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Kondo M, Aoki M, Hirai K, Sagami T, Ito R, Tsuzuki M, Sato N. slr2103, a homolog of type-2 diacylglycerol acyltransferase genes, for plastoquinone-related neutral lipid synthesis and NaCl-stress acclimatization in a cyanobacterium, Synechocystis sp. PCC 6803. FRONTIERS IN PLANT SCIENCE 2023; 14:1181180. [PMID: 37180399 PMCID: PMC10171310 DOI: 10.3389/fpls.2023.1181180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 04/10/2023] [Indexed: 05/16/2023]
Abstract
A cyanobacterium, Synechocystis sp. PCC 6803, contains a lipid with triacylglycerol-like TLC mobility but its identity and physiological roles remain unknown. Here, on ESI-positive LC-MS2 analysis, it is shown that the triacylglycerol-like lipid (lipid X) is related to plastoquinone and can be grouped into two subclasses, Xa and Xb, the latter of which is esterified by 16:0 and 18:0. This study further shows that a Synechocystis homolog of type-2 diacylglycerol acyltransferase genes, slr2103, is essential for lipid X synthesis: lipid X disappears in a Synechocystis slr2103-disruptant whereas it appears in an slr2103-overexpressing transformant (OE) of Synechococcus elongatus PCC 7942 that intrinsically lacks lipid X. The slr2103 disruption causes Synechocystis cells to accumulate plastoquinone-C at an abnormally high level whereas slr2103 overexpression in Synechococcus causes the cells to almost completely lose it. It is thus deduced that slr2103 encodes a novel acyltransferase that esterifies 16:0 or 18:0 with plastoquinone-C for the synthesis of lipid Xb. Characterization of the slr2103-disruptant in Synechocystis shows that slr2103 contributes to sedimented-cell growth in a static culture, and to bloom-like structure formation and its expansion by promoting cell aggregation and floatation upon imposition of saline stress (0.3-0.6 M NaCl). These observations provide a basis for elucidation of the molecular mechanism of a novel cyanobacterial strategy to acclimatize to saline stress, and one for development of a system of seawater-utilization and economical harvesting of cyanobacterial cells with high-value added compounds, or blooming control of toxic cyanobacteria.
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Nam JW, Lee HG, Do H, Kim HU, Seo PJ. Transcriptional regulation of triacylglycerol accumulation in plants under environmental stress conditions. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:2905-2917. [PMID: 35560201 DOI: 10.1093/jxb/erab554] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/15/2021] [Indexed: 06/15/2023]
Abstract
Triacylglycerol (TAG), a major energy reserve in lipid form, accumulates mainly in seeds. Although TAG concentrations are usually low in vegetative tissues because of the repression of seed maturation programs, these programs are derepressed upon the exposure of vegetative tissues to environmental stresses. Metabolic reprogramming of TAG accumulation is driven primarily by transcriptional regulation. A substantial proportion of transcription factors regulating seed TAG biosynthesis also participates in stress-induced TAG accumulation in vegetative tissues. TAG accumulation leads to the formation of lipid droplets and plastoglobules, which play important roles in plant tolerance to environmental stresses. Toxic lipid intermediates generated from environmental-stress-induced lipid membrane degradation are captured by TAG-containing lipid droplets and plastoglobules. This review summarizes recent advances in the transcriptional control of metabolic reprogramming underlying stress-induced TAG accumulation, and provides biological insight into the plant adaptive strategy, linking TAG biosynthesis with plant survival.
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Affiliation(s)
- Jeong-Won Nam
- Department of Chemistry, Seoul National University, Seoul, South Korea
| | - Hong Gil Lee
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea
| | - Hyungju Do
- Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul, South Korea
| | - Hyun Uk Kim
- Department of Bioindustry and Bioresource Engineering, Plant Engineering Research Institute, Sejong University, Seoul, South Korea
| | - Pil Joon Seo
- Department of Chemistry, Seoul National University, Seoul, South Korea
- Plant Genomics and Breeding Institute, Seoul National University, Seoul, South Korea
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Oishi Y, Otaki R, Iijima Y, Kumagai E, Aoki M, Tsuzuki M, Fujiwara S, Sato N. Diacylglyceryl-N,N,N-trimethylhomoserine-dependent lipid remodeling in a green alga, Chlorella kessleri. Commun Biol 2022; 5:19. [PMID: 35017659 PMCID: PMC8752610 DOI: 10.1038/s42003-021-02927-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 11/29/2021] [Indexed: 11/08/2022] Open
Abstract
Membrane lipid remodeling contributes to the environmental acclimation of plants. In the green lineage, a betaine lipid, diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), is included exclusively among green algae and nonflowering plants. Here, we show that the green alga Chlorella kessleri synthesizes DGTS under phosphorus-deficient conditions through the eukaryotic pathway via the ER. Simultaneously, phosphatidylcholine and phosphatidylethanolamine, which are similar to DGTS in their zwitterionic properties, are almost completely degraded to release 18.1% cellular phosphorus, and to provide diacylglycerol moieties for a part of DGTS synthesis. This lipid remodeling system that substitutes DGTS for extrachloroplast phospholipids to lower the P-quota operates through the expression induction of the BTA1 gene. Investigation of this lipid remodeling system is necessary in a wide range of lower green plants for a comprehensive understanding of their phosphorus deficiency acclimation strategies.
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Affiliation(s)
- Yutaro Oishi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachioji, Tokyo, 192-0392, Japan
| | - Rie Otaki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachioji, Tokyo, 192-0392, Japan
| | - Yukari Iijima
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachioji, Tokyo, 192-0392, Japan
| | - Eri Kumagai
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachioji, Tokyo, 192-0392, Japan
| | - Motohide Aoki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachioji, Tokyo, 192-0392, Japan
| | - Mikio Tsuzuki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachioji, Tokyo, 192-0392, Japan
| | - Shoko Fujiwara
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachioji, Tokyo, 192-0392, Japan
| | - Norihiro Sato
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Horinouchi 1432-1, Hachioji, Tokyo, 192-0392, Japan.
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Wang J, Wang Y, Wu Y, Fan Y, Zhu C, Fu X, Chu Y, Chen F, Sun H, Mou H. Application of Microalgal Stress Responses in Industrial Microalgal Production Systems. Mar Drugs 2021; 20:30. [PMID: 35049885 PMCID: PMC8779474 DOI: 10.3390/md20010030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/15/2021] [Accepted: 12/23/2021] [Indexed: 11/29/2022] Open
Abstract
Adaptive laboratory evolution (ALE) has been widely utilized as a tool for developing new biological and phenotypic functions to explore strain improvement for microalgal production. Specifically, ALE has been utilized to evolve strains to better adapt to defined conditions. It has become a new solution to improve the performance of strains in microalgae biotechnology. This review mainly summarizes the key results from recent microalgal ALE studies in industrial production. ALE designed for improving cell growth rate, product yield, environmental tolerance and wastewater treatment is discussed to exploit microalgae in various applications. Further development of ALE is proposed, to provide theoretical support for producing the high value-added products from microalgal production.
