderate light on the regulation of carotenoid, lipid, starch, and other key metabolic pathways in Chlorella sorokiniana. To gain knowledge about this, we performed transcriptome profiling on C. sorokiniana strain NIES-2168 in response to moderate light stress supplemented with glucose under mixotrophic conditions. A total of 60,982,352 raw paired-end (PE) reads 100 bp in length was obtained from both normal, and mixotrophic samples of C. sorokiniana. After pre-processing, 93.63% high-quality PE reads were obtained, and 18,310 predicted full-length transcripts were assembled. Differential gene expression showed that a total of 937, and 1124 genes were upregulated, and downregulated in mixotrophic samples, respectively. Transcriptome analysis revealed that the mixotrophic condition caused upregulation of genes involved in carotenoids production (specifically lutein biosynthesis), fatty acid biosynthesis, TAG accumulation, and the majority of the carbon fixation pathways. Conversely, starch biosynthesis, sucrose biosynthesis, and isoprenoid biosynthesis were downregulated. Novel insights into the pathways that link the enhanced production of valuable metabolites (such as carotenoids in C. sorokiniana) grown under mixotrophic conditions is presented.
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Affiliation(s)
- Siti Nor Ani Azaman
- Centre of Foundation Studies for Agricultural Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- Aquatic Animal Health and Therapeutics Laboratory (AquaHealth), Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Darren C J Wong
- Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT, 2600, Australia
| | - Sheau Wei Tan
- Laboratory of Vaccine and Biomolecules (VacBio), Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Fatimah M Yusoff
- International Institute of Aquaculture and Aquatic Sciences (I-AQUAS), Universiti Putra Malaysia, Port Dickson, Negeri Sembilan, Malaysia
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
| | - Norio Nagao
- Aquatic Animal Health and Therapeutics Laboratory (AquaHealth), Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia
- , 102 Naname-go, Shinkamigoto-cho, Minami Matsuura-Gun, Nagasaki, 857-4214, Japan
| | - Swee Keong Yeap
- China-ASEAN College of Marine Sciences, Xiamen University Malaysia, Sepang, Selangor, Malaysia.
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27
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Proteomic and Transcriptomic Patterns during Lipid Remodeling in Nannochloropsis gaditana. Int J Mol Sci 2020; 21:ijms21186946. [PMID: 32971781 PMCID: PMC7554720 DOI: 10.3390/ijms21186946] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/16/2020] [Accepted: 09/17/2020] [Indexed: 12/24/2022] Open
Abstract
Nutrient limited conditions are common in natural phytoplankton communities and are often used to increase the yield of lipids from industrial microalgae cultivations. Here we studied the effects of bioavailable nitrogen (N) and phosphorus (P) deprivation on the proteome and transcriptome of the oleaginous marine microalga Nannochloropsis gaditana. Turbidostat cultures were used to selectively apply either N or P deprivation, controlling for variables including the light intensity. Global (cell-wide) changes in the proteome were measured using Tandem Mass Tag (TMT) and LC-MS/MS, whilst gene transcript expression of the same samples was quantified by Illumina RNA-sequencing. We detected 3423 proteins, where 1543 and 113 proteins showed significant changes in abundance in N and P treatments, respectively. The analysis includes the global correlation between proteomic and transcriptomic data, the regulation of subcellular proteomes in different compartments, gene/protein functional groups, and metabolic pathways. The results show that triacylglycerol (TAG) accumulation under nitrogen deprivation was associated with substantial downregulation of protein synthesis and photosynthetic activity. Oil accumulation was also accompanied by a diverse set of responses including the upregulation of diacylglycerol acyltransferase (DGAT), lipase, and lipid body associated proteins. Deprivation of phosphorus had comparatively fewer, weaker effects, some of which were linked to the remodeling of respiratory metabolism.
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28
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Han X, Song X, Li F, Lu Y. Improving lipid productivity by engineering a control-knob gene in the oleaginous microalga Nannochloropsis oceanica. Metab Eng Commun 2020; 11:e00142. [PMID: 32995270 PMCID: PMC7516279 DOI: 10.1016/j.mec.2020.e00142] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/06/2020] [Accepted: 08/19/2020] [Indexed: 01/08/2023] Open
Abstract
Nannochloropsis spp. are promising industrial microalgae for scalable oil production and the lipid production can be boosted by nutrient starvation and high irradiance. However, these stimuli halt growth, thereby decreasing overall productivity. In this study, we created transgenic N. oceanica where AtDXS gene encoding 1-deoxy-D-xylulose 5-phosphate synthase (DXS) derived from Arabidopsis thaliana was overexpressed in vivo. Compared with the wild type (WT), engineered Nannochloropsis showed a higher CO2 absorption capacity and produced more biomass, lipids, and carbohydrates with more robust growth in either preferred conditions or various stressed conditions (low light, high light, nitrogen starvation, and trace element depletion). Specifically, relative to the WT, lipid production increased by ~68.6% in nitrogen depletion (~1.08 g L−1) and ~110.6% in high light (~1.15 g L−1) in the transgenic strains. As for neutral lipid (triacylglycerol, TAG), the engineered strains produced ~93.2% more in nitrogen depletion (~0.77 g L−1) and ~148.6% more in high light (~0.80 g L−1) than the WT. These values exceed available records in engineered industrial microalgae. Therefore, engineering control-knob genes could modify multiple biological processes simultaneously and enable efficient carbon partitioning to lipid biosynthesis with elevated biomass productivity. It could be further exploited for simultaneous enhancement of growth property and oil productivity in more industrial microalgae. An oil-rich strain Nannochloropsis AtDXSoe3 was genetically created. AtDXSoe3 produces ~110.6% more total lipids than wild-type stain. AtDXSoe3 produces ~148.6% more neutral lipid than wild-type stain. AtDXSoe3 exceeds documented engineered microalgae in oil production. Crucial algal traits could be improved by engineering a single ‘control knob’ gene.
