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Assobhi B, Bouchelta Y, Alsubih M, LamiaTrabelsi, Alaoui-Sossé B, Bourgeade P, Aleya L, Mhamdi MA, Bahhou J. What are the growth kinetics and biochemical compositions of microalgae isolated from diverse aquatic ecosystems in Morocco, France, and Tunisia? ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:32680-32693. [PMID: 38662296 DOI: 10.1007/s11356-024-33412-9] [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: 10/26/2023] [Accepted: 04/17/2024] [Indexed: 04/26/2024]
Abstract
Thirty-six microalgae belonging to five taxonomic groups (Cyanobacteria, Chlorophyceae, Diatomophyceae, Euglenophyceae, and Eustigmatophyceae) were identified from six freshwater ecosystems in Morocco, two treatment stations in Etueffont landfill in France and three hot spring waters in Tunisia. Investigations on species growth kinetics and growth rates showed that the cyanobacterium Leptolyngbya gelatinosa exhibited both the highest biomass and growth rate with 4 g DW L-1 and 0.282 day-1, respectively. A significant protein production (more than 40% DW) was observed across the studied species. Cyanobacteria and chlorophytes stood out for their increased protein production with a maximum (66.63 ± 3.84% DW) attained by the cyanobacterium Leptolyngbya sp. Chlorophytes produced substantial amounts of carbohydrates (more than 20% DW). Euglenophytes including Phacus orbicularis and Euglena ehrenbergii along with the chlorophyte Graesiella sp. accumulated significant amounts of lipids (up to 31.12% DW).
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Affiliation(s)
- Bouchra Assobhi
- Faculty of Sciences Dhar El Mahraz, Laboratory of Biotechnology, Conservation and Valorization of Natural Resources, Sidi Mohammed Ben Abdellah University of Fez, P.O. Box 1796, Atlas-, Fez, Morocco
| | - Yamina Bouchelta
- Faculty of Sciences Dhar El Mahraz, Laboratory of Biotechnology, Conservation and Valorization of Natural Resources, Sidi Mohammed Ben Abdellah University of Fez, P.O. Box 1796, Atlas-, Fez, Morocco
| | - Majed Alsubih
- Department of Civil Engineering, King Khalid University, Guraiger, Abha, 62529, Kingdom of Saudi Arabia
| | - LamiaTrabelsi
- Marine Biodiversity Laboratory, National Institute of Marine Sciences and Technology (INSTM), 2025 Salammbo, University of Carthage, Tunis, Tunisia.
| | - Badr Alaoui-Sossé
- Laboratoire de Chrono-Environnement, UMR CNRS 6249, Université de Bourgogne Franche-Comté, La Bouloie, F-25030, Besançon Cedex, France
| | - Pascale Bourgeade
- Laboratoire de Chrono-Environnement, UMR CNRS 6249, Université de Bourgogne Franche-Comté, La Bouloie, F-25030, Besançon Cedex, France
| | - Lotfi Aleya
- Laboratoire de Chrono-Environnement, UMR CNRS 6249, Université de Bourgogne Franche-Comté, La Bouloie, F-25030, Besançon Cedex, France
| | - Mohammed Alaoui Mhamdi
- Faculty of Sciences Dhar El Mahraz, Laboratory of Biotechnology, Conservation and Valorization of Natural Resources, Sidi Mohammed Ben Abdellah University of Fez, P.O. Box 1796, Atlas-, Fez, Morocco
| | - Jamila Bahhou
- Faculty of Sciences Dhar El Mahraz, Laboratory of Biotechnology, Conservation and Valorization of Natural Resources, Sidi Mohammed Ben Abdellah University of Fez, P.O. Box 1796, Atlas-, Fez, Morocco
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Sato N, Toyoshima M. Dynamism of Metabolic Carbon Flow of Starch and Lipids in Chlamydomonas debaryana. FRONTIERS IN PLANT SCIENCE 2021; 12:646498. [PMID: 33868347 PMCID: PMC8047662 DOI: 10.3389/fpls.2021.646498] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 03/08/2021] [Indexed: 06/01/2023]
Abstract
