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Zong G, Cao G, Fu J, Zhang P, Chen X, Yan W, Xin L, Wang Z, Xu Y, Zhang R. Novel mechanism of hydrogen peroxide for promoting efficient natamycin synthesis in Streptomyces. Microbiol Spectr 2023; 11:e0087923. [PMID: 37695060 PMCID: PMC10580950 DOI: 10.1128/spectrum.00879-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/21/2023] [Indexed: 09/12/2023] Open
Abstract
The mechanism of regulation of natamycin biosynthesis by Streptomyces in response to oxidative stress is unclear. Here, we first show cholesterol oxidase SgnE, which catalyzes the formation of H2O2 from sterols, triggered a series of redox-dependent interactions to stimulate natamycin production in S. gilvosporeus. In response to reactive oxygen species, residues Cys212 and Cys221 of the H2O2-sensing consensus sequence of OxyR were oxidized, resulting in conformational changes in the protein: OxyR extended its DNA-binding domain to interact with four motifs of promoter p sgnM . This acted as a redox-dependent switch to turn on/off gene transcription of sgnM, which encodes a cluster-situated regulator, by controlling the affinity between OxyR and p sgnM , thus regulating the expression of 12 genes in the natamycin biosynthesis gene cluster. OxyR cooperates with SgnR, another cluster-situated regulator and an upstream regulatory factor of SgnM, synergistically modulated natamycin biosynthesis by masking/unmasking the -35 region of p sgnM depending on the redox state of OxyR in response to the intracellular H2O2 concentration. IMPORTANCE Cholesterol oxidase SgnE is an indispensable factor, with an unclear mechanism, for natamycin biosynthesis in Streptomyces. Oxidative stress has been attributed to the natamycin biosynthesis. Here, we show that SgnE catalyzes the formation of H2O2 from sterols and triggers a series of redox-dependent interactions to stimulate natamycin production in S. gilvosporeus. OxyR, which cooperates with SgnR, acted as a redox-dependent switch to turn on/off gene transcription of sgnM, which encodes a cluster-situated regulator, by masking/unmasking its -35 region, to control the natamycin biosynthesis gene cluster. This work provides a novel perspective on the crosstalk between intracellular ROS homeostasis and natamycin biosynthesis. Application of these findings will improve antibiotic yields via control of the intracellular redox pressure in Streptomyces.
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Affiliation(s)
- Gongli Zong
- Key Laboratory of Industrial Biotechnology of Ministry of Education & School of Biotechnology, Jiangnan University, Wuxi, China
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan, China
| | - Guangxiang Cao
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan, China
| | - Jiafang Fu
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan, China
| | - Peipei Zhang
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan, China
| | - Xi Chen
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan, China
| | - Wenxiu Yan
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan, China
| | - Lulu Xin
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan, China
| | - Zhongxue Wang
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji’nan, China
| | - Yan Xu
- Key Laboratory of Industrial Biotechnology of Ministry of Education & School of Biotechnology, Jiangnan University, Wuxi, China
| | - Rongzhen Zhang
- Key Laboratory of Industrial Biotechnology of Ministry of Education & School of Biotechnology, Jiangnan University, Wuxi, China
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Physiological analysis of the improved ε-polylysine production induced by reactive oxygen species. Appl Microbiol Biotechnol 2023; 107:881-896. [PMID: 36585512 DOI: 10.1007/s00253-022-12343-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 12/10/2022] [Accepted: 12/14/2022] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Epsilon-poly-L-lysine (ε-PL) is produced by Streptomyces species in acidic and aerobic conditions, which inevitably induces rapid generation of reactive oxygen species (ROS). The devastating effects of ROS on biomolecules and cell vitality have been well-studied, while the positive effects of ROS are rarely reported. RESULTS In this study, we found that a proper dose of intracellular ROS (about 3.3 μmol H2O2 /g DCW) could induce a physiological modification to promote the ε-PL production (from 1.2 to 1.5 g/L). It resulted in larger sizes of colony and mycelial pellets as well as vibrant, aggregated, and more robust mycelia, which were of high capability of ROS detoxication. Physiological studies showed that appropriate doses of ROS activated the metabolism of the pentose phosphate pathway at both transcriptional and enzymatic levels, which was beneficial for biomass accumulation. The biosynthesis of lysine was also promoted in terms of transcriptional regulatory overexpression, increased transcription and enzymatic activity of key genes, larger pools of metabolites in the TCA cycle, replenishment pathway, and diaminoheptanedioic acid pathway. In addition, energy provision was ensured by activated metabolism of the TCA cycle, a larger pool of NADH, and higher activity of the electron transport system. Increased transcription of HrdD and pls further accelerated the ε-PL biosynthesis. SIGNIFICANCE These results indicated that ROS at proper intracellular dose could act as an inducing signal to activate the ε-PL biosynthesis, which laid a foundation for further process regulation to maintain optimal ROS dose in industrial ε-PL production and was of theoretical and practical significance. KEY POINTS • A proper dose of intracellular ROS positively influences the ε-PL production. • Proper dose of ROS enhanced the mycelial activity and antioxidative capability. • ROS increased lysine synthesis metabolism, energy provision and pls expression.
