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Şirin PA, Serdar S. Effects of nitrogen starvation on growth and biochemical composition of some microalgae species. Folia Microbiol (Praha) 2024; 69:889-902. [PMID: 38285280 DOI: 10.1007/s12223-024-01136-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 01/12/2024] [Indexed: 01/30/2024]
Abstract
Nitrogen is one of the most important nutrient sources for the growth of microalgae. We studied the effects of nitrogen starvation on the growth responses, biochemical composition, and fatty acid profile of Dunaliella tertiolecta, Phaeodactylum tricornutum, and Nannochloropsis oculata. The lack of nitrogen caused changes in carbohydrate, protein, lipid, and fatty acid composition in all examined microalgae. The carbohydrate content increased 59% in D. tertiolecta, while the lipid level increased 139% in P. tricornutum under nitrogen stress conditions compared to the control groups. Nitrogen starvation increased the oligosaccharide and polysaccharide contents of D. tertiolecta 4.1-fold and 3.6-fold, respectively. Furthermore, triacylglycerol (TAG) levels in N. oculata and P. tricornutum increased 2.3-fold and 7.4-fold, respectively. The dramatic increase in the amount of TAG is important for the use of these microalgae as raw materials in biodiesel. Nitrogen starvation increased the amounts of oligosaccharides and polysaccharides of D. tertiolecta, while increased eicosapentaenoic acid (EPA) in N. oculata and docosahexaenoic acid (DHA) content in P. tricornutum. The amount of polyunsaturated fatty acids (PUFAs), EPA, DHA, oligosaccharides, and polysaccharides in microalgal species can be increased without using the too costly nitrogen source in the culture conditions, which can reduce the most costly of living feeding.
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Affiliation(s)
- Pınar Akdoğan Şirin
- Fatsa Faculty of Marine Science, Department of Fisheries Technology Engineering, Ordu University, 52400, Fatsa, Ordu, Turkey.
| | - Serpil Serdar
- Faculty of Fisheries, Department of Aquaculture, Ege University, 35030, Bornova, Izmir, Turkey
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2
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Ahmad A, Amin KA, Ashraf SS. Biological effects of culture medium on Tetraselmis chuii and Dunaliella tertiolecta: Implications for emerging pollutants degradation. CHEMOSPHERE 2024; 363:142868. [PMID: 39025305 DOI: 10.1016/j.chemosphere.2024.142868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 07/09/2024] [Accepted: 07/14/2024] [Indexed: 07/20/2024]
Abstract
In this study, laboratory-scale cultivation of T. chuii and D. tertiolecta was conducted using Conway, F/2, and TMRL media to evaluate their biochemical composition and economic costs. The highest cell density (30.36 × 106 cells/mL) and dry weight (0.65 g/L) for T. chuii were achieved with Conway medium. This medium also produced biomass with maximum lipid content (25.65%), proteins (27.84%), and total carbohydrates (8.45%) compared with F/2 and TMRL media. D. tertiolecta reached a maximum cell density of 17.50 × 106 cells/mL in F/2 medium, which was notably lower than that of T. chuii. Furthermore, the media cost varied from US$0.23 to US$0.74 for each 1 L of media, primarily due to the addition of Na3PO4, KNO3, and cyanocobalamin. Thus, biomass production rates varied between US$38.81 and US$128.80 per kg on a dry weight basis. These findings comprehensively compare laboratory conditions and the costs associated with biomass production in different media. Additionally, this study explored the potential of T. chuii and D. tertiolecta strains, as well as their consortia with bacteria, for the degradation of various emerging pollutants (EPs), including caffeine, salicylic acid, DEET, imidacloprid, MBT, cimetidine, venlafaxine, methylparaben, thiabendazole, and paracetamol. Both microalgal strains demonstrated effective degradation of EPs, with enhanced degradation observed in microalgae-bacterial consortia. These results suggest that the symbiotic relationship between microalgae and bacteria can be harnessed for the bioremediation of EPs, thereby offering valuable insights into the environmental applications of microalgal cultivation.
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Affiliation(s)
- Ashfaq Ahmad
- Department of Biological Sciences, College of Medicine and Health Sciences, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates; ASPIRE Research Institute for Food Security in the Drylands (ARIFSID), United Arab Emirates University, P.O. Box 15551, Al Ain, United Arab Emirates.
| | - Khadije Ahmad Amin
- Department of Biological Sciences, College of Medicine and Health Sciences, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates
| | - Syed Salman Ashraf
- Department of Biological Sciences, College of Medicine and Health Sciences, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Center for Biotechnology (BTC), Khalifa University Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Center for Membranes and Advanced Water Technology (CMAT), Khalifa University Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates; ASPIRE Research Institute for Food Security in the Drylands (ARIFSID), United Arab Emirates University, P.O. Box 15551, Al Ain, United Arab Emirates.
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Keil L, Qoura FM, Breitsameter JM, Rieger B, Garbe D, Brück TB. Evaluation of Chemical and Physical Triggers for Enhanced Photosynthetic Glycerol Production in Different Dunaliella Isolates. Microorganisms 2024; 12:1318. [PMID: 39065087 PMCID: PMC11278730 DOI: 10.3390/microorganisms12071318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 07/28/2024] Open
Abstract
The salt-tolerant marine microalgae Dunaliella tertiolecta is reported to generate significant amounts of intracellular glycerol as an osmoprotectant under high salt conditions. This study highlights the phylogenetic distribution and comparative glycerol biosynthesis of seven new Dunaliella isolates compared to a D. tertiolecta reference strain. Phylogenetic analysis indicates that all Dunaliella isolates are newly discovered and do not relate to the D. tertiolecta reference. Several studies have identified light color and intensity and salt concentration alone as the most inducing factors impacting glycerol productivity. This study aims to optimize glycerol production by investigating these described factors singularly and in combination to improve the glycerol product titer. Glycerol production data indicate that cultivation with white light of an intensity between 500 and 2000 μmol m-2 s-1 as opposed to 100 μmol m-2 s-1 achieves higher biomass and thereby higher glycerol titers for all our tested Dunaliella strains. Moreover, applying higher light intensity in a cultivation of 1.5 M NaCl and an increase to 3 M NaCl resulted in hyperosmotic stress conditions, providing the highest glycerol titer. Under these optimal light intensity and salt conditions, the glycerol titer of D. tertiolecta could be doubled to 0.79 mg mL-1 in comparison to 100 μmol m-2 s-1 and salt stress to 2 M NaCl, and was higher compared to singularly optimized conditions. Furthermore, under the same conditions, glycerol extracts from new Dunaliella isolates did provide up to 0.94 mg mL-1. This highly pure algae-glycerol obtained under optimal production conditions can find widespread applications, e.g., in the pharmaceutical industry or the production of sustainable carbon fibers.
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Affiliation(s)
- Linda Keil
- Werner Siemens Laboratory of Synthetic Biotechnology, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany;
| | - Farah Mitry Qoura
- Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, Nobelstraße 12, 70569 Stuttgart, Germany;
| | - Jonas Martin Breitsameter
- Wacker-Laboratory of Macromolecular Chemistry, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany; (J.M.B.); (B.R.)
| | - Bernhard Rieger
- Wacker-Laboratory of Macromolecular Chemistry, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany; (J.M.B.); (B.R.)
| | - Daniel Garbe
- Werner Siemens Laboratory of Synthetic Biotechnology, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany;
| | - Thomas Bartholomäus Brück
- Werner Siemens Laboratory of Synthetic Biotechnology, TUM-School of Natural Sciences, Technical University of Munich (TUM), 85748 Garching, Germany;
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4
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Panahi B, Farhadian M, Hosseinzadeh Gharajeh N, Mohammadi SA, Hejazi MA. Meta-analysis of transcriptomic profiles in Dunaliella tertiolecta reveals molecular pathway responses to different abiotic stresses. FUNCTIONAL PLANT BIOLOGY : FPB 2024; 51:FP23002. [PMID: 38388445 DOI: 10.1071/fp23002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 02/04/2024] [Indexed: 02/24/2024]
Abstract
Microalgae are photosynthetic organisms and a potential source of sustainable metabolite production. However, different stress conditions might affect the production of various metabolites. In this study, a meta-analysis of RNA-seq experiments in Dunaliella tertiolecta was evaluated to compare metabolite biosynthesis pathways in response to abiotic stress conditions such as high light, nitrogen deficiency and high salinity. Results showed downregulation of light reaction, photorespiration, tetrapyrrole and lipid-related pathways occurred under salt stress. Nitrogen deficiency mostly induced the microalgal responses of light reaction and photorespiration metabolism. Phosphoenol pyruvate carboxylase, phosphoglucose isomerase, bisphosphoglycerate mutase and glucose-6-phosphate-1-dehydrogenase (involved in central carbon metabolism) were commonly upregulated under salt, light and nitrogen stresses. Interestingly, the results indicated that the meta-genes (modules of genes strongly correlated) were located in a hub of stress-specific protein-protein interaction (PPI) network. Module enrichment of meta-genes PPI networks highlighted the cross-talk between photosynthesis, fatty acids, starch and sucrose metabolism under multiple stress conditions. Moreover, it was observed that the coordinated expression of the tetrapyrrole intermediated with meta-genes was involved in starch biosynthesis. Our results also showed that the pathways of vitamin B6 metabolism, methane metabolism, ribosome biogenesis and folate biosynthesis responded specifically to different stress factors. Since the results of this study revealed the main pathways underlying the abiotic stress, they might be applied in optimised metabolite production by the microalga Dunaliella in future studies. PRISMA check list was also included in the study.
