1
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Halim NFAA, Ali MSM, Leow ATC, Rahman RNZRA. Membrane fatty acid desaturase: biosynthesis, mechanism, and architecture. Appl Microbiol Biotechnol 2022; 106:5957-5972. [PMID: 36063178 DOI: 10.1007/s00253-022-12142-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 11/25/2022]
Abstract
Fatty acid desaturase catalyzes the desaturation reactions by inserting double bonds into the fatty acyl chain, producing unsaturated fatty acids, which play a vital part in the synthesis of polyunsaturated fatty acids. Though soluble fatty acid desaturases have been described extensively in advanced organisms, there are very limited studies of membrane fatty acid desaturases due to their difficulties in producing a sufficient amount of recombinant desaturases. However, the advancement of technology has shown substantial progress towards the development of elucidating crystal structures of membrane fatty acid desaturase, thus, allowing modification of structure to be manipulated. Understanding the structure, mechanism, and biosynthesis of fatty acid desaturase lay a foundation for the potential production of various strategies associated with alteration and modifications of polyunsaturated fatty acids. This manuscript presents the current state of knowledge and understanding about the structure, mechanisms, and biosynthesis of fatty acid desaturase. In addition, the role of unsaturated fatty acid desaturases in health and diseases is also encompassed. This will be useful in understanding the molecular basis and structural protein of fatty acid desaturase that are significant for the advancement of therapeutic strategies associated with the improvement of health status. KEY POINTS: • Current state of knowledge and understanding about the biosynthesis, mechanisms, and structure of fatty acid desaturase. • The role of unsaturated fatty acid desaturase. • The molecular basis and structural protein elucidated the crystal structure of fatty acid desaturase.
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Affiliation(s)
- Nur Farah Anis Abd Halim
- Enzyme and Microbial Technology Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Mohd Shukuri Mohamad Ali
- Enzyme and Microbial Technology Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
- Department of Biochemistry, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Adam Thean Chor Leow
- Enzyme and Microbial Technology Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
- Department of Cell and Molecular Biology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Raja Noor Zaliha Raja Abd Rahman
- Enzyme and Microbial Technology Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
- Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
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2
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Kihika JK, Wood SA, Rhodes L, Smith KF, Miller MR, Pochon X, Thompson L, Butler J, Schattschneider J, Oakley C, Ryan KG. Cryopreservation of six Symbiodiniaceae genera and assessment of fatty acid profiles in response to increased salinity treatments. Sci Rep 2022; 12:12408. [PMID: 35859115 PMCID: PMC9300622 DOI: 10.1038/s41598-022-16735-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/14/2022] [Indexed: 11/09/2022] Open
Abstract
Symbiodiniaceae are a diverse group of dinoflagellates, the majority of which are free-living and/or associated with a variety of protists and other invertebrate hosts. Maintenance of isolated cultures is labour-intensive and expensive, and cryopreservation provides an excellent avenue for their long-term storage. We aimed to cryopreserve 15 cultured isolates from six Symbiodiniaceae genera using dimethyl sulfoxide (DMSO) as the cryoprotectant agent (CPA). Under 15% DMSO, 10 isolates were successfully cryopreserved using either rapid freezing or controlled-rate freezing. Cultures that failed or had low survival, were subjected to (1) a reduction of CPA to 10%, or (2) increased salinity treatment before freezing. At 10% DMSO, three further isolates were successfully cryopreserved. At 15% DMSO there were high cell viabilities in Symbiodinium pilosum treated with 44 parts per thousand (ppt) and 54 ppt culture medium. An isolate of Fugacium sp. successfully cryopreserved after salinity treatments of 54 ppt and 64 ppt. Fatty acid (FA) analyses of S. pilosum after 54 ppt salinity treatment showed increased saturated FA levels, whereas Fugacium sp. had low poly-unsaturated FAs compared to normal salinity (34 ppt). Understanding the effects of salinity and roles of FAs in cryopreservation will help in developing protocols for these ecologically important taxa.
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Affiliation(s)
- Joseph Kanyi Kihika
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand. .,School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand.