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Li S, Mao Y, Zhang L, Wang M, Meng J, Liu X, Bai Y, Guo Y. Recent advances in microbial ε-poly-L-lysine fermentation and its diverse applications. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:65. [PMID: 35710433 PMCID: PMC9205021 DOI: 10.1186/s13068-022-02166-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
The naturally occurring homo-polyamide biopolymer, ε-poly-L-lysine (ε-PL) consists of 25-35 L-lysine residues with amide linkages between α-carboxyl groups and ε-amino groups. ɛ-PL exhibits several useful properties because of its unusual structure, such as biodegradability, water solubility, no human toxicity, and broad-spectrum antibacterial activities; it is widely applied in the fields of food, medicine, clinical chemistry and electronics. However, current industrial production of ε-PL is only performed in a few countries. Based on an analysis of the physiological characteristics of ε-PL fermentation, current advances that enhance ε-PL fermentation, from strain improvement to product isolation are systematically reviewed, focusing on: (1) elucidating the metabolic pathway and regulatory mechanism of ε-PL synthesis; (2) enhancing biosynthetic performance through mutagenesis, fermentation optimization and metabolic engineering; and (3) understanding and improving the biological activity and functional properties of ε-PL. Finally, perspectives on engineering and exploiting ε-PL as a source material for the production of various advanced materials are also discussed, providing scientific guidelines for researchers to further improve the ε-PL fermentation process.
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Affiliation(s)
- Shubo Li
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Yunren Mao
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Lifei Zhang
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Miao Wang
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Jinhao Meng
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Xiaoling Liu
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Yunxia Bai
- College of Light Industry and Food Engineering, Guangxi University, Nanning, 530004, China
| | - Yuan Guo
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, 530004, China.
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A Study of Type II ɛ-PL Degrading Enzyme (pldII) in Streptomyces albulus through the CRISPRi System. Int J Mol Sci 2022; 23:ijms23126691. [PMID: 35743134 PMCID: PMC9223678 DOI: 10.3390/ijms23126691] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/11/2022] [Accepted: 06/13/2022] [Indexed: 02/04/2023] Open
Abstract
ε-Poly-L-lysine (ε-PL) is a widely used antibacterial peptide polymerized of 25–35 L-lysine residues. The antibacterial effect of ε-PL is closely related to the polymerization degree. However, the mechanism of ε-PL degradation in S. albulus remains unclear. This study utilized the integrative plasmid pSET152-based CRISPRi system to transcriptionally repress the ε-PL degrading enzyme (pldII). The expression of pldII is regulated by changing the recognition site of dCas9. Through the ε-PL bacteriostatic experiments of repression strains, it was found that the repression of pldII improves the antibacterial effect of the ε-PL product. The consecutive MALDI-TOF-MS results confirmed that the molecular weight distribution of the ε-PL was changed after repression. The repression strain S1 showed a particular peak with a polymerization degree of 44, and other repression strains also generated ε-PL with a polymerization degree of over 40. Furthermore, the homology modeling and substrate docking of pldII, a typical endo-type metallopeptidase, were performed to resolve the degradation mechanism of ε-PL in S. albulus. The hydrolysis of ε-PL within pldII, initiated from the N-terminus by two amino acid-binding residues, Thr194 and Glu281, led to varying levels of polymerization of ε-PL.