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Affiliation(s)
- Xiao Han
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan University, Haikou, 570228, Hainan Province, China
| | - Xiaojin Song
- Shandong Provincial Key Laboratory of Energy Genetics, CAS Key Laboratory of Biofuels, Qingdao Engineering Laboratory of Single Cell Oil, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, Shandong, China
| | - Falan Li
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan University, Haikou, 570228, Hainan Province, China
| | - Yandu Lu
- State Key Laboratory of Marine Resource Utilization in South China Sea, College of Oceanology, Hainan University, Haikou, 570228, Hainan Province, China
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Kareya MS, Mariam I, Shaikh KM, Nesamma AA, Jutur PP. Photosynthetic Carbon Partitioning and Metabolic Regulation in Response to Very-Low and High CO 2 in Microchloropsis gaditana NIES 2587. FRONTIERS IN PLANT SCIENCE 2020; 11:981. [PMID: 32719702 PMCID: PMC7348049 DOI: 10.3389/fpls.2020.00981] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 06/16/2020] [Indexed: 05/06/2023]
Abstract
Photosynthetic organisms fix inorganic carbon through carbon capture machinery (CCM) that regulates the assimilation and accumulation of carbon around ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). However, few constraints that govern the central carbon metabolism are regulated by the carbon capture and partitioning machinery. In order to divert the cellular metabolism toward lipids and/or biorenewables it is important to investigate and understand the molecular mechanisms of the CO2-driven carbon partitioning. In this context, strategies for enhancement of CO2 fixation which will increase the overall biomass and lipid yields, can provide clues on understanding the carbon assimilation pathway, and may lead to new targets for genetic engineering in microalgae. In the present study, we have focused on the physiological and metabolomic response occurring within marine oleaginous microalgae Microchloropsis gaditana NIES 2587, under the influence of very-low CO2 (VLC; 300 ppm, or 0.03%) and high CO2 (HC; 30,000 ppm, or 3% v/v). Our results demonstrate that HC supplementation in M. gaditana channelizes the carbon flux toward the production of long chain polyunsaturated fatty acids (LC-PUFAs) and also increases the overall biomass productivities (up to 2.0 fold). Also, the qualitative metabolomics has identified nearly 31 essential metabolites, among which there is a significant fold change observed in accumulation of sugars and alcohols such as galactose and phytol in VLC as compared to HC. In conclusion, our focus is to understand the entire carbon partitioning and metabolic regulation within these photosynthetic cell factories, which will be further evaluated through multiomics approach for enhanced productivities of biomass, biofuels, and bioproducts (B3).
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Affiliation(s)
| | | | | | | | - Pannaga Pavan Jutur
- Omics of Algae Group, Industrial Biotechnology, International Centre for Genetic Engineering and Biotechnology, New Delhi, India
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30
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Cecchin M, Berteotti S, Paltrinieri S, Vigliante I, Iadarola B, Giovannone B, Maffei ME, Delledonne M, Ballottari M. Improved lipid productivity in Nannochloropsis gaditana in nitrogen-replete conditions by selection of pale green mutants. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:78. [PMID: 32336989 PMCID: PMC7175523 DOI: 10.1186/s13068-020-01718-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/15/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Nannochloropsis gaditana is a photosynthetic unicellular microalgae considered one of the most interesting marine algae to produce biofuels and food additive due to its rapid growth rate and high lipid accumulation. Although microalgae are attractive platforms for solar energy bioconversion, the overall efficiency of photosynthesis is reduced due to the steep light gradient in photobioreactors. Moreover, accumulation of lipids in microalgae for biofuels production is usually induced in a two-phase cultivation process by nutrient starvation, with additional time and costs associated. In this work, a biotechnological approach was directed for the isolation of strains with improved light penetration in photobioreactor combined with increased lipids productivity. RESULTS Mutants of Nannochloropsis gaditana were obtained by chemical mutagenesis and screened for having both a reduced chlorophyll content per cell and increased affinity for Nile red, a fluorescent dye which binds to cellular lipid fraction. Accordingly, one mutant, called e8, was selected and characterized for having a 30% reduction of chlorophyll content per cell and an almost 80% increase of lipid productivity compared to WT in nutrient-replete conditions, with C16:0 and C18:0 fatty acids being more than doubled in the mutant. Whole-genome sequencing revealed mutations in 234 genes in e8 mutant among which there is a non-conservative mutation in the dgd1 synthase gene. This gene encodes for an enzyme involved in the biosynthesis of DGDG, one of the major lipids found in the thylakoid membrane and it is thus involved in chloroplast biogenesis. Lipid biosynthesis is strongly influenced by light availability in several microalgae species, including Nannochloropsis gaditana: reduced chlorophyll content per cell and more homogenous irradiance in photobioreactor is at the base for the increased lipid productivity observed in the e8 mutant. CONCLUSIONS The results herein obtained presents a promising strategy to produce algal biomass enriched in lipid fraction to be used for biofuel and biodiesel production in a single cultivation process, without the additional complexity of the nutrient starvation phase. Genome sequencing and identification of the mutations introduced in e8 mutant suggest possible genes responsible for the observed phenotypes, identifying putative target for future complementation and biotechnological application.