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Affiliation(s)
- Bahman Panahi
- Department of Genomics, Branch for Northwest & West Region, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran
| | - Mohammad Farhadian
- Department of Neurology, School of Medicine, Technical University of Munich, Munich, Germany
| | | | | | - Mohammad Amin Hejazi
- Department of Food Biotechnology, Branch for Northwest & West Region, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran
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Mohanta A, Prasad N, Khadim SR, Singh P, Singh S, Singh A, Kayastha AM, Asthana RK. Optimizing light regimes for neutral lipid accumulation in Dunaliella salina MCC 43: a study on physiological status and carbon allocation. World J Microbiol Biotechnol 2024; 40:82. [PMID: 38285311 DOI: 10.1007/s11274-024-03893-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 01/10/2024] [Indexed: 01/30/2024]
Abstract
Dunaliella salina is a favourable source of high lipid feedstock for biofuel and medicinal chemicals. Low biomass output from microalgae is a significant barrier to industrial-scale commercialisation. The current study aimed to determine how photosynthetic efficiency, carbon fixation, macromolecular synthesis, accumulation of neutral lipids, and antioxidative defence (ROS scavenging enzyme activities) of D. salina cells were affected by different light intensities (LI) (50, 100, 200, and 400 µmol m-2 s-1). The cells when exposed to strong light (400 µmol m-2 s-1) led to reduction in chlorophyll a but the carotenoid content increased by 19% in comparison to the control (LI 100). The amount of carbohydrate changed significantly under high light and in spite of stress inflicted on the cells by high irradiation, a considerable increase in activity of carbonic anhydrase and fixation rate of CO2 were recorded, thus, preserving the biomass content. The high light exposed biomass when subjected to nitrogen-deficient medium led to increase in lipid content (59.92% of the dry cell weight). However, neutral lipid made up 78.26% of the total lipid while other lipids like phospholipid and glycolipid content decreased, showing that the lipid was redistributed in these cells under nitrogen deprivation, making the organism more appropriate for biodiesel/jet fuel use. Although D. salina cells had a relatively longer generation time (3.5 d) than other microalgal cells, an economic analysis concluded that the amount of carotenoid they produced and the quality of their lipids made them more suited for commercialization.
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Affiliation(s)
- Abhishek Mohanta
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Nitesh Prasad
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Sk Riyazat Khadim
- P.G. Department of Botany, Dhenkanal Autonomous College, Dhenkanal, Odisha, India
| | - Prabhakar Singh
- Biochemistry Department, North-Eastern Hill University, Shillong, Meghalaya, 793022, India
| | - Savita Singh
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India
| | - Avinash Singh
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India
| | - A M Kayastha
- School of Biotechnology, Banaras Hindu University, Varanasi, 221005, India
| | - R K Asthana
- R. N. Singh Memorial Laboratory, Centre of Advanced Study in Botany, Banaras Hindu University, Varanasi, 221005, India.
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López-Pacheco IY, Ayala-Moreno VG, Mejia-Melara CA, Rodríguez-Rodríguez J, Cuellar-Bermudez SP, González-González RB, Coronado-Apodaca KG, Farfan-Cabrera LI, González-Meza GM, Iqbal HMN, Parra-Saldívar R. Growth Behavior, Biomass Composition and Fatty Acid Methyl Esters (FAMEs) Production Potential of Chlamydomonas reinhardtii, and Chlorella vulgaris Cultures. Mar Drugs 2023; 21:450. [PMID: 37623731 PMCID: PMC10455958 DOI: 10.3390/md21080450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 08/02/2023] [Accepted: 08/08/2023] [Indexed: 08/26/2023] Open
Abstract
The production of biomolecules by microalgae has a wide range of applications in the development of various materials and products, such as biodiesel, food supplements, and cosmetics. Microalgae biomass can be produced using waste and in a smaller space than other types of crops (e.g., soja, corn), which shows microalgae's great potential as a source of biomass. Among the produced biomolecules of greatest interest are carbohydrates, proteins, lipids, and fatty acids. In this study, the production of these biomolecules was determined in two strains of microalgae (Chlamydomonas reinhardtii and Chlorella vulgaris) when exposed to different concentrations of nitrogen, phosphorus, and sulfur. Results show a significant microalgal growth (3.69 g L-1) and carbohydrates (163 mg g-1) increase in C. reinhardtii under low nitrogen concentration. Also, higher lipids content was produced under low sulfur concentration (246 mg g-1). It was observed that sulfur variation could affect in a negative way proteins production in C. reinhardtii culture. In the case of C. vulgaris, a higher biomass production was obtained in the standard culture medium (1.37 g L-1), and under a low-phosphorus condition, C. vulgaris produced a higher lipids concentration (248 mg g-1). It was observed that a low concentration of nitrogen had a better effect on the accumulation of fatty acid methyl esters (FAMEs) (C16-C18) in both microalgae. These results lead us to visualize the effects that the variation in macronutrients can have on the growth of microalgae and their possible utility for the production of microalgae-based subproducts.
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Affiliation(s)
- Itzel Y. López-Pacheco
- Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey 64849, Mexico; (I.Y.L.-P.); (J.R.-R.); (S.P.C.-B.); (R.B.G.-G.); (K.G.C.-A.); (L.I.F.-C.); (G.M.G.-M.)
- Tecnologico de Monterrey, Institute of Advanced Materials for Sustainable Manufacturing, Monterrey 64849, Mexico
| | - Victoria Guadalupe Ayala-Moreno
- Francisco Morazán Department, Escuela Agrícola Panamericana, Zamorano, Km 30 Carretera de Tegucigalpa a Danlí, Valle del Yeguare, Municipio de San Antonio de Oriente, Tegucigalpa 11101, Honduras; (V.G.A.-M.); (C.A.M.-M.)
| | - Catherinne Arlette Mejia-Melara
- Francisco Morazán Department, Escuela Agrícola Panamericana, Zamorano, Km 30 Carretera de Tegucigalpa a Danlí, Valle del Yeguare, Municipio de San Antonio de Oriente, Tegucigalpa 11101, Honduras; (V.G.A.-M.); (C.A.M.-M.)
| | - José Rodríguez-Rodríguez
- Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey 64849, Mexico; (I.Y.L.-P.); (J.R.-R.); (S.P.C.-B.); (R.B.G.-G.); (K.G.C.-A.); (L.I.F.-C.); (G.M.G.-M.)
| | - Sara P. Cuellar-Bermudez
- Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey 64849, Mexico; (I.Y.L.-P.); (J.R.-R.); (S.P.C.-B.); (R.B.G.-G.); (K.G.C.-A.); (L.I.F.-C.); (G.M.G.-M.)
- Tecnologico de Monterrey, Institute of Advanced Materials for Sustainable Manufacturing, Monterrey 64849, Mexico
| | - Reyna Berenice González-González
- Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey 64849, Mexico; (I.Y.L.-P.); (J.R.-R.); (S.P.C.-B.); (R.B.G.-G.); (K.G.C.-A.); (L.I.F.-C.); (G.M.G.-M.)
- Tecnologico de Monterrey, Institute of Advanced Materials for Sustainable Manufacturing, Monterrey 64849, Mexico
| | - Karina G. Coronado-Apodaca
- Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey 64849, Mexico; (I.Y.L.-P.); (J.R.-R.); (S.P.C.-B.); (R.B.G.-G.); (K.G.C.-A.); (L.I.F.-C.); (G.M.G.-M.)
- Tecnologico de Monterrey, Institute of Advanced Materials for Sustainable Manufacturing, Monterrey 64849, Mexico
| | - Leonardo I. Farfan-Cabrera
- Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey 64849, Mexico; (I.Y.L.-P.); (J.R.-R.); (S.P.C.-B.); (R.B.G.-G.); (K.G.C.-A.); (L.I.F.-C.); (G.M.G.-M.)
| | - Georgia María González-Meza
- Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey 64849, Mexico; (I.Y.L.-P.); (J.R.-R.); (S.P.C.-B.); (R.B.G.-G.); (K.G.C.-A.); (L.I.F.-C.); (G.M.G.-M.)
- Tecnologico de Monterrey, Institute of Advanced Materials for Sustainable Manufacturing, Monterrey 64849, Mexico
| | - Hafiz M. N. Iqbal
- Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey 64849, Mexico; (I.Y.L.-P.); (J.R.-R.); (S.P.C.-B.); (R.B.G.-G.); (K.G.C.-A.); (L.I.F.-C.); (G.M.G.-M.)
- Tecnologico de Monterrey, Institute of Advanced Materials for Sustainable Manufacturing, Monterrey 64849, Mexico
| | - Roberto Parra-Saldívar
- Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey 64849, Mexico; (I.Y.L.-P.); (J.R.-R.); (S.P.C.-B.); (R.B.G.-G.); (K.G.C.-A.); (L.I.F.-C.); (G.M.G.-M.)
