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Wei H, He P, Yu D, Liu S, Li C, Qiu D. Characterization of the Positive Transcription Regulator PfaR for Improving Eicosapentaenoic Acid Production in Shewanella putrefaciens W3-18-1. Appl Environ Microbiol 2023; 89:e0002123. [PMID: 36916911 PMCID: PMC10132093 DOI: 10.1128/aem.00021-23] [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: 01/05/2023] [Accepted: 02/17/2023] [Indexed: 03/15/2023] Open
Abstract
The biosynthetic pathway of eicosapentaenoic acid (EPA) has previously been reported in marine bacteria, while the regulatory mechanism remains poorly understood. In this study, a putative transcriptional regulator PfaR encoded adjacent to the PFA biosynthesis gene cluster (pfaEABCD) was computationally and experimentally characterized. Comparative analyses on the wild type (WT) strain, in-frame deletion, and overexpression mutants revealed that PfaR positively regulated EPA synthesis at low temperature. RNA-Seq and real-time quantitative PCR analyses demonstrated that PfaR stimulated the transcription of pfaABCD. The transcription start site of pfaR was mapped by using primer extension and highly conserved promoter motifs bound by the housekeeping Sigma 70 factor that were identified in the upstream of pfaR. Moreover, overexpression of PfaR in WT strain W3-18-1 at low temperature could improve EPA productivity from 0.07% to 0.13% (percentage of EPA to dry weight, mg/mg) of dry weight. Taken together, these findings could provide important implications into the transcriptional control and metabolic engineering in terms of EPA productivity for industrial strains. IMPORTANCE We have experimentally confirmed that PfaR is a positive transcription regulator that promotes EPA synthesis at low temperature in Shewanella putrefaciens W3-18-1. Overexpression of PfaR in WT strain W3-18-1 could lead to a 1.8-fold increase in EPA productivity at low temperature. It is further shown that PfaR may be regulated by housekeeping Sigma 70 factor at low temperature.
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Affiliation(s)
- Hehong Wei
- College of Energy and Environmental Engineering, Hebei University of Engineering, Handan, China
| | - Penghui He
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, China
| | - Dianzhen Yu
- SIBS-UGENT-SJTU Joint Laboratory of Mycotoxin Research, CAS Key Laboratory of Nutrition, Metabolism and Food Safety, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, China
| | - Shuangyuan Liu
- Eco-Environmental Monitoring and Research Center, Pearl River Valley and South China Sea Ecology and Environment Administration, Ministry of Ecology and Environment, Guangzhou, China
| | - Chengtao Li
- College of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, China
| | - Dongru Qiu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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2
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Jia YL, Du F, Nong FT, Li J, Huang PW, Ma W, Gu Y, Sun XM. Function of the Polyketide Synthase Domains of Schizochytrium sp. on Fatty Acid Synthesis in Yarrowia lipolytica. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:2446-2454. [PMID: 36696156 DOI: 10.1021/acs.jafc.2c08383] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
It is well known that polyunsaturated fatty acids (PUFAs) in Schizochytrium sp. are mainly synthesized via the polyketide synthase (PKS) pathway. However, the specific mechanism of PKS in fatty acid synthesis is still unclear. In this work, the functions of ORFA, ORFB, ORFC, and their individual functional domain genes on fatty acid synthesis were investigated through heterologous expression in Yarrowia lipolytica. The results showed that the expression of ORFA, ORFB, ORFC, and their individual functional domains all led to the increase of the very long-chain PUFA content (mainly eicosapentaenoic acid). Furthermore, the transcriptomic analysis showed that except for the 3-ketoacyl-ACP synthase (KS) domain of ORFB, the expression of an individual functional domain, including malonyl-CoA: ACP acyltransferase, 3-hydroxyacyl-ACP dehydratase (DH), 3-ketoacyl-ACP reductase, and KS domains of ORFA, acyltransferase domains of ORFB, and two DH domains of ORFC resulted in upregulation of the tricarboxylic acid cycle and pentose phosphate pathway, downregulation of the triacylglycerol biosynthesis, fatty acid synthesis pathway, and β-oxidation in Yarrowia lipolytica. These results provide a theoretical basis for revealing the function of PKS in fatty acid synthesis in Y. lipolytica and elucidate the possible mechanism for PUFA biosynthesis.