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Affiliation(s)
- Jia Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.W.); (Y.W.); (Y.F.); (C.Z.)
| | - Yuxin Wang
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.W.); (Y.W.); (Y.F.); (C.Z.)
| | - Yijian Wu
- School of Foreign Languages, Lianyungang Technical College, Lianyungang 222000, China;
| | - Yuwei Fan
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.W.); (Y.W.); (Y.F.); (C.Z.)
| | - Changliang Zhu
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.W.); (Y.W.); (Y.F.); (C.Z.)
| | - Xiaodan Fu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China;
| | - Yawen Chu
- Heze Zonghoo Jianyuan Biotech Co., Ltd, Heze 274000, China;
| | - Feng Chen
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China;
| | - Han Sun
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.W.); (Y.W.); (Y.F.); (C.Z.)
| | - Haijin Mou
- College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.W.); (Y.W.); (Y.F.); (C.Z.)
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Lipid Induction in Scenedesmus abundans GH-D11 by Reusing the Volatile Fatty Acids in the Effluent of Dark Anaerobic Fermentation of Biohydrogen. Appl Biochem Biotechnol 2020; 191:258-272. [DOI: 10.1007/s12010-020-03294-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/12/2020] [Indexed: 12/21/2022]
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Mao X, Lao Y, Sun H, Li X, Yu J, Chen F. Time‑resolved transcriptome analysis during transitions of sulfur nutritional status provides insight into triacylglycerol (TAG) and astaxanthin accumulation in the green alga Chromochloris zofingiensis. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:128. [PMID: 32695224 PMCID: PMC7367374 DOI: 10.1186/s13068-020-01768-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 07/11/2020] [Indexed: 05/03/2023]
Abstract
BACKGROUND Chromochloris zofingiensis, an oleaginous microalga, is a promising feedstock for the co-production of triacylglycerol (TAG)-based biodiesel and the high-value product astaxanthin. To reveal the molecular mechanism of TAG and astaxanthin biosynthesis during transitions of sulfur nutritional status, namely sulfur-starvation (SS) and sulfur-replenishment (SR), the physiological responses and the transcriptomic dynamics of C. zofingiensis were examined. RESULTS The results revealed a reversible TAG and astaxanthin accumulation under SS, which is correlated with the reduction of cell growth and protein content, indicating the reallocation of carbon. By correlating the data on the physiological and transcriptional responses to different sulfur nutritional status, a model for the underlying mechanism of TAG and astaxanthin accumulation in C. zofingiensis was postulated, which involved up-regulation of key genes including diacylglycerol acyltransferase (DGTT5) and beta-carotene ketolase (BKT1), increased energy and NADPH supply by elevating the tricarboxylic acid (TCA) cycle and the oxidative pentose phosphate (OPP) pathway, and the increased carbon precursors (pyruvate and acetyl-CoA) through central carbon metabolism. In addition, the net enhancement of the de novo biosynthesis of fatty acids and the re-direction of the terpenoid precursors toward the branch catalyzed by lycopene beta cyclase (LCYb) and BKT1 escalated the substrate availability for the biosynthesis of TAG and astaxanthin, respectively. CONCLUSIONS In this study, the time-resolved transcriptional analysis of C. zofingiensis under SS and SR conditions was reported for the first time to elucidate the regulatory roles of key enzymes, including DGTT5, BKT1 and LCYb, in the underlying mechanisms of TAG and astaxanthin accumulation.
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Affiliation(s)
- Xuemei Mao
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
| | - Yongmin Lao
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
| | - Han Sun
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
| | - Xiaojie Li
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
| | - Jianfeng Yu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
| | - Feng Chen
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060 China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, 518060 China
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Chaffai R, Cherif A. The cadmium-induced changes in the polar and neutral lipid compositions suggest the involvement of triacylglycerol in the defense response in maize. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2020; 26:15-23. [PMID: 32158117 PMCID: PMC7036388 DOI: 10.1007/s12298-019-00734-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 10/26/2019] [Accepted: 11/18/2019] [Indexed: 05/03/2023]
Abstract
Cadmium (Cd) is a heavy metal ion leading to morphological and physiological disorders in plants; a specific toxicity target is the membrane lipids. The total lipids were separated by thin-layer chromatography, and the fatty acid composition of the total (TLs), polar lipids (PLs) and triacylglycerol (TAG)-a neutral lipid-was analyzed in maize seedlings in hydroponics and treated by various Cd concentrations (0-200 µM Cd). The TLs and PLs significantly decreased in roots after Cd treatment, suggesting the onset of lipid peroxidation mediated by oxygen free radicals, that induce alterations of the membrane structure and function. There were also increases in the TAG from 28.2 to 36.9% of TLs, and the TAG/PLs ratio varied from 0.59 to 0.84, in control and after exposure to 200 µM Cd, respectively. The TAG plays potent roles in membrane turnover serving as energy and carbon resources for the biosynthesis of membrane lipids, to preserve membrane structure and function, and therefore cell homeostasis in response to Cd. In shoots, a significant increase in the levels of C16:0, C18:1, and C18:2, while a decrease in that of C18:3 was observed, suggesting inhibition of desaturases enzymes. These lead to impairment of the chloroplast membrane. The total lipid content did not change under Cd stress. The PLs, however, decreased from 22.4 to 13.6 mg g-1 DW; their percent to TLs varied from 86.6 to 52.5%, in control, and after Cd treatment, respectively. In conclusion, the accumulation of TAG may represent a defense strategy by which maize seedlings can withstand the effects of Cd toxicity, leading to reduced oxidative stress.
