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Tiemblo-Martín M, Pistorio V, Saake P, Mahdi L, Campanero-Rhodes MA, Di Girolamo R, Di Carluccio C, Marchetti R, Molinaro A, Solís D, Zuccaro A, Silipo A. Structure and properties of the exopolysaccharide isolated from Flavobacterium sp. Root935. Carbohydr Polym 2024; 343:122433. [PMID: 39174078 DOI: 10.1016/j.carbpol.2024.122433] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Revised: 06/21/2024] [Accepted: 06/24/2024] [Indexed: 08/24/2024]
Abstract
Flavobacterium strains exert a substantial influence on roots and leaves of plants. However, there is still limited understanding of how the specific interactions between Flavobacterium and their plant hosts are and how these bacteria thrive in this competitive environment. A crucial step in understanding Flavobacterium - plant interactions is to unravel the structure of bacterial envelope components and the molecular features that facilitate initial contact with the host environment. Here, we have revealed structure and properties of the exopolysaccharides (EPS) produced by Flavobacterium sp. Root935. Chemical analyses revealed a complex and interesting branched heptasaccharidic repeating unit, containing a variety of sugar moieties, including Rha, Fuc, GlcN, Fuc4N, Gal, Man and QuiN and an important and extended substitution pattern, including acetyl and lactyl groups. Additionally, conformational analysis using molecular dynamics simulation showed an extended hydrophobic interface and a distinctly elongated, left-handed helicoidal arrangement. Furthermore, properties of the saccharide chain, and likely the huge substitution pattern prevented interaction and recognition by host lectins and possessed a low immunogenic potential, highlighting a potential role of Flavobacterium sp. Root935 in plant-microbial crosstalk.
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Affiliation(s)
- Marta Tiemblo-Martín
- Department of Chemical Sciences and Task Force for Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Valeria Pistorio
- Department of Chemical Sciences and Task Force for Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Pia Saake
- University of Cologne Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, D-50674 Cologne, Germany
| | - Lisa Mahdi
- University of Cologne Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, D-50674 Cologne, Germany
| | - María Asunción Campanero-Rhodes
- Instituto de Química Física Blas Cabrera, CSIC, Serrano 119, 28006 Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Avda Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Rocco Di Girolamo
- Department of Chemical Sciences and Task Force for Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Cristina Di Carluccio
- Department of Chemical Sciences and Task Force for Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Roberta Marchetti
- Department of Chemical Sciences and Task Force for Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Antonio Molinaro
- Department of Chemical Sciences and Task Force for Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy
| | - Dolores Solís
- Instituto de Química Física Blas Cabrera, CSIC, Serrano 119, 28006 Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Avda Monforte de Lemos 3-5, 28029 Madrid, Spain
| | - Alga Zuccaro
- University of Cologne Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, D-50674 Cologne, Germany
| | - Alba Silipo
- Department of Chemical Sciences and Task Force for Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy.
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Yang L, Zhu X, Chen Y, Wang J. Enhanced bacterial cellulose production in Gluconacetobacter xylinus by overexpression of two genes (bscC and bcsD) and a modified static culture. Int J Biol Macromol 2024; 260:129552. [PMID: 38242407 DOI: 10.1016/j.ijbiomac.2024.129552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/09/2024] [Accepted: 01/15/2024] [Indexed: 01/21/2024]
Abstract
Bacterial cellulose (BC), a nanostructured material, is renowned for its excellent properties. However, its production by bacteria is costly due to low medium utilization and conversion rates. To enhance the yield of BC, this study aimed to increase BC yield through genetic modification, specifically by overexpressing bcsC and bcsD in Gluconacetobacter xylinus, and by developing a modified culture method to reduce medium viscosity by adding water during fermentation. As a result, BC yields of 5.4, 6.2, and 6.8 g/L were achieved from strains overexpressing genes bcsC, bcsD, and bcsCD, significantly surpassing the yield of 2.2 g/L from wild-type (WT) strains. In the modified culture, the BC yields of all four strains increased by >1 g/L with the addition of 20 mL of water during fermentation. Upon comparing the properties of BC, minimal differences were observed between the WT and pbcsC strains, as well as between the static and modified cultures. In contrast, BC produced by strains overexpressing bcsD had a denser microstructural network and exhibited demonstrated higher tensile strength and elongation-to-break. Compared to WT, BC from bcsD overexpressed strains also displayed enhanced crystallinity, higher degree of polymerization and improved thermal stability.