Microalgae have the potential to recycle CO2 as starch and triacylglycerol (TAG), which provide alternative source of biofuel and high added-value chemicals. Starch accumulates in the chloroplast, whereas TAG accumulates in the cytoplasmic lipid droplets (LD). Preferential accumulation of starch or TAG may be achieved by switching intracellular metabolic carbon flow, but our knowledge on this control remains limited. Are these two products mutually exclusive? Or, does starch act as a precursor to TAG synthesis, or vice versa? To answer these questions, we analyzed carbon flow in starch and lipids using a stable isotope 13C in Chlamydomonas debaryana NIES-2212, which accumulates, without nutrient limitation, starch in the exponential growth phase and TAG in the stationary phase. Pulse labeling experiments as well as pulse labeling and chase experiments were conducted, and then, gas chromatography-mass spectrometry (GC-MS) analysis was performed on starch-derived glucose and lipid-bound fatty acids. We exploited the previously developed method of isotopomer analysis to estimate the proportion of various pools with different isotopic abundance. Starch turned over rapidly to provide carbon for the synthesis of fatty acids in the exponential phase cells. Most fatty acids showed rapid and slow components of metabolism, whereas oleic acid decayed according to a single exponential curve. Highly labeled population of fatty acids that accumulated during the initial labeling decreased rapidly, and replaced by low abundance population during the chase time, indicating that highly labeled fatty acids were degraded and the resulting carbons were re-used in the re-synthesis with about 9-fold unlabeled, newly fixed carbons. Elongation of C16-C18 acids in vivo was indicated by partially labeled C18 acids. The accumulation of TAG in the stationary growth phase was accounted for by both de novo synthesis and remodeling of membrane lipids. These results suggest that de novo synthesis of starch and TAG was rapid and transient, and also almost independent to each other, but there is a pool of starch quickly turning over for the synthesis of fatty acids. Fatty acids were also subject to re-synthesis. Evidence was also provided for remodeling of lipids, namely, re-use of acyl groups in polar lipids for TAG synthesis.
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Kumar G, Shekh A, Jakhu S, Sharma Y, Kapoor R, Sharma TR. Bioengineering of Microalgae: Recent Advances, Perspectives, and Regulatory Challenges for Industrial Application. Front Bioeng Biotechnol 2020; 8:914. [PMID: 33014997 PMCID: PMC7494788 DOI: 10.3389/fbioe.2020.00914] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 07/15/2020] [Indexed: 01/14/2023] Open
Abstract
Microalgae, due to their complex metabolic capacity, are being continuously explored for nutraceuticals, pharmaceuticals, and other industrially important bioactives. However, suboptimal yield and productivity of the bioactive of interest in local and robust wild-type strains are of perennial concerns for their industrial applications. To overcome such limitations, strain improvement through genetic engineering could play a decisive role. Though the advanced tools for genetic engineering have emerged at a greater pace, they still remain underused for microalgae as compared to other microorganisms. Pertaining to this, we reviewed the progress made so far in the development of molecular tools and techniques, and their deployment for microalgae strain improvement through genetic engineering. The recent availability of genome sequences and other omics datasets form diverse microalgae species have remarkable potential to guide strategic momentum in microalgae strain improvement program. This review focuses on the recent and significant improvements in the omics resources, mutant libraries, and high throughput screening methodologies helpful to augment research in the model and non-model microalgae. Authors have also summarized the case studies on genetically engineered microalgae and highlight the opportunities and challenges that are emerging from the current progress in the application of genome-editing to facilitate microalgal strain improvement. Toward the end, the regulatory and biosafety issues in the use of genetically engineered microalgae in commercial applications are described.