- Tecnologico de Monterrey, Institute of Advanced Materials for Sustainable Manufacturing, Monterrey 64849, Mexico
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Bakku RK, Yamamoto Y, Inaba Y, Hiranuma T, Gianino E, Amarianto L, Mahrous W, Suzuki H, Suzuki K. New insights into raceway cultivation of Euglena gracilis under long-term semi-continuous nitrogen starvation. Sci Rep 2023; 13:7123. [PMID: 37130945 PMCID: PMC10154353 DOI: 10.1038/s41598-023-34164-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 04/25/2023] [Indexed: 05/04/2023] Open
Abstract
This study aimed to investigate the physiological responses of Euglena gracilis (E. gracilis) when subjected to semicontinuous N-starvation (N-) for an extended period in open ponds. The results indicated that the growth rates of E. gracilis under the N- condition (11 ± 3.3 g m-2 d-1) were higher by 23% compared to the N-sufficient (N+, 8.9 ± 2.8 g m-2 d-1) condition. Furthermore, the paramylon content of E.gracilis was above 40% (w/w) of dry biomass in N- condition compared to N+ (7%) condition. Interestingly, E. gracilis exhibited similar cell numbers regardless of nitrogen concentrations after a certain time point. Additionally, it demonstrated relatively smaller cell size over time, and unaffected photosynthetic apparatus under N- condition. These findings suggest that there is a tradeoff between cell growth and photosynthesis in E. gracilis, as it adapts to semi-continuous N- conditions without a decrease in its growth rate and paramylon productivity. Notably, to the author's knowledge, this is the only study reporting high biomass and product accumulation by a wild-type E. gracilis strain under N- conditions. This newly identified long-term adaptation ability of E. gracilis may offer a promising direction for the algal industry to achieve high productivity without relying on genetically modified organisms.
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Affiliation(s)
- Ranjith Kumar Bakku
- Algae Energy Technology Research Institute, 649-17 Nishiyama, Taki-cho, Taki-gun, Mie, 519-2171, Japan.
- Euglena Co., Ltd., G-BASE Tamachi 2nd and 3rd Floor, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan.
| | - Yoshimasa Yamamoto
- Algae Energy Technology Research Institute, 649-17 Nishiyama, Taki-cho, Taki-gun, Mie, 519-2171, Japan
- Euglena Co., Ltd., G-BASE Tamachi 2nd and 3rd Floor, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan
| | - Yu Inaba
- Algae Energy Technology Research Institute, 649-17 Nishiyama, Taki-cho, Taki-gun, Mie, 519-2171, Japan
- Euglena Co., Ltd., G-BASE Tamachi 2nd and 3rd Floor, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan
| | - Taro Hiranuma
- Algae Energy Technology Research Institute, 649-17 Nishiyama, Taki-cho, Taki-gun, Mie, 519-2171, Japan
- Euglena Co., Ltd., G-BASE Tamachi 2nd and 3rd Floor, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan
| | - Enrico Gianino
- Algae Energy Technology Research Institute, 649-17 Nishiyama, Taki-cho, Taki-gun, Mie, 519-2171, Japan
- Euglena Co., Ltd., G-BASE Tamachi 2nd and 3rd Floor, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan
| | - Lawi Amarianto
- Algae Energy Technology Research Institute, 649-17 Nishiyama, Taki-cho, Taki-gun, Mie, 519-2171, Japan
- Euglena Co., Ltd., G-BASE Tamachi 2nd and 3rd Floor, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan
| | - Waleed Mahrous
- Algae Energy Technology Research Institute, 649-17 Nishiyama, Taki-cho, Taki-gun, Mie, 519-2171, Japan
- Euglena Co., Ltd., G-BASE Tamachi 2nd and 3rd Floor, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan
| | - Hideyuki Suzuki
- Algae Energy Technology Research Institute, 649-17 Nishiyama, Taki-cho, Taki-gun, Mie, 519-2171, Japan.
- Euglena Co., Ltd., G-BASE Tamachi 2nd and 3rd Floor, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan.
| | - Kengo Suzuki
- Euglena Co., Ltd., G-BASE Tamachi 2nd and 3rd Floor, 5-29-11, Shiba, Minato-ku, Tokyo, 108-0014, Japan
- Microalgae Production Control Technology Laboratory, RIKEN 1-7-22, Suehiro, Tsurumi, Yokohama, Kanagawa, 230-0045, Japan
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8
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Iglesias MJ, Soengas R, López-Ortiz F, Biondi N, Tredici MR, Gutiérrez-Del-Río I, López-Ibáñez S, Villar CJ, Lombó F, López Y, Gabasa Y, Soto S. Effect of culture conditions at lab-scale on metabolite composition and antibacterial and antibiofilm activities of Dunaliella tertiolecta. JOURNAL OF PHYCOLOGY 2023; 59:356-369. [PMID: 36690599 DOI: 10.1111/jpy.13316] [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: 09/30/2022] [Revised: 12/02/2022] [Accepted: 12/19/2022] [Indexed: 05/28/2023]
Abstract
Dunaliella tertiolecta RCC6 was cultivated indoors in glass bubble column photobioreactors operated under batch and semi-continuous regimens and using two different conditions of light and temperature. Biomass was harvested by centrifugation, frozen, and then lyophilized. The soluble material was obtained by sequential extraction of the lyophilized biomass with solvents with a gradient of polarity (hexane, ethyl acetate, and methanol) and its metabolic composition was investigated through nuclear magnetic resonance (NMR) spectroscopy. The effect of light on chlorophyll biosynthesis was clearly shown through the relative intensities of the 1 H NMR signals due to pheophytins. The highest signal intensity was observed for the biomasses obtained at lower light intensity, resulting in a lower light availability per cell. Under high temperature and light conditions, the 1 H NMR spectra of the hexane extracts showed an incipient accumulation of triacylglycerols. In these conditions and under semi-continuous regimen, an enhancement of β-carotene and sterols production was observed. The antibacterial and antibiofilm activities of the extracts were also tested. Antibacterial activity was not detected, regardless of culture conditions. In contrast, the minimal biofilm inhibitory concentrations (MBICs) against Escherichia coli for the hexane extract obtained under semi-continuous regimen using high temperature and irradiance conditions was promising.
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Affiliation(s)
- María José Iglesias
- Área de Química Orgánica, Research Centre CIAIMBITAL, Universidad de Almería, Almería, Spain
| | - Raquel Soengas
- Área de Química Orgánica, Research Centre CIAIMBITAL, Universidad de Almería, Almería, Spain
| | - Fernando López-Ortiz
- Área de Química Orgánica, Research Centre CIAIMBITAL, Universidad de Almería, Almería, Spain
| | - Natascia Biondi
- Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Florence, Italy
| | - Mario R Tredici
- Department of Agriculture, Food, Environment and Forestry (DAGRI), University of Florence, Florence, Italy
| | - Ignacio Gutiérrez-Del-Río
- Área de Microbiología, Research Group BIONUC, Universidad de Oviedo, IUOPA (Instituto Universitario de Oncología del Principado de Asturias), ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), Oviedo, Spain
| | - Sara López-Ibáñez
- Área de Microbiología, Research Group BIONUC, Universidad de Oviedo, IUOPA (Instituto Universitario de Oncología del Principado de Asturias), ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), Oviedo, Spain
| | - Claudio J Villar
- Área de Microbiología, Research Group BIONUC, Universidad de Oviedo, IUOPA (Instituto Universitario de Oncología del Principado de Asturias), ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), Oviedo, Spain
| | - Felipe Lombó
- Área de Microbiología, Research Group BIONUC, Universidad de Oviedo, IUOPA (Instituto Universitario de Oncología del Principado de Asturias), ISPA (Instituto de Investigación Sanitaria del Principado de Asturias), Oviedo, Spain
| | - Yuly López
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Yaiza Gabasa
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
| | - Sara Soto
- ISGlobal, Hospital Clínic-Universitat de Barcelona, Barcelona, Spain
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9
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Expression profile of genes associated with the accumulation of triacylglycerol (TAG) in Auxenochlorella protothecoides KP7 under alkaline pH and nitrogen starvation conditions. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2023. [DOI: 10.1016/j.bcab.2023.102628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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10
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Transcriptomic Analysis Revealed the Differences in Lipid Accumulation between Spores and Mycelia of Mucor circinelloides WJ11 under Solid–State Fermentation. FERMENTATION 2022. [DOI: 10.3390/fermentation8120667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The oleaginous fungus Mucor circinelloides has been studied for microbial oil production. Solid–state fermentation may be more suitable for lipid production than submerged fermentation due to its special filamentous structure and lower fermentation costs. M. circinelloides WJ11 under solid–state fermentation indicated that the total fatty acid content of mycelia was significantly higher than that of spores (15.0 and 10.4% in mycelia and spores after 192 h, respectively), while the biomass of the fungal mycelia was lower than that of the spores, reaching 78.2 and 86.9 mg/g, respectively. Transcriptomic studies showed that a total of 9069 genes were differentially expressed between spores and mycelia during solid–state fermentation, of which 4748 were up-regulated and 4321 were down-regulated. Among them, triglyceride-related synthases in M. circinelloides were significantly up-regulated in the mycelia. The mRNA expression level of ATP: citrate lyase was obviously increased to provide more acetyl-CoA for fatty acid synthesis in mycelia, moreover, the metabolism of leucine and isoleucine can also produce more acetyl-CoA for lipid accumulation in M. circinelloides. For NADPH supply, the expression of the pentose phosphate pathway was significantly up-regulated in mycelia, while NADP+-dependent malic enzyme was also increased by 9.5-fold under solid–state fermentation. Compared with gene expression in spores, the autophagy pathway was clearly up-regulated in mycelia to prove that autophagy was related to lipid accumulation in M. circinelloides.
