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Peng J, Xu W, Ni D, Zhang W, Zhang T, Guang C, Mu W. Preparation of a novel water-soluble gel from Erwinia amylovora levan. Int J Biol Macromol 2018; 122:469-478. [PMID: 30342147 DOI: 10.1016/j.ijbiomac.2018.10.093] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/01/2018] [Accepted: 10/14/2018] [Indexed: 02/04/2023]
Abstract
Less attention has been focused on the industrial applications of levan-type fructan than that of inulin. Levan-type fructan is a unique homopolysaccharide consisting of fructose residues with a β-(2, 6) linkage that possesses unique physiochemical properties such as low intrinsic viscosity. In this study, the recombinant levansucrase from Erwinia amylovora was used to efficiently produce levan from sucrose, and under optimised conditions, 195 g/L levan was produced from 500 g/L sucrose, with the highest conversion rate of 59%. The physicochemical properties of E. amylovora levan, such as surface morphology, thermal behaviour, rheology behaviour and texture analysis, were evaluated and compared with those of commercial gels, including xanthan, guar, carrageenan and Arabic gums. The produced E. amylovora levan showed a series of acceptable physicochemical properties, indicating a potential application for levan as a novel water-soluble micro gel. The conclusions of this study support the exploration of the use of more hydrogels in the food, medicinal and cosmetic industries.
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Affiliation(s)
- Jiaying Peng
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wei Xu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Dawei Ni
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wenli Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Tao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China
| | - Cuie Guang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China
| | - Wanmeng Mu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China.
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Bartho JD, Bellini D, Wuerges J, Demitri N, Toccafondi M, Schmitt AO, Zhao Y, Walsh MA, Benini S. The crystal structure of Erwinia amylovora AmyR, a member of the YbjN protein family, shows similarity to type III secretion chaperones but suggests different cellular functions. PLoS One 2017; 12:e0176049. [PMID: 28426806 PMCID: PMC5398634 DOI: 10.1371/journal.pone.0176049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 04/04/2017] [Indexed: 11/18/2022] Open
Abstract
AmyR is a stress and virulence associated protein from the plant pathogenic Enterobacteriaceae species Erwinia amylovora, and is a functionally conserved ortholog of YbjN from Escherichia coli. The crystal structure of E. amylovora AmyR reveals a class I type III secretion chaperone-like fold, despite the lack of sequence similarity between these two classes of protein and lacking any evidence of a secretion-associated role. The results indicate that AmyR, and YbjN proteins in general, function through protein-protein interactions without any enzymatic action. The YbjN proteins of Enterobacteriaceae show remarkably low sequence similarity with other members of the YbjN protein family in Eubacteria, yet a high level of structural conservation is observed. Across the YbjN protein family sequence conservation is limited to residues stabilising the protein core and dimerization interface, while interacting regions are only conserved between closely related species. This study presents the first structure of a YbjN protein from Enterobacteriaceae, the most highly divergent and well-studied subgroup of YbjN proteins, and an in-depth sequence and structural analysis of this important but poorly understood protein family.