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Affiliation(s)
- Leyun Yang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China.
| | - Xinxin Zhu
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China
| | - Yong Chen
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China
| | - Jun Wang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100, China; Key Laboratory of Silkworm and Mulberry Genetic Improvement, Ministry of Agriculture and Rural Affairs, The Sericultural Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100, China
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Ramírez-Parra E, De la Rosa L. Designing Novel Strategies for Improving Old Legumes: An Overview from Common Vetch. PLANTS (BASEL, SWITZERLAND) 2023; 12:1275. [PMID: 36986962 PMCID: PMC10058852 DOI: 10.3390/plants12061275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 06/19/2023]
Abstract
Common vetch (Vicia sativa L.) is a grain legume used in animal feeding, rich in protein content, fatty acid, and mineral composition that makes for a very adequate component to enrich feedstuff. In addition, relevant pharmacological properties have been reported in humans. The common vetch, similar to other legumes, can fix atmospheric nitrogen, a crucial feature for sustainable agricultural systems. These properties enhance the use of vetch as a cover crop and its sowing in intercropping systems. Moreover, several studies have recently pointed out the potential of vetch in the phytoremediation of contaminated soils. These characteristics make vetch a relevant crop, which different potential improvements target. Varieties with different yields, flowering times, shattering resistance, nutritional composition, rhizobacteria associations, drought tolerance, nitrogen fixation capacity, and other agronomic-relevant traits have been identified when different vetch accessions are compared. Recently, the analysis of genomic and transcriptomic data has allowed the development of different molecular markers to be used for assisted breeding purposes, promoting crop improvement. Here, we review the potential of using the variability of V. sativa genetic resources and new biotechnological and molecular tools for selecting varieties with improved traits to be used in sustainable agriculture systems.
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Affiliation(s)
- Elena Ramírez-Parra
- Centro de Biotecnología y Genómica de Plantas, (CBGP, UPM-INIA/CSIC) Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas, Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Lucía De la Rosa
- Centro de Recursos Fitogenéticos, (CRF-INIA/CSIC) Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Consejo Superior de Investigaciones Científicas, Alcalá de Henares, 28805 Madrid, Spain
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Identification of an Exopolysaccharide Biosynthesis Gene in Bradyrhizobium diazoefficiens USDA110. Microorganisms 2021; 9:microorganisms9122490. [PMID: 34946092 PMCID: PMC8707904 DOI: 10.3390/microorganisms9122490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/24/2021] [Accepted: 11/25/2021] [Indexed: 01/27/2023] Open
Abstract
Exopolysaccharides (EPS) play critical roles in rhizobium-plant interactions. However, the EPS biosynthesis pathway in Bradyrhizobium diazoefficiens USDA110 remains elusive. Here we used transposon (Tn) mutagenesis with the aim to identify genetic elements required for EPS biosynthesis in B. diazoefficiens USDA110. Phenotypic screening of Tn5 insertion mutants grown on agar plates led to the identification of a mutant with a transposon insertion site in the blr2358 gene. This gene is predicted to encode a phosphor-glycosyltransferase that transfers a phosphosugar onto a polyprenol phosphate substrate. The disruption of the blr2358 gene resulted in defective EPS synthesis. Accordingly, the blr2358 mutant showed a reduced capacity to induce nodules and stimulate the growth of soybean plants. Glycosyltransferase genes related to blr2358 were found to be well conserved and widely distributed among strains of the Bradyrhizobium genus. In conclusion, our study resulted in identification of a gene involved in EPS biosynthesis and highlights the importance of EPS in the symbiotic interaction between USDA110 and soybeans.
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Simunović V. Genomic and molecular evidence reveals novel pathways associated with cell surface polysaccharides in bacteria. FEMS Microbiol Ecol 2021; 97:6355432. [PMID: 34415013 DOI: 10.1093/femsec/fiab119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/18/2021] [Indexed: 11/13/2022] Open
Abstract
Amino acid (acyl carrier protein) ligases (AALs) are a relatively new family of bacterial amino acid adenylating enzymes with unknown function(s). Here, genomic enzymology tools that employ sequence similarity networks and genome context analyses were used to hypothesize the metabolic function(s) of AALs. In over 50% of species, aal and its cognate acyl carrier protein (acp) genes, along with three more genes, formed a highly conserved AAL cassette. AAL cassettes were strongly associated with surface polysaccharide gene clusters in Proteobacteria and Actinobacteria, yet were prevalent among soil and rhizosphere-associated α- and β-Proteobacteria, including symbiotic α- and β-rhizobia and some Mycolata. Based on these associations, AAL cassettes were proposed to encode a noncanonical Acp-dependent polysaccharide modification route. Genomic-inferred predictions were substantiated by published experimental evidence, revealing a role for AAL cassettes in biosynthesis of biofilm-forming exopolysaccharide in pathogenic Burkholderia and expression of aal and acp genes in nitrogen-fixing Rhizobium bacteroids. Aal and acp genes were associated with dltBD-like homologs that modify cell wall teichoic acids with d-alanine, including in Paenibacillus and certain other bacteria. Characterization of pathways that involve AAL and Acp may lead to developing new plant and human disease-controlling agents as well as strains with improved nitrogen fixation capacity.