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Affiliation(s)
- Michela Cecchin
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Silvia Berteotti
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Stefania Paltrinieri
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Ivano Vigliante
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135 Turin, Italy
| | - Barbara Iadarola
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Barbara Giovannone
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Massimo E. Maffei
- Dipartimento di Scienze della Vita e Biologia dei Sistemi, Unità di Fisiologia Vegetale, Università di Torino, Via Quarello 15/a, 10135 Turin, Italy
| | - Massimo Delledonne
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
| | - Matteo Ballottari
- Dipartimento di Biotecnologie, Università degli Studi di Verona, Strada le Grazie 15, 37134 Verona, Italy
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Red Light Variation an Effective Alternative to Regulate Biomass and Lipid Profiles in Phaeodactylum tricornutum. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10072531] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Marine water diatom Phaeodactylum tricornutum is a photosynthetic organism that is known to respond to the changing light environment and adapt to different temperatures to prevent photoinhibition and maintain its metabolic functions. The objective of the present study was to test whether light shift variations in different growth phases impact the growth and lipid metabolism of P. tricornutum. Thus, we investigated R exposure in different growth phases to find the most effective light shift condition. The results showed that substituting white light (W) by red light (R) under autotrophic conditions, a condition called red shift (RS), increased biomass and lipid content compared to levels found under continuous W or R exposure alone. We observed an increase by 2-fold biomass and 2.3-fold lipid content in RS as compared to W. No significant change was observed in the morphology of lipid droplets, but the fatty acid (FA) composition was altered. Specifically, polyunsaturated FAs were increased, whereas monounsaturated FAs decreased in P. tricornutum grown in RS compared to W control. Therefore, we propose that a light shift during the beginning of the stationary phase is a low-cost cultivation strategy to boost the total biomass and lipids in P. tricornutum.
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32
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Wang B, Jia J. Photoprotection mechanisms of Nannochloropsis oceanica in response to light stress. ALGAL RES 2020. [DOI: 10.1016/j.algal.2019.101784] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Jaussaud A, Lupette J, Salvaing J, Jouhet J, Bastien O, Gromova M, Maréchal E. Stepwise Biogenesis of Subpopulations of Lipid Droplets in Nitrogen Starved Phaeodactylum tricornutum Cells. FRONTIERS IN PLANT SCIENCE 2020; 11:48. [PMID: 32117386 PMCID: PMC7026457 DOI: 10.3389/fpls.2020.00048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 01/14/2020] [Indexed: 05/05/2023]
Abstract
Diatoms are unicellular heterokonts, living in oceans and freshwaters, exposed to frequent environmental variations. They have a sophisticated membrane compartmentalization and are bounded by a siliceous cell-wall. Formation of lipid droplets (LDs), filled with triacylglycerol (TAG), is a common response to stress. The proteome of mature-LDs from Phaeodactylum tricornutum highlighted the lack of proteins involved in early-LD formation, TAG biosynthesis or LD-to-LD connections. These features suggest that cytosolic LDs might reach a size limit. We analyzed the dynamics of LD formation in P. tricornutum (Pt1 8.6; CCAP 1055/1) during 7 days of nitrogen starvation, by monitoring TAG by mass spectrometry-based lipidomics, and LD radius using epifluorescence microscopy and pulse field gradient nuclear magnetic resonance. We confirmed that mature LDs reach a maximal size. Based on pulse field gradient nuclear magnetic resonance, we did not detect any LD-LD fusion. Three LD subpopulations were produced, each with a different maximal size, larger-sized LDs (radius 0.675 ± 0.125 µm) being generated first. Mathematical modeling showed how smaller LDs are produced once larger LDs have reached their maximum radius. In a mutant line having larger cells, the maximal size of the first LD subpopulation was higher (0.941 ± 0.169 µm), while the principle of stepwise formation of distinct LD populations was maintained. Results suggest that LD size is determined by available cytosolic space and sensing of an optimal size reached in the previous LD subpopulation. Future perspectives include the unraveling of LD-size control mechanisms upon nitrogen shortage. This study also provides novel prospects for the optimization of oleaginous microalgae for biotechnological applications.
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Affiliation(s)
- Antoine Jaussaud
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National de la Recherche Scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, IRIG, CEA-Grenoble, Grenoble, France
| | - Josselin Lupette
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National de la Recherche Scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, IRIG, CEA-Grenoble, Grenoble, France
- Plant Research Laboratory, Department of Energy, Michigan State University, MI, East Lansing, USA
| | - Juliette Salvaing
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National de la Recherche Scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, IRIG, CEA-Grenoble, Grenoble, France
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National de la Recherche Scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, IRIG, CEA-Grenoble, Grenoble, France
| | - Olivier Bastien
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National de la Recherche Scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, IRIG, CEA-Grenoble, Grenoble, France
| | - Marina Gromova
- Laboratoire Modélisation et Exploration des Matériaux, Université Grenoble Alpes, Commissariat à l'énergie atomique et aux énergies alternatives, IRIG, CEA-Grenoble, Grenoble, France
- *Correspondence: Marina Gromova, ; Eric Maréchal,
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, Université Grenoble Alpes, Centre National de la Recherche Scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement, IRIG, CEA-Grenoble, Grenoble, France
- *Correspondence: Marina Gromova, ; Eric Maréchal,
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34
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Transcriptomic and metabolomic adaptation of Nannochloropsis gaditana grown under different light regimes. ALGAL RES 2020. [DOI: 10.1016/j.algal.2019.101735] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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35
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Cecchin M, Marcolungo L, Rossato M, Girolomoni L, Cosentino E, Cuine S, Li‐Beisson Y, Delledonne M, Ballottari M. Chlorella vulgaris genome assembly and annotation reveals the molecular basis for metabolic acclimation to high light conditions. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:1289-1305. [PMID: 31437318 PMCID: PMC6972661 DOI: 10.1111/tpj.14508] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/05/2019] [Accepted: 08/07/2019] [Indexed: 05/05/2023]
Abstract
Chlorella vulgaris is a fast-growing fresh-water microalga cultivated on the industrial scale for applications ranging from food to biofuel production. To advance our understanding of its biology and to establish genetics tools for biotechnological manipulation, we sequenced the nuclear and organelle genomes of Chlorella vulgaris 211/11P by combining next generation sequencing and optical mapping of isolated DNA molecules. This hybrid approach allowed us to assemble the nuclear genome in 14 pseudo-molecules with an N50 of 2.8 Mb and 98.9% of scaffolded genome. The integration of RNA-seq data obtained at two different irradiances of growth (high light, HL versus low light, LL) enabled us to identify 10 724 nuclear genes, coding for 11 082 transcripts. Moreover, 121 and 48 genes, respectively, were found in the chloroplast and mitochondrial genome. Functional annotation and expression analysis of nuclear, chloroplast and mitochondrial genome sequences revealed particular features of Chlorella vulgaris. Evidence of horizontal gene transfers from chloroplast to mitochondrial genome was observed. Furthermore, comparative transcriptomic analyses of LL versus HL provided insights into the molecular basis for metabolic rearrangement under HL versus LL conditions leading to enhanced de novo fatty acid biosynthesis and triacylglycerol accumulation. The occurrence of a cytosolic fatty acid biosynthetic pathway could be predicted and its upregulation upon HL exposure was observed, consistent with the increased lipid amount under HL conditions. These data provide a rich genetic resource for future genome editing studies, and potential targets for biotechnological manipulation of Chlorella vulgaris or other microalgae species to improve biomass and lipid productivity.