| | - Susanna A Wood
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - Lesley Rhodes
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - Kirsty F Smith
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand.,School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand
| | | | - Xavier Pochon
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand.,Institute of Marine Science, University of Auckland, Private Bag 349, Warkworth, 0941, New Zealand
| | - Lucy Thompson
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | - Juliette Butler
- Cawthron Institute, Private Bag 2, Nelson, 7042, New Zealand
| | | | - Clint Oakley
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Ken G Ryan
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
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3
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Zhuang XY, Zhang YH, Xiao AF, Zhang AH, Fang BS. Key Enzymes in Fatty Acid Synthesis Pathway for Bioactive Lipids Biosynthesis. Front Nutr 2022; 9:851402. [PMID: 35284441 PMCID: PMC8905437 DOI: 10.3389/fnut.2022.851402] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
Dietary bioactive lipids, one of the three primary nutrients, is not only essential for growth and provides nutrients and energy for life's activities but can also help to guard against disease, such as Alzheimer's and cardiovascular diseases, which further strengthen the immune system and maintain many body functions. Many microorganisms, such as yeast, algae, and marine fungi, have been widely developed for dietary bioactive lipids production. These biosynthetic processes were not limited by the climate and ground, which are also responsible for superiority of shorter periods and high conversion rate. However, the production process was also exposed to the challenges of low stability, concentration, and productivity, which was derived from the limited knowledge about the critical enzyme in the metabolic pathway. Fortunately, the development of enzymatic research methods provides powerful tools to understand the catalytic process, including site-specific mutagenesis, protein dynamic simulation, and metabolic engineering technology. Thus, we review the characteristics of critical desaturase and elongase involved in the fatty acids' synthesis metabolic pathway, which aims to not only provide extensive data for enzyme rational design and modification but also provides a more profound and comprehensive understanding of the dietary bioactive lipids' synthetic process.
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Affiliation(s)
- Xiao-Yan Zhuang
- College of Food and Biological Engineering, Jimei University, Xiamen, China
| | - Yong-Hui Zhang
- College of Food and Biological Engineering, Jimei University, Xiamen, China
| | - An-Feng Xiao
- College of Food and Biological Engineering, Jimei University, Xiamen, China
| | - Ai-Hui Zhang
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
- *Correspondence: Ai-Hui Zhang
| | - Bai-Shan Fang
- College of Food and Biological Engineering, Jimei University, Xiamen, China
- Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, China
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4
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Calhoun S, Bell TAS, Dahlin LR, Kunde Y, LaButti K, Louie KB, Kuftin A, Treen D, Dilworth D, Mihaltcheva S, Daum C, Bowen BP, Northen TR, Guarnieri MT, Starkenburg SR, Grigoriev IV. A multi-omic characterization of temperature stress in a halotolerant Scenedesmus strain for algal biotechnology. Commun Biol 2021; 4:333. [PMID: 33712730 PMCID: PMC7955037 DOI: 10.1038/s42003-021-01859-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 02/16/2021] [Indexed: 01/31/2023] Open
Abstract
Microalgae efficiently convert sunlight into lipids and carbohydrates, offering bio-based alternatives for energy and chemical production. Improving algal productivity and robustness against abiotic stress requires a systems level characterization enabled by functional genomics. Here, we characterize a halotolerant microalga Scenedesmus sp. NREL 46B-D3 demonstrating peak growth near 25 °C that reaches 30 g/m2/day and the highest biomass accumulation capacity post cell division reported to date for a halotolerant strain. Functional genomics analysis revealed that genes involved in lipid production, ion channels and antiporters are expanded and expressed. Exposure to temperature stress shifts fatty acid metabolism and increases amino acids synthesis. Co-expression analysis shows that many fatty acid biosynthesis genes are overexpressed with specific transcription factors under cold stress. These and other genes involved in the metabolic and regulatory response to temperature stress can be further explored for strain improvement.
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Affiliation(s)
- Sara Calhoun
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Tisza Ann Szeremy Bell
- Applied Genomics Team, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
- Division of Biological Sciences, Genome Core, University of Montana, Missoula, MT, USA
| | - Lukas R Dahlin
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Yuliya Kunde
- Applied Genomics Team, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Kurt LaButti
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Katherine B Louie
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Andrea Kuftin
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Daniel Treen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - David Dilworth
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sirma Mihaltcheva
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Christopher Daum
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Benjamin P Bowen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Trent R Northen
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Michael T Guarnieri
- National Bioenergy Center, National Renewable Energy Laboratory, Golden, CO, USA
| | - Shawn R Starkenburg
- Applied Genomics Team, Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA.
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA.
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5
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Benaud N, Zhang E, van Dorst J, Brown MV, Kalaitzis JA, Neilan BA, Ferrari BC. Harnessing long-read amplicon sequencing to uncover NRPS and Type I PKS gene sequence diversity in polar desert soils. FEMS Microbiol Ecol 2020; 95:5372416. [PMID: 30848780 DOI: 10.1093/femsec/fiz031] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 03/07/2019] [Indexed: 02/02/2023] Open
Abstract
The severity of environmental conditions at Earth's frigid zones present attractive opportunities for microbial biomining due to their heightened potential as reservoirs for novel secondary metabolites. Arid soil microbiomes within the Antarctic and Arctic circles are remarkably rich in Actinobacteria and Proteobacteria, bacterial phyla known to be prolific producers of natural products. Yet the diversity of secondary metabolite genes within these cold, extreme environments remain largely unknown. Here, we employed amplicon sequencing using PacBio RS II, a third generation long-read platform, to survey over 200 soils spanning twelve east Antarctic and high Arctic sites for natural product-encoding genes, specifically targeting non-ribosomal peptides (NRPS) and Type I polyketides (PKS). NRPS-encoding genes were more widespread across the Antarctic, whereas PKS genes were only recoverable from a handful of sites. Many recovered sequences were deemed novel due to their low amino acid sequence similarity to known protein sequences, particularly throughout the east Antarctic sites. Phylogenetic analysis revealed that a high proportion were most similar to antifungal and biosurfactant-type clusters. Multivariate analysis showed that soil fertility factors of carbon, nitrogen and moisture displayed significant negative relationships with natural product gene richness. Our combined results suggest that secondary metabolite production is likely to play an important physiological component of survival for microorganisms inhabiting arid, nutrient-starved soils.