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Affiliation(s)
- Joseph D. Bartho
- Bioorganic Chemistry and Bio-Crystallography laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, Bolzano, Italy
| | - Dom Bellini
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, United Kingdom
- Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, United Kingdom
| | - Jochen Wuerges
- Bioorganic Chemistry and Bio-Crystallography laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, Bolzano, Italy
| | - Nicola Demitri
- Elettra–Sincrotrone Trieste, S.S 14 km 163.5 in Area Science Park, Basovizza, Trieste, Italy
| | - Mirco Toccafondi
- Bioorganic Chemistry and Bio-Crystallography laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, Bolzano, Italy
| | - Armin O. Schmitt
- Bioorganic Chemistry and Bio-Crystallography laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, Bolzano, Italy
- Georg-August-Universität Göttingen, Dept. Nutztierwissenschaften, Breeding informatics, Margarethe von Wrangell-Weg 7, Göttingen, Germany
| | - Youfu Zhao
- Department of Crop Sciences, University of Illinois, 1201 W. Gregory Dr., Urbana, IL, United States of America
| | - Martin A. Walsh
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, United Kingdom
- Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, United Kingdom
| | - Stefano Benini
- Bioorganic Chemistry and Bio-Crystallography laboratory (B2Cl), Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, Bolzano, Italy
- * E-mail:
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Caputi L, Nepogodiev SA, Malnoy M, Rejzek M, Field RA, Benini S. Biomolecular characterization of the levansucrase of Erwinia amylovora, a promising biocatalyst for the synthesis of fructooligosaccharides. J Agric Food Chem 2013; 61:12265-12273. [PMID: 24274651 DOI: 10.1021/jf4023178] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Erwinia amylovora is a plant pathogen that affects Rosaceae, such as apple and pear. In E. amylovora the fructans, produced by the action of a levansucrase (EaLsc), play a role in virulence and biofilm formation. Fructans are bioactive compounds, displaying health-promoting properties in their own right. Their use as food and feed supplements is increasing. In this study, we investigated the biomolecular properties of EaLsc using HPAEC-PAD, MALDI-TOF MS, and spectrophotometric assays. The enzyme, which was heterologously expressed in Escherichia coli in high yield, was shown to produce mainly fructooligosaccharides (FOSs) with a degree of polymerization between 3 and 6. The kinetic properties of EaLsc were similar to those of other phylogenetically related Gram-negative bacteria, but the good yield of FOSs, the product spectrum, and the straightforward production of the enzyme suggest that EaLsc is an interesting biocatalyst for future studies aimed at producing tailor-made fructans.
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Affiliation(s)
- Lorenzo Caputi
- Laboratory of Bioorganic Chemistry and Crystallography, Faculty of Science and Technology, Free University of Bolzano , Piazza Università 5, 39100 Bolzano, Italy
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Schollmeyer M, Langlotz C, Huber A, Coplin DL, Geider K. Variations in the molecular masses of the capsular exopolysaccharides amylovoran, pyrifolan and stewartan. Int J Biol Macromol 2012; 50:518-22. [PMID: 22266385 DOI: 10.1016/j.ijbiomac.2012.01.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 12/30/2011] [Accepted: 01/07/2012] [Indexed: 11/19/2022]
Abstract
Erwinia amylovora, causing fire blight of apple, pear and some ornamentals, Erwinia pyrifoliae, causing Asian pear blight, and Pantoea stewartii, causing Stewart's wilt of sweet maize, synthesize capsular extracellular polysaccharides (EPSs) with a high molecular mass. The EPSs are virulence factors and form viscous aggregates, which participate in clogging vessels of infected plants and causing wilting. The sizes of EPSs produced under different environmental growth conditions were determined by analysis with large pore HPLC columns. Their molecular mass of ca. 5 MDa, when isolated from agar plates, decreases to ca. 1 MDa for E. amylovora amylovoran from freeze-dried supernatants from liquid cultures and to 2 MDa for freeze-dried preparations of P. stewartii stewartan. Size changes were also found following growth in various other media and for different strains. Stewartan, amylovoran and E. pyrifoliae pyrifolan were also shown to be completely degraded by a bacteriophage EPS depolymerase.
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Obradovic D, Kevresan S. Optimization of PCR in application of hot start Taq DNA polymerase for detection of Erwinia amylovora with primers FER1-F and FER1-R. Mikrobiologiia 2010; 79:819-823. [PMID: 21446634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
There are two approaches in detection of bacterium Erwinia amylovora by PCR. One is based on detection of plasmid pEA29 and the other is based on detection of a chromosomal DNA sequence, specific for E. amylovora, in a sample. Since pathogenic strains without pEA29 have been isolated from the environment, methods based on this plasmid have been compromised and PCR methods based on chromosomal DNA species specific sequences became only reliable methods. PCR method with chromosomal primers FER1-F and FER1-R is currently the most reliable method due to its high sensitivity and specificity. The goal of this research is to make a significant improvement of the method by optimization of PCR in application of hot start DNA Taq polymerase, instead of wax, to obtain a hot start reaction. This enzyme, which is currently widely applied, can provide simpler achievement of hot start, saving labor and time and decreasing possibility of cross contamination of samples. Experiments showed that simple replacement of a regular recombinant Taq DNA polymerase by a hot start Taq DNA polymerase leads to complete failure of the reaction. Many optimization experiments had to be carried out to obtain an operational and reliable PCR which simultaneously has high sensitivity and specificity. Content of the reaction mixture, as well as temperature and time parameters of PCR, were significantly changed to achieve proper optimization.