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Affiliation(s)
- Radhouane Chaffai
- The University of Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020 Ariana, Tunisia
- Department of Fundamental Sciences, ISBST, Biotechpole Sidi Thabet, 2020 Ariana, Tunisia
| | - Ameur Cherif
- The University of Manouba, ISBST, BVBGR-LR11ES31, Biotechpole Sidi Thabet, 2020 Ariana, Tunisia
- Department of Fundamental Sciences, ISBST, Biotechpole Sidi Thabet, 2020 Ariana, Tunisia
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Hirai K, Nojo M, Sato Y, Tsuzuki M, Sato N. Contribution of protein synthesis depression to poly-β-hydroxybutyrate accumulation in Synechocystis sp. PCC 6803 under nutrient-starved conditions. Sci Rep 2019; 9:19944. [PMID: 31882765 PMCID: PMC6934822 DOI: 10.1038/s41598-019-56520-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 12/11/2019] [Indexed: 12/24/2022] Open
Abstract
Poly-β-hydroxybutyrate (PHB) in cyanobacteria, which accumulates as energy and carbon sources through the action of photosynthesis, is expected to substitute for petroleum-based plastics. This study first demonstrated that PHB accumulation was induced, with the appearance of lipid droplets, in sulfur (S)-starved cells of a cyanobacterium, Synechocystis sp. PCC 6803, however, to a lower level than in nitrogen (N)- or phosphorus (P)-starved cells. Concomitantly found was repression of the accumulation of total cellular proteins in the S-starved cells to a similar level to that in N-starved cells, and a severer level than in P-starved cells. Intriguingly, PHB accumulation was induced in Synechocystis even under nutrient-replete conditions, upon repression of the accumulation of total cellular proteins through treatment of the wild type cells with a protein synthesis inhibitor, chloramphenicol, or through disruption of the argD gene for Arg synthesis. Meanwhile, the expression of the genes for PHB synthesis was hardly induced in S-starved cells, in contrast to their definite up-regulation in N- or P-starved cells. It therefore seemed that PHB accumulation in S-starved cells is achieved through severe repression of protein synthesis, but is smaller than in N- or P-starved cells, owing to little induction of the expression of PHB synthesis genes.
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Affiliation(s)
- Kazuho Hirai
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Miki Nojo
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Yosuke Sato
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Mikio Tsuzuki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Norihiro Sato
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan.
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Sasaki M, Takagi A, Ota S, Kawano S, Sasaki D, Asayama M. Coproduction of lipids and extracellular polysaccharides from the novel green alga Parachlorella sp. BX1.5 depending on cultivation conditions. ACTA ACUST UNITED AC 2019; 25:e00392. [PMID: 31871922 PMCID: PMC6909058 DOI: 10.1016/j.btre.2019.e00392] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 10/03/2019] [Accepted: 10/29/2019] [Indexed: 12/22/2022]
Abstract
A novel strain of microalga Parachlorella sp. BX1.5 was isolated and its unique properties of producing lipids and extracellular polysaccharides (EPS) characterized. The cells could extracellularly produce a large amount of acidic EPS, when cultured in nitrogen-deficient BG110 medium (BG11–N) with 2 % CO2-air supply. The main component of intracellularly accumulated lipids was triacylglycerol (TAG), depending on the different cultivation conditions of BG11, BG11–N, BG11–P (phosphate depleted), and BG11–N–P (nitrogen and phosphate depleted). Fatty-methyl-esters (FAMEs), methyl-esterification of total lipids, consisted of abundant saturated C16 and unsaturated C18 fatty acids under the culture conditions. Cell spot assays on BG11 plates revealed the resistance of cells to pH 2–11, high temperatures of 50–70 °C, ultraviolet irradiation, and drought, under different culture conditions, thereby suggesting the biological significance of lipid and EPS accumulation. The prospects of BX1.5 as a dual producer has also been discussed for biorefineries.
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Affiliation(s)
- Mitsuki Sasaki
- College of Agriculture, Ibaraki University, 3-21-1 Ami, Ibaraki, 300-0393, Japan
| | - Akari Takagi
- College of Agriculture, Ibaraki University, 3-21-1 Ami, Ibaraki, 300-0393, Japan
| | - Shuhei Ota
- Department of Integrated Sciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba, Ibaraki, 305-8506, Japan
| | - Shigeyuki Kawano
- Department of Integrated Sciences, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-0882, Japan
- Future Center Initiative, The University of Tokyo, 178-4-4 Wakashiba, Kashiwa, Chiba, 277-0871, Japan
| | - Daisaku Sasaki
- BioX Chemical Industries Co. Ltd., 2-20-11 Inokuchidai, Nishi-ku, Hiroshima 733-0844, Japan
| | - Munehiko Asayama
- College of Agriculture, Ibaraki University, 3-21-1 Ami, Ibaraki, 300-0393, Japan
- United Graduate School of Agricultural Science, Tokyo University of Agriculture and Technology, 3-5-8 Fuchu, Tokyo, 183-8509, Japan
- Corresponding author at: College of Agriculture, Ibaraki University, 3-21-1 Ami, Ibaraki, 300-0393, Japan.
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Hidayati NA, Yamada‐Oshima Y, Iwai M, Yamano T, Kajikawa M, Sakurai N, Suda K, Sesoko K, Hori K, Obayashi T, Shimojima M, Fukuzawa H, Ohta H. Lipid remodeling regulator 1 (LRL1) is differently involved in the phosphorus-depletion response from PSR1 in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 100:610-626. [PMID: 31350858 PMCID: PMC6899820 DOI: 10.1111/tpj.14473] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/03/2019] [Accepted: 07/09/2019] [Indexed: 05/05/2023]
Abstract
The elucidation of lipid metabolism in microalgae has attracted broad interest, as their storage lipid, triacylglycerol (TAG), can be readily converted into biofuel via transesterification. TAG accumulates in the form of oil droplets, especially when cells undergo nutrient deprivation, such as for nitrogen (N), phosphorus (P), or sulfur (S). TAG biosynthesis under N-deprivation has been comprehensively studied in the model microalga Chlamydomonas reinhardtii, during which TAG accumulates dramatically. However, the resulting rapid breakdown of chlorophyll restricts overall oil yield productivity and causes cessation of cell growth. In contrast, P-deprivation results in oil accumulation without disrupting chloroplast integrity. We used a reverse genetics approach based on co-expression analysis to identify a transcription factor (TF) that is upregulated under P-depleted conditions. Transcriptomic analysis revealed that the mutants showed repression of genes typically associated with lipid remodeling under P-depleted conditions, such as sulfoquinovosyl diacylglycerol 2 (SQD2), diacylglycerol acyltransferase (DGTT1), and major lipid droplet protein (MLDP). As accumulation of sulfoquinovosyl diacylglycerol and TAG were suppressed in P-depleted mutants, we designated the protein as lipid remodeling regulator 1 (LRL1). LRL1 mutants showed slower growth under P-depletion. Moreover, cell size in the mutant was significantly reduced, and TAG and starch accumulation per cell were decreased. Transcriptomic analysis also suggested the repression of several genes typically upregulated in adaptation to P-depletion that are associated with the cell cycle and P and lipid metabolism. Thus, our analysis of LRL1 provides insights into P-allocation and lipid remodeling under P-depleted conditions in C. reinhardtii. OPEN RESEARCH BADGES: This article has earned an Open Data Badge for making publicly available the digitally-shareable data necessary to reproduce the reported results. The sequencing data were made publicly available under the BioProject Accession number PRJDB6733 and an accession number LC488724 at the DNA Data Bank of Japan (DDBJ). The data is available at https://trace.ddbj.nig.ac.jp/BPSearch/bioproject?acc=PRJDB6733; http://getentry.ddbj.nig.ac.jp/getentry/na/LC488724. The metabolome data were made publicly available and can be accessed at http://metabolonote.kazusa.or.jp/SE195:/; http://webs2.kazusa.or.jp/data/nur/.