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Affiliation(s)
- Yu-Lei Jia
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210000, China
| | - Fei Du
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210000, China
| | - Fang-Tong Nong
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210000, China
| | - Jin Li
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210000, China
| | - Peng-Wei Huang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210000, China
| | - Wang Ma
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210000, China
| | - Yang Gu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210000, China
| | - Xiao-Man Sun
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210000, China
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3
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Jia YL, Geng SS, Du F, Xu YS, Wang LR, Sun XM, Wang QZ, Li Q. Progress of metabolic engineering for the production of eicosapentaenoic acid. Crit Rev Biotechnol 2021; 42:838-855. [PMID: 34779326 DOI: 10.1080/07388551.2021.1971621] [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] [Indexed: 10/19/2022]
Abstract
Eicosapentaenoic Acid (EPA) is an essential ω-3 polyunsaturated fatty acid for human health. Currently, high-quality EPA production is largely dependent on the extraction of fish oil, but this unsustainable approach cannot meet its rising market demand. Biotechnological approaches for EPA production from microorganisms have received increasing attention due to their suitability for large-scale production and independence of the seasonal or climate restrictions. This review summarizes recent research on different microorganisms capable of producing EPA, such as microalgae, bacteria, and fungi, and introduces the different EPA biosynthesis pathways. Notably, some novel engineering strategies have been applied to endow and improve the abilities of microorganisms to synthesize EPA, including the construction and optimization of the EPA biosynthesis pathway, an increase in the acetyl-CoA pool supply, the increase of NADPH and the inhibition of competing pathways. This review aims to provide an updated summary of EPA production.
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Affiliation(s)
- Yu-Lei Jia
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Shan-Shan Geng
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Fei Du
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Ying-Shuang Xu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Ling-Ru Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Xiao-Man Sun
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Qing-Zhuo Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Qi Li
- College of Life Sciences, Sichuan Normal University, Chengdu, People's Republic of China
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Guo T, Wan C, Huang F, Wei C, Xiang X. Process optimization and characterization of arachidonic acid oil degumming using ultrasound-assisted enzymatic method. ULTRASONICS SONOCHEMISTRY 2021; 78:105720. [PMID: 34469850 PMCID: PMC8408658 DOI: 10.1016/j.ultsonch.2021.105720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 08/02/2021] [Accepted: 08/12/2021] [Indexed: 06/13/2023]
Abstract
Ultrasound assisted enzymatic method was applied to the degumming of arachidonic acid (ARA) oil produced by Mortierella alpina. The conditions of degumming process were optimized by response surface methodology with Box- Behnken design. A dephosphorization rate of 98.82% was achieved under optimum conditions of a 500 U/kg of Phospholipase A1 (PLA1) dosage, 2.8 mL/100 g of water volume, 120 min of ultrasonic time, and 135 W of ultrasonic power. The phosphorus content of ultrasonic assisted enzymatic degumming oil (UAEDO) was 4.79 mg/kg, which was significantly lower than that of enzymatic degumming oil (EDO, 17.98 mg/kg). Crude Oil (CO), EDO and UAEDO revealed the similar fatty acid compositions, and ARA was dominated (50.97 ~ 52.40%). The oxidation stability of UAEDO was equivalent to EDO and weaker than CO, while UAEDO presented the strongest thermal stability, followed by EDO and CO. Furthermore, aldehydes, acids and alcohols were identified the main volatile flavor components for the three oils. The proportions of major contributing components such as hexanal, nonanal, (E)-2-nonanal, (E, E)-2,4-decadienal, (E)-2-nonenal and aldehydes in UAEDO and EDO were all lower than CO. Overall, Ultrasound assisted enzymatic degumming proved to be an efficient and superior method for degumming of ARA oil.
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Affiliation(s)
- Tingting Guo
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China; Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, China; Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory, Wuhan, China
| | - Chuyun Wan
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China; Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, China; Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory, Wuhan, China.
