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Du X, Ma X, Gao Y. The physiological function of squalene and its application prospects in animal husbandry. Front Vet Sci 2024; 10:1284500. [PMID: 38292136 PMCID: PMC10824843 DOI: 10.3389/fvets.2023.1284500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 12/26/2023] [Indexed: 02/01/2024] Open
Abstract
Squalene, which is a natural triterpenoid unsaturated hydrocarbon, is abundant in shark liver and plant seeds. Squalene has various physiological functions such as being anti-inflammatory and antioxidant. This paper reviews the physiological functions of squalene and its application prospects in livestock and poultry production, with a view to providing a theoretical basis for its in-depth application in animal husbandry.
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Affiliation(s)
- Xin Du
- College of Life Science, Baicheng Normal University, Baicheng, China
| | - Xue Ma
- College of Life Science, Baicheng Normal University, Baicheng, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Yang Gao
- College of Life Science, Baicheng Normal University, Baicheng, China
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Recent advances in the microbial production of squalene. World J Microbiol Biotechnol 2022; 38:91. [PMID: 35426523 PMCID: PMC9010451 DOI: 10.1007/s11274-022-03273-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 03/30/2022] [Indexed: 11/06/2022]
Abstract
Squalene is a triterpene hydrocarbon, a biochemical precursor for all steroids in plants and animals. It is a principal component of human surface lipids, in particular of sebum. Squalene has several applications in the food, pharmaceutical, and medical sectors. It is essentially used as a dietary supplement, vaccine adjuvant, moisturizer, cardio-protective agent, anti-tumor agent and natural antioxidant. With the increased demand for squalene along with regulations on shark-derived squalene, there is a need to find alternatives for squalene production which are low-cost as well as sustainable. Microbial platforms are being considered as a potential option to meet such challenges. Considerable progress has been made using both wild-type and engineered microbial strains for improved productivity and yields of squalene. Native strains for squalene production are usually limited by low growth rates and lesser titers. Metabolic engineering, which is a rational strain engineering tool, has enabled the development of microbial strains such as Saccharomyces cerevisiae and Yarrowia lipolytica, to overproduce the squalene in high titers. This review focuses on key strain engineering strategies involving both in-silico and in-vitro techniques. Emphasis is made on gene manipulations for improved precursor pool, enzyme modifications, cofactor regeneration, up-regulation of limiting reactions, and downregulation of competing reactions during squalene production. Process strategies and challenges related to both upstream and downstream during mass cultivation are detailed.
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Xu W, Wang D, Fan J, Zhang L, Ma X, Yao J, Wang Y. Improving squalene production by blocking the competitive branched pathways and expressing rate-limiting enzymes in Rhodopseudomonas palustris. Biotechnol Appl Biochem 2021; 69:1502-1508. [PMID: 34278608 DOI: 10.1002/bab.2222] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Accepted: 07/12/2021] [Indexed: 12/15/2022]
Abstract
Squalene is a medically valuable bioactive compound that can be used as a raw material for fuels. Microbial fermentation is the preferred method for the squalene production. In this study, we employed several metabolic engineering strategies to increase squalene yield in Rhodopseudomonas palustris. A 57% increase in squalene titer was achieved by blocking the carotenoid pathway, thus directing more FPP into the squalene biosynthetic pathway. In order to cut down the conversion of squalene to haponoids, a recombinant strain R. palustris [Δshc, ΔcrtB] in which both carotenoid and haponoid pathways were blocked was then constructed, resulting in a 50-fold increase in squalene titer. Based on the expression of rate-limiting enzymes involved in the squalene pathway, the final squalene content reached 23.3 mg/g DCW, which was 178-times higher than that of the wild-type strain. In this study, several methods effective in improving squalene yield have been described and the potential of R. palustris for producing squalene has been demonstrated.