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Affiliation(s)
- Nicole Benaud
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
| | - Eden Zhang
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
| | - Josie van Dorst
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
| | - Mark V Brown
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - John A Kalaitzis
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
| | - Brett A Neilan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, 2308, Australia
| | - Belinda C Ferrari
- School of Biotechnology and Biomolecular Sciences, UNSW, Sydney, NSW, 2052, Australia
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6
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Molecular cloning and functional analysis of a Δ 12-fatty acid desaturase from the Antarctic microalga Chlamydomonas sp. ICE-L. 3 Biotech 2019; 9:328. [PMID: 31406650 DOI: 10.1007/s13205-019-1858-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 08/02/2019] [Indexed: 12/22/2022] Open
Abstract
Chlamydomonas sp. ICE-L, which can thrive in extreme environments of the Antarctic, could represent a promising alternative for polyunsaturated fatty acid (PUFA) production. A new Δ12-fatty acid desaturase (FAD)-encoding gene (Δ 12 CiFAD), 1269 bp in size, was cloned from Chlamydomonas sp. ICE-L. Bioinformatics analysis showed that Δ 12 CiFAD-encoded protein was homologous to known FADs with conserved histidine motifs, and localized to the chloroplast. Functional analysis of Δ 12 CiFAD indicated that recombinant Synechococcus 6803 expressing Δ12CiFAD could accumulate C18:2, whereas recombinant Saccharomyces cerevisiae expressing this enzyme could not accumulate C18:2 or any other new fatty acids. These results indicate that Δ12CiFAD is a functional enzyme in the chloroplast that can adjust Chlamydomonas sp. ICE-L cell membrane fluidity to adapt to Antarctic extreme low-temperature environments, which give us insights into the frigostable and cold-resistant mechanisms of hypothermic organisms.
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7
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Rong C, Chen H, Tang X, Gu Z, Zhao J, Zhang H, Chen W, Chen YQ. Characterization and molecular docking of new Δ17 fatty acid desaturase genes from Rhizophagus irregularis and Octopus bimaculoides. RSC Adv 2019; 9:6871-6880. [PMID: 35518462 PMCID: PMC9061052 DOI: 10.1039/c9ra00535h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 02/19/2019] [Indexed: 01/19/2023] Open
Abstract
Fatty acid desaturases are key enzymes in the biosynthesis of n-3 polyunsaturated fatty acids (PUFAs) via conversion of n-6 polyunsaturates to their n-3 counterparts.
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Affiliation(s)
- Chunchi Rong
- State Key Laboratory of Food Science and Technology
- Jiangnan University
- Wuxi
- P. R. China
- School of Food Science and Technology
| | - Haiqin Chen
- State Key Laboratory of Food Science and Technology
- Jiangnan University
- Wuxi
- P. R. China
- School of Food Science and Technology
| | - Xin Tang
- State Key Laboratory of Food Science and Technology
- Jiangnan University
- Wuxi
- P. R. China
- School of Food Science and Technology
| | - Zhennan Gu
- State Key Laboratory of Food Science and Technology
- Jiangnan University
- Wuxi
- P. R. China
- School of Food Science and Technology
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Technology
- Jiangnan University
- Wuxi
- P. R. China
- School of Food Science and Technology
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology
- Jiangnan University
- Wuxi
- P. R. China
- School of Food Science and Technology
| | - Wei Chen
- State Key Laboratory of Food Science and Technology
- Jiangnan University
- Wuxi
- P. R. China
- School of Food Science and Technology
| | - Yong Q. Chen
- State Key Laboratory of Food Science and Technology
- Jiangnan University
- Wuxi
- P. R. China
- School of Food Science and Technology
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8
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Rong C, Chen H, Wang M, Gu Z, Zhao J, Zhang H, Chen W, Chen YQ. Molecular mechanism of substrate preference for ω-3 fatty acid desaturase from Mortierella alpina by mutational analysis and molecular docking. Appl Microbiol Biotechnol 2018; 102:9679-9689. [DOI: 10.1007/s00253-018-9321-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 08/06/2018] [Accepted: 08/09/2018] [Indexed: 11/30/2022]
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9
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Xing G, Yuan H, Yang J, Li J, Gao Q, Li W, Wang E. Integrated analyses of transcriptome, proteome and fatty acid profilings of the oleaginous microalga Auxenochlorella protothecoides UTEX 2341 reveal differential reprogramming of fatty acid metabolism in response to low and high temperatures. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.04.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Zorin B, Pal-Nath D, Lukyanov A, Smolskaya S, Kolusheva S, Didi-Cohen S, Boussiba S, Cohen Z, Khozin-Goldberg I, Solovchenko A. Arachidonic acid is important for efficient use of light by the microalga Lobosphaera incisa under chilling stress. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:853-868. [DOI: 10.1016/j.bbalip.2017.04.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/25/2017] [Accepted: 04/30/2017] [Indexed: 12/11/2022]