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Affiliation(s)
- Michela Cecchin
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Luca Marcolungo
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Marzia Rossato
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Laura Girolomoni
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Emanuela Cosentino
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Stephan Cuine
- Institute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265Aix‐Marseille UniversityCEACNRSCEA CadaracheSaint‐Paul‐lez DuranceF‐13108France
| | - Yonghua Li‐Beisson
- Institute of Biosciences and Biotechnologies of Aix‐Marseille, UMR7265Aix‐Marseille UniversityCEACNRSCEA CadaracheSaint‐Paul‐lez DuranceF‐13108France
| | - Massimo Delledonne
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
| | - Matteo Ballottari
- Dipartimento di BiotecnologieUniversità di VeronaStrada Le Grazie 1537134Verona, Italy
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36
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Wase N, Tu B, Rasineni GK, Cerny R, Grove R, Adamec J, Black PN, DiRusso CC. Remodeling of Chlamydomonas Metabolism Using Synthetic Inducers Results in Lipid Storage during Growth. PLANT PHYSIOLOGY 2019; 181:1029-1049. [PMID: 31501300 PMCID: PMC6836844 DOI: 10.1104/pp.19.00758] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 08/23/2019] [Indexed: 05/19/2023]
Abstract
Microalgae accumulate lipids during stress such as that of nutrient deprivation, concomitant with cessation of growth and depletion of chloroplasts. By contrast, certain small chemical compounds selected by high-throughput screening in Chlamydomonas reinhardtii can induce lipid accumulation during growth, maintaining biomass. Comprehensive pathway analyses using proteomics, transcriptomics, and metabolomics data were acquired from Chlamydomonas cells grown in the presence of one of two structurally distinct lipid activators. WD10784 stimulates both starch and lipid accumulation, whereas WD30030-treated cells accumulate only lipids. The differences in starch accumulation are largely due to differential effects of the two compounds on substrate levels that feed into starch synthesis and on genes encoding starch metabolic enzymes. The compounds had differential effects on photosynthesis, respiration, and oxidative stress pathways. Cells treated with WD10784 showed slowed growth over time and reduced abundance of photosynthetic proteins, decreased respiration, and increased oxidative stress proteins, glutathione, and reactive oxygen species specific to this compound. Both compounds maintained central carbon and nitrogen metabolism, including the tricarboxylic acid cycle, glycolysis, respiration, and the Calvin-Benson-Bassham cycle. There were few changes in proteins and transcripts related to fatty acid biosynthesis, whereas proteins and transcripts for triglyceride production were elevated, suggesting that lipid synthesis is largely driven by substrate availability. This study reports that the compound WD30030 and, to a lesser extent WD10784, increases lipid and lipid droplet synthesis and storage without restricting growth or biomass accumulation by mechanisms that are substantially different from nutrient deprivation.
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Affiliation(s)
- Nishikant Wase
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Boqiang Tu
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | | | - Ronald Cerny
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Ryan Grove
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Jiri Adamec
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Paul N Black
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Concetta C DiRusso
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
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37
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Balzano S, Villanueva L, de Bar M, Sahonero Canavesi DX, Yildiz C, Engelmann JC, Marechal E, Lupette J, Sinninghe Damst� JS, Schouten S. Biosynthesis of Long Chain Alkyl Diols and Long Chain Alkenols in Nannochloropsis spp. (Eustigmatophyceae). PLANT & CELL PHYSIOLOGY 2019; 60:1666-1682. [PMID: 31058972 PMCID: PMC6872974 DOI: 10.1093/pcp/pcz078] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 04/26/2019] [Indexed: 05/05/2023]
Abstract
We investigated potential biosynthetic pathways of long chain alkenols (LCAs), long chain alkyl diols (LCDs), and long chain hydroxy fatty acids (LCHFAs) in Nannochloropsis oceanica and Nannochloropsis gaditana, by combining culturing experiments with genomic and transcriptomic analyses. Incubation of Nannochloropsis spp. in the dark for 1 week led to significant increases in the cellular concentrations of LCAs and LCDs in both species. Consistently, 13C-labelled substrate experiments confirmed that both LCA and LCD were actively produced in the dark from C14-18 fatty acids by either condensation or elongation/hydroxylation, although no enzymatic evidence was found for the former pathway. Nannochloropsis spp. did, however, contain (i) multiple polyketide synthases (PKSs) including one type (PKS-Clade II) that might catalyze incomplete fatty acid elongations leading to the formation of 3-OH-fatty acids, (ii) 3-hydroxyacyl dehydratases (HADs), which can possibly form Δ2/Δ3 monounsaturated fatty acids, and (iii) fatty acid elongases (FAEs) that could elongate 3-OH-fatty acids and Δ2/Δ3 monounsaturated fatty acids to longer products. The enzymes responsible for reduction of the long chain fatty acids to LCDs and LCAs are, however, unclear. A putative wax ester synthase/acyl coenzyme A (acyl-CoA): diacylglycerol acyltransferase is likely to be involved in the esterification of LCAs and LCDs in the cell wall. Our data thus provide useful insights in predicting the biosynthetic pathways of LCAs and LCDs in phytoplankton suggesting a key role of FAE and PKS enzymes.