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Affiliation(s)
- Gulshan Kumar
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Ajam Shekh
- Plant Cell Biotechnology Department, CSIR-Central Food Technological Research Institute (CFTRI), Mysuru, India
| | - Sunaina Jakhu
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Yogesh Sharma
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Ritu Kapoor
- Agricultural Biotechnology Division, National Agri-Food Biotechnology Institute (NABI), Sahibzada Ajit Singh Nagar, India
| | - Tilak Raj Sharma
- Division of Crop Science, Indian Council of Agricultural Research, New Delhi, India
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Yoshitomi T, Kaminaga S, Sato N, Toyoshima M, Moriyama T, Yoshimoto K. Formation of Spherical Palmelloid Colony with Enhanced Lipid Accumulation by Gel Encapsulation of Chlamydomonas debaryana NIES-2212. PLANT & CELL PHYSIOLOGY 2020; 61:158-168. [PMID: 31589321 DOI: 10.1093/pcp/pcz188] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 09/20/2019] [Indexed: 06/10/2023]
Abstract
Microalgae such as Chlamydomonas reinhardtii accumulate triacylglycerol (TAG), which is a potential source of biofuels, under stress conditions such as nitrogen deprivation, whereas Chlamydomonas debaryana NIES-2212 has previously been identified and characterized as one of the rare species of Chlamydomonas, which massively accumulates TAG in the stationary phase without external stress. As the high density of the cells in the stationary phase was supposed to act as a trigger for the accumulation of TAG in C. debaryana, in this study, C. debaryana was encapsulated in a Ca2+-alginate gel for the culture with high cell density. We discovered that the growth of the encapsulated cells resulted in the formation of spherical palmelloid colonies with high cell density, where daughter cells with truncated flagella remained wrapped within the mother cell walls. Interestingly, gel encapsulation markedly promoted proliferation of C. debaryana cells, and the encapsulated cells reached the stationary phase earlier than that of the free-living cells. Gel encapsulation also enhanced TAG accumulation. Gene expression analysis revealed that two genes of acyltransferases, DGAT1 and DGTT3, were upregulated in the stationary phase of free-living C. debaryana. In addition, the gene expression of these acyltransferases increased earlier in the encapsulated cells than that in the free-living cells. The enhanced production of TAG by alginate gel encapsulation was not found in C. reinhardtii which is known to use a different repertoire of acyltransferases in lipid accumulation.
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Affiliation(s)
- Toru Yoshitomi
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902 Japan
| | - Saeko Kaminaga
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902 Japan
| | - Naoki Sato
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902 Japan
| | - Masakazu Toyoshima
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902 Japan
| | - Takashi Moriyama
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902 Japan
| | - Keitaro Yoshimoto
- Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902 Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902 Japan
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Toyoshima M, Sato N. Optimization of triacylglycerol and starch production in Chlamydomonas debaryana NIES-2212 with regard to light intensity and CO2 concentration. MICROBIOLOGY-SGM 2018; 164:359-368. [PMID: 29458672 DOI: 10.1099/mic.0.000603] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Triacylglycerol (TAG) and starch produced by micro-algae are potential sources of biofuel. Our previous studies showed that the unicellular green alga, Chlamydomonas debaryana NIES-2212, which is a rare species of Chlamydomonas that possesses phosphatidylcholine (PC), is a seed organism for the development of biofuel producers. This alga accumulates large amounts of TAG and starch under completely photo-autotrophic conditions during stationary phase without nutrient deprivation. The present study was performed to optimize the growth conditions of this alga with regard to light intensity and CO2 concentration to improve the efficiency of TAG and starch production. The growth rate of C. debaryana was greater at higher light intensity, although there was no significant difference in the final cell density of the culture. The highest contents of TAG and starch, approximately 200 fmol cell-1 and 600 pg cell-1, respectively, were achieved with a light intensity of 200 µmol m-2 s-1 bubbled with air containing 5.0 % CO2. These results suggest that optimization of light intensity and CO2 concentration can enhance the productivity of TAG and starch by C. debaryana NIES-2212.