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11
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Carnovale G, Lama C, Torres S, Rosa F, Mantecón L, Horn SJ, Skjånes K, Infante C. Metabolic pathways for biosynthesis and degradation of starch in Tetraselmis chui during nitrogen deprivation and recovery. BIORESOURCE TECHNOLOGY 2022; 354:127222. [PMID: 35477101 DOI: 10.1016/j.biortech.2022.127222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/20/2022] [Accepted: 04/21/2022] [Indexed: 06/14/2023]
Abstract
Tetraselmis chui is known to accumulate starch when subjected to stress. This phenomenon is widely studied for the purpose of industrial production and process development. Yet, knowledge about the metabolic pathways involved is still immature. Hence, in this study, transcription of 27 starch-related genes was monitored under nitrogen deprivation and resupply in 25 L tubular photobioreactors. T. chui proved to be an efficient starch producer under nitrogen deprivation, accumulating starch up to 56% of relative biomass content. The prolonged absence of nitrogen led to an overall down-regulation of the tested genes, in most instances maintained even after nitrogen replenishment when starch was actively degraded. These gene expression patterns suggest post-transcriptional regulatory mechanisms play a key role in T. chui under nutrient stress. Finally, the high productivity combined with an efficient recovery after nitrogen restitution makes this species a suitable candidate for industrial production of high-starch biomass.
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Affiliation(s)
- Giorgia Carnovale
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Biotechnology and Plant Health, PO 115, NO-1431 Ås, Norway; Norwegian University of Life Sciences (NMBU), Faculty of Chemistry, Biotechnology and Food Science, P.O. Box 5003, NO-1432 Ås, Norway
| | - Carmen Lama
- Fitoplancton Marino, S.L., Dársena comercial s/n (Muelle pesquero), 11500 El Puerto de Santa María, Cádiz, Spain
| | - Sonia Torres
- Fitoplancton Marino, S.L., Dársena comercial s/n (Muelle pesquero), 11500 El Puerto de Santa María, Cádiz, Spain
| | - Filipa Rosa
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Biotechnology and Plant Health, PO 115, NO-1431 Ås, Norway
| | - Lalia Mantecón
- Fitoplancton Marino, S.L., Dársena comercial s/n (Muelle pesquero), 11500 El Puerto de Santa María, Cádiz, Spain
| | - Svein Jarle Horn
- Norwegian University of Life Sciences (NMBU), Faculty of Chemistry, Biotechnology and Food Science, P.O. Box 5003, NO-1432 Ås, Norway
| | - Kari Skjånes
- Norwegian Institute of Bioeconomy Research (NIBIO), Division of Biotechnology and Plant Health, PO 115, NO-1431 Ås, Norway.
| | - Carlos Infante
- Fitoplancton Marino, S.L., Dársena comercial s/n (Muelle pesquero), 11500 El Puerto de Santa María, Cádiz, Spain
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12
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Woyda-Ploszczyca AM, Rybak AS. How can the commercial potential of microalgae from the Dunaliella genus be improved? The importance of nucleotide metabolism with a focus on nucleoside diphosphate kinase (NDPK). ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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13
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Chang L, Lu H, Chen H, Tang X, Zhao J, Zhang H, Chen YQ, Chen W. Lipid metabolism research in oleaginous fungus Mortierella alpina: Current progress and future prospects. Biotechnol Adv 2021; 54:107794. [PMID: 34245810 DOI: 10.1016/j.biotechadv.2021.107794] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 06/11/2021] [Accepted: 07/04/2021] [Indexed: 12/19/2022]
Abstract
The oleaginous fungus Mortierella alpina has distinct advantages in long-chain PUFAs production, and it is the only source for dietary arachidonic acid (ARA) certificated by FDA and European Commission. This review provides an overall introduction to M. alpina, including its major research methods, key factors governing lipid biosynthesis, metabolic engineering and omics studies. Currently, the research interests in M. alpina focus on improving lipid yield and fatty acid desaturation degree by enhancing fatty acid precursors and the reducing power NADPH, and genetic manipulation on PUFAs synthetic pathways is carried to optimise fatty acid composition. Besides, multi-omics studies have been applied to elucidate the global regulatory mechanism of lipogenesis in M. alpina. However, research challenges towards achieving a lipid cell factory lie in strain breeding and cost control due to the coenocytic mycelium, long fermentation period and insufficient conversion rate from carbon to lipid. We also proposed future research goals based on a multilevel regulating strategy: obtaining ideal chassis by directional evolution and high-throughput screening; rewiring central carbon metabolism and inhibiting competitive pathways by multi-gene manipulation system to enhance carbon to lipid conversion rate; optimisation of protein function based on post-translational modification; application of dynamic fermentation strategies suitable for different fermentation phases. By reviewing the comprehensive research progress of this oleaginous fungus, we aim to further comprehend the fungal lipid metabolism and provide reference information and guidelines for the exploration of microbial oils from the perspectives of fundamental research to industrial application.
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Affiliation(s)
- Lulu Chang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
| | - Hengqian Lu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
| | - Haiqin Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
| | - Xin Tang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
| | - Yong Q Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; Wuxi School of Medicine, Jiangnan University, Wuxi, Jiangsu 214122, PR China; National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, Jiangsu 214122, PR China; Wuxi Translational Medicine Research Center, Jiangsu Translational Medicine Research Institute Wuxi Branch, Wuxi, Jiangsu 214122, PR China; Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, USA.
| | - Wei Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
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14
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Chen H, Wang Q. Regulatory mechanisms of lipid biosynthesis in microalgae. Biol Rev Camb Philos Soc 2021; 96:2373-2391. [PMID: 34101323 DOI: 10.1111/brv.12759] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 02/01/2023]
Abstract
Microalgal lipids are highly promising feedstocks for biofuel production. Microalgal lipids, especially triacylglycerol, and practical applications of these compounds have received increasing attention in recent years. For the commercial use of microalgal lipids to be feasible, many fundamental biological questions must be addressed based on detailed studies of algal biology, including how lipid biosynthesis occurs and is regulated. Here, we review the current understanding of microalgal lipid biosynthesis, with a focus on the underlying regulatory mechanisms. We also present possible solutions for overcoming various obstacles to understanding the basic biology of microalgal lipid biosynthesis and the practical application of microalgae-based lipids. This review will provide a theoretical reference for both algal researchers and decision makers regarding the future directions of microalgal research, particularly pertaining to microalgal-based lipid biosynthesis.
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Affiliation(s)
- Hui Chen
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China
| | - Qiang Wang
- State Key Laboratory of Crop Stress Adaptation and Improvement, School of Life Sciences, Henan University, Kaifeng, 475004, China
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15
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Tang X, Chang L, Gu S, Zhang H, Chen YQ, Chen H, Zhao J, Chen W. Role of beta-isopropylmalate dehydrogenase in lipid biosynthesis of the oleaginous fungus Mortierella alpina. Fungal Genet Biol 2021; 152:103572. [PMID: 34015432 DOI: 10.1016/j.fgb.2021.103572] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/13/2022]
Abstract
Branched-chain amino acids (BCAAs) play an important role in lipid metabolism by serving as signal molecules as well as a potential acetyl-CoA source. Our previous study found that in the oleaginous fungus Mucor circinelloides, beta-isopropylmalate dehydrogenase (IPMDH), an important enzyme participating in the key BCAA leucine biosynthesis, was differentially expressed during lipid accumulation phase and has a positive role on lipogenesis. To further analyze its effects on lipogenesis in another oleaginous fungus Mortierella alpina, the IPMDH-encoding gene MaLeuB was homologously expressed. It was found that the total fatty acid content in the recombinant strain was increased by 20.2% compared with the control strain, which correlated with a 4-fold increase in the MaLeuB transcriptional level. Intracellular metabolites analysis revealed significant changes in amino acid biosynthesis and metabolism, tricarboxylic acid cycle and butanoate metabolism; specifically, leucine and isoleucine levels were upregulated by 6.4-fold and 2.2-fold, respectively. Our genetic engineering approach and metabolomics study demonstrated that MaLeuB is involved in fatty acid metabolism in M. alpina by affecting BCAAs metabolism, and this newly discovered role of IPMDH provides a potential bypass route to increase lipogenesis in oleaginous fungi.