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Krol E, Schäper S, Becker A. Cyclic di-GMP signaling controlling the free-living lifestyle of alpha-proteobacterial rhizobia. Biol Chem 2021; 401:1335-1348. [PMID: 32990642 DOI: 10.1515/hsz-2020-0232] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 09/14/2020] [Indexed: 12/12/2022]
Abstract
Cyclic-di-GMP (c-di-GMP) is a ubiquitous bacterial second messenger which has been associated with a motile to sessile lifestyle switch in many bacteria. Here, we review recent insights into c-di-GMP regulated processes related to environmental adaptations in alphaproteobacterial rhizobia, which are diazotrophic bacteria capable of fixing nitrogen in symbiosis with their leguminous host plants. The review centers on Sinorhizobium meliloti, which in the recent years was intensively studied for its c-di-GMP regulatory network.
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Affiliation(s)
- Elizaveta Krol
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, D-35032 Marburg, Germany.,Department of Biology, Philipps-Universität Marburg, D-35032 Marburg, Germany
| | - Simon Schäper
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, D-35032 Marburg, Germany
| | - Anke Becker
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, D-35032 Marburg, Germany.,Department of Biology, Philipps-Universität Marburg, D-35032 Marburg, Germany
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7
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Computational characterizations of GDP-mannose 4,6-dehydratase (NoeL) Rhizobial proteins. Curr Genet 2021; 67:769-784. [PMID: 33837815 DOI: 10.1007/s00294-021-01184-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/19/2021] [Accepted: 03/29/2021] [Indexed: 10/21/2022]
Abstract
A growing body of evidence suggests that Nod Factors molecules are the critical structural components in nitrogen fixation. These molecules have been implicated in plant-microbe signaling. Many enzymes involved in Nod factors biosynthesis; however, the enzymes that decorate (modify) nod factor main structure play a vital role. Here, the computational analysis of GDP-mannose 4,6-dehydratase (NoeL) proteins with great impact in modification of nod factor structure in four genomes of agriculturally important rhizobia (Bradyrhizobium, Mesorhizobium, Rhizobium, Sinorhizobium) presented. The NoeL number of amino acids was in the range of 147 (M5AMF5) to 372 (A0A023XWX0, Q89TZ1). The molecular weights were around 41 KDa. The results showed that the strain-specific purification strategy should apply as the pI of the sequences varied significantly (in the range of 5.59 to 9.12). The enzyme sequences and eight 3-dimensional structures predicted with homology modeling and machine learning representing the phylogenetic tree revealed the stability of enzymes in different conditions (Instability and Aliphatic index); however, this stability is also strain-specific. Disulphide bonds were observed in some species; however, the pattern was not detected in all members of the same species. Alpha helix was the dominant secondary structure predicted in all cytoplasmic NoeL. All models were homo-tetramer with acceptable sequence identity, GMEAN and coverage (60, - 1.80, 88, respectively). Additionally, Ramachandran maps showed that more than 94% of residues are in favored regions. We also highlight several key characterizations of NoeL from four rhizobia genomes annotation. These findings provide novel insights into the complexity and diversity of NoeL enzymes among important rhizobia and suggest considering a broader framework of biofilm for future research.