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Affiliation(s)
- Nur A. Hidayati
- Graduate School of Bioscience and BiotechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Yui Yamada‐Oshima
- Graduate School of Bioscience and BiotechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Masako Iwai
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Takashi Yamano
- Graduate School of BiostudiesKyoto UniversityKyoto606‐8502Japan
| | | | - Nozomu Sakurai
- Technology DevelopmentKazusa DNA Research InstituteKazusa‐kamatari 2‐6‐7KisarazuChiba292‐0818Japan
- Present address:
National Institute of Genetics Bioinformation & DDBJ Center1111 YataMishimaShizuoka411‐8540Japan
| | - Kunihiro Suda
- Technology DevelopmentKazusa DNA Research InstituteKazusa‐kamatari 2‐6‐7KisarazuChiba292‐0818Japan
| | - Kanami Sesoko
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Koichi Hori
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Takeshi Obayashi
- Graduate School of Information SciencesTohoku University6‐3‐09, Aramaki‐Aza‐Aoba, Aoba‐kuSendai980‐8679Japan
| | - Mie Shimojima
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
| | - Hideya Fukuzawa
- Graduate School of BiostudiesKyoto UniversityKyoto606‐8502Japan
| | - Hiroyuki Ohta
- School of Life Science and TechnologyTokyo Institute of Technology4259‐B‐65 Nagatsuta‐cho, Midori‐kuYokohama226‐8501Japan
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Otaki R, Oishi Y, Abe S, Fujiwara S, Sato N. Regulatory carbon metabolism underlying seawater-based promotion of triacylglycerol accumulation in Chlorella kessleri. BIORESOURCE TECHNOLOGY 2019; 289:121686. [PMID: 31238290 DOI: 10.1016/j.biortech.2019.121686] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/03/2019] [Accepted: 06/18/2019] [Indexed: 06/09/2023]
Abstract
Chlorella kessleri accumulates triacylglycerol usable for biodiesel-fuel production to >20% dry cell weight in three days when cultured in three-fold diluted seawater, which imposes the combinatory stress of hyperosmosis and nutrients limitation. The quantitative behavior of major C-compounds, and related-gene expression patterns were investigated in Chlorella cells stressed with hyperosmosis, nutrients limitation, or their combination, to elucidate the C-metabolism for economical seawater-based triacylglycerol accumulation. Combinatory-stress cells showed repressed protein synthesis with initially accumulated starch being degraded later, the C-metabolic flow thereby being diverted to fatty acid and subsequent triacylglycerol accumulation. This C-flow diversion was induced by cooperative actions of nutrients-limitation and hyperosmosis. Semi-quantitative PCR analysis implied positive rewiring of the diverted C-flow into triacylglycerol in combinatory-stress cells through upregulation of gene expression concerning fatty acid and triacylglycerol synthesis, and starch synthesis and degradation. The information of regulatory C-metabolism will help reinforce the seawater-based triacylglycerol accumulation ability in algae including Chlorella.
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Affiliation(s)
- Rie Otaki
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Yutaro Oishi
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Seiya Abe
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Shoko Fujiwara
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan
| | - Norihiro Sato
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo 192-0392, Japan.
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Kokabi K, Gorelova O, Ismagulova T, Itkin M, Malitsky S, Boussiba S, Solovchenko A, Khozin-Goldberg I. Metabolomic foundation for differential responses of lipid metabolism to nitrogen and phosphorus deprivation in an arachidonic acid-producing green microalga. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 283:95-115. [PMID: 31128719 DOI: 10.1016/j.plantsci.2019.02.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 01/05/2019] [Accepted: 02/11/2019] [Indexed: 05/08/2023]
Abstract
The green oleaginous microalga Lobosphaera incisa accumulates storage lipids triacylglycerols (TAG) enriched in the long-chain polyunsaturated fatty acid arachidonic acid under nitrogen (N) deprivation. In contrast, under phosphorous (P) deprivation, the production of the monounsaturated oleic acid prevails. We compared physiological responses, ultrastructural, and metabolic consequences of L. incisa acclimation to N and P deficiency to provide novel insights into the key determinants of ARA accumulation. Differential responses to nutrient deprivation on growth performance, carbon-to-nitrogen stoichiometry, membrane lipid composition and TAG accumulation were demonstrated. Ultrastructural analyses suggested a dynamic role for vacuoles in sustaining cell homeostasis under conditions of different nutrient availability and their involvement in autophagy in L. incisa. Paralleling ARA-rich TAG accumulation in lipid droplets, N deprivation triggered intensive chloroplast dismantling and promoted catabolic processes. Metabolome analysis revealed depletion of amino acids and pyrimidines, and repression of numerous biosynthetic hubs to favour TAG biosynthesis under N deprivation. Under P deprivation, despite the relatively low growth penalties, the presence of the endogenous P reserves and the characteristic lipid remodelling, metabolic signatures of energy deficiency were revealed. Metabolome adjustments to P deprivation included depletion in ATP and phosphorylated nucleotides, increased levels of TCA-cycle intermediates and osmoprotectants. We conclude that characteristic cellular and metabolome adjustments tailor the adaptive responses of L. incisa to N and P deprivation modulating its LC-PUFA production.
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Affiliation(s)
- Kamilya Kokabi
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, 8499000, Israel
| | - Olga Gorelova
- Department of Bioengineering, Faculty of Biology, Moscow State University, GSP-1, Moscow, 119234, Russia
| | - Tatiana Ismagulova
- Department of Bioengineering, Faculty of Biology, Moscow State University, GSP-1, Moscow, 119234, Russia
| | - Maxim Itkin
- Metabolic Profiling Unit, Life Science Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Sergey Malitsky
- Metabolic Profiling Unit, Life Science Core Facilities, Weizmann Institute of Science, Rehovot, Israel
| | - Sammy Boussiba
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, 8499000, Israel
| | - Alexei Solovchenko
- Department of Bioengineering, Faculty of Biology, Moscow State University, GSP-1, Moscow, 119234, Russia; Peoples Friendship University of Russia (RUDN University), Moscow, 117198, Russia
| | - Inna Khozin-Goldberg
- Microalgal Biotechnology Laboratory, The French Associates Institute for Agriculture and Biotechnology of Drylands, The J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede-Boqer Campus, Midreshet Ben-Gurion, 8499000, Israel.