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Affiliation(s)
- Sergio Balzano
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Corresponding author: E-mail, ; Fax, +39 081 7641355. Present address: Stazione Zoologica Anton Dohrn, Istituto Nazionale di Biologia Ecologia e Biotecnologie Marine, Villa Comunale, Napoli, Italy
| | - Laura Villanueva
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Marijke de Bar
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Diana X Sahonero Canavesi
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Caglar Yildiz
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Julia C Engelmann
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
| | - Eric Marechal
- Laboratoire de Physiologie Cellulaire et V�g�tale, Unit� mixte de recherche CNRS, CEA, INRA, Universit� Grenoble Alpes, CEA Grenoble, 17 Avenue des Martyrs, Grenoble, France
| | - Josselin Lupette
- Laboratoire de Physiologie Cellulaire et V�g�tale, Unit� mixte de recherche CNRS, CEA, INRA, Universit� Grenoble Alpes, CEA Grenoble, 17 Avenue des Martyrs, Grenoble, France
- Present address: MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Jaap S Sinninghe Damst�
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
| | - Stefan Schouten
- Department of Marine Microbiology and Biogeochemistry (MMB), NIOZ Royal Netherlands Institute for Sea Research, Utrecht University, AB Den Burg, The Netherlands
- Department of Earth Sciences, Faculty of Geosciences, Utrecht University, Utrecht, The Netherlands
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Knockdown of carbonate anhydrase elevates Nannochloropsis productivity at high CO2 level. Metab Eng 2019; 54:96-108. [DOI: 10.1016/j.ymben.2019.03.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/13/2019] [Accepted: 03/14/2019] [Indexed: 01/07/2023]
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39
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Coppola M, Diretto G, Digilio MC, Woo SL, Giuliano G, Molisso D, Pennacchio F, Lorito M, Rao R. Transcriptome and Metabolome Reprogramming in Tomato Plants by Trichoderma harzianum strain T22 Primes and Enhances Defense Responses Against Aphids. Front Physiol 2019; 10:745. [PMID: 31293434 PMCID: PMC6599157 DOI: 10.3389/fphys.2019.00745] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 05/31/2019] [Indexed: 12/02/2022] Open
Abstract
Beneficial fungi in the genus Trichoderma are among the most widespread biocontrol agents of plant pathogens. Their role in triggering plant defenses against pathogens has been intensely investigated, while, in contrast, very limited information is available on induced barriers active against insects. The growing experimental evidence on this latter topic looks promising, and paves the way toward the development of Trichoderma strains and/or consortia active against multiple targets. However, the predictability and reproducibility of the effects that these beneficial fungi is still somewhat limited by the lack of an in-depth understanding of the molecular mechanisms underlying the specificity of their interaction with different crop varieties, and on how the environmental factors modulate this interaction. To fill this research gap, here we studied the transcriptome changes in tomato plants (cultivar "Dwarf San Marzano") induced by Trichoderma harzianum (strain T22) colonization and subsequent infestation by the aphid Macrosiphum euphorbiae. A wide transcriptome reprogramming, related to metabolic processes, regulation of gene expression and defense responses, was induced both by separate experimental treatments, which showed a synergistic interaction when concurrently applied. The most evident expression changes of defense genes were associated with the multitrophic interaction Trichoderma-tomato-aphid. Early and late genes involved in direct defense against insects were induced (i.e., peroxidase, GST, kinases and polyphenol oxidase, miraculin, chitinase), along with indirect defense genes, such as sesquiterpene synthase and geranylgeranyl phosphate synthase. Targeted and untargeted semi-polar metabolome analysis revealed a wide metabolome alteration showing an increased accumulation of isoprenoids in Trichoderma treated plants. The wide array of transcriptomic and metabolomics changes nicely fit with the higher mortality of aphids when feeding on Trichoderma treated plants, herein reported, and with the previously observed attractiveness of these latter toward the aphid parasitoid Aphidius ervi. Moreover, Trichoderma treated plants showed the over-expression of transcripts coding for several families of defense-related transcription factors (bZIP, MYB, NAC, AP2-ERF, WRKY), suggesting that the fungus contributes to the priming of plant responses against pest insects. Collectively, our data indicate that Trichoderma treatment of tomato plants induces transcriptomic and metabolomic changes, which underpin both direct and indirect defense responses.
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Affiliation(s)
| | | | - Maria Cristina Digilio
- Department of Agricultural Sciences, Portici, Italy
- Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
| | - Sheridan Lois Woo
- Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
- National Research Council, Institute for Sustainable Plant Protection, Portici, Italy
| | | | | | - Francesco Pennacchio
- Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Matteo Lorito
- Department of Agricultural Sciences, Portici, Italy
- Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
- National Research Council, Institute for Sustainable Plant Protection, Portici, Italy
| | - Rosa Rao
- Department of Agricultural Sciences, Portici, Italy
- Task Force on Microbiome Studies, University of Naples Federico II, Naples, Italy
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Osorio H, Jara C, Fuenzalida K, Rey-Jurado E, Vásquez M. High-efficiency nuclear transformation of the microalgae Nannochloropsis oceanica using Tn5 Transposome for the generation of altered lipid accumulation phenotypes. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:134. [PMID: 31168324 PMCID: PMC6545213 DOI: 10.1186/s13068-019-1475-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 05/23/2019] [Indexed: 06/09/2023]
Abstract
BACKGROUND One of the major problems in the production of lipids for biotechnological purposes using microalgae is maintaining a high productivity of these molecules without reducing cellular biomass. High production rates are usually obtained by cultivating microalgae under different stress conditions. However, many of these changes usually result in lower biomass productivity. Therefore, the optimization of the culture conditions and genetic modification techniques in these organisms is needed to generate robust new strains for profitable economic use. RESULTS In this work, we describe a new strategy for random mutation of genomic DNA in the microalgae Nannochloropsis oceanica by insertion of a Transposome complex Tn5. This complex contains an antibiotic-resistance cassette commanded by a CMV viral promoter that allows high efficiency of transformation and the generation of mutants. This strategy, complemented with a large-scale identification and selection system for mutants, such as flow cytometry with cell selection, allowed us to obtain clonal cultures of mutants with altered phenotypes in the accumulation of intracellular lipids. The characterization of some of these mutants uncovered new genes that are likely to be involved in the regulation of lipid synthesis, revealing possible cellular responses that influence the intracellular homeostasis of lipids. CONCLUSION The strategies proposed here are easy to implement in different types of microalgae and provide a promising scenario for improving biotechnological applications.