| | - Fenghong Huang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China; Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory, Wuhan, China
| | - Chunlei Wei
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China; Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, China; Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory, Wuhan, China
| | - Xia Xiang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan, China; Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, China; Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory, Wuhan, China
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5
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Jia YL, Wang LR, Zhang ZX, Gu Y, Sun XM. Recent advances in biotechnological production of polyunsaturated fatty acids by Yarrowia lipolytica. Crit Rev Food Sci Nutr 2021; 62:8920-8934. [PMID: 34120537 DOI: 10.1080/10408398.2021.1937041] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Owing to the important physiological functions, polyunsaturated fatty acids (PUFAs) play a vital role in protecting human health, such as preventing cancer, cardiovascular disease, and diabetes. Specifically, Yarrowia lipolytica has been identified as the most popular non-conventional oleaginous yeast, which can accumulate the abundant intracellular lipids, indicating that has great potential as an industrial host for production of PUFAs. Notably, some novel engineering strategies have been applied to endow and improve the abilities of Y. lipolytica to synthesize PUFAs, including construction and optimization of PUFAs biosynthetic pathways, improvement of preucrsors acetyl-coA and NADPH supply, inhibition of competing pathways, knockout of β-oxidation pathways, regulation of oxidative stress defense pathways, and regulation of genes involved in upstream lipid metabolism. Besides, some bypass approaches, such as strain mating, evolutionary engineering, and computational model based on omics, also have been proposed to improve the performance of engineering strains. Generally, in this review, we summarized the recent advances in engineering strategies and bypass approaches for improving PUFAs production by Y. lipolytica. In addition, we further summarized the latest efforts of CRISPR/Cas genome editing technology in Y. lipolytica, which is aimed to provide its potential applications in PUFAs production.
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Affiliation(s)
- Yu-Lei Jia
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Ling-Ru Wang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Zi-Xu Zhang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Yang Gu
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
| | - Xiao-Man Sun
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing, People's Republic of China
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6
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Yang Q, Lu T, Yan J, Li J, Zhou H, Pan X, Lu Y, He N, Ling X. Regulation of polyunsaturated fatty acids synthesis by enhancing carotenoid-mediated endogenous antioxidant capacity in Schizochytrium sp. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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7
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Functions of Enyolreductase ( ER) Domains of PKS Cluster in Lipid Synthesis and Enhancement of PUFAs Accumulation in Schizochytrium limacinum SR21 Using Triclosan as a Regulator of ER. Microorganisms 2020; 8:microorganisms8020300. [PMID: 32098234 PMCID: PMC7074904 DOI: 10.3390/microorganisms8020300] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/09/2020] [Accepted: 02/19/2020] [Indexed: 01/10/2023] Open
Abstract
The polyketide synthase (PKS) cluster genes are supposed to synthesize polyunsaturated fatty acids (PUFAs) in S. limacinum. In this study, two enyolreductase (ER) genes located on PKS cluster were knocked out through homologous recombination to explore their functions. The knock-out of OrfB-ER (located on OrfB subunit) decreased lipid content and had obvious decrease on PUFAs content, indicating OrfB-ER domain played a vital role on PUFAs synthesis; the knock-out of OrfC-ER (located on OrfC subunit) decreased SFAs content and increased total lipid content, indicating OrfC-ER domain was likely to be related with SFAs synthesis, and lipid production could be improved by down-regulating OrfC-ER domain expression. Therefore, the addition of triclosan as a reported regulator of ER domain induced the increase of PUFAs production by 51.74% and lipids yield by 47.63%. Metabolic analysis indicated triclosan played its role through inhibiting the expression of OrfC-ER to reduce the feedback inhibition of SFAs and further to enhance NADPH synthesis for lipid production, and by weakening mevalonate pathway and tricarboxylic acid (TCA) cycle to shift precursors for lipid and PUFAs synthesis. This research illuminates functions of two ER domains in S. limacinum and provides a potential targets for improving lipid production.
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8
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Liang MH, Wang L, Wang Q, Zhu J, Jiang JG. High-value bioproducts from microalgae: Strategies and progress. Crit Rev Food Sci Nutr 2018; 59:2423-2441. [PMID: 29676930 DOI: 10.1080/10408398.2018.1455030] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Microalgae have been considered as alternative sustainable resources for high-value bioproducts such as lipids (especially triacylglycerides [TAGs]), polyunsaturated fatty acids (PUFAs), and carotenoids, due to their relatively high photosynthetic efficiency, no arable land requirement, and ease of scale-up. It is of great significance to exploit microalgae for the production of high-value bioproducts. How to improve the content or productivity of specific bioproducts has become one of the most urgent challenges. In this review, we will describe high-value bioproducts from microalgae and their biosynthetic pathways (mainly for lipids, PUFAs, and carotenoids). Recent progress and strategies for the enhanced production of bioproducts from microalgae are also described in detail, and these strategies take advantages of optimized cultivation conditions with abiotic stress, chemical stress (addition of metabolic precursors, phytohormones, chemical inhibitors, and chemicals inducing oxidative stress response), and molecular approaches such as metabolic engineering, transcriptional engineering, and gene disruption strategies (mainly RNAi, antisense RNA, miRNA-based knockdown, and CRISPR/Cas9).