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Lai YH, Puspanadan S, Lee CK. Nutritional optimization of Arthrospira platensis for starch and Total carbohydrates production. Biotechnol Prog 2019; 35:e2798. [PMID: 30828976 DOI: 10.1002/btpr.2798] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 01/24/2019] [Accepted: 02/27/2019] [Indexed: 01/17/2023]
Abstract
Present study aims to optimize the production of starch and total carbohydrates from Arthrospira platensis. Growing concerns toward unprecedented environmental issues associated with plastic pollution has created a tremendous impetus to develop new biomaterials for the production of bioplastic. Starch-based biopolymers from algae serve as sustainable feedstock for thermoplastic starch production due to their abundant availability and low cost. A. platensis was cultivated in Zarrouk's medium at 32 ± 1°C and exposed to red light with a photoperiod of 12:12 hr light/dark. Growth kinetics studies showed that the maximum specific growth rate (μmax ) obtained was 0.059 day-1 with the doubling time (td ) of 11.748 days. Subsequently, Zarrouk's medium with different concentrations of sulfur, phosphorus and nitrogen was prepared to establish the nutrient-limiting conditions to enhance the accumulation of starch and total carbohydrates. In this study, the highest starch accumulated was 6.406 ± 0.622 mg L-1 under optimized phosphorus limitation (0.025 g L-1 ) conditions. Nitrogen limitation (0.250 g L-1 ) results demonstrated significant influenced (p < 0.05) on total carbohydrates (67.573 ± 2.893 mg L-1 ) accumulation in A. platensis. The starch accumulation in A. platensis was significantly affected (p < 0.05) by phosphorus limitation (0.0025 g L-1 ). Subsequently, the optimized phosphorus concentration was coupled with mixotrophic cultivation to further enhance the starch accumulation. The results obtained indicated that, the starch (11.426 ± 0.314 mg L-1 ) and carbohydrates (43.053 ± 2.986 mg L-1 ) concentration obtained was significantly high (p < 0.05) under mixotrophic cultivation. Therefore, it shown that nutrient limitation and mixotrophic cultivation are viable strategies to enhance the accumulation of starch and total carbohydrates in A. platensis.
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Affiliation(s)
- Yuen Hing Lai
- Bioprocess Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Penang, Malaysia
| | - Soopna Puspanadan
- Bioprocess Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Penang, Malaysia
| | - Chee Keong Lee
- Bioprocess Technology Division, School of Industrial Technology, Universiti Sains Malaysia, Penang, Malaysia
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Toyoshima M, Sakata M, Ohnishi K, Tokumaru Y, Kato Y, Tokutsu R, Sakamoto W, Minagawa J, Matsuda F, Shimizu H. Targeted proteome analysis of microalgae under high-light conditions by optimized protein extraction of photosynthetic organisms. J Biosci Bioeng 2019; 127:394-402. [DOI: 10.1016/j.jbiosc.2018.09.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 08/23/2018] [Accepted: 09/02/2018] [Indexed: 12/14/2022]
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Colina F, Amaral J, Carbó M, Pinto G, Soares A, Cañal MJ, Valledor L. Genome-wide identification and characterization of CKIN/SnRK gene family in Chlamydomonas reinhardtii. Sci Rep 2019; 9:350. [PMID: 30674892 PMCID: PMC6344539 DOI: 10.1038/s41598-018-35625-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 11/09/2018] [Indexed: 12/29/2022] Open
Abstract
The SnRK (Snf1-Related protein Kinase) gene family plays an important role in energy sensing and stress-adaptive responses in plant systems. In this study, Chlamydomonas CKIN family (SnRK in Arabidopsis) was defined after a genome-wide analysis of all sequenced Chlorophytes. Twenty-two sequences were defined as plant SnRK orthologs in Chlamydomonas and classified into two subfamilies: CKIN1 and CKIN2. While CKIN1 subfamily is reduced to one conserved member and a close protein (CKIN1L), a large CKIN2 subfamily clusters both plant-like and algae specific CKIN2s. The responsiveness of these genes to abiotic stress situations was tested by RT-qPCR. Results showed that almost all elements were sensitive to osmotic stress while showing different degrees of sensibility to other abiotic stresses, as occurs in land plants, revealing their specialization and the family pleiotropy for some elements. The regulatory pathway of this family may differ from land plants since these sequences shows unique regulatory features and some of them are sensitive to ABA, despite conserved ABA receptors (PYR/PYL/RCAR) and regulatory domains are not present in this species. Core Chlorophytes and land plant showed divergent stress signalling, but SnRKs/CKINs share the same role in cell survival and stress response and adaption including the accumulation of specific biomolecules. This fact places the CKIN family as well-suited target for bioengineering-based studies in microalgae (accumulation of sugars, lipids, secondary metabolites), while promising new findings in stress biology and specially in the evolution of ABA-signalling mechanisms.
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Affiliation(s)
- Francisco Colina
- Plant Physiology, Department of Organisms and Systems Biology and University Institute of Biotechnology (IUBA), University of Oviedo, Oviedo, Spain
| | - Joana Amaral
- Department of Biology and CESAM, University of Aveiro, Aveiro, Portugal
| | - María Carbó
- Plant Physiology, Department of Organisms and Systems Biology and University Institute of Biotechnology (IUBA), University of Oviedo, Oviedo, Spain
| | - Gloria Pinto
- Department of Biology and CESAM, University of Aveiro, Aveiro, Portugal
| | - Amadeu Soares
- Department of Biology and CESAM, University of Aveiro, Aveiro, Portugal
| | - María Jesús Cañal
- Plant Physiology, Department of Organisms and Systems Biology and University Institute of Biotechnology (IUBA), University of Oviedo, Oviedo, Spain
| | - Luis Valledor
- Plant Physiology, Department of Organisms and Systems Biology and University Institute of Biotechnology (IUBA), University of Oviedo, Oviedo, Spain.
- Department of Biology and CESAM, University of Aveiro, Aveiro, Portugal.