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Affiliation(s)
- Wen Xu
- The Xi'an Key Laboratory of Pathogenic Microorganism and Tumor Immunity, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Danyang Wang
- Department of Prosthodontics, School of Stomatology, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Jinbo Fan
- The Xi'an Key Laboratory of Pathogenic Microorganism and Tumor Immunity, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Lei Zhang
- The Xi'an Key Laboratory of Pathogenic Microorganism and Tumor Immunity, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Xi Ma
- The Xi'an Key Laboratory of Pathogenic Microorganism and Tumor Immunity, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Jia Yao
- The Xi'an Key Laboratory of Pathogenic Microorganism and Tumor Immunity, Xi'an Medical University, Xi'an, Shaanxi, China
| | - Yang Wang
- The Xi'an Key Laboratory of Pathogenic Microorganism and Tumor Immunity, Xi'an Medical University, Xi'an, Shaanxi, China
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Muhammad A, Feng X, Rasool A, Sun W, Li C. Production of plant natural products through engineered Yarrowia lipolytica. Biotechnol Adv 2020; 43:107555. [DOI: 10.1016/j.biotechadv.2020.107555] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/13/2020] [Accepted: 05/12/2020] [Indexed: 12/18/2022]
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Daletos G, Katsimpouras C, Stephanopoulos G. Novel Strategies and Platforms for Industrial Isoprenoid Engineering. Trends Biotechnol 2020; 38:811-822. [DOI: 10.1016/j.tibtech.2020.03.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/16/2020] [Accepted: 03/17/2020] [Indexed: 12/13/2022]
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Self-Redirection of Metabolic Flux Toward Squalene and Ethanol Pathways by Engineered Yeast. Metabolites 2020; 10:metabo10020056. [PMID: 32024107 PMCID: PMC7074498 DOI: 10.3390/metabo10020056] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 01/28/2020] [Accepted: 01/30/2020] [Indexed: 11/30/2022] Open
Abstract
We have previously reported that squalene overproducing yeast self-downregulate the expression of the ethanol pathway (non-essential pathway) to divert the metabolic flux to the squalene pathway. In this study, the effect of co-production of squalene and ethanol on other non-essential pathways (fusel alcohol pathway, FA) of Saccharomyces cerevisiae was evaluated. However, before that, 13 constitutive promoters, like IRA1p, PET9p, RHO1p, CMD1p, ATP16p, USA3p,RER2p, COQ1p, RIM1p, GRS1p, MAK5p, and BRN1p, were engineered using transcription factor bindings sites from strong promoters HHF2p (−300 to −669 bp) and TEF1p (−300 to −579 bp), and employed to co-overexpress squalene and ethanol pathways in S. cerevisiae. The FSE strain overexpressing the key genes of the squalene pathway accumulated 56.20 mg/L squalene, a 16.43-fold higher than wild type strain (WS). The biogenesis of lipid droplets was stimulated by overexpressing DGA1 and produced 106 mg/L squalene in the FSE strain. AFT1p and CTR1p repressible promoters were also characterized and employed to downregulate the expression of ERG1, which also enhanced the production of squalene in FSE strain up to 42.85- (148.67 mg/L) and 73.49-fold (255.11 mg/L) respectively. The FSE strain was further engineered by overexpressing the key genes of the ethanol pathway and produced 40.2 mg/mL ethanol in the FSE1 strain, 3.23-fold higher than the WS strain. The FSE1 strain also self-downregulated the expression of the FA pathway up to 73.9%, perhaps by downregulating the expression of GCN4 by 2.24-fold. We demonstrate the successful tuning of the strength of yeast promoters and highest coproduction of squalene and ethanol in yeast, and present GCN4 as a novel metabolic regulator that can be manipulated to divert the metabolic flux from the non-essential pathway to engineered pathways.
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Ahmed MS, Ikram S, Rasool A, Li C. Design and construction of short synthetic terminators for β-amyrin production in Saccharomyces cerevisiae. Biochem Eng J 2019. [DOI: 10.1016/j.bej.2019.03.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Gohil N, Bhattacharjee G, Khambhati K, Braddick D, Singh V. Corrigendum: Engineering Strategies in Microorganisms for the Enhanced Production of Squalene: Advances, Challenges and Opportunities. Front Bioeng Biotechnol 2019; 7:114. [PMID: 31192199 PMCID: PMC6547300 DOI: 10.3389/fbioe.2019.00114] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 05/07/2019] [Indexed: 01/05/2023] Open
Abstract
[This corrects the article DOI: 10.3389/fbioe.2019.00050.].