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Affiliation(s)
- Ming-Hua Liang
- a College of Food Science and Engineering, South China University of Technology , Guangzhou , China
| | - Ling Wang
- b School of Biotechnology, Jiangsu University of Science and Technology , Zhenjiang , China
| | - Qiming Wang
- c College of Bioscience and Biotechnology, Hunan Agricultural University , Changsha , China
| | - Jianhua Zhu
- b School of Biotechnology, Jiangsu University of Science and Technology , Zhenjiang , China.,c College of Bioscience and Biotechnology, Hunan Agricultural University , Changsha , China.,d Department of Plant Science and Landscape Architecture, University of Maryland , College Park , Maryland , USA
| | - Jian-Guo Jiang
- a College of Food Science and Engineering, South China University of Technology , Guangzhou , China
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9
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Polyunsaturated fatty acids in marine bacteria and strategies to enhance their production. Appl Microbiol Biotechnol 2018; 102:5811-5826. [PMID: 29749565 DOI: 10.1007/s00253-018-9063-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 04/26/2018] [Accepted: 04/30/2018] [Indexed: 10/16/2022]
Abstract
Polyunsaturated fatty acids (PUFAs) play an important role in human diet. Despite the wide-ranging importance and benefits from heart health to brain functions, humans and mammals cannot synthesize PUFAs de novo. The primary sources of PUFA are fish and plants. Due to the increasing concerns associated with food security as well as issues of environmental contaminants in fish oil, there has been considerable interest in the production of polyunsaturated fatty acids from alternative resources which are more sustainable, safer, and economical. For instance, marine bacteria, particularly the genus of Shewanella, Photobacterium, Colwellia, Moritella, Psychromonas, Vibrio, and Alteromonas, are found to be one among the major microbial producers of polyunsaturated fatty acids. Recent developments in the area with a focus on the production of polyunsaturated fatty acids from marine bacteria as well as the metabolic engineering strategies for the improvement of PUFA production are discussed.
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Mao X, Liu Z, Sun J, Lee SY. Metabolic engineering for the microbial production of marine bioactive compounds. Biotechnol Adv 2017; 35:1004-1021. [DOI: 10.1016/j.biotechadv.2017.03.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/01/2017] [Accepted: 03/01/2017] [Indexed: 01/22/2023]
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11
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Eicosapentaenoic Acid from Porphyridium Cruentum: Increasing Growth and Productivity of Microalgae for Pharmaceutical Products. ENERGIES 2015. [DOI: 10.3390/en80910487] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Řezanka T, Lukavský J, Sigler K, Nedbalová L, Vítová M. Temperature dependence of production of structured triacylglycerols in the alga Trachydiscus minutus. PHYTOCHEMISTRY 2015; 110:37-45. [PMID: 25564261 DOI: 10.1016/j.phytochem.2014.12.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/10/2014] [Accepted: 12/11/2014] [Indexed: 06/04/2023]
Abstract
This study describes the identification of regioisomers and enantiomers of triacylglycerols of C20 polyunsaturated fatty acids (PUFAs) in the alga Trachydiscus minutus cultivated at different temperatures using reversed- and chiral-phase liquid chromatography-mass spectrometry. The use of the two different phases contributes to ready identification, both qualitative and semiquantitative, of regioisomers and enantiomers of triacylglycerols containing eicosapentaenoic and arachidonic in the molecule. The ratio of regioisomers and enantiomers of triacylglycerols (TAG) depends on the temperature of cultivation; with lowering temperature the proportion of the achiral TAG increases and the enantiomer ratio diverges from 1:1.
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Affiliation(s)
- Tomáš Řezanka
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic.