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Takeuchi T, Benning C. Nitrogen-dependent coordination of cell cycle, quiescence and TAG accumulation in Chlamydomonas. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:292. [PMID: 31890020 PMCID: PMC6927116 DOI: 10.1186/s13068-019-1635-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 12/12/2019] [Indexed: 05/07/2023]
Abstract
Microalgae hold great promises as sustainable cellular factories for the production of alternative fuels, feeds, and biopharmaceuticals for human health. While the biorefinery approach for fuels along with the coproduction of high-value compounds with industrial, therapeutic, or nutraceutical applications have the potential to make algal biofuels more economically viable, a number of challenges continue to hamper algal production systems at all levels. One such hurdle includes the metabolic trade-off often observed between the increased yields of desired products, such as triacylglycerols (TAG), and the growth of an organism. Initial genetic engineering strategies to improve lipid productivity in microalgae, which focused on overproducing the enzymes involved in fatty acid and TAG biosynthesis or inactivating competing carbon (C) metabolism, have seen some successes albeit at the cost of often greatly reduced biomass. Emergent approaches that aim at modifying the dynamics of entire metabolic pathways by engineering of pertinent transcription factors or signaling networks appear to have successfully achieved a balance between growth and neutral lipid accumulation. However, the biological knowledge of key signaling networks and molecular components linking these two processes is still incomplete in photosynthetic eukaryotes, making it difficult to optimize metabolic engineering strategies for microalgae. Here, we focus on nitrogen (N) starvation of the model green microalga, Chlamydomonas reinhardtii, to present the current understanding of the nutrient-dependent switch between proliferation and quiescence, and the drastic reprogramming of metabolism that results in the storage of C compounds following N starvation. We discuss the potential components mediating the transcriptional repression of cell cycle genes and the establishment of quiescence in Chlamydomonas, and highlight the importance of signaling pathways such as those governed by the target of rapamycin (TOR) and sucrose nonfermenting-related (SnRK) kinases in the coordination of metabolic status with cellular growth. A better understanding of how the cell division cycle is regulated in response to nutrient scarcity and of the signaling pathways linking cellular growth to energy and lipid homeostasis, is essential to improve the prospects of biofuels and biomass production in microalgae.
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Affiliation(s)
- Tomomi Takeuchi
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 USA
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
| | - Christoph Benning
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824 USA
- Department of Energy-Plant Research Laboratory, Michigan State University, East Lansing, MI 48824 USA
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824 USA
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Yamazaki T, Konosu E, Takeshita T, Hirata A, Ota S, Kazama Y, Abe T, Kawano S. Independent regulation of the lipid and starch synthesis pathways by sulfate metabolites in the green microalga Parachlorella kessleri under sulfur starvation conditions. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.09.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Wase N, Black P, DiRusso C. Innovations in improving lipid production: Algal chemical genetics. Prog Lipid Res 2018; 71:101-123. [DOI: 10.1016/j.plipres.2018.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 06/25/2018] [Accepted: 07/06/2018] [Indexed: 01/01/2023]
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19
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Hayashi T, Otaki R, Hirai K, Tsuzuki M, Sato N. Optimization of seawater-based triacylglycerol accumulation in a freshwater green alga, Chlorella kessleri , through simultaneous imposition of lowered-temperature and enhanced-light intensity. ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.10.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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20
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Esquível MG, Matos A.R, Marques Silva J. Rubisco mutants of Chlamydomonas reinhardtii display divergent photosynthetic parameters and lipid allocation. Appl Microbiol Biotechnol 2017; 101:5569-5580. [DOI: 10.1007/s00253-017-8322-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 04/19/2017] [Accepted: 04/29/2017] [Indexed: 11/29/2022]
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21
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Shin SE, Koh HG, Kang NK, Suh WI, Jeong BR, Lee B, Chang YK. Isolation, phenotypic characterization and genome wide analysis of a Chlamydomonas reinhardtii strain naturally modified under laboratory conditions: towards enhanced microalgal biomass and lipid production for biofuels. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:308. [PMID: 29296121 PMCID: PMC5740574 DOI: 10.1186/s13068-017-1000-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 12/14/2017] [Indexed: 05/21/2023]
Abstract
BACKGROUND Microalgal strain development through genetic engineering has received much attention as a way to improve the traits of microalgae suitable for biofuel production. However, there are still some limitations in application of genetically modified organisms. In this regard, there has been recent interest in the isolation and characterization of superior strains naturally modified and/or adapted under a certain condition and on the interpretation of phenotypic changes through the whole genome sequencing. RESULTS In this study, we isolated and characterized a novel derivative of C. reinhardtii, whose phenotypic traits diverged significantly from its ancestral strain, C. reinhardtii CC-124. This strain, designated as CC-124H, displayed cell population containing increased numbers of larger cells, which resulted in an increased biomass productivity compared to its ancestor CC-124. CC-124H was further compared with the CC-124 wild-type strain which underwent long-term storage under low light condition, designated as CC-124L. In an effort to evaluate the potential of CC-124H for biofuel production, we also found that CC-124H accumulated 116 and 66% greater lipids than that of the CC-124L, after 4 days under nitrogen and sulfur depleted conditions, respectively. Taken together, our results revealed that CC-124H had significantly increased fatty acid methyl ester (FAME) yields that were 2.66 and 1.98 times higher than that of the CC-124L at 4 days after the onset of cultivation under N and S depleted conditions, respectively, and these higher FAME yields were still maintained by day 8. We next analyzed single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) based on the whole genome sequencing. The result revealed that of the 44 CDS region alterations, 34 resulted in non-synonymous substitutions within 33 genes which may mostly be involved in cell cycle, division or proliferation. CONCLUSION Our phenotypic analysis, which emphasized lipid productivity, clearly revealed that CC-124H had a dramatically enhanced biomass and lipid content compared to the CC-124L. Moreover, SNPs and indels analysis enabled us to identify 34 of non-synonymous substitutions which may result in phenotypic changes of CC-124H. All of these results suggest that the concept of adaptive evolution combined with genome wide analysis can be applied to microalgal strain development for biofuel production.
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Affiliation(s)
- 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
| | - Hyun Gi Koh
- 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
| | - William I. Suh
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Byeong-ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Bongsoo Lee
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
| | - Yong Keun Chang
- Department of Chemical and Biomolecular Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
- Advanced Biomass R&D Center, 291 Daehak-ro, Yuseong-gu, Daejeon, 34141 Republic of Korea
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Tan KWM, Lin H, Shen H, Lee YK. Nitrogen-induced metabolic changes and molecular determinants of carbon allocation in Dunaliella tertiolecta. Sci Rep 2016; 6:37235. [PMID: 27849022 PMCID: PMC5110973 DOI: 10.1038/srep37235] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Accepted: 10/25/2016] [Indexed: 01/06/2023] Open
Abstract
Certain species of microalgae are natural accumulators of lipids, while others are more inclined to store starch. However, what governs the preference to store lipids or starch is not well understood. In this study, the microalga Dunaliella tertiolecta was used as a model to study the global gene expression profile regulating starch accumulation in microalgae. D. tertiolecta, when depleted of nitrogen, produced only 1% of dry cell weight (DCW) in neutral lipids, while starch was rapidly accumulated up to 46% DCW. The increased in starch content was accompanied by a coordinated overexpression of genes shunting carbon towards starch synthesis, a response not seen in the oleaginous microalgae Nannochloropsis oceanica, Chlamydomonas reinhardtii or Chlorella vulgaris. Genes in the central carbon metabolism pathways, particularly those of the tricarboxylic acid cycle, were also simultaneously upregulated, indicating a robust interchange of carbon skeletons for anabolic and catabolic processes. In contrast, fatty acid and triacylglycerol synthesis genes were downregulated or unchanged, suggesting that lipids are not a preferred form of storage in these cells. This study reveals the transcriptomic influence behind storage reserve allocation in D. tertiolecta and provides valuable insights into the possible manipulation of genes for engineering microorganisms to synthesize products of interest.