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Jung W, Kim EJ, Han SJ, Kang SH, Choi HG, Kim S. Enzymatic modification by point mutation and functional analysis of an omega-6 fatty acid desaturase from Arctic Chlamydomonas sp. Prep Biochem Biotechnol 2017; 47:143-150. [PMID: 27191514 DOI: 10.1080/10826068.2016.1188311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Arctic Chlamydomonas sp. is a dominant microalgal strain in cold or frozen freshwater in the Arctic region. The full-length open reading frame of the omega-6 fatty acid desaturase gene (AChFAD6) was obtained from the transcriptomic database of Arctic Chlamydomonas sp. from the KOPRI culture collection of polar micro-organisms. Amino acid sequence analysis indicated the presence of three conserved histidine-rich segments as unique characteristics of omega-6 fatty acid desaturases, and three transmembrane regions transported to plastidic membranes by chloroplast transit peptides in the N-terminal region. The AChFAD6 desaturase activity was examined by expressing wild-type and V254A mutant (Mut-AChFAD6) heterologous recombinant proteins. Quantitative gas chromatography indicated that the concentration of linoleic acids in AChFAD6-transformed cells increased more than 3-fold [6.73 ± 0.13 mg g-1 dry cell weight (DCW)] compared with cells transformed with vector alone. In contrast, transformation with Mut-AChFAD6 increased the concentration of oleic acid to 9.23 ± 0.18 mg g-1 DCW, indicating a change in enzymatic activity to mimic that of stearoyl-CoA desaturase. These results demonstrate that AChFAD6 of Arctic Chlamydomonas sp. increases membrane fluidity by enhancing denaturation of C18 fatty acids and facilitates production of large quantities of linoleic fatty acids in prokaryotic expression systems.
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Affiliation(s)
- Woongsic Jung
- a Division of Polar Life Sciences, Korea Polar Research Institute , Korea Institute of Ocean Science and Technology , Incheon , Republic of Korea
| | - Eun Jae Kim
- a Division of Polar Life Sciences, Korea Polar Research Institute , Korea Institute of Ocean Science and Technology , Incheon , Republic of Korea.,b Department of Polar Life Sciences , University of Science and Technology , Incheon , Republic of Korea
| | - Se Jong Han
- a Division of Polar Life Sciences, Korea Polar Research Institute , Korea Institute of Ocean Science and Technology , Incheon , Republic of Korea.,b Department of Polar Life Sciences , University of Science and Technology , Incheon , Republic of Korea
| | - Sung-Ho Kang
- c Division of Polar Ocean Sciences, Korea Polar Research Institute , Korea Institute of Ocean Science and Technology , Incheon , Republic of Korea
| | - Han-Gu Choi
- a Division of Polar Life Sciences, Korea Polar Research Institute , Korea Institute of Ocean Science and Technology , Incheon , Republic of Korea
| | - Sanghee Kim
- a Division of Polar Life Sciences, Korea Polar Research Institute , Korea Institute of Ocean Science and Technology , Incheon , Republic of Korea
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12
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Chilling out: the evolution and diversification of psychrophilic algae with a focus on Chlamydomonadales. Polar Biol 2016. [DOI: 10.1007/s00300-016-2045-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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13
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Jung W, Kim EJ, Han SJ, Choi HG, Kim S. Characterization of Stearoyl-CoA Desaturases from a Psychrophilic Antarctic Copepod, Tigriopus kingsejongensis. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2016; 18:564-574. [PMID: 27627903 DOI: 10.1007/s10126-016-9714-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 07/25/2016] [Indexed: 06/06/2023]
Abstract
Stearoyl-CoA desaturase is a key regulator in fatty acid metabolism that catalyzes the desaturation of stearic acid to oleic acid and controls the intracellular levels of monounsaturated fatty acids (MUFAs). Two stearoyl-CoA desaturases (SCD, Δ9 desaturases) genes were identified in an Antarctic copepod, Tigriopus kingsejongensis, that was collected in a tidal pool near the King Sejong Station, King George Island, Antarctica. Full-length complementary DNA (cDNA) sequences of two T. kingsejongensis SCDs (TkSCDs) were obtained from next-generation sequencing and isolated by reverse transcription PCR. DNA sequence lengths of the open reading frames of TkSCD-1 and TkSCD-2 were determined to be 1110 and 681 bp, respectively. The molecular weights deduced from the corresponding genes were estimated to be 43.1 kDa (TkSCD-1) and 26.1 kDa (TkSCD-2). The amino acid sequences were compared with those of fatty acid desaturases and sterol desaturases from various organisms and used to analyze the relationships among TkSCDs. As assessed by heterologous expression of recombinant proteins in Escherichia coli, the enzymatic functions of both stearoyl-CoA desaturases revealed that the amount of C16:1 and C18:1 fatty acids increased by greater than 3-fold after induction with isopropyl β-D-thiogalactopyranoside. In particular, C18:1 fatty acid production increased greater than 10-fold in E. coli expressing TkSCD-1 and TkSCD-2. The results of this study suggest that both SCD genes from an Antarctic marine copepod encode a functional desaturase that is capable of increasing the amounts of palmitoleic acid and oleic acid in a prokaryotic expression system.