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Affiliation(s)
- D Obradovic
- University of Montenegro, Faculty of Science, Department of Biology, P. O. Box 211, 81000 Podgorica, Montenegro, Serbia.
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Oh CS, Carpenter SCD, Hayes ML, Beer SV. Secretion and translocation signals and DspB/F-binding domains in the type III effector DspA/E of Erwinia amylovora. Microbiology (Reading) 2010; 156:1211-1220. [PMID: 20110301 DOI: 10.1099/mic.0.027144-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2023]
Abstract
DspA/E is a type III effector of Erwinia amylovora, the bacterial pathogen that causes fire blight disease in roseaceous plants. This effector is indispensable for disease development, and it is translocated into plant cells. A DspA/E-specific chaperone, DspB/F, is necessary for DspA/E secretion and possibly for its translocation. In this work, DspB/F-binding sites and secretion and translocation signals in the DspA/E protein were determined. Based on yeast two-hybrid assays, DspB/F was found to bind DspA/E within the first 210 amino acids of the protein. Surprisingly, both DspB/F and OrfA, the putative chaperone of Eop1, also interacted with the C-terminal 1059 amino acids of DspA/E; this suggests another chaperone-binding site. Secretion and translocation assays using serial N-terminal lengths of DspA/E fused with the active form of AvrRpt2 revealed that at least the first 109 amino acids, including the first N-terminal chaperone-binding motif and DspB/F, were required for efficient translocation of DspA/E, although the first 35 amino acids were sufficient for its secretion and the presence of DspB/F was not required. These results indicate that secretion and translocation signals are present in the N terminus of DspA/E, and that at least one DspB/F-binding motif is required for efficient translocation into plant cells.
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Affiliation(s)
- Chang-Sik Oh
- Department of Plant Pathology and Plant Microbe-Biology, Cornell University, Ithaca, NY 14853, USA
| | - Sara C D Carpenter
- Department of Plant Pathology and Plant Microbe-Biology, Cornell University, Ithaca, NY 14853, USA
| | - Marshall L Hayes
- Department of Plant Pathology and Plant Microbe-Biology, Cornell University, Ithaca, NY 14853, USA
| | - Steven V Beer
- Department of Plant Pathology and Plant Microbe-Biology, Cornell University, Ithaca, NY 14853, USA
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Malnoy M, Faize M, Venisse JS, Geider K, Chevreau E. Expression of viral EPS-depolymerase reduces fire blight susceptibility in transgenic pear. Plant Cell Rep 2005; 23:632-8. [PMID: 15375629 DOI: 10.1007/s00299-004-0855-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Revised: 07/16/2004] [Accepted: 07/16/2004] [Indexed: 05/12/2023]
Abstract
Erwinia amylovora is the causal agent of fire blight of Maloideae. One of the main pathogenicity factors of this bacterium is the exopolysaccharide (EPS) of its capsule. In this paper, we used genetic transformation tools to constitutively express an EPS-depolymerase transgene in the pear (Pyrus communis L.) cv. Passe Crassane with the aim of decreasing its high susceptibility to fire blight. Expression of the depolymerase gene in 15 independent transgenic clones led, on average, to low depolymerase activity, although relatively high expression was observed at the transcriptional and translational levels. Only two of the transgenic clones (9X and 10M) consistently showed a decrease in fire blight susceptibility in vitro and in the greenhouse. These clones were also among the highest expressers of depolymerase at the RNA and enzyme activity levels. The correlation observed among all transgenic clones between depolymerase expression and fire blight resistance suggested the potential of this strategy.
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Affiliation(s)
- Mickaël Malnoy
- UMR Génétique et Horticulture (INRA/INH/UA), 42 rue Georges Morel, BP60057, 49071, Beaucouzé cedex, France
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