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Affiliation(s)
- Xin Tang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122 PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China
| | - Lulu Chang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122 PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China
| | - Shujie Gu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122 PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122 PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, Jiangsu 214122, PR China; Wuxi Translational Medicine Research Center and Jiangsu Translational Medicine Research Institute Wuxi Branch, Wuxi, Jiangsu 214122, PR China
| | - Yong Q Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122 PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, Jiangsu 214122, PR China; Wuxi Translational Medicine Research Center and Jiangsu Translational Medicine Research Institute Wuxi Branch, Wuxi, Jiangsu 214122, PR China
| | - Haiqin Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122 PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122 PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China.
| | - Wei Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122 PR China; School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, PR China; National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, Jiangsu 214122, PR China; Beijing Innovation Centre of Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Beijing 100048, PR China
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16
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Soós V, Shetty P, Maróti G, Incze N, Badics E, Bálint P, Ördög V, Balázs E. Biomolecule composition and draft genome of a novel, high-lipid producing Scenedesmaceae microalga. ALGAL RES 2021. [DOI: 10.1016/j.algal.2020.102181] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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17
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18
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Mhlongo SI, Ezeokoli OT, Roopnarain A, Ndaba B, Sekoai PT, Habimana O, Pohl CH. The Potential of Single-Cell Oils Derived From Filamentous Fungi as Alternative Feedstock Sources for Biodiesel Production. Front Microbiol 2021; 12:637381. [PMID: 33584636 PMCID: PMC7876240 DOI: 10.3389/fmicb.2021.637381] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 01/07/2021] [Indexed: 11/13/2022] Open
Abstract
Microbial lipids, also known as single-cell oils (SCOs), are highly attractive feedstocks for biodiesel production due to their fast production rates, minimal labor requirements, independence from seasonal and climatic changes, and ease of scale-up for industrial processing. Among the SCO producers, the less explored filamentous fungi (molds) exhibit desirable features such as a repertoire of hydrolyzing enzymes and a unique pellet morphology that facilitates downstream harvesting. Although several oleaginous filamentous fungi have been identified and explored for SCO production, high production costs and technical difficulties still make the process less attractive compared to conventional lipid sources for biodiesel production. This review aims to highlight the ability of filamentous fungi to hydrolyze various organic wastes for SCO production and explore current strategies to enhance the efficiency and cost-effectiveness of the SCO production and recovery process. The review also highlights the mechanisms and components governing lipogenic pathways, which can inform the rational designs of processing conditions and metabolic engineering efforts for increasing the quality and accumulation of lipids in filamentous fungi. Furthermore, we describe other process integration strategies such as the co-production with hydrogen using advanced fermentation processes as a step toward a biorefinery process. These innovative approaches allow for integrating upstream and downstream processing units, thus resulting in an efficient and cost-effective method of simultaneous SCO production and utilization for biodiesel production.
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Affiliation(s)
- Sizwe I. Mhlongo
- Discipline of Medical Microbiology, School of Laboratory Medicine and Medical Sciences, Medical School, University of KwaZulu-Natal, Durban, South Africa
| | - Obinna T. Ezeokoli
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
| | - Ashira Roopnarain
- Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Pretoria, South Africa
| | - Busiswa Ndaba
- Microbiology and Environmental Biotechnology Research Group, Institute for Soil, Climate and Water, Agricultural Research Council, Pretoria, South Africa
| | - Patrick T. Sekoai
- The School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Olivier Habimana
- The School of Biological Sciences, The University of Hong Kong, Pokfulam, Hong Kong
| | - Carolina H. Pohl
- Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
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19
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Role of C/N ratio on microalgae growth in mixotrophy and incorporation of titanium nanoparticles for cell flocculation and lipid enhancement in economical biodiesel application. 3 Biotech 2020; 10:331. [PMID: 32656064 DOI: 10.1007/s13205-020-02323-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 06/24/2020] [Indexed: 10/23/2022] Open
Abstract
Present study aimed to evaluate the influence of carbon/nitrogen ratio (C/N) on mixotrophic growth of microalgae and role of nanomaterial in cell recovery and lipid improvement. In this study, three microalgae species were isolated, screened from local freshwater body for lipid assimilation. The microalgae were identified as Chlorococcum sp., Scenedesmus sp., and Euglena sp. Mixotrophic cultivation of each microalgae strain using various organic carbon sources was preferred in contrast with photoautotrophic mode. Sucrose represented as the preeminent source for enhancing the microalgae biomass of 3.5 g/L and lipid content of 58.35%, which was a significant improvement as compared to control. Later, response surface methodology-central composite design (RSM-CCD), tool was employed to optimize the C/N ratio and demonstrated the maximum biomass production of 5.02 g/L along with the increased lipid content of 60.34%. Ti nanoparticles (Ti nps) were added to the culture for lipid enhancement in the stationary phase and biomass removal was performed by nanoparticle (np)-mediated flocculation technique. Optimized concentration of 15 ppm Ti nps determined the cell harvesting efficacy of 82.46% during 45 min of sedimentation time and 1.23-fold lipid enhancement was reported. Extracted lipid was converted to fatty acid methyl esters (FAME) by the process of transesterification and analyzed by gas chromatography-mass spectrometry (GC-MS). Characterization of FAME revealed the presence of 56.31% of saturated fatty acid (SFA) and 29.06% unsaturated fatty acids (UFA) that could be processed towards sustainable biodiesel production. Hence, our results suggested that integration of mixotrophic cultivation and Ti nps emerged as a new cost-effective approach for biomass and lipid enhancement in microalgae Chlorococcum sp.
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20
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Huang B, Mimouni V, Lukomska E, Morant-Manceau A, Bougaran G. Carbon Partitioning and Lipid Remodeling During Phosphorus and Nitrogen Starvation in the Marine Microalga Diacronema lutheri (Haptophyta). JOURNAL OF PHYCOLOGY 2020; 56:908-922. [PMID: 32215912 DOI: 10.1111/jpy.12995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 03/03/2020] [Indexed: 06/10/2023]
Abstract
The domesticated marine microalga Diacronema lutheri is of great interest for producing various highly valuable molecules like lipids, particularly long-chain polyunsaturated fatty acids (LC-PUFA). In this study, we investigated the impact of phosphorus (P) and nitrogen (N) starvation on growth, carbon fixation (photosynthetic activity) and partitioning, and membrane lipid remodeling in this alga during batch culture. Our results show that the photosynthetic machinery was similarly affected by P and N stress. Under N starvation, we observed a much lower photosynthetic rate and biomass productivity. The degradation and re-use of cellular N-containing compounds contributed to triacylglycerol (TAG) accumulation. On the other hand, P-starved cells maintained pigment content and a carbon partitioning pattern more similar to the control, ensuring a high biomass. Betaine lipids constitute the major compounds of non-plastidial membranes, which are rich in eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Under P and N starvations, EPA was transferred from the recycling of membrane polar lipids, most likely contributing to TAG accumulation.
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Affiliation(s)
- Bing Huang
- Laboratoire Mer, Molécules, Santé (IUML - FR 3473 CNRS), UFR Sciences et Techniques, Le Man Université, Avenue Olivier Messiaen, 72085, Le Mans Cedex 09, France
| | - Virginie Mimouni
- Laboratoire Mer, Molécules, Santé (IUML - FR 3473 CNRS), IUT de Laval, Département Génie Biologique, Le Mans Université, 52 rue des Docteurs Calmette et Guérin, 53020, Laval Cedex 9, France
| | - Ewa Lukomska
- Laboratoire Physiologie et Biotechnologie des Algues, IFREMER, rue de l'Ile d'Yeu, BP 21105, 44311, Nantes Cedex 03, France
| | - Annick Morant-Manceau
- Laboratoire Mer, Molécules, Santé (IUML - FR 3473 CNRS), UFR Sciences et Techniques, Le Man Université, Avenue Olivier Messiaen, 72085, Le Mans Cedex 09, France
| | - Gaël Bougaran
- Laboratoire Physiologie et Biotechnologie des Algues, IFREMER, rue de l'Ile d'Yeu, BP 21105, 44311, Nantes Cedex 03, France
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Nagappan S, Devendran S, Tsai PC, Jayaraman H, Alagarsamy V, Pugazhendhi A, Ponnusamy VK. Metabolomics integrated with transcriptomics and proteomics: Evaluation of systems reaction to nitrogen deficiency stress in microalgae. Process Biochem 2020. [DOI: 10.1016/j.procbio.2019.11.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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22
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He Q, Lin Y, Tan H, Zhou Y, Wen Y, Gan J, Li R, Zhang Q. Transcriptomic profiles of Dunaliella salina in response to hypersaline stress. BMC Genomics 2020; 21:115. [PMID: 32013861 PMCID: PMC6998148 DOI: 10.1186/s12864-020-6507-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 01/20/2020] [Indexed: 11/24/2022] Open
Abstract
Background Dunaliella salina is a good model organism for studying salt stress. In order to have a global understanding of the expression profiles of Dunaliella salina in response to hypersaline stress, we performed quantitative transcriptomic analysis of Dunaliella salina under hypersaline stress (2.5 M NaCl) of different time duration by the second and third generation sequencing method. Results Functional enrichment of the up-regulated genes was used to analyze the expression profiles. The enrichment of photosynthesis was observed, accompanied by enrichments of carbon fixation, pigment biosynthetic process and heme biosynthetic process, which also imply the enhancement of photosynthesis. Genes responsible for starch hydrolysis and glycerol synthesis were significantly up-regulated. The enrichment of biosynthesis of unsaturated fatty acids implies the plasma membrane undergoes changes in desaturation pattern. The enrichment of endocytosis implies the degradation of plasma membrane and might help the synthesis of new glycerophospholipid with unsaturated fatty acids. Co-enrichments of protein synthesis and degradation imply a higher protein turnover rate. The enrichments of spliceosome and protein processing in endoplasmic reticulum imply the enhancement of regulations at post-transcriptional and post-translational level. No up-regulation of any Na+ or Cl− channels or transporters was detected, which implies that the extra exclusion of the ions by membrane transporters is possibly not needed. Voltage gated Na+ and Cl− channels, mechanosensitive ion channel are possible signal receptors of salt stress, and Ca2+ and MAP kinase pathways might play a role in signal transduction. Conclusion At global transcriptomic level, the response of Dunaliella salina to hypersaline stress is a systematic work, possibly involving enhancements of photosynthesis, carbon fixation, and heme biosynthetic process, acceleration of protein turnover, spliceosome, protein processing in endoplasmic reticulum, and endocytosis, as well as degradation of starch, synthesis of glycerol, membrane lipid desaturation. Altogether, the changes of these biological processes occurred at trancriptomic level will help understand how a new intracellular balance achieved in Dunaliella salina to adapt to hypersaline environment, which are worth being confirmed at the physiological levels.