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Affiliation(s)
- Woongsic Jung
- Division of Polar Life Sciences, Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea
| | - Eun Jae Kim
- Division of Polar Life Sciences, Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea
- Department of Polar Life Sciences, University of Science and Technology, Incheon, 21990, Republic of Korea
| | - Se Jong Han
- Division of Polar Life Sciences, Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea
- Department of Polar Life Sciences, University of Science and Technology, Incheon, 21990, Republic of Korea
| | - Han-Gu Choi
- Division of Polar Life Sciences, Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea
| | - Sanghee Kim
- Division of Polar Life Sciences, Korea Polar Research Institute, KIOST, Incheon, 21990, Republic of Korea.
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14
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Acclimation of Antarctic Chlamydomonas to the sea-ice environment: a transcriptomic analysis. Extremophiles 2016; 20:437-50. [PMID: 27161450 DOI: 10.1007/s00792-016-0834-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 04/25/2016] [Indexed: 10/21/2022]
Abstract
The Antarctic green alga Chlamydomonas sp. ICE-L was isolated from sea ice. As a psychrophilic microalga, it can tolerate the environmental stress in the sea-ice brine, such as freezing temperature and high salinity. We performed a transcriptome analysis to identify freezing stress responding genes and explore the extreme environmental acclimation-related strategies. Here, we show that many genes in ICE-L transcriptome that encoding PUFA synthesis enzymes, molecular chaperon proteins, and cell membrane transport proteins have high similarity to the gens from Antarctic bacteria. These ICE-L genes are supposed to be acquired through horizontal gene transfer from its symbiotic microbes in the sea-ice brine. The presence of these genes in both sea-ice microalgae and bacteria indicated the biological processes they involved in are possibly contributing to ICE-L success in sea ice. In addition, the biological pathways were compared between ICE-L and its closely related sister species, Chlamydomonas reinhardtii and Volvox carteri. In ICE-L transcripome, many sequences homologous to the plant or bacteria proteins in the post-transcriptional, post-translational modification, and signal-transduction KEGG pathways, are absent in the nonpsychrophilic green algae. These complex structural components might imply enhanced stress adaptation capacity. At last, differential gene expression analysis at the transcriptome level of ICE-L indicated that genes that associated with post-translational modification, lipid metabolism, and nitrogen metabolism are responding to the freezing treatment. In conclusion, the transcriptome of Chlamydomonas sp. ICE-L is very useful for exploring the mutualistic interaction between microalgae and bacteria in sea ice; and discovering the specific genes and metabolism pathways responding to the freezing acclimation in psychrophilic microalgae.
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15
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Abstract
Microalgae present a huge and still insufficiently tapped resource of very long-chain omega-3 and omega-6 polyunsaturated fatty acids (VLC-PUFA) for human nutrition and medicinal applications. This chapter describes the diversity of unicellular eukaryotic microalgae in respect to VLC-PUFA biosynthesis. Then, we outline the major biosynthetic pathways mediating the formation of VLC-PUFA by sequential desaturation and elongation of C18-PUFA acyl groups. We address the aspects of spatial localization of those pathways and elaborate on the role for VLC-PUFA in microalgal cells. Recent progress in microalgal genetic transformation and molecular engineering has opened the way to increased production efficiencies for VLC-PUFA. The perspectives of photobiotechnology and metabolic engineering of microalgae for altered or enhanced VLC-PUFA production are also discussed.
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Affiliation(s)
- Inna Khozin-Goldberg
- Microalgal Biotechnology Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel.