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Biotechnological production and application of epsilon-poly-L-lysine (ε-PL): biosynthesis and its metabolic regulation. World J Microbiol Biotechnol 2022; 38:123. [PMID: 35637397 DOI: 10.1007/s11274-022-03304-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 05/06/2022] [Indexed: 10/18/2022]
Abstract
Epsilon-poly-L-lysine (ε-PL) is an unusual biopolymer composed of L-lysine produced by several microorganisms, especially by the genus Streptomyces. Due to its excellent antimicrobial activity, good water solubility, high safety, and biodegradable nature, ε-PL with a GRAS status has been widely used in food and pharmaceutical industries. In the past years, studies have focused on the biotechnological production of ɛ-PL, the biosynthetic mechanism of microbial ɛ-PL, and its application. To provide new perspectives from recent advances, the review introduced the methods for the isolation of ɛ-PL producing strains and the biosynthetic mechanism of microbial ɛ-PL. We summarized the strategies for the improvement of ɛ-PL producing strains, including physical and chemical mutagenesis, ribosome engineering and gene engineering, and compared the different metabolic regulation strategies for improving ɛ-PL production, including medium optimization, nutrient supply, pH control, and dissolved oxygen control. Then, the downstream purification methods of ɛ-PL and its recent applications in food and medicine industries were introduced. Finally, we also proposed the potential challenges and the perspectives for the production of ε-PL.
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Zong G, Fu J, Zhang P, Zhang W, Xu Y, Cao G, Zhang R. Use of elicitors to enhance or activate the antibiotic production in streptomyces. Crit Rev Biotechnol 2021; 42:1260-1283. [PMID: 34706600 DOI: 10.1080/07388551.2021.1987856] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Streptomyces is the largest and most significant genus of Actinobacteria, comprising 961 species. These Gram-positive bacteria produce many versatile and important bioactive compounds; of these, antibiotics, specifically the enhancement or activation of their production, have received extensive research attention. Recently, various biotic and abiotic elicitors have been reported to modify the antibiotic metabolism of Streptomyces, which promotes the production of new antibiotics and bioactive metabolites for improvement in the yields of endogenous products. However, some elicitors that obviously contribute to secondary metabolite production have not yet received sufficient attention. In this study, we have reviewed the functions and mechanisms of chemicals, novel microbial metabolic elicitors, microbial interactions, enzymes, enzyme inhibitors, environmental factors, and novel combination methods regarding antibiotic production in Streptomyces. This review has aimed to identify potentially valuable elicitors for stimulating the production of latent antibiotics or enhancing the synthesis of subsistent antibiotics in Streptomyces. Future applications and challenges in the discovery of new antibiotics and enhancement of existing antibiotic production using elicitors are discussed.
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Affiliation(s)
- Gongli Zong
- Key Laboratory of Industrial Biotechnology of Ministry of Education & School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China.,Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Jiafang Fu
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Peipei Zhang
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Wenchi Zhang
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yan Xu
- Key Laboratory of Industrial Biotechnology of Ministry of Education & School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
| | - Guangxiang Cao
- Biomedical Sciences College & Shandong Medicinal Biotechnology Centre, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Rongzhen Zhang
- Key Laboratory of Industrial Biotechnology of Ministry of Education & School of Biotechnology, Jiangnan University, Wuxi, Jiangsu, China
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Li Z, Tan H, Lu N, Zhang Z, Chang J. Enhanced ATP and antioxidant levels for cAMP biosynthesis by Arthrobacter sp. CCTCC 2013431 with polyphosphate addition. Biotechnol Lett 2021; 43:2223-2231. [PMID: 34676500 DOI: 10.1007/s10529-021-03197-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 10/13/2021] [Indexed: 01/10/2023]
Abstract
OBJECTIVES When citrate and pyruvate were utilized to strengthen ATP generation for high cAMP production, oxidative stress became more severe in cells resulting in lower cell viability and cAMP formation at the late fermentation phase. To further improve cAMP biosynthesis, the effects of polyphosphate on cAMP fermentation performance together with intracellular ATP and oxidation levels were investigated under high oxidative stress condition and then high efficient cAMP fermentation process based on polyphosphate and salvage synthesis was developed and studied. RESULTS With 2 g/L-broth sodium hexametaphosphate added at 24 h was determined as the optimal condition for cAMP production by Arthrobacter sp. CCTCC 2013431 in shake flasks. Under high oxidative stress condition caused by adding 15 mg/L-broth menadione, cAMP contents and cell viability were improved greatly due to hexametaphosphate addition and also exceeded those of control (without hexametaphosphate and menadione added) when fermentations were conducted in a 7 L bioreactor. Meanwhile, ATP levels and antioxidant capacity were improved obviously by hexametaphosphate as well. Moreover, a fermentation process with hexametaphosphate and hypoxanthine coupling added was developed by which cAMP concentration reached 7.25 g/L with an increment of 87.1% when compared with only hypoxanthine added batch and the high ROS contents generated from salvage synthesis were reduced significantly. CONCLUSION Polyphosphate could improve intracellular ATP levels and antioxidant capacity significantly under high oxidative stress condition resulting in enhanced cell viability and cAMP fermentation production no matter by de novo synthesis or salvage synthesis.