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8
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Wanke A, Malisic M, Wawra S, Zuccaro A. Unraveling the sugar code: the role of microbial extracellular glycans in plant-microbe interactions. JOURNAL OF EXPERIMENTAL BOTANY 2021; 72:15-35. [PMID: 32929496 PMCID: PMC7816849 DOI: 10.1093/jxb/eraa414] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 09/14/2020] [Indexed: 05/14/2023]
Abstract
To defend against microbial invaders but also to establish symbiotic programs, plants need to detect the presence of microbes through the perception of molecular signatures characteristic of a whole class of microbes. Among these molecular signatures, extracellular glycans represent a structurally complex and diverse group of biomolecules that has a pivotal role in the molecular dialog between plants and microbes. Secreted glycans and glycoconjugates such as symbiotic lipochitooligosaccharides or immunosuppressive cyclic β-glucans act as microbial messengers that prepare the ground for host colonization. On the other hand, microbial cell surface glycans are important indicators of microbial presence. They are conserved structures normally exposed and thus accessible for plant hydrolytic enzymes and cell surface receptor proteins. While the immunogenic potential of bacterial cell surface glycoconjugates such as lipopolysaccharides and peptidoglycan has been intensively studied in the past years, perception of cell surface glycans from filamentous microbes such as fungi or oomycetes is still largely unexplored. To date, only few studies have focused on the role of fungal-derived cell surface glycans other than chitin, highlighting a knowledge gap that needs to be addressed. The objective of this review is to give an overview on the biological functions and perception of microbial extracellular glycans, primarily focusing on their recognition and their contribution to plant-microbe interactions.
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Affiliation(s)
- Alan Wanke
- University of Cologne, Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, Cologne, Germany
- Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Milena Malisic
- University of Cologne, Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, Cologne, Germany
| | - Stephan Wawra
- University of Cologne, Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, Cologne, Germany
| | - Alga Zuccaro
- University of Cologne, Cluster of Excellence on Plant Sciences (CEPLAS), Institute for Plant Sciences, Cologne, Germany
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Velichko NS, Grinev VS, Fedonenko YP. Characterization of biopolymers produced by planktonic and biofilm cells of Herbaspirillum lusitanum P6-12. J Appl Microbiol 2020; 129:1349-1363. [PMID: 32216024 DOI: 10.1111/jam.14647] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 01/31/2020] [Accepted: 03/20/2020] [Indexed: 11/30/2022]
Abstract
AIMS The goal of this study was to characterize biopolymers from two modes of the Herbaspirillum lusitanum P6-12 growth: planktonic, in which cells are free swimming, and biofilm life style, in which the cells are sessile. METHODS AND RESULTS Differences in biopolymers composition from planktonic and biofilm cells of H. lusitanum strain P6-12 were analysed using Fourier transform infrared spectroscopy (FTIR), sodium dodecyl sulphate-polyacrylamide gel electrophoresis, gas-liquid chromatography and spectrophotometry. A high degree of polymer separation and purification was achieved by ultracentrifugation, and column chromatography allowed us to identify the chemical differences between biopolymers from biofilm and planktonic H. lusitanum. It was shown that planktonic cells of H. lusitanum P6-12 when cultivated in a liquid medium to the end of the exponential phase of growth, produced two high-molecular-weight glycoconjugates (were arbitrarily called CPS-I and CPS-II) of a lipopolysaccharide (LPS) nature and a lipid-polysacharide complex (were arbitrarily called EPS). The EPS, CPS-I, CPS-II had different monosaccharide and lipid compositions. The extracellular polymeric matrix (EPM) produced by the biofilm cells was mostly proteinaceous, with a small amount of carbohydrates (up to 3%). From the biofilm culture medium, a free extracellular polymeric substance (was arbitrarily called fEPS) was obtained that contained proteins and carbohydrates (up to 7%). The cells outside the biofilm had capsules containing high-molecular-weight glycoconjugate (was arbitrarily called CPSFBC ) that consisted of carbohydrates (up to 10%), proteins (up to 16%) and lipids (up to 70%). CONCLUSIONS During biofilm formation, the bacteria secreted surface biopolymers that differed from those of the planktonic cells. The heterogeneity of the polysaccharide containing biopolymers of the H. lusitanum P6-12 surface is probably conditioned by their different functions in plant colonization and formation of an efficient symbiosis, as well as in cell adaptation to existence in plant tissues. SIGNIFICANCE AND IMPACT OF THE STUDY The results of the study permit a better understanding of the physiological properties of the biopolymers, for example, in plant-microbe interactions.