| | - Stefan Leu
- Microalgal Biotechnology Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel
| | - Sammy Boussiba
- Microalgal Biotechnology Laboratory, French Associates Institute for Agriculture and Biotechnology of Drylands, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Israel
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16
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Li C, Ma L, Mou S, Wang Y, Zheng Z, Liu F, Qi X, An M, Chen H, Miao J. Cyclobutane pyrimidine dimers photolyase from extremophilic microalga: remarkable UVB resistance and efficient DNA damage repair. Mutat Res 2015; 773:37-42. [PMID: 25769185 DOI: 10.1016/j.mrfmmm.2014.07.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 07/13/2014] [Accepted: 07/18/2014] [Indexed: 10/24/2022]
Abstract
Bacteria living in the Antarctic region have developed several adaptive features for growth and survival under extreme conditions. Chlamydomonas sp. ICE-Lis well adapted to high levels of solar UV radiation. A putative photolyase was identified in the Chlamydomonas sp. ICE-L transcriptome. The complete cDNA sequence was obtained by RACE-PCR. This PHR encoding includes a polypeptide of 579 amino acids with clear photolyase signatures belonging to class II CPD-photolyases, sharing a high degree of homology with Chlamydomonas reinhardtii (68%). Real-time PCR was performed to investigate the potential DNA damage and responses following UVB exposure. CPD photolyase mRNA expression level increased over 50-fold in response to UVB radiation for 6h. Using photolyase complementation assay, we demonstrated that DNA photolyase increased photo-repair more than 116-fold in Escherichia coli strain SY2 under 100μw/cm(2) UVB radiation. To determine whether photolyase is active in vitro, CPD photolyase was over-expressed. It was shown that pyrimidine dimers were split by the action of PHR2. This study reports the unique structure and high activity of the enzyme. These findings are relevant for further understanding of molecular mechanisms of photo-reactivation, and will accelerate the utilization of photolyase in the medical field.
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Affiliation(s)
- Chongjie Li
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China
| | - Li Ma
- Key Laboratory of Biofuels, and Shandong Provincial Key Laboratory of Energy Genetics, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China
| | - Shanli Mou
- Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Yibin Wang
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China.
| | - Zhou Zheng
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China
| | - Fangming Liu
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China
| | - Xiaoqing Qi
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China
| | - Meiling An
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China
| | - Hao Chen
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China
| | - Jinlai Miao
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061, China; State Key Laboratory of Biological Fermentation Engineering of Beer (In Preparation), Qingdao, China.
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17
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Huerlimann R, Steinig EJ, Loxton H, Zenger KR, Jerry DR, Heimann K. Effects of growth phase and nitrogen starvation on expression of fatty acid desaturases and fatty acid composition of Isochrysis aff. galbana (TISO). Gene 2014; 545:36-44. [PMID: 24802118 DOI: 10.1016/j.gene.2014.05.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 04/24/2014] [Accepted: 05/02/2014] [Indexed: 11/25/2022]
Abstract
Very long-chain polyunsaturated fatty acids (VLC-PUFAs) are important dietary requirements for maintaining human health. Many marine microalgae are naturally high in ω-3 VLC-PUFAs, however, the molecular mechanisms underpinning fatty acid (FA) desaturation and elongation in algae are poorly understood. An advanced molecular understanding would facilitate improvements of this nascent industry. We aimed to investigate expression responses of four front-end fatty acid desaturase genes and downstream effects on FA profiles to nitrogen limitation and cultivation growth stage in Isochrysis aff. galbana (TISO). Cultures were grown in nitrogen-replete and -deplete medium; samples were harvested during logarithmic, late logarithmic and stationary growth phases to analyse FA content/composition and gene expression of ∆(6)-, ∆(8)-, ∆(5)- and ∆(4)-desaturases (d6FAD (putative), d8FAD, d5FAD and d4FAD, respectively). d6FAD (putative) exhibited no differential expression, while d8FAD, d5FAD and d4FAD were significantly upregulated during logarithmic growth of nutrient-replete cultures, coinciding with rapid cell division. In conclusion, it is demonstrated that expression of some FADs in I. aff. galbana varies with culture age and nitrogen status which has downstream consequences on FA desaturation levels. This has implications for the commercial production of VLC-PUFAs where a trade-off between total lipid yield and VLC-PUFAs has to be made.
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Affiliation(s)
- Roger Huerlimann
- School of Marine and Tropical Biology, James Cook University, Townsville 4811, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, Townsville 4811, Australia; James Cook University, Comparative Genomics Centre, Townsville, Queensland 4811, Australia
| | - Eike J Steinig
- School of Marine and Tropical Biology, James Cook University, Townsville 4811, Australia
| | - Heather Loxton
- School of Marine and Tropical Biology, James Cook University, Townsville 4811, Australia
| | - Kyall R Zenger
- School of Marine and Tropical Biology, James Cook University, Townsville 4811, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, Townsville 4811, Australia
| | - Dean R Jerry
- School of Marine and Tropical Biology, James Cook University, Townsville 4811, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, Townsville 4811, Australia
| | - Kirsten Heimann
- School of Marine and Tropical Biology, James Cook University, Townsville 4811, Australia; Centre for Sustainable Tropical Fisheries and Aquaculture, Townsville 4811, Australia; James Cook University, Comparative Genomics Centre, Townsville, Queensland 4811, Australia; Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Townsville, Queensland 4811, Australia.