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Affiliation(s)
- Qinghua He
- Key Laboratory of Qinghai-Tibetan Plateau Animal genetic Resource Reservation and Utilization, College of Life Science and Technology, Southwest Minzu University, Chengdu, People's Republic of China
| | - Yaqiu Lin
- Key Laboratory of Qinghai-Tibetan Plateau Animal genetic Resource Reservation and Utilization, College of Life Science and Technology, Southwest Minzu University, Chengdu, People's Republic of China
| | - Hong Tan
- Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu, People's Republic of China
| | - Yu Zhou
- Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu, People's Republic of China
| | - Yongli Wen
- Institute of Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu, People's Republic of China
| | - Jiajia Gan
- Key Laboratory of Qinghai-Tibetan Plateau Animal genetic Resource Reservation and Utilization, College of Life Science and Technology, Southwest Minzu University, Chengdu, People's Republic of China
| | - Ruiwen Li
- Reproductive and endocrine laboratory, Chengdu Woman-Child Central Hospital, Chengdu, 610051, People's Republic of China.
| | - Qinglian Zhang
- School of Laboratory Medicine, Chengdu Medical College, Chengdu, 610500, People's Republic of China.
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23
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Ran W, Wang H, Liu Y, Qi M, Xiang Q, Yao C, Zhang Y, Lan X. Storage of starch and lipids in microalgae: Biosynthesis and manipulation by nutrients. BIORESOURCE TECHNOLOGY 2019; 291:121894. [PMID: 31387839 DOI: 10.1016/j.biortech.2019.121894] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 05/28/2023]
Abstract
Microalgae accumulate starch and lipid as storage metabolites under nutrient depletion, which can be used as sustainable feedstock for biorefinery. Omics analysis coupled with enzymatic and genetic verifications uncovered a partial picture of pathways and important enzymes or regulators related to starch and lipid biosynthesis as well as the carbon partitioning between them under nutrient depletion conditions. Depletion of macronutrients (N, P, and S) resulted in considerable enhancement of starch and/or lipid content in microalgae, but the accompanying declined photosynthesis hampered the achievements of high concentrations. This review summarized the current knowledge on the pathways and the committed steps as well as their carbon allocation involved in starch and lipid biosynthesis, and focused on the manipulation of different nutrients and the alleviation of oxidative stress for enhanced storage metabolites production. The biological and engineering approaches to cope with the conflict between biomass production and storage metabolites accumulation are proposed.
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Affiliation(s)
- Wenyi Ran
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Haitao Wang
- National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, Liaoning 116034, China
| | - Yinghui Liu
- Information Management Center of Sichuan University, Chengdu, Sichuan 610065, China
| | - Man Qi
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Qi Xiang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Changhong Yao
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China.
| | - Yongkui Zhang
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
| | - Xianqiu Lan
- Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu, Sichuan 610065, China
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24
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Grossmann L, Hinrichs J, Weiss J. Cultivation and downstream processing of microalgae and cyanobacteria to generate protein-based technofunctional food ingredients. Crit Rev Food Sci Nutr 2019; 60:2961-2989. [DOI: 10.1080/10408398.2019.1672137] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Lutz Grossmann
- Department of Food Physics and Meat Science, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany
| | - Jörg Hinrichs
- Department of Soft Matter Science and Dairy Technology, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany
| | - Jochen Weiss
- Department of Food Physics and Meat Science, Institute of Food Science and Biotechnology, University of Hohenheim, Stuttgart, Germany
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25
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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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26
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Chang L, Tang X, Lu H, Zhang H, Chen YQ, Chen H, Chen W. Role of Adenosine Monophosphate Deaminase during Fatty Acid Accumulation in Oleaginous Fungus Mortierella alpina. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:9551-9559. [PMID: 31379157 DOI: 10.1021/acs.jafc.9b03603] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In oleaginous micro-organisms, nitrogen limitation activates adenosine monophosphate deaminase (AMPD) and promotes lipogenesis via the inhibition of isocitrate dehydrogenase. We found that the overexpression of homologous AMPD in Mortierella alpina favored lipid synthesis over cell growth. Total fatty acid content in the recombinant strain was 15.0-34.3% higher than that in the control, even though their biomass was similar. During the early fermentation stage, the intracellular AMP level reduced by 40-60%, together with a 1.9-2.7-fold increase in citrate content compared with the control, therefore provided more precursors for fatty acid synthesis. Moreover, the decreased AMP level resulted in metabolic reprogramming, reflected by the blocked TCA cycle and reduction of amino acids, distributing more carbon to lipid synthesis pathways. By coupling the energy balance with lipogenesis, this study provides new insights into cell metabolism under nitrogen-limited conditions and targets the regulation of fatty acid accumulation in oleaginous micro-organisms.
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Affiliation(s)
| | | | | | - Hao Zhang
- Wuxi Translational Medicine Research Center and Jiangsu Translational Medicine Research Institute Wuxi Branch , Wuxi , Jiangsu 214122 , P. R. China
| | - Yong Q Chen
- Wuxi Translational Medicine Research Center and Jiangsu Translational Medicine Research Institute Wuxi Branch , Wuxi , Jiangsu 214122 , P. R. China
| | | | - Wei Chen
- Beijing Innovation Centre of Food Nutrition and Human Health , Beijing Technology and Business University (BTBU) , Beijing 100048 , P. R. China
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27
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Kang NK, Kim EK, Sung MG, Kim YU, Jeong BR, Chang YK. Increased biomass and lipid production by continuous cultivation of Nannochloropsis salina transformant overexpressing a bHLH transcription factor. Biotechnol Bioeng 2019; 116:555-568. [PMID: 30536876 PMCID: PMC6590115 DOI: 10.1002/bit.26894] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 11/22/2018] [Accepted: 12/06/2018] [Indexed: 12/28/2022]
Abstract
Microalgae are promising feedstocks for sustainable and eco-friendly production of biomaterials, which can be improved by genetic engineering. It is also necessary to optimize the processes to produce biomaterials from engineered microalgae. We previously reported that genetic improvements of an industrial microalga Nannochloropsis salina by overexpressing a basic helix-loop-helix transcription factor (NsbHLH2). These transformants showed an improved growth and lipid production particularly during the early phase of culture under batch culture. However, they had faster uptake of nutrients, resulting in earlier starvation and reduced growth during the later stages. We attempted to optimize the growth and lipid production by growing one of the transformants in continuous culture with variable dilution rate and feed nitrogen concentration. Relative to wild-type, NsbHLH2 transformant consumed more nitrate at a high dilution rate (0.5 day -1 ), and had greater biomass production. Subsequently, nitrogen limitation at continuous cultivation led to an increased fatty acid methyl ester production by 83.6 mg l -1 day -1 . To elucidate genetic mechanisms, we identified the genes containing E-boxes, known as binding sites for bHLH transcription factors. Among these, we selected 18 genes involved in the growth and lipid metabolism, and revealed their positive contribution to the phenotypes via quantitative real-time polymerase chain reaction. These results provide proof-of-concept that NsbHLH2 can be used to produce biomass and lipids.