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Affiliation(s)
- Hector Osorio
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Carol Jara
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Karen Fuenzalida
- Departamento de Fisiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Emma Rey-Jurado
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
| | - Mónica Vásquez
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O´Higgins 340, Santiago, Chile
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Nobusawa T, Yamakawa-Ayukawa K, Saito F, Nomura S, Takami A, Ohta H. A homolog of Arabidopsis SDP1 lipase in Nannochloropsis is involved in degradation of de novo-synthesized triacylglycerols in the endoplasmic reticulum. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1185-1193. [PMID: 31152796 DOI: 10.1016/j.bbalip.2019.05.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 04/26/2019] [Accepted: 05/25/2019] [Indexed: 01/22/2023]
Abstract
Organisms of the microalgal genus Nannochloropsis produce high levels of triacylglycerols (TAGs), an efficient raw material for biofuels. A complete understanding of the TAG-breakdown pathway is critical for improving the productivity of TAGs to meet future needs. Among a number of lipases annotated as TAG lipase in the genomes of every organism, Arabidopsis SUGAR-DEPENDENT 1 (AtSDP1) lipases are characterized as a type of crucial TAG lipase in plants, similar to ScTgl3-5 in Saccharomyces cerevisiae. Homologs of the AtSDP1 TAG lipases are universally found in the genomes of plants, fungi, and algae. Here we identified two homologs of AtSDP1 TAG lipases in the oleaginous microalga species Nannochloropsis oceanica, NoTGL1 and NoTGL2. We generated single- and double-knockout strains for these lipases by homologous recombination. Whereas overall TAG content in the NoTGL2 single-knockout mutant was identical to that of wild type, the NoTGL1 knockout showed a two-fold increase in TAG content per cell in early log phase under nutrient-sufficient conditions without affecting growth. Homologs of AtSDP1 in S. cerevisiae are localized to the surface of lipid droplets, and AtSDP1 is transported from peroxisomes to the surface of lipid droplets. In contrast, NoTGL1 localized to the endoplasmic reticulum in both Nannochloropsis and yeast. We suggest that homologs of AtSDP1 lipases in Nannochloropsis modulate de novo TAG biosynthesis in the endoplasmic reticulum, unlike the roles of these lipases in other organisms. These results provide important insights into the mechanisms of TAG metabolism catalyzed by homologs of AtSDP1 lipase, which are highly conserved across species.
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Affiliation(s)
- Takashi Nobusawa
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan; Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-3, Kagamiyama, Higashi-Hiroshima 739-8526, Japan
| | - Kaoru Yamakawa-Ayukawa
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Fumihiko Saito
- Technical Research Center, Mazda Motor Corporation, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima, 730-8670, Japan
| | - Seiji Nomura
- Technical Research Center, Mazda Motor Corporation, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima, 730-8670, Japan
| | - Akihide Takami
- Technical Research Center, Mazda Motor Corporation, 3-1, Shinchi, Fuchu-cho, Aki-gun, Hiroshima, 730-8670, Japan
| | - Hiroyuki Ohta
- School of Life Science and Technology, Tokyo Institute of Technology, 4259-B-65 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan.
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Perin G, Bellan A, Bernardi A, Bezzo F, Morosinotto T. The potential of quantitative models to improve microalgae photosynthetic efficiency. PHYSIOLOGIA PLANTARUM 2019; 166:380-391. [PMID: 30578540 DOI: 10.1111/ppl.12915] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/14/2018] [Accepted: 12/18/2018] [Indexed: 06/09/2023]
Abstract
The massive increase in carbon dioxide concentration in the atmosphere driven by human activities is causing huge negative consequences and new sustainable sources of energy, food and materials are highly needed. Algae are unicellular photosynthetic microorganisms that can provide a highly strategic contribution to this challenge as alternative source of biomass to complement crops cultivation. Algae industrial cultures are commonly limited by light availability, and biomass accumulation is strongly dependent on their photon-to-biomass conversion efficiency. Investigation of algae photosynthetic metabolism is thus strategic for the generation of more efficient strains with higher productivity. Algae are cultivated at industrial scale in conditions highly different from the natural niches they adapted to and strains development efforts must fully consider the seminal influence on productivity of regulatory mechanism of photosynthesis as well as of cultivation parameters like cells concentration, light distribution in the culture, mixing, nutrients and carbon dioxide availability. In this review we will focus in particular on how mathematical models can account for the complex influence of all environmental parameters and can be exploited for development of improved algae strains.