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18
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Lyon BR, Mock T. Polar Microalgae: New Approaches towards Understanding Adaptations to an Extreme and Changing Environment. BIOLOGY 2014; 3:56-80. [PMID: 24833335 PMCID: PMC4009763 DOI: 10.3390/biology3010056] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 01/22/2014] [Accepted: 01/24/2014] [Indexed: 02/02/2023]
Abstract
Polar Regions are unique and highly prolific ecosystems characterized by extreme environmental gradients. Photosynthetic autotrophs, the base of the food web, have had to adapt physiological mechanisms to maintain growth, reproduction and metabolic activity despite environmental conditions that would shut-down cellular processes in most organisms. High latitudes are characterized by temperatures below the freezing point, complete darkness in winter and continuous light and high UV in the summer. Additionally, sea-ice, an ecological niche exploited by microbes during the long winter seasons when the ocean and land freezes over, is characterized by large salinity fluctuations, limited gas exchange, and highly oxic conditions. The last decade has been an exciting period of insights into the molecular mechanisms behind adaptation of microalgae to the cryosphere facilitated by the advancement of new scientific tools, particularly "omics" techniques. We review recent insights derived from genomics, transcriptomics, and proteomics studies. Genes, proteins and pathways identified from these highly adaptable polar microbes have far-reaching biotechnological applications. Furthermore, they may provide insights into life outside this planet, as well as glimpses into the past. High latitude regions also have disproportionately large inputs into global biogeochemical cycles and are the region most sensitive to climate change.
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Affiliation(s)
- Barbara R Lyon
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
| | - Thomas Mock
- School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK.
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19
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Wang M, Chen H, Gu Z, Zhang H, Chen W, Chen YQ. ω3 fatty acid desaturases from microorganisms: structure, function, evolution, and biotechnological use. Appl Microbiol Biotechnol 2013; 97:10255-62. [PMID: 24177732 DOI: 10.1007/s00253-013-5336-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 10/12/2013] [Accepted: 10/15/2013] [Indexed: 01/09/2023]
Abstract
The biosynthesis of very-long-chain polyunsaturated fatty acids involves an alternating process of fatty acid desaturation and elongation catalyzed by complex series of enzymes. ω3 desaturase plays an important role in converting ω6 fatty acids into ω3 fatty acids. Genes for this desaturase have been identified and characterized in a wide range of microorganisms, including cyanobacteria, yeasts, molds, and microalgae. Like all fatty acid desaturases, ω3 desaturase is structurally characterized by the presence of three highly conserved histidine-rich motifs; however, unlike some desaturases, it lacks a cytochrome b5-like domain. Understanding the structure, function, and evolution of ω3 desaturases, particularly their substrate specificities in the biosynthesis of very-long-chain polyunsaturated fatty acids, lays the foundation for potential production of various ω3 fatty acids in transgenic microorganisms.
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Affiliation(s)
- Mingxuan Wang
- State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122, People's Republic of China
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20
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An M, Mou S, Zhang X, Ye N, Zheng Z, Cao S, Xu D, Fan X, Wang Y, Miao J. Temperature regulates fatty acid desaturases at a transcriptional level and modulates the fatty acid profile in the Antarctic microalga Chlamydomonas sp. ICE-L. BIORESOURCE TECHNOLOGY 2013; 134:151-157. [PMID: 23500572 DOI: 10.1016/j.biortech.2013.01.142] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 01/23/2013] [Accepted: 01/24/2013] [Indexed: 06/01/2023]
Abstract
Chlamydomonas sp. ICE-L which can thrive in extreme environments of the Antarctic is a major biomass producer. The FAD genes in Chlamydomonas sp. ICE-L were obtained and sequence alignment showed that these genes are homologous to known FADs with conserved histidine motifs. In this study, we analyzed the transcription of five FADs and FA compositions at different temperatures. The results showed that the expressions of Δ9CiFAD, ω3CiFAD1 and ω3CiFAD2 were apparently up-regulated at 0°C, however, the up-regulation of Δ6CiFAD intensified with rising temperature. Meanwhile, analysis of the FA compositions showed that PUFAs were dominant compositions, accounting for more than 75% TFA in Chlamydomonas sp. ICE-L. Furthermore, PUFAs were significantly increased at 0 and 5°C, which may be attributed to higher proportions of C18:3 and C20:3. Moreover, PUFAs were significantly decreased at 15°C whereas SFAs were significantly increased.