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Affiliation(s)
- Nam Kyu Kang
- Advanced Biomass R&D Center, Yuseong-gu, Daejeon, Republic of Korea
| | - Eun Kyung Kim
- Advanced Biomass R&D Center, Yuseong-gu, Daejeon, Republic of Korea
| | - Min-Gyu Sung
- Department of Chemical and Biomolecular Engineering, KAIST, Yuseong-gu, Daejeon, Republic of Korea
| | - Young Uk Kim
- Advanced Biomass R&D Center, Yuseong-gu, Daejeon, Republic of Korea
| | - Byeong-Ryool Jeong
- Department of Chemical and Biomolecular Engineering, KAIST, Yuseong-gu, Daejeon, Republic of Korea
| | - Yong Keun Chang
- Advanced Biomass R&D Center, Yuseong-gu, Daejeon, Republic of Korea.,Department of Chemical and Biomolecular Engineering, KAIST, Yuseong-gu, Daejeon, Republic of Korea
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28
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Kajikawa M, Yamauchi M, Shinkawa H, Tanaka M, Hatano K, Nishimura Y, Kato M, Fukuzawa H. Isolation and Characterization of Chlamydomonas Autophagy-Related Mutants in Nutrient-Deficient Conditions. PLANT & CELL PHYSIOLOGY 2019; 60:126-138. [PMID: 30295899 DOI: 10.1093/pcp/pcy193] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 09/17/2018] [Indexed: 05/08/2023]
Abstract
Autophagy is a recycling system for amino acids and carbon- and nitrogen (N)-containing compounds. To date, the functional importance of autophagy in microalgae in nutrient-deficient conditions has not been evaluated by using autophagy-defective mutants. Here, we provide evidence which supports the following notions by characterizing an insertional mutant of the autophagy-related gene ATG8, encoding a ubiquitin-like protein necessary for the formation of the autophagosome in the green alga, Chlamydomonas reinhardtii. First, ATG8 is required for maintenance of cell survival and Chl content in N-, sulfur- and phosphate-deficient conditions. Secondly, ATG8 supports the degradation of triacylglycerol and lipid droplets after the resupply of N to cells cultured in N-limiting conditions. Thirdly, ATG8 is also necessary for accumulation of starch in phosphate-deficient conditions. Additionally, autophagy is not essential for maternal inheritance of the organelle genomes in gametogenesis.
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Affiliation(s)
| | - Marika Yamauchi
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
| | - Haruka Shinkawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Manabu Tanaka
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | - Kyoko Hatano
- Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan
| | | | - Misako Kato
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan
| | - Hideya Fukuzawa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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29
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Malerba ME, Palacios MM, Marshall DJ. Do larger individuals cope with resource fluctuations better? An artificial selection approach. Proc Biol Sci 2018; 285:rspb.2018.1347. [PMID: 30068687 DOI: 10.1098/rspb.2018.1347] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 07/11/2018] [Indexed: 11/12/2022] Open
Abstract
Size determines the rate at which organisms acquire and use resources but it is unclear what size should be favoured under unpredictable resource regimes. Some theories claim smaller organisms can grow faster following a resource pulse, whereas others argue larger species can accumulate more resources and maintain growth for longer periods between resource pulses. Testing these theories has relied on interspecific comparisons, which tend to confound body size with other life-history traits. As a more direct approach, we used 280 generations of artificial selection to evolve a 10-fold difference in mean body size between small- and large-selected phytoplankton lineages of Dunaliella tertiolecta, while controlling for biotic and abiotic variables. We then quantified how body size affected the ability of this species to grow at nutrient-replete conditions and following periods of nitrogen or phosphorous deprivation. Overall, smaller cells showed slower growth, lower storage capacity and poorer recovery from phosphorous depletion, as predicted by the 'fasting endurance hypothesis'. However, recovery from nitrogen limitation was independent of size-a finding unanticipated by current theories. Phytoplankton species are responsible for much of the global carbon fixation and projected trends of cell size decline could reduce primary productivity by lowering the ability of a cell to store resources.
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Affiliation(s)
- Martino E Malerba
- Centre for Geometric Biology, School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia .,School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Maria M Palacios
- Centre for Geometric Biology, School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia.,School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
| | - Dustin J Marshall
- Centre for Geometric Biology, School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia.,School of Biological Sciences, Monash University, Melbourne, Victoria 3800, Australia
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30
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Willette S, Gill SS, Dungan B, Schaub TM, Jarvis JM, St. Hilaire R, Omar Holguin F. Alterations in lipidome and metabolome profiles of Nannochloropsis salina in response to reduced culture temperature during sinusoidal temperature and light. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.03.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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31
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Lin H, Shen H, Lee YK. Cellular and Molecular Responses of Dunaliella tertiolecta by Expression of a Plant Medium Chain Length Fatty Acid Specific Acyl-ACP Thioesterase. Front Microbiol 2018; 9:619. [PMID: 29670594 PMCID: PMC5893845 DOI: 10.3389/fmicb.2018.00619] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2017] [Accepted: 03/16/2018] [Indexed: 01/18/2023] Open
Abstract
Metabolic engineering of microalgae to accumulate high levels of medium chain length fatty acids (MCFAs) has met with limited success. Traditional approaches employ single introduction of MCFA specific acyl-ACP thioesterases (TEs), but our current research in transgenic Dunaliella tertiolecta line has highlighted that, there is no single rate-limiting approach that can effectively increase MCFA levels. Here, we explore the accumulation of MCFAs in D. tertiolecta after transgenic expression of myristic acid biased TE (C14TE). We observe that the MCFA levels were negatively correlated to the fatty acid (FA) synthesis genes, ketoacyl-ACP synthase II (KASII), stearoyl-CoA-9-desaturase (Δ9D), and oleoyl-CoA-12-desaturase (Δ12D). To further examine the molecular mechanism of MCFA accumulation in microalgae, we investigate the transcriptomic dynamics of the MCFA producing strain of D. tertiolecta. At the transcript level, enhanced MCFA accumulation primarily involved up-regulation of photosynthetic genes and down-regulation of genes from central carbon metabolic processes, resulting in an overall decrease in carbon precursors for FA synthesis. We additionally observe that MCFA specific peroxisomal β-oxidation gene (ACX3) was greatly enhanced to prevent excessive build-up of unusual MCFA levels. Besides, long chain acyl-CoA synthetase gene (LACS) was down-regulated, likely in attempt to control fatty acyl supply flux to FA synthesis cycle. This article provides a spatial regulation model of unusual FA accumulation in microalgae and a platform for additional metabolic engineering targeting pathways from FA synthesis, FA transport, and peroxisomal β-oxidation to achieve microalgae oils with higher levels of MCFAs.
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Affiliation(s)
- Huixin Lin
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Hui Shen
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Yuan K Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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32
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Sirikhachornkit A, Suttangkakul A, Vuttipongchaikij S, Juntawong P. De novo transcriptome analysis and gene expression profiling of an oleaginous microalga Scenedesmus acutus TISTR8540 during nitrogen deprivation-induced lipid accumulation. Sci Rep 2018; 8:3668. [PMID: 29487383 PMCID: PMC5829077 DOI: 10.1038/s41598-018-22080-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 02/16/2018] [Indexed: 11/30/2022] Open
Abstract
Nitrogen deprivation (-N) has been used as a technique to promote lipid accumulation in various microalgae. Scenedesmus acutus is a promising oleaginous green microalga that can be cultivated in organic wastewater for biodiesel production. Nevertheless, the molecular mechanisms controlling S. acutus lipid accumulation in response to -N remain unidentified. Physiological study determined that -N reduced cell growth and photosynthetic pigments. On the other hand, it promoted carbohydrate and neutral lipid accumulation. To find the mechanisms underlying lipid accumulation, we performed de novo transcriptome profiling of the non-model S. acutus in response to -N. The transcriptome analysis revealed that glycolysis and starch degradation were up-regulated; on the contrary, gluconeogenesis, photosynthesis, triacylglycerol (TAG) degradation and starch synthesis were down-regulated by -N. Under -N, the carbon flux was shifted toward fatty acid and TAG synthesis, and the down regulation of TAG lipase genes may contribute to TAG accumulation. A comparative analysis of the -N transcriptomes of oleaginous microalgae identified that the down-regulation of multiple lipase genes was a specific mechanism found only in the -N transcriptome of S. acutus. Our study unraveled the mechanisms controlling -N-induced lipid accumulation in S. acutus, and provided new perspectives for the genetic manipulation of biodiesel-producing microalgae.
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Affiliation(s)
- Anchalee Sirikhachornkit
- Special Research Unit in Microalgal Molecular Genetics and Functional genomics, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Bangkok, Thailand
| | - Anongpat Suttangkakul
- Special Research Unit in Microalgal Molecular Genetics and Functional genomics, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Bangkok, Thailand
| | - Supachai Vuttipongchaikij
- Special Research Unit in Microalgal Molecular Genetics and Functional genomics, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Bangkok, Thailand
| | - Piyada Juntawong
- Special Research Unit in Microalgal Molecular Genetics and Functional genomics, Department of Genetics, Faculty of Science, Kasetsart University, Bangkok, Thailand.
- Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University, Bangkok, Thailand.