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Affiliation(s)
- Nisarg Gohil
- School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area, Gandhinagar, India
| | - Gargi Bhattacharjee
- School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area, Gandhinagar, India
| | - Khushal Khambhati
- School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area, Gandhinagar, India
| | - Darren Braddick
- Department of R&D, Cementic S. A. S., Genopole, Paris, France
| | - Vijai Singh
- School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area, Gandhinagar, India
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Sun W, Qin L, Xue H, Yu Y, Ma Y, Wang Y, Li C. Novel trends for producing plant triterpenoids in yeast. Crit Rev Biotechnol 2019; 39:618-632. [DOI: 10.1080/07388551.2019.1608503] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Wentao Sun
- Department of Biochemical Engineering, Institute for Synthetic Biosystem, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Lei Qin
- Department of Biochemical Engineering, Institute for Synthetic Biosystem, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Haijie Xue
- Department of Biochemical Engineering, Institute for Synthetic Biosystem, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Yang Yu
- Department of Biochemical Engineering, Institute for Synthetic Biosystem, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Yihua Ma
- The High School Affiliated to Renmin University of China, Beijing, China
| | - Ying Wang
- Department of Biochemical Engineering, Institute for Synthetic Biosystem, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
| | - Chun Li
- Department of Biochemical Engineering, Institute for Synthetic Biosystem, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Beijing, China
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Gohil N, Bhattacharjee G, Khambhati K, Braddick D, Singh V. Engineering Strategies in Microorganisms for the Enhanced Production of Squalene: Advances, Challenges and Opportunities. Front Bioeng Biotechnol 2019; 7:50. [PMID: 30968019 PMCID: PMC6439483 DOI: 10.3389/fbioe.2019.00050] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 03/01/2019] [Indexed: 12/20/2022] Open
Abstract
The triterpene squalene is a natural compound that has demonstrated an extraordinary diversity of uses in pharmaceutical, nutraceutical, and personal care industries. Emboldened by this range of uses, novel applications that can gain profit from the benefits of squalene as an additive or supplement are expanding, resulting in its increasing demand. Ever since its discovery, the primary source has been the deep-sea shark liver, although recent declines in their populations and justified animal conservation and protection regulations have encouraged researchers to identify a novel route for squalene biosynthesis. This renewed scientific interest has profited from immense developments in synthetic biology, which now allows fine-tuning of a wider range of plants, fungi, and microorganisms for improved squalene production. There are numerous naturally squalene producing species and strains; although they generally do not make commercially viable yields as primary shark liver sources can deliver. The recent advances made toward improving squalene output from natural and engineered species have inspired this review. Accordingly, it will cover in-depth knowledge offered by the studies of the natural sources, and various engineering-based strategies that have been used to drive the improvements in the pathways toward large-scale production. The wide uses of squalene are also discussed, including the notable developments in anti-cancer applications and in augmenting influenza vaccines for greater efficacy.
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Affiliation(s)
- Nisarg Gohil
- School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area, Gandhinagar, India
| | - Gargi Bhattacharjee
- School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area, Gandhinagar, India
| | - Khushal Khambhati
- School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area, Gandhinagar, India
| | - Darren Braddick
- Department of R&D, Cementic S. A. S., Genopole, Paris, France
| | - Vijai Singh
- School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area, Gandhinagar, India
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Patel A, Rova U, Christakopoulos P, Matsakas L. Simultaneous production of DHA and squalene from Aurantiochytrium sp. grown on forest biomass hydrolysates. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:255. [PMID: 31687043 PMCID: PMC6820942 DOI: 10.1186/s13068-019-1593-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 10/16/2019] [Indexed: 05/12/2023]
Abstract
BACKGROUND Recent evidence points to the nutritional importance of docosahexaenoic acid (DHA) in the human diet. Thraustochytrids are heterotrophic marine oleaginous microorganisms capable of synthesizing high amounts of DHA, as well as other nutraceutical compounds such as squalene, in their cellular compartment. Squalene is a natural triterpene and an important biosynthetic precursor to all human steroids. It has a wide range of applications in the cosmetic and pharmaceutical industries, with benefits that include boosting immunity and antioxidant activity. Apart from its nutritional quality, it can also be utilized for high-grade bio-jet fuel by catalytic conversion. RESULTS In the present study, the potential of thraustochytrid strain Aurantiochytrium sp. T66 to produce DHA and squalene was evaluated. When the strain was cultivated on organosolv-pretreated birch hydrolysate (30 g/L glucose) in flask, it resulted in 10.39 g/L of cell dry weight and 4.98 g/L of total lipids, of which 25.98% was DHA. In contrast, when the strain was grown in a bioreactor, cell dry weight, total lipid, and DHA increased to 11.24 g/L, 5.90 g/L, and 35.76%, respectively. The maximum squalene yield was 69.31 mg/gCDW (0.72 g/L) when the strain was cultivated in flask, but it increased to 88.47 mg/gCDW (1.0 g/L), when cultivation shifted to a bioreactor. CONCLUSIONS This is the first report demonstrating the utilization of low cost non-edible lignocellulosic feedstock to cultivate the marine oleaginous microorganism Aurantiochytrium sp. for the production of nutraceutical vital compounds. Owing to the simultaneous generation of DHA and squalene, the strain is suitable for industrial-scale production of nutraceuticals.