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Affiliation(s)
- Zhigang Li
- Collaborative Innovation Center of Modem Biological Breeding of Henan Province, Xinxiang, 453003, China.,School of Life Science and Technology, Henan Institute of Science and Technology, 90 Hualan Road, Xinxiang, 453003, Henan Province, China
| | - Hai Tan
- School of Life Science and Technology, Henan Institute of Science and Technology, 90 Hualan Road, Xinxiang, 453003, Henan Province, China
| | - Nanxun Lu
- School of Life Science and Technology, Henan Institute of Science and Technology, 90 Hualan Road, Xinxiang, 453003, Henan Province, China
| | - Zhonghua Zhang
- School of Life Science and Technology, Henan Institute of Science and Technology, 90 Hualan Road, Xinxiang, 453003, Henan Province, China
| | - Jingling Chang
- School of Life Science and Technology, Henan Institute of Science and Technology, 90 Hualan Road, Xinxiang, 453003, Henan Province, China.
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Wang L, Zhang C, Zhang J, Rao Z, Xu X, Mao Z, Chen X. Epsilon-poly-L-lysine: Recent Advances in Biomanufacturing and Applications. Front Bioeng Biotechnol 2021; 9:748976. [PMID: 34650962 PMCID: PMC8506220 DOI: 10.3389/fbioe.2021.748976] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 09/15/2021] [Indexed: 11/30/2022] Open
Abstract
ε-poly-L-lysine (ε-PL) is a naturally occurring poly(amino acid) of varying polymerization degree, which possesses excellent antimicrobial activity and has been widely used in food and pharmaceutical industries. To provide new perspectives from recent advances, this review compares several conventional and advanced strategies for the discovery of wild strains and development of high-producing strains, including isolation and culture-based traditional methods as well as genome mining and directed evolution. We also summarize process engineering approaches for improving production, including optimization of environmental conditions and utilization of industrial waste. Then, efficient downstream purification methods are described, including their drawbacks, followed by the brief introductions of proposed antimicrobial mechanisms of ε-PL and its recent applications. Finally, we discuss persistent challenges and future perspectives for the commercialization of ε-PL.
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Affiliation(s)
- Liang Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Chongyang Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Jianhua Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Zhiming Rao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xueming Xu
- School of Food Science and Technology, Jiangnan University, Wuxi, China
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Zhonggui Mao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | - Xusheng Chen
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
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Li S, Ji J, Hu S, Chen G. Enhancement of ε-poly-L-lysine production in Streptomyces griseofuscus by addition of exogenous astaxanthin. Bioprocess Biosyst Eng 2020; 43:1813-1821. [PMID: 32399749 DOI: 10.1007/s00449-020-02372-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 05/02/2020] [Indexed: 11/25/2022]
Abstract
Addition of exogenous astaxanthin for improving ε-poly-L-lysine (ε-PL) production in Streptomyces griseofuscus was investigated in this study. By this unique strategy, the ε-PL production in shaker-flask fermentation was 2.48 g/L, which was 67.5% higher than the control at the addition dosage of 1.0 g/L, owing to the oxidation resistance of astaxanthin. In fed-batch fermentation, the ε-PL production reached 36.1 g/L, a 36.3% increase compared to the control. Intracellular response for oxidation in S. griseofuscus such as ROS generation and lipid peroxidation was reduced by astaxanthin addition. Illumina RNA deep sequencing (RNA-seq) technology further revealed that S. griseofuscus with astaxanthin addition showed down-regulated transcriptions of genes involved in oxidative stress. This research proved that the beneficial effect of astaxanthin addition was far better than glutathione (GSH) owing to the stronger antioxidant capacity, and provided a novel approach to regulate ε-PL synthesis.
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Affiliation(s)
- Shu Li
- Marine College, Shandong University, Weihai, 264209, Shandong, China.
| | - Jinyi Ji
- Marine College, Shandong University, Weihai, 264209, Shandong, China
| | - Shengjie Hu
- Marine College, Shandong University, Weihai, 264209, Shandong, China
| | - Guanjun Chen
- Marine College, Shandong University, Weihai, 264209, Shandong, China
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