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33
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Pick U, Avidan O. Triacylglycerol is produced from starch and polar lipids in the green alga Dunaliella tertiolecta. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:4939-4950. [PMID: 28992231 PMCID: PMC5853294 DOI: 10.1093/jxb/erx280] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
The halotolerant green alga Dunaliella tertiolecta accumulates starch and triacylglycerol (TAG) amounting to 70% and 10-15% of total cellular carbon, respectively, when exposed to nitrogen (N) deprivation. The purpose of this study was to clarify the inter-relationships between the biosynthesis of TAG, starch, and polar lipids (PLs) in this alga. Pulse labeling with [14C]bicarbonate was utilized to label starch and [14C]palmitic acid (PlA) to label lipids. Transfer of 14C into TAG was measured and used to calculate rates of synthesis. About two-thirds of the carbon in TAG originates from starch, and one-third is made de novo by direct CO2 assimilation. The level made from degradation of pre-formed PLs is estimated to be very small. Most of the de novo synthesis involves fatty acid transfer through PLs made during the first day of N deprivation. The results suggest that starch made by photosynthetic carbon assimilation at the early stages of N deprivation is utilized for synthesis of TAG. Trans-acylation from PLs is the second major contributor to TAG biosynthesis. The utilization of starch for TAG biosynthesis may have biotechnological applications to optimize TAG biosynthesis in algae.
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Affiliation(s)
- Uri Pick
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, Israel
- Correspondence:
| | - Omri Avidan
- Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany
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34
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Driver T, Trivedi DK, McIntosh OA, Dean AP, Goodacre R, Pittman JK. Two Glycerol-3-Phosphate Dehydrogenases from Chlamydomonas Have Distinct Roles in Lipid Metabolism. PLANT PHYSIOLOGY 2017; 174:2083-2097. [PMID: 28588114 PMCID: PMC5543956 DOI: 10.1104/pp.17.00491] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 06/04/2017] [Indexed: 05/03/2023]
Abstract
The metabolism of glycerol-3-phosphate (G3P) is important for environmental stress responses by eukaryotic microalgae. G3P is an essential precursor for glycerolipid synthesis and the accumulation of triacylglycerol (TAG) in response to nutrient starvation. G3P dehydrogenase (GPDH) mediates G3P synthesis, but the roles of specific GPDH isoforms are currently poorly understood. Of the five GPDH enzymes in the model alga Chlamydomonas reinhardtii, GPD2 and GPD3 were shown to be induced by nutrient starvation and/or salt stress. Heterologous expression of GPD2, a putative chloroplastic GPDH, and GPD3, a putative cytosolic GPDH, in a yeast gpd1Δ mutant demonstrated the functionality of both enzymes. C. reinhardtii knockdown mutants for GPD2 and GPD3 showed no difference in growth but displayed significant reduction in TAG concentration compared with the wild type in response to phosphorus or nitrogen starvation. Overexpression of GPD2 and GPD3 in C. reinhardtii gave distinct phenotypes. GPD2 overexpression lines showed only subtle metabolic phenotypes and no significant alteration in growth. In contrast, GPD3 overexpression lines displayed significantly inhibited growth and chlorophyll concentration, reduced glycerol concentration, and changes to lipid composition compared with the wild type, including increased abundance of phosphatidic acids but reduced abundance of diglycerides, triglycerides, and phosphatidylglycerol lipids. This may indicate a block in the downstream glycerolipid metabolism pathway in GPD3 overexpression lines. Thus, lipid engineering by GPDH modification may depend on the activities of other downstream enzyme steps. These results also suggest that GPD2 and GPD3 GPDH isoforms are important for nutrient starvation-induced TAG accumulation but have distinct metabolic functions.
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Affiliation(s)
- Thomas Driver
- Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Drupad K Trivedi
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester M1 7DN, United Kingdom
| | - Owen A McIntosh
- School of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester M13 9PT, United Kingdom
| | - Andrew P Dean
- School of Science and the Environment, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester M1 5GD, United Kingdom
| | - Royston Goodacre
- Manchester Institute of Biotechnology, School of Chemistry, University of Manchester, Manchester M1 7DN, United Kingdom
| | - Jon K Pittman
- School of Earth and Environmental Sciences, Faculty of Science and Engineering, University of Manchester, Manchester M13 9PT, United Kingdom
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35
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Lin H, Lee YK. Genetic engineering of medium-chain-length fatty acid synthesis in Dunaliella tertiolecta for improved biodiesel production. JOURNAL OF APPLIED PHYCOLOGY 2017; 29:2811-2819. [PMID: 29213182 PMCID: PMC5705751 DOI: 10.1007/s10811-017-1210-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 06/22/2017] [Accepted: 06/22/2017] [Indexed: 06/07/2023]
Abstract
Genetic engineering of microalgae to accumulate high levels of medium-chain-length fatty acids (MCFAs) represents an attractive strategy to improve the quality of microalgae-based biodiesel, but it has thus far been least successful. We demonstrate that one limitation is the availability of fatty acyl-acyl carrier protein (ACP) substrate pool for acyl-ACP thioesterase (TE). A combinational expression platform that involved plant lauric acid-biased TE (C12TE) and MCFA-specific ketoacyl-ACP synthase (KASIV) increased lauric acid (C12:0) and myristic acid (C14:0) accumulation by almost sevenfold and fourfold, respectively, compared with native strain. These findings suggest a platform for further investigation into the enlargement of MCFA acyl-ACP substrate pool as an approach to sustainably improve quality of microalgae-based biodiesel with regard to MCFA production.
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Affiliation(s)
- Huixin Lin
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Block MD4, 5 Science Drive 2, Singapore, 117545 Singapore
| | - Yuan Kun Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Block MD4, 5 Science Drive 2, Singapore, 117545 Singapore
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36
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Tan KWM, Lee YK. Expression of the heterologous Dunaliella tertiolecta fatty acyl-ACP thioesterase leads to increased lipid production in Chlamydomonas reinhardtii. J Biotechnol 2017; 247:60-67. [PMID: 28279815 DOI: 10.1016/j.jbiotec.2017.03.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 03/03/2017] [Accepted: 03/04/2017] [Indexed: 12/22/2022]
Abstract
Biofuel production from genetically-engineered microalgae is currently among the most widely studied strategies in generating renewable energy. However, microalgae currently suffer from low oil yields which limit the commercial feasibility of industrial-scale production. A major bottleneck in cost-efficient biofuel production from microalgae is the dilemma between biomass productivity and lipid accumulation. When grown under stressful culture conditions such as nitrogen depletion, microalgae accumulate large amounts of neutral lipids, but it comes at the expense of growth which negatively impacts overall lipid productivity. Overexpression of acyl-ACP thioesterases (TE) had been successful in increasing the production of fatty acids (FA) in prokaryotes such as E. coli and cyanobacteria, but has not been effectively tested in microalgae. In this study, we introduced a TE from D. tertiolecta (DtTE) into C. reinhardtii to investigate its effects on FA production without compromising growth. The results indicate that C. reinhardtii transformants were able to produce 63 and 94% more neutral lipids than the wild-type, which translates to an approximately 56% improvement in total lipids, without compromising growth. These findings demonstrate the cross-species functionality of TE, and provide a platform for further studies into using TE as a strategy to increase biofuel production from microalgae.
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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, Singapore 117545
| | - Yuan Kun Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545.
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Yao L, Tan KWM, Tan TW, Lee YK. Exploring the transcriptome of non-model oleaginous microalga Dunaliella tertiolecta through high-throughput sequencing and high performance computing. BMC Bioinformatics 2017; 18:122. [PMID: 28228091 PMCID: PMC5322580 DOI: 10.1186/s12859-017-1551-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 02/16/2017] [Indexed: 12/31/2022] Open
Abstract
Background RNA-Seq technology has received a lot of attention in recent years for microalgal global transcriptomic profiling. It is widely used in transcriptome-wide analysis of gene expression., particularly for microalgal strains with potential as biofuel sources. However, insufficient genomic or transcriptomic information of non-model microalgae has limited the understanding of their regulatory mechanisms and hampered genetic manipulation to enhance biofuel production. As such, an optimal microalgal transcriptomic database construction is a subject of urgent investigation. Results Dunaliella tertiolecta, a non-model oleaginous microalgal species, was sequenced via Illumina MISEQ and HISEQ 4000 in RNA-Seq studies. The high quality high-throughout sequencing data were explored using high performance computing (HPC) in a petascale data center and subjected to de novo assembly and parallelized mpiBLASTX search with multiple species. As a result, a transcriptome database of 17,845 was constructed (~95% completeness). This enlarged database constructed fueled the RNA-Seq data analysis, which was validated by a nitrogen deprivation (ND) study that induces triacylglycerol (TAG) production. Conclusions The new paralleled assembly and annotation method under HPC presented here allows the solution of large-scale data processing problems in acceptable computation time. There is significant increase in the number of transcriptomic data achieved and observable heterogeneity in the performance to identify differentially expressed genes in the ND treatment paradigm. The results provide new insights as to how response to ND treatment in microalgae is regulated. ND analyses highlight the advantages of this database generated in this study that could also serve as a useful resource for future gene manipulation and transcriptome-wide analysis. We thus demonstrate the usefulness of exploring the transcriptome as an informative platform for functional studies and genetic manipulations in similar species. Electronic supplementary material The online version of this article (doi:10.1186/s12859-017-1551-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lina Yao
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545, Singapore
| | - Kenneth Wei Min Tan
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545, Singapore
| | - Tin Wee Tan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117596, Singapore.,National Supercomputing Centre (NSCC), Singapore, 138632, Singapore
| | - Yuan Kun Lee
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117545, Singapore.
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