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Affiliation(s)
- Alok Patel
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, 971 87, Luleå, Sweden
| | - Ulrika Rova
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, 971 87, Luleå, Sweden
| | - Paul Christakopoulos
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, 971 87, Luleå, Sweden
| | - Leonidas Matsakas
- Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental, and Natural Resources Engineering, Luleå University of Technology, 971 87, Luleå, Sweden
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Xiong L, Zeng Y, Tang RQ, Alper HS, Bai FW, Zhao XQ. Condition-specific promoter activities in Saccharomyces cerevisiae. Microb Cell Fact 2018; 17:58. [PMID: 29631591 PMCID: PMC5891911 DOI: 10.1186/s12934-018-0899-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/26/2018] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Saccharomyces cerevisiae is widely studied for production of biofuels and biochemicals. To improve production efficiency under industrially relevant conditions, coordinated expression of multiple genes by manipulating promoter strengths is an efficient approach. It is known that gene expression is highly dependent on the practically used environmental conditions and is subject to dynamic changes. Therefore, investigating promoter activities of S. cerevisiae under different culture conditions in different time points, especially under stressful conditions is of great importance. RESULTS In this study, the activities of various promoters in S. cerevisiae under stressful conditions and in the presence of xylose were characterized using yeast enhanced green fluorescent protein (yEGFP) as a reporter. The stresses include toxic levels of acetic acid and furfural, and high temperature, which are related to fermentation of lignocellulosic hydrolysates. In addition to investigating eight native promoters, the synthetic hybrid promoter P3xC-TEF1 was also evaluated. The results revealed that P TDH3 and the synthetic promoter P3xC-TEF1 showed the highest strengths under almost all the conditions. Importantly, these two promoters also exhibited high stabilities throughout the cultivation. However, the strengths of P ADH1 and P PGK1 , which are generally regarded as 'constitutive' promoters, decreased significantly under certain conditions, suggesting that cautions should be taken to use such constitutive promoters to drive gene expression under stressful conditions. Interestingly, P HSP12 and P HSP26 were able to response to both high temperature and acetic acid stress. Moreover, P HSP12 also led to moderate yEGFP expression when xylose was used as the sole carbon source, indicating that this promoter could be used for inducing proper gene expression for xylose utilization. CONCLUSION The results here revealed dynamic changes of promoter activities in S. cerevisiae throughout batch fermentation in the presence of inhibitors as well as using xylose. These results provide insights in selection of promoters to construct S. cerevisiae strains for efficient bioproduction under practical conditions. Our results also encouraged applications of synthetic promoters with high stability for yeast strain development.
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Affiliation(s)
- Liang Xiong
- School of Life Science and Biotechnology, Dalian University of Technology, Dalian, 116024, China
| | - Yu Zeng
- State Key Laboratory of Microbial Metabolism (SKLMM), School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Rui-Qi Tang
- State Key Laboratory of Microbial Metabolism (SKLMM), School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Hal S Alper
- Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Feng-Wu Bai
- State Key Laboratory of Microbial Metabolism (SKLMM), School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Xin-Qing Zhao
- State Key Laboratory of Microbial Metabolism (SKLMM), School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.
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Iterative integration of multiple-copy pathway genes in Yarrowia lipolytica for heterologous β-carotene production. Metab Eng 2017; 41:192-201. [PMID: 28414174 DOI: 10.1016/j.ymben.2017.04.004] [Citation(s) in RCA: 162] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 04/10/2017] [Accepted: 04/12/2017] [Indexed: 11/24/2022]
Abstract
β-Carotene is a terpenoid molecule with high hydrophobicity that is often used as an additive in foods and feed. Previous work has demonstrated the heterologous biosynthesis of β-carotene from an intrinsic high flux of acetyl-CoA in 12 steps through 11 genes in Yarrowia lipolytica. Here, an efficient biosynthetic pathway capable of producing 100-fold more β-carotene than the baseline construct was generated using strong promoters and multiple gene copies for each of the 12 steps. Using fed-batch fermentation with an optimized medium, the engineered pathway could produce 4g/L β-carotene, which was stored in lipid droplets within engineered Y. lipolytica cells. Expansion of these cells for squalene production also demonstrated that Y. lipolytica could be an industrially relevant platform for hydrophobic terpenoid production.
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