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Affiliation(s)
- Giorgio Perin
- Department of Biology, University of Padova, Via Ugo Bassi 58/B 35131, Padova, Italy
| | - Alessandra Bellan
- Department of Biology, University of Padova, Via Ugo Bassi 58/B 35131, Padova, Italy
| | - Andrea Bernardi
- Department of Industrial Engineering, University of Padova, Via Marzolo 9 35131, Padova, Italy
- Centre for Process Systems Engineering, Department of Chemical Engineering, Imperial College London, SW7 2AZ, London, UK
| | - Fabrizio Bezzo
- Department of Industrial Engineering, University of Padova, Via Marzolo 9 35131, Padova, Italy
| | - Tomas Morosinotto
- Department of Biology, University of Padova, Via Ugo Bassi 58/B 35131, Padova, Italy
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Stoyneva-Gärtner M, Uzunov B, Gärtner G, Borisova C, Draganova P, Radkova M, Stoykova P, Atanassov I. Current bioeconomical interest in stramenopilic Eustigmatophyceae: a review. BIOTECHNOL BIOTEC EQ 2019. [DOI: 10.1080/13102818.2019.1573154] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Maya Stoyneva-Gärtner
- Department of Botany, Faculty of Biology, Sofia University “St Kliment Ohridski”, Sofia, Bulgaria
| | - Blagoy Uzunov
- Department of Botany, Faculty of Biology, Sofia University “St Kliment Ohridski”, Sofia, Bulgaria
| | - Georg Gärtner
- Institute of Botany, Faculty of Biology, University of Innsbruck, Innsbruck, Austria
| | - Cvetanka Borisova
- Department of Botany, Faculty of Biology, Sofia University “St Kliment Ohridski”, Sofia, Bulgaria
| | - Petya Draganova
- Department of Botany, Faculty of Biology, Sofia University “St Kliment Ohridski”, Sofia, Bulgaria
| | - Mariana Radkova
- Functional Genetics Legumes Group, AgroBioInstitute, Agricultural Academy, Sofia, Bulgaria
| | - Petya Stoykova
- Functional Genetics Legumes Group, AgroBioInstitute, Agricultural Academy, Sofia, Bulgaria
| | - Ivan Atanassov
- Molecular Genetics Group, AgroBioInstitute, Agricultural Academy, Sofia, Bulgaria
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Li-Beisson Y, Thelen JJ, Fedosejevs E, Harwood JL. The lipid biochemistry of eukaryotic algae. Prog Lipid Res 2019; 74:31-68. [PMID: 30703388 DOI: 10.1016/j.plipres.2019.01.003] [Citation(s) in RCA: 162] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 01/22/2019] [Accepted: 01/23/2019] [Indexed: 02/06/2023]
Abstract
Algal lipid metabolism fascinates both scientists and entrepreneurs due to the large diversity of fatty acyl structures that algae produce. Algae have therefore long been studied as sources of genes for novel fatty acids; and, due to their superior biomass productivity, algae are also considered a potential feedstock for biofuels. However, a major issue in a commercially viable "algal oil-to-biofuel" industry is the high production cost, because most algal species only produce large amounts of oils after being exposed to stress conditions. Recent studies have therefore focused on the identification of factors involved in TAG metabolism, on the subcellular organization of lipid pathways, and on interactions between organelles. This has been accompanied by the development of genetic/genomic and synthetic biological tools not only for the reference green alga Chlamydomonas reinhardtii but also for Nannochloropsis spp. and Phaeodactylum tricornutum. Advances in our understanding of enzymes and regulatory proteins of acyl lipid biosynthesis and turnover are described herein with a focus on carbon and energetic aspects. We also summarize how changes in environmental factors can impact lipid metabolism and describe present and potential industrial uses of algal lipids.
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Affiliation(s)
- Yonghua Li-Beisson
- Aix-Marseille Univ, CEA, CNRS, BIAM, UMR7265, CEA Cadarache, Saint-Paul-lez Durance F-13108, France.
| | - Jay J Thelen
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - Eric Fedosejevs
- Department of Biochemistry, University of Missouri, Christopher S. Bond Life Sciences Center, Columbia, MO 65211, United States.
| | - John L Harwood
- School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK.
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Koh HG, Kang NK, Jeon S, Shin SE, Jeong BR, Chang YK. Heterologous synthesis of chlorophyll b in Nannochloropsis salina enhances growth and lipid production by increasing photosynthetic efficiency. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:122. [PMID: 31114631 PMCID: PMC6515666 DOI: 10.1186/s13068-019-1462-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/04/2019] [Indexed: 05/16/2023]
Abstract
BACKGROUND Chlorophylls play important roles in photosynthesis, and thus are critical for growth and related metabolic pathways in photosynthetic organisms. They are particularly important in microalgae, emerging as the next generation feedstock for biomass and biofuels. Nannochloropsis are industrial microalgae for these purposes, but are peculiar in that they lack accessory chlorophylls. In addition, the localization of heterologous proteins to the chloroplast of Nannochloropsis has not been fully studied, due to the secondary plastid surrounded by four membranes. This study addressed questions of correct localization and functional benefits of heterologous expression of chlorophyllide a oxygenase from Chlamydomonas (CrCAO) in Nannochloropsis. RESULTS We cloned CrCAO from Chlamydomonas, which catalyzes oxidation of Chla producing Chlb, and overexpressed it in N. salina to reveal effects of the heterologous Chlb for photosynthesis, growth, and lipid production. For correct localization of CrCAO into the secondary plastid in N. salina, we added the signal-recognition sequence and the transit peptide (cloned from an endogenous chloroplast-localized protein) to the N terminus of CrCAO. We obtained two transformants that expressed CrCAO and produced Chlb. They showed improved growth under medium light (90 μmol/m2/s) conditions, and their photosynthetic efficiency was increased compared to WT. They also showed increased expression of certain photosynthetic proteins, accompanied by an increased maximum electron-transfer rate up to 15.8% and quantum yields up to 17%, likely supporting the faster growth. This improved growth resulted in increased biomass production, and more importantly lipid productivity particularly with medium light. CONCLUSIONS We demonstrated beneficial effects of heterologous expression of CrCAO in Chlb-less organism N. salina, where the newly produced Chlb enhanced photosynthesis and growth. Accordingly, transformants showed improved production of biomass and lipids, important traits of microalgae from the industrial perspectives. Our transformants are the first Nannochloropsis cells that produced Chlb in the whole evolutionary path. We also succeeded in delivering a heterologous protein into the secondary plastid for the first time in Nannochloropsis. Taken together, our data showed that manipulation of photosynthetic pigments, including Chlb, can be employed in genetic improvements of microalgae for production of biofuels and other biomaterials.