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Affiliation(s)
- Meiling An
- Key Laboratory of Marine Bioactive Substance, The First Institute of Oceanography, State Oceanic Administration, Qingdao, China
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21
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Polyextremophiles and the Constraints for Terrestrial Habitability. CELLULAR ORIGIN, LIFE IN EXTREME HABITATS AND ASTROBIOLOGY 2013. [DOI: 10.1007/978-94-007-6488-0_1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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22
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Liu C, Wu G, Huang X, Liu S, Cong B. Validation of housekeeping genes for gene expression studies in an ice alga Chlamydomonas during freezing acclimation. Extremophiles 2012; 16:419-25. [PMID: 22527038 DOI: 10.1007/s00792-012-0441-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Accepted: 03/22/2012] [Indexed: 10/28/2022]
Abstract
Antarctic ice alga Chlamydomonas sp. ICE-L can endure extreme low temperature and high salinity stress under freezing conditions. To elucidate the molecular acclimation mechanisms using gene expression analysis, the expression stabilities of ten housekeeping genes of Chlamydomonas sp. ICE-L during freezing stress were analyzed. Some discrepancies were detected in the ranking of the candidate reference genes between geNorm and NormFinder programs, but there was substantial agreement between the groups of genes with the most and the least stable expression. RPL19 was ranked as the best candidate reference genes. Pairwise variation (V) analysis indicated the combination of two reference genes was sufficient for qRT-PCR data normalization under the experimental conditions. Considering the co-regulation between RPL19 and RPL32 (the most stable gene pairs given by geNorm program), we propose that the mean data rendered by RPL19 and GAPDH (the most stable gene pairs given by NormFinder program) be used to normalize gene expression values in Chlamydomonas sp. ICE-L more accurately. The example of FAD3 gene expression calculation demonstrated the importance of selecting an appropriate category and number of reference genes to achieve an accurate and reliable normalization of gene expression during freeze acclimation in Chlamydomonas sp. ICE-L.
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Affiliation(s)
- Chenlin Liu
- The First Institute of Oceanography, Marine Ecological Center, State Oceanic Administration, Qingdao, 266061, China.
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23
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Stengel DB, Connan S, Popper ZA. Algal chemodiversity and bioactivity: sources of natural variability and implications for commercial application. Biotechnol Adv 2011; 29:483-501. [PMID: 21672617 DOI: 10.1016/j.biotechadv.2011.05.016] [Citation(s) in RCA: 242] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 05/29/2011] [Accepted: 05/30/2011] [Indexed: 02/06/2023]
Abstract
There has been significant recent interest in the commercial utilisation of algae based on their valuable chemical constituents many of which exhibit multiple bioactivities with applications in the food, cosmetic, agri- and horticultural sectors and in human health. Compounds of particular commercial interest include pigments, lipids and fatty acids, proteins, polysaccharides and phenolics which all display considerable diversity between and within taxa. The chemical composition of natural algal populations is further influenced by spatial and temporal changes in environmental parameters including light, temperature, nutrients and salinity, as well as biotic interactions. As reported bioactivities are closely linked to specific compounds it is important to understand, and be able to quantify, existing chemical diversity and variability. This review outlines the taxonomic, ecological and chemical diversity between, and within, different algal groups and the implications for commercial utilisation of algae from natural populations. The biochemical diversity and complexity of commercially important types of compounds and their environmental and developmental control are addressed. Such knowledge is likely to help achieve higher and more consistent levels of bioactivity in natural samples and may allow selective harvesting according to algal species and local environmental conditions for different groups of compounds.
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Affiliation(s)
- Dagmar B Stengel
- Botany and Plant Science, School of Natural Sciences, Ryan Institute for Environmental, Marine and Energy Research, National University of Ireland Galway, Ireland.
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Zhang YM, Wang CC, Hu HH, Yang L. Cloning and expression of three fatty acid desaturase genes from cold-sensitive lima bean (Phaseolus lunatus L.). Biotechnol Lett 2010; 33:395-401. [PMID: 20953666 DOI: 10.1007/s10529-010-0432-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2010] [Accepted: 09/28/2010] [Indexed: 10/18/2022]
Abstract
The critical chilling temperature of cold-sensitive lima bean (Phaseolus lunatus L.) seedlings was determined to be approx. 8°C. The full-length cDNAs of PlSAD, PlFAD2, and PlFAD3 encoding three fatty acid desaturases were isolated from lima bean leaves. The PlSAD open reading frame (ORF) had 1,317 bp and a single intron of 601 bp, encoding a polypeptide of 438 amino acids that showing 86% homology with the plastidial stearoyl-acyl carrier protein desaturase in soybean. The PlFAD2 ORF contained 1,059 bp and was uninterrupted, encoding a polypeptide of 352 amino acids having 85% identity with the microsomal omega-6 desaturase GmFAD2-3 in soybean. PlFAD3 ORF had 1,116 bp and seven introns, encoding a polypeptide of 371 amino acids showing 91% homology with the microsomal omega-3 desaturase FAD3 in cowpea. PlSAD and PlFAD2 were expressed highly in leaves but poorly in roots and stems, while PlFAD3 was expressed in three tissues. All three genes were significantly induced in leaves by drought. PlSAD and PlFAD3 in leaves were down-regulated by high temperature and salinity, whereas PlFAD2 was up-regulated by the two stresses. The expression patterns of the three genes in lima bean leaves under suboptimal temperature, 18°C, were different from those under 8°C. The down-regulation of PlSAD transcript at chilling temperature might be an important factor contributing to chilling susceptibility for lima bean plants.
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Affiliation(s)
- Y M Zhang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, 321004 Zhejiang, China
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