| | - Jaromír Lukavský
- Institute of Botany, Academy of Sciences of the Czech Republic, Biorefinery Res. Centre of Competence, Dukelská 135, 379 82 Třeboň, Czech Republic
| | - Karel Sigler
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Linda Nedbalová
- Department of Ecology, Faculty of Science, Charles University in Prague, Viničná 7, 128 44 Prague 2, Czech Republic
| | - Milada Vítová
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Laboratory of Cell Cycles of Algae, Centre Algatech, Opatovický mlýn 237, 379 81 Třeboň, Czech Republic
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Ruiz-Lopez N, Usher S, Sayanova OV, Napier JA, Haslam RP. Modifying the lipid content and composition of plant seeds: engineering the production of LC-PUFA. Appl Microbiol Biotechnol 2015; 99:143-54. [PMID: 25417743 PMCID: PMC4286622 DOI: 10.1007/s00253-014-6217-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 11/05/2014] [Accepted: 11/05/2014] [Indexed: 01/05/2023]
Abstract
Omega-3 fatty acids are characterized by a double bond at the third carbon atom from the end of the carbon chain. Latterly, long chain polyunsaturated omega-3 fatty acids such as eicosapentaenoic acid (EPA; 20:5Δ5,8,11,14,17) and docosahexanoic acid (DHA; 22:6 Δ4,7,10,13,16,19), which typically only enter the human diet via the consumption of oily fish, have attracted much attention. The health benefits of the omega-3 LC-PUFAs EPA and DHA are now well established. Given the desire for a sustainable supply of omega-LC-PUFA, efforts have focused on enhancing the composition of vegetable oils to include these important fatty acids. Specifically, EPA and DHA have been the focus of much study, with the ultimate goal of producing a terrestrial plant-based source of these so-called fish oils. Over the last decade, many genes encoding the primary LC-PUFA biosynthetic activities have been identified and characterized. This has allowed the reconstitution of the LC-PUFA biosynthetic pathway in oilseed crops, producing transgenic plants engineered to accumulate omega-3 LC-PUFA to levels similar to that found in fish oil. In this review, we will describe the most recent developments in this field and the challenges of overwriting endogenous seed lipid metabolism to maximize the accumulation of these important fatty acids.
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Affiliation(s)
- Noemi Ruiz-Lopez
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Sarah Usher
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Olga V. Sayanova
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Johnathan A. Napier
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
| | - Richard P. Haslam
- Department of Biological Chemistry, Rothamsted Research, Harpenden, Herts AL5 2JQ UK
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14
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Metabolic engineering of microorganisms to produce omega-3 very long-chain polyunsaturated fatty acids. Prog Lipid Res 2014; 56:19-35. [PMID: 25107699 DOI: 10.1016/j.plipres.2014.07.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/14/2014] [Indexed: 12/28/2022]
Abstract
Omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs) have received growing attention due to their significant roles in human health. Currently the main source of these nutritionally and medically important fatty acids is marine fish, which has not met ever-increasing global demand. Microorganisms are an important alternative source also being explored. Although many microorganisms accumulate omega-3 LC-PUFAs naturally, metabolic engineering might still be necessary for significantly improving their yields. Here, we review recent research involving the engineering of microorganisms for production of omega-3 LC-PUFAs, including eicospentaenoic acid and docosohexaenoic acid. Both reconstitution of omega-3 LC-PUFA biosynthetic pathways and modification of existing pathways in microorganisms have demonstrated the potential to produce high levels of omega-3 LC-PUFAs. However, the yields of omega-3 LC-PUFAs in host systems have been substantially limited by potential metabolic bottlenecks, which might be caused partly by inefficient flux of fatty acid intermediates between the acyl-CoA and different lipid class pools. Although fatty acid flux in both native and heterologous microbial hosts might be controlled by several acyltransferases, evidence has suggested that genetic manipulation of one acyltransferase alone could significantly increase the accumulation of LC-PUFAs. The number of oleaginous microorganisms that can be genetically transformed is increasing, which will advance engineering efforts to maximize LC-PUFA yields in microbial strains.