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Affiliation(s)
- Hyun Gi Koh
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Nam Kyu Kang
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL USA
| | - Seungjib Jeon
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Sung-Eun Shin
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Present Address: LG Chem, 188 Munji-ro, Yuseong-gu, Daejeon, 34122 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
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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Simultaneous extraction and fractionation of omega-3 acylglycerols and glycolipids from wet microalgal biomass of Nannochloropsis gaditana using pressurized liquids. ALGAL RES 2019. [DOI: 10.1016/j.algal.2018.11.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Molino A, Iovine A, Casella P, Mehariya S, Chianese S, Cerbone A, Rimauro J, Musmarra D. Microalgae Characterization for Consolidated and New Application in Human Food, Animal Feed and Nutraceuticals. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2018; 15:E2436. [PMID: 30388801 PMCID: PMC6266511 DOI: 10.3390/ijerph15112436] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/20/2018] [Accepted: 10/26/2018] [Indexed: 12/27/2022]
Abstract
The exploration of new food sources and natural products is the result of the increase in world population as well as the need for a healthier diet; in this context, microalgae are undoubtedly an interesting solution. With the intent to enhance their value in new commercial applications, this paper aims to characterize microalgae that have already been recognized as safe or authorized as additives for humans and animals (Chlorella vulgaris, Arthrospira platensis, Haematococcus pluvialis, Dunaliella salina) as well as those that have not yet been marketed (Scenedesmus almeriensis and Nannocholoropsis sp.). In this scope, the content of proteins, carbohydrates, lipids, total dietary fiber, humidity, ash, and carotenoids has been measured via standard methods. In addition, individual carotenoids (beta-carotene, astaxanthin, and lutein) as well as individual saturated, monounsaturated, and polyunsaturated fatty acids have been identified and quantified chromatographically. The results confirm the prerogative of some species to produce certain products such as carotenoids, polyunsaturated fatty acids, and proteins, but also show how their cellular content is rich and diverse. H. pluvialis green and red phases, and Nannochloropsis sp., in addition to producing astaxanthin and omega-3, contain about 25⁻33% w/w proteins on a dry basis. D. salina is rich in beta-carotene (3.45% w/w on a dry basis), S. Almeriensis is a source of lutein (0.30% w/w on a dry basis), and the C. vulgaris species is a protein-based microalgae (45% w/w on a dry basis). All, however, can also produce important fatty acids such as palmitic acid, γ-linolenic acid, and oleic acid. Considering their varied composition, these microalgae can find applications in multiple sectors. This is true for microalgae already on the market as well as for promising new sources of bioproducts such as S. almeriensis and Nannochloropsis sp.
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Affiliation(s)
- Antonio Molino
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability-CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy.
| | - Angela Iovine
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability-CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy.
- Department of Engineering, University of Campania "Luigi Vanvitelli", Real Casa dell'Annunziata, Via Roma 29, 81031 Aversa (CE), Italy.
| | - Patrizia Casella
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability-CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy.
| | - Sanjeet Mehariya
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability-CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy.
- Department of Engineering, University of Campania "Luigi Vanvitelli", Real Casa dell'Annunziata, Via Roma 29, 81031 Aversa (CE), Italy.
| | - Simeone Chianese
- Department of Engineering, University of Campania "Luigi Vanvitelli", Real Casa dell'Annunziata, Via Roma 29, 81031 Aversa (CE), Italy.
| | - Antonietta Cerbone
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability-CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy.
- Department of Engineering, University of Campania "Luigi Vanvitelli", Real Casa dell'Annunziata, Via Roma 29, 81031 Aversa (CE), Italy.
| | - Juri Rimauro
- ENEA, Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Department of Sustainability-CR Portici. P. Enrico Fermi, 1, 80055 Portici (NA), Italy.
| | - Dino Musmarra
- Department of Engineering, University of Campania "Luigi Vanvitelli", Real Casa dell'Annunziata, Via Roma 29, 81031 Aversa (CE), Italy.
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Poliner E, Farré EM, Benning C. Advanced genetic tools enable synthetic biology in the oleaginous microalgae Nannochloropsis sp. PLANT CELL REPORTS 2018; 37:1383-1399. [PMID: 29511798 DOI: 10.1007/s00299-018-2270-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 02/26/2018] [Indexed: 05/16/2023]
Abstract
Nannochloropsis is a genus of fast-growing microalgae that are regularly used for biotechnology applications. Nannochloropsis species have a high triacylglycerol content and their polar lipids are rich in the omega-3 long-chain polyunsaturated fatty acid, eicosapentaenoic acid. Placed in the heterokont lineage, the Nannochloropsis genus has a complex evolutionary history. Genome sequences are available for several species, and a number of transcriptomic datasets have been produced, making this genus a facile model for comparative genomics. There is a growing interest in Nannochloropsis species as models for the study of microalga lipid metabolism and as a chassis for synthetic biology. Recently, techniques for gene stacking, and targeted gene disruption and repression in the Nannochloropsis genus have been developed. These tools enable gene-specific, mechanistic studies and have already allowed the engineering of improved Nannochloropsis strains with superior growth, or greater bioproduction.
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Affiliation(s)
- Eric Poliner
- Cell and Molecular Biology Program, Michigan State University, East Lansing, MI, USA
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Eva M Farré
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA
| | - Christoph Benning
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA.
- Department of Plant Biology, Michigan State University, East Lansing, MI, USA.
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA.
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Xing G, Yuan H, Yang J, Li J, Gao Q, Li W, Wang E. Integrated analyses of transcriptome, proteome and fatty acid profilings of the oleaginous microalga Auxenochlorella protothecoides UTEX 2341 reveal differential reprogramming of fatty acid metabolism in response to low and high temperatures. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.04.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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