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Affiliation(s)
- Masakazu Toyoshima
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo, Tokyo 153-8902, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo 102-0076, Japan.,Present address: Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Naoki Sato
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo, Tokyo 153-8902, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo 102-0076, Japan
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Lipid metabolism and potentials of biofuel and high added-value oil production in red algae. World J Microbiol Biotechnol 2017; 33:74. [DOI: 10.1007/s11274-017-2236-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 03/01/2017] [Indexed: 10/20/2022]
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Sato N, Mori N, Hirashima T, Moriyama T. Diverse pathways of phosphatidylcholine biosynthesis in algae as estimated by labeling studies and genomic sequence analysis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 87:281-92. [PMID: 27133435 DOI: 10.1111/tpj.13199] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 04/07/2016] [Accepted: 04/15/2016] [Indexed: 05/03/2023]
Abstract
Phosphatidylcholine (PC) is an almost ubiquitous phospholipid in eukaryotic algae and plants but is not found in a few species, for example Chlamydomonas reinhardtii. We recently found that some species of the genus Chlamydomonas possess PC. In the universal pathway, PC is synthesized de novo by methylation of phosphatidylethanolamine (PE) or transfer of phosphocholine from cytidine diphosphate (CDP)-choline to diacylglycerol. Phosphocholine, the direct precursor to CDP-choline, is synthesized either by methylation of phosphoethanolamine or phosphorylation of choline. Here we analyzed the mechanism of PC biosynthesis in two species of Chlamydomonas (asymmetrica and sphaeroides) as well as in a red alga, Cyanidioschyzon merolae. Comparative genomic analysis of enzymes involved in PC biosynthesis indicated that C. merolae possesses only the PE methylation pathway. Radioactive tracer experiments using [(32) P]phosphate showed delayed labeling of PC with respect to PE, which was consistent with the PE methylation pathway. In Chlamydomonas asymmetrica, labeling of PC was detected from the early time of incubation with [(32) P]phosphate, suggesting the operation of phosphoethanolamine methylation pathway. Genomic analysis indeed detected the genes for the phosphoethanolamine methylation pathway. In contrast, the labeling of PC in C. sphaeroides was slow, suggesting that the PE methylation pathway was at work. These results as well as biochemical and computational results uncover an unexpected diversity of the mechanisms for PC biosynthesis in algae. Based on these results, we will discuss plausible mechanisms for the scattered distribution of the ability to biosynthesize PC in the genus Chlamydomonas.
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Affiliation(s)
- Naoki Sato
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo, 153-8902, Japan.
- JST, CREST, K's Gobancho, 7, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan.
| | - Natsumi Mori
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo, 153-8902, Japan
- JST, CREST, K's Gobancho, 7, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan
| | - Takashi Hirashima
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo, 153-8902, Japan
- JST, CREST, K's Gobancho, 7, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan
| | - Takashi Moriyama
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba, Meguro-ku, Tokyo, 153-8902, Japan
- JST, CREST, K's Gobancho, 7, Gobancho, Chiyoda-ku, Tokyo, 102-0076, Japan
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Toyoshima M, Mori N, Moriyama T, Misumi O, Sato N. Analysis of triacylglycerol accumulation under nitrogen deprivation in the red alga Cyanidioschyzon merolae. MICROBIOLOGY-SGM 2016; 162:803-812. [PMID: 26925574 DOI: 10.1099/mic.0.000261] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Triacylglycerol (TAG) produced by microalgae is a potential source of biofuel. Although various metabolic pathways in TAG synthesis have been identified in land plants, the pathway of TAG synthesis in microalgae remains to be clarified. The unicellular rhodophyte Cyanidioschyzon merolae has unique properties as a producer of biofuel because of easy culture and feasibility of genetic engineering. Additionally, it is useful in the investigation of the pathway of TAG synthesis, because all of the nuclear, mitochondrial and plastid genomes have been completely sequenced. We found that this alga accumulated TAG under nitrogen deprivation. Curiously, the amount and composition of plastid membrane lipids did not change significantly, whereas the amount of endoplasmic reticulum (ER) lipids increased with considerable changes in fatty acid composition. The nitrogen deprivation did not decrease photosynthetic oxygen evolution per chlorophyll significantly, while phycobilisomes were degraded preferentially. These results suggest that the synthesis of fatty acids is maintained in the plastid, which is used for the synthesis of TAG in the ER. The accumulated TAG contained mainly 18 : 2(9,12) at the C-2 position, which could be derived from phosphatidylcholine, which also contains this acid at the C-2 position.
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Affiliation(s)
- Masakazu Toyoshima
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo,Tokyo,Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
| | - Natsumi Mori
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo,Tokyo,Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
| | - Takashi Moriyama
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo,Tokyo,Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
| | - Osami Misumi
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
- Department of Biological Science and Chemistry, Faculty of Science, Graduate School of Medicine, Yamaguchi University,Yamaguchi,Japan
| | - Naoki Sato
- Department of Life Sciences, Graduate School of Arts and Science, The University of Tokyo,Tokyo,Japan
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency,Tokyo,Japan
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