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15
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Huerlimann R, Steinig EJ, Loxton H, Zenger KR, Jerry DR, Heimann K. The effect of nitrogen limitation on acetyl-CoA carboxylase expression and fatty acid content in Chromera velia and Isochrysis aff. galbana (TISO). Gene 2014; 543:204-11. [DOI: 10.1016/j.gene.2014.04.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 04/08/2014] [Accepted: 04/11/2014] [Indexed: 10/25/2022]
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16
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Cao Y, Liu W, Xu X, Zhang H, Wang J, Xian M. Production of free monounsaturated fatty acids by metabolically engineered Escherichia coli. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:59. [PMID: 24716602 PMCID: PMC4021618 DOI: 10.1186/1754-6834-7-59] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2013] [Accepted: 03/17/2014] [Indexed: 05/22/2023]
Abstract
BACKGROUND Monounsaturated fatty acids (MUFAs) are the best components for biodiesel when considering the low temperature fluidity and oxidative stability. However, biodiesel derived from vegetable oils or microbial lipids always consists of significant amounts of polyunsaturated and saturated fatty acids (SFAs) alkyl esters, which hampers its practical applications. Therefore, the fatty acid composition should be modified to increase MUFA contents as well as enhancing oil and lipid production. RESULTS The model microorganism Escherichia coli was engineered to produce free MUFAs. The fatty acyl-ACP thioesterase (AtFatA) and fatty acid desaturase (SSI2) from Arabidopsis thaliana were heterologously expressed in E. coli BL21 star(DE3) to specifically release free unsaturated fatty acids (UFAs) and convert SFAs to UFAs. In addition, the endogenous fadD gene (encoding acyl-CoA synthetase) was disrupted to block fatty acid catabolism while the native acetyl-CoA carboxylase (ACCase) was overexpressed to increase the malonyl coenzyme A (malonyl-CoA) pool and boost fatty acid biosynthesis. The finally engineered strain BL21ΔfadD/pE-AtFatAssi2&pA-acc produced 82.6 mg/L free fatty acids (FFAs) under shake-flask conditions and FFAs yield on glucose reached about 3.3% of the theoretical yield. Two types of MUFAs, palmitoleate (16:1Δ9) and cis-vaccenate (18:1Δ11) made up more than 75% of the FFA profiles. Fed-batch fermentation of this strain further enhanced FFAs production to a titer of 1.27 g/L without affecting fatty acid compositions. CONCLUSIONS This study demonstrated the possibility to regulate fatty acid composition by using metabolic engineering approaches. FFAs produced by the recombinant E. coli strain consisted of high-level MUFAs and biodiesel manufactured from these fatty acids would be more suitable for current diesel engines.
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Affiliation(s)
- Yujin Cao
- CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Wei Liu
- CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Xin Xu
- CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Haibo Zhang
- CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Jiming Wang
- CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
| | - Mo Xian
- CAS Key Laboratory of Bio-based Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, China
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Fermentative succinate production: an emerging technology to replace the traditional petrochemical processes. BIOMED RESEARCH INTERNATIONAL 2013; 2013:723412. [PMID: 24396827 PMCID: PMC3874355 DOI: 10.1155/2013/723412] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 10/13/2013] [Accepted: 11/01/2013] [Indexed: 11/17/2022]
Abstract
Succinate is a valuable platform chemical for multiple applications. Confronted with the exhaustion of fossil energy resources, fermentative succinate production from renewable biomass to replace the traditional petrochemical process is receiving an increasing amount of attention. During the past few years, the succinate-producing process using microbial fermentation has been made commercially available by the joint efforts of researchers in different fields. In this review, recent attempts and experiences devoted to reduce the production cost of biobased succinate are summarized, including strain improvement, fermentation engineering, and downstream processing. The key limitations and challenges faced in current microbial production systems are also proposed.
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18
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Production of EPA and DHA in aquatic ecosystems and their transfer to the land. Prostaglandins Other Lipid Mediat 2013; 107:117-26. [DOI: 10.1016/j.prostaglandins.2013.03.002] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 03/02/2013] [Accepted: 03/05/2013] [Indexed: 12/28/2022]
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Production of long-chain hydroxy fatty acids by microbial conversion. Appl Microbiol Biotechnol 2013; 97:3323-31. [PMID: 23494626 DOI: 10.1007/s00253-013-4815-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2012] [Revised: 02/24/2013] [Accepted: 02/26/2013] [Indexed: 10/27/2022]
Abstract
Hydroxy fatty acids (HFAs) are very important chemicals for versatile applications in biodegradable polymer materials and cosmetic and pharmaceutical industries. They are difficult to be synthesized via chemical routes due to the inertness of the fatty acyl chain. In contrast, these fatty acids make up a major class of natural products widespread among bacteria, yeasts, and fungi. A number of microorganisms capable of producing HFAs from fatty acids or vegetable oils have been reported. Therefore, HFAs could be produced by biotechnological strategies, especially by microbial conversion processes. Microorganisms could oxidize fatty acids either at the terminal carbon or inside the acyl chain to produce various HFAs, including α-HFAs, β-HFAs, mid-position HFAs, ω-HFAs, di-HFAs, and tri-HFAs. The enzymes and their encoded genes responsible for the hydroxylation of the carbon chain have been identified and characterized during the past few years. The involved microbes and catalytic mechanisms for the production of different types of HFAs are systematically demonstrated in this review. It provides a better view of HFA biosynthesis and lays the foundation for further industrial production.
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