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Affiliation(s)
- Kenneth Wei Min Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Huixin Lin
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Hui Shen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Yuan Kun Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
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Zuliani L, Frison N, Jelic A, Fatone F, Bolzonella D, Ballottari M. Microalgae Cultivation on Anaerobic Digestate of Municipal Wastewater, Sewage Sludge and Agro-Waste. Int J Mol Sci 2016; 17:ijms17101692. [PMID: 27735859 PMCID: PMC5085724 DOI: 10.3390/ijms17101692] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/16/2016] [Accepted: 09/29/2016] [Indexed: 02/08/2023] Open
Abstract
Microalgae are fast-growing photosynthetic organisms which have the potential to be exploited as an alternative source of liquid fuels to meet growing global energy demand. The cultivation of microalgae, however, still needs to be improved in order to reduce the cost of the biomass produced. Among the major costs encountered for algal cultivation are the costs for nutrients such as CO2, nitrogen and phosphorous. In this work, therefore, different microalgal strains were cultivated using as nutrient sources three different anaerobic digestates deriving from municipal wastewater, sewage sludge or agro-waste treatment plants. In particular, anaerobic digestates deriving from agro-waste or sewage sludge treatment induced a more than 300% increase in lipid production per volume in Chlorella vulgaris cultures grown in a closed photobioreactor, and a strong increase in carotenoid accumulation in different microalgae species. Conversely, a digestate originating from a pilot scale anaerobic upflow sludge blanket (UASB) was used to increase biomass production when added to an artificial nutrient-supplemented medium. The results herein demonstrate the possibility of improving biomass accumulation or lipid production using different anaerobic digestates.
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Affiliation(s)
- Luca Zuliani
- Dipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy.
| | - Nicola Frison
- Dipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy.
| | - Aleksandra Jelic
- Dipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy.
| | - Francesco Fatone
- Dipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy.
| | - David Bolzonella
- Dipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy.
| | - Matteo Ballottari
- Dipartimento di Biotecnologie, Università di Verona, Strada le Grazie 15, 37134 Verona, Italy.
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Strategies for Lipid Production Improvement in Microalgae as a Biodiesel Feedstock. BIOMED RESEARCH INTERNATIONAL 2016; 2016:8792548. [PMID: 27725942 PMCID: PMC5048031 DOI: 10.1155/2016/8792548] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/20/2016] [Accepted: 07/25/2016] [Indexed: 01/04/2023]
Abstract
In response to the energy crisis, global warming, and climate changes, microalgae have received a great deal of attention as a biofuel feedstock. Due to a high lipid content in microalgal cells, microalgae present as a promising alternative source for the production of biodiesel. Environmental and culturing condition variations can alter lipid production as well as chemical compositions of microalgae. Therefore, application of the strategies to activate lipid accumulation opens the door for lipid overproduction in microalgae. Until now, many original studies regarding the approaches for enhanced microalgal lipid production have been reported in an effort to push forward the production of microalgal biodiesel. However, the current literature demonstrates fragmented information available regarding the strategies for lipid production improvement. From the systematic point of view, the review highlights the main approaches for microalgal lipid accumulation induction to expedite the application of microalgal biodiesel as an alternative to fossil diesel for sustainable environment. Of the several strategies discussed, the one that is most commonly applied is the design of nutrient (e.g., nitrogen, phosphorus, and sulfur) starvation or limitation. Other viable approaches such as light intensity, temperature, carbon dioxide, salinity stress, and metal influence can also achieve enhanced microalgal lipid production.
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Hyperosmosis and its combination with nutrient-limitation are novel environmental stressors for induction of triacylglycerol accumulation in cells of Chlorella kessleri. Sci Rep 2016; 6:25825. [PMID: 27184595 PMCID: PMC4869002 DOI: 10.1038/srep25825] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 04/25/2016] [Indexed: 11/24/2022] Open
Abstract
Triacylglycerols of oleaginous algae are promising for production of food oils and biodiesel fuel. Air-drying of cells induces triacylglycerol accumulation in a freshwater green alga, Chlorella kessleri, therefore, it seems that dehydration, i.e., intracellular hyperosmosis, and/or nutrient-limitation are key stressors. We explored this possibility in liquid-culturing C. kessleri cells. Strong hyperosmosis with 0.9 M sorbitol or 0.45 M NaCl for two days caused cells to increase the triacylglycerol content in total lipids from 1.5 to 48.5 and 75.3 mol%, respectively, on a fatty acid basis, whereas nutrient-limitation caused its accumulation to 41.4 mol%. Even weak hyperosmosis with 0.3 M sorbitol or 0.15 M NaCl, when nutrient-limitation was simultaneously imposed, induced triacylglycerol accumulation to 61.9 and 65.7 mol%, respectively. Furthermore, culturing in three-fold diluted seawater, the chemical composition of which resembled that of the medium for the combinatory stress, enabled the cells to accumulate triacylglycerol up to 24.7 weight% of dry cells in only three days. Consequently, it was found that hyperosmosis is a novel stressor for triacylglycerol accumulation, and that weak hyperosmosis, together with nutrient-limitation, exerts a strong stimulating effect on triacylglycerol accumulation. A similar combinatory stress would contribute to the triacylglycerol accumulation in air-dried C. kessleri cells.
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Schulz-Raffelt M, Chochois V, Auroy P, Cuiné S, Billon E, Dauvillée D, Li-Beisson Y, Peltier G. Hyper-accumulation of starch and oil in a Chlamydomonas mutant affected in a plant-specific DYRK kinase. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:55. [PMID: 26958078 PMCID: PMC4782384 DOI: 10.1186/s13068-016-0469-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 02/19/2016] [Indexed: 05/08/2023]
Abstract
BACKGROUND Because of their high biomass productivity and their ability to accumulate high levels of energy-rich reserve compounds such as oils or starch, microalgae represent a promising feedstock for the production of biofuel. Accumulation of reserve compounds takes place when microalgae face adverse situations such as nutrient shortage, conditions which also provoke a stop in cell division, and down-regulation of photosynthesis. Despite growing interest in microalgal biofuels, little is known about molecular mechanisms controlling carbon reserve formation. In order to discover new regulatory mechanisms, and identify genes of interest to boost the potential of microalgae for biofuel production, we developed a forward genetic approach in the model microalga Chlamydomonas reinhardtii. RESULTS By screening an insertional mutant library on the ability of mutants to accumulate and re-mobilize reserve compounds, we isolated a Chlamydomonas mutant (starch degradation 1, std1) deficient for a dual-specificity tyrosine-phosphorylation-regulated kinase (DYRK). The std1 mutant accumulates higher levels of starch and oil than wild-type and maintains a higher photosynthetic activity under nitrogen starvation. Phylogenetic analysis revealed that this kinase (named DYRKP) belongs to a plant-specific subgroup of the evolutionarily conserved DYRK kinase family. Furthermore, hyper-accumulation of storage compounds occurs in std1 mostly under low light in photoautotrophic condition, suggesting that the kinase normally acts under conditions of low energy status to limit reserve accumulation. CONCLUSIONS The DYRKP kinase is proposed to act as a negative regulator of the sink capacity of photosynthetic cells that integrates nutrient and energy signals. Inactivation of the kinase strongly boosts accumulation of reserve compounds under photoautotrophic nitrogen deprivation and allows maintaining high photosynthetic activity. The DYRKP kinase therefore represents an attractive target for improving the energy density of microalgae or crop plants.
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Affiliation(s)
- Miriam Schulz-Raffelt
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
- />Molecular Biotechnology and Systems Biology, TU Kaiserslautern, Paul-Ehrlich-Straße 23, 67663 Kaiserslautern, Germany
| | - Vincent Chochois
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
- />Research School of Biology College of Medicine, Biology and Environment, Linneaus Building 134, The Australian National University, Canberra, ACT 2601 Australia
| | - Pascaline Auroy
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
| | - Stéphan Cuiné
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
| | - Emmanuelle Billon
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
| | - David Dauvillée
- />UMR8576, CNRS, Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq, France
| | - Yonghua Li-Beisson
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
| | - Gilles Peltier
- />CEA, CNRS, Aix-Marseille Université, Institut de Biosciences et Biotechnologies Aix Marseille, Laboratoire de Bioénergétique et Biotechnologie des Bactéries et Microalgues, CEA Cadarache, 13108 Saint-Paul-lez-Durance, France
- />CNRS, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13108 Saint-Paul-lez-Durance, France
- />Aix Marseille Université, Biologie Végétale et Microbiologie Environnementale, UMR7265, 13284 Marseille, France
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Identification of gene transcripts involved in lipid biosynthesis in Chlamydomonas reinhardtii under nitrogen, iron and sulfur deprivation. World J Microbiol Biotechnol 2016; 32:55. [DOI: 10.1007/s11274-016-2008-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 01/04/2016] [Indexed: 10/22/2022]
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Kajikawa M, Sawaragi Y, Shinkawa H, Yamano T, Ando A, Kato M, Hirono M, Sato N, Fukuzawa H. Algal dual-specificity tyrosine phosphorylation-regulated kinase, triacylglycerol accumulation regulator1, regulates accumulation of triacylglycerol in nitrogen or sulfur deficiency. PLANT PHYSIOLOGY 2015; 168:752-64. [PMID: 25922058 PMCID: PMC4453788 DOI: 10.1104/pp.15.00319] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2015] [Accepted: 04/24/2015] [Indexed: 05/17/2023]
Abstract
Although microalgae accumulate triacylglycerol (TAG) and starch in response to nutrient-deficient conditions, the regulatory mechanisms are poorly understood. We report here the identification and characterization of a kinase, triacylglycerol accumulation regulator1 (TAR1), that is a member of the yeast (Saccharomyces cerevisiae) Yet another kinase1 (Yak1) subfamily in the dual-specificity tyrosine phosphorylation-regulated kinase family in a green alga (Chlamydomonas reinhardtii). The kinase domain of TAR1 showed auto- and transphosphorylation activities. A TAR1-defective mutant, tar1-1, accumulated TAG to levels 0.5- and 0.1-fold of those of a wild-type strain in sulfur (S)- and nitrogen (N)-deficient conditions, respectively. In N-deficient conditions, tar1-1 showed more pronounced arrest of cell division than the wild type, had increased cell size and cell dry weight, and maintained chlorophyll and photosynthetic activity, which were not observed in S-deficient conditions. In N-deficient conditions, global changes in expression levels of N deficiency-responsive genes in N assimilation and tetrapyrrole metabolism were noted between tar1-1 and wild-type cells. These results indicated that TAR1 is a regulator of TAG accumulation in S- and N-deficient conditions, and it functions in cell growth and repression of photosynthesis in conditions of N deficiency.
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Affiliation(s)
- Masataka Kajikawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan (Ma.K., Y.S., H.S., T.Y., H.F.);Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan (A.A., Mi.K.);Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan (M.H.); andGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan (N.S.)
| | - Yuri Sawaragi
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan (Ma.K., Y.S., H.S., T.Y., H.F.);Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan (A.A., Mi.K.);Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan (M.H.); andGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan (N.S.)
| | - Haruka Shinkawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan (Ma.K., Y.S., H.S., T.Y., H.F.);Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan (A.A., Mi.K.);Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan (M.H.); andGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan (N.S.)
| | - Takashi Yamano
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan (Ma.K., Y.S., H.S., T.Y., H.F.);Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan (A.A., Mi.K.);Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan (M.H.); andGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan (N.S.)
| | - Akira Ando
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan (Ma.K., Y.S., H.S., T.Y., H.F.);Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan (A.A., Mi.K.);Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan (M.H.); andGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan (N.S.)
| | - Misako Kato
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan (Ma.K., Y.S., H.S., T.Y., H.F.);Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan (A.A., Mi.K.);Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan (M.H.); andGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan (N.S.)
| | - Masafumi Hirono
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan (Ma.K., Y.S., H.S., T.Y., H.F.);Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan (A.A., Mi.K.);Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan (M.H.); andGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan (N.S.)
| | - Naoki Sato
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan (Ma.K., Y.S., H.S., T.Y., H.F.);Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan (A.A., Mi.K.);Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan (M.H.); andGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan (N.S.)
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan (Ma.K., Y.S., H.S., T.Y., H.F.);Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan (A.A., Mi.K.);Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan (M.H.); andGraduate School of Arts and Sciences, University of Tokyo, Tokyo 153-8902, Japan (N.S.)
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