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Affiliation(s)
- N S Velichko
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov, Russia
| | - V S Grinev
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov, Russia
| | - Y P Fedonenko
- Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, Saratov, Russia
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Eida AA, Bougouffa S, L’Haridon F, Alam I, Weisskopf L, Bajic VB, Saad MM, Hirt H. Genome Insights of the Plant-Growth Promoting Bacterium Cronobacter muytjensii JZ38 With Volatile-Mediated Antagonistic Activity Against Phytophthora infestans. Front Microbiol 2020; 11:369. [PMID: 32218777 PMCID: PMC7078163 DOI: 10.3389/fmicb.2020.00369] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 02/19/2020] [Indexed: 12/12/2022] Open
Abstract
Salinity stress is a major challenge to agricultural productivity and global food security in light of a dramatic increase of human population and climate change. Plant growth promoting bacteria can be used as an additional solution to traditional crop breeding and genetic engineering. In the present work, the induction of plant salt tolerance by the desert plant endophyte Cronobacter sp. JZ38 was examined on the model plant Arabidopsis thaliana using different inoculation methods. JZ38 promoted plant growth under salinity stress via contact and emission of volatile compounds. Based on the 16S rRNA and whole genome phylogenetic analysis, fatty acid analysis and phenotypic identification, JZ38 was identified as Cronobacter muytjensii and clearly separated and differentiated from the pathogenic C. sakazakii. Full genome sequencing showed that JZ38 is composed of one chromosome and two plasmids. Bioinformatic analysis and bioassays revealed that JZ38 can grow under a range of abiotic stresses. JZ38 interaction with plants is correlated with an extensive set of genes involved in chemotaxis and motility. The presence of genes for plant nutrient acquisition and phytohormone production could explain the ability of JZ38 to colonize plants and sustain plant growth under stress conditions. Gas chromatography-mass spectrometry analysis of volatiles produced by JZ38 revealed the emission of indole and different sulfur volatile compounds that may play a role in contactless plant growth promotion and antagonistic activity against pathogenic microbes. Indeed, JZ38 was able to inhibit the growth of two strains of the phytopathogenic oomycete Phytophthora infestans via volatile emission. Genetic, transcriptomic and metabolomics analyses, combined with more in vitro assays will provide a better understanding the highlighted genes' involvement in JZ38's functional potential and its interaction with plants. Nevertheless, these results provide insight into the bioactivity of C. muytjensii JZ38 as a multi-stress tolerance promoting bacterium with a potential use in agriculture.
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Affiliation(s)
- Abdul Aziz Eida
- DARWIN21, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Salim Bougouffa
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- BioScience Core Lab, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | | | - Intikhab Alam
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Laure Weisskopf
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Vladimir B. Bajic
- Computational Bioscience Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Maged M. Saad
- DARWIN21, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Heribert Hirt
- DARWIN21, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
- Max F. Perutz Laboratories, University of Vienna, Vienna, Austria
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11
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Caneschi WL, Sanchez AB, Felestrino ÉB, Lemes CGDC, Cordeiro IF, Fonseca NP, Villa MM, Vieira IT, Moraes LÂG, Assis RDAB, do Carmo FF, Kamino LHY, Silva RS, Ferro JA, Ferro MIT, Ferreira RM, Santos VL, Silva UDCM, Almeida NF, Varani ADM, Garcia CCM, Setubal JC, Moreira LM. Serratia liquefaciens FG3 isolated from a metallophyte plant sheds light on the evolution and mechanisms of adaptive traits in extreme environments. Sci Rep 2019; 9:18006. [PMID: 31784663 PMCID: PMC6884506 DOI: 10.1038/s41598-019-54601-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 10/31/2019] [Indexed: 12/02/2022] Open
Abstract
Serratia liquefaciens strain FG3 (SlFG3), isolated from the flower of Stachytarpheta glabra in the Brazilian ferruginous fields, has distinctive genomic, adaptive, and biotechnological potential. Herein, using a combination of genomics and molecular approaches, we unlocked the evolution of the adaptive traits acquired by S1FG3, which exhibits the second largest chromosome containing the largest conjugative plasmids described for Serratia. Comparative analysis revealed the presence of 18 genomic islands and 311 unique protein families involved in distinct adaptive features. S1FG3 has a diversified repertoire of genes associated with Nonribosomal peptides (NRPs/PKS), a complete and functional cluster related to cellulose synthesis, and an extensive and functional repertoire of oxidative metabolism genes. In addition, S1FG3 possesses a complete pathway related to protocatecuate and chloroaromatic degradation, and a complete repertoire of genes related to DNA repair and protection that includes mechanisms related to UV light tolerance, redox process resistance, and a laterally acquired capacity to protect DNA using phosphorothioation. These findings summarize that SlFG3 is well-adapted to different biotic and abiotic stress situations imposed by extreme conditions associated with ferruginous fields, unlocking the impact of the lateral gene transfer to adjust the genome for extreme environments, and providing insight into the evolution of prokaryotes.
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Affiliation(s)
- Washington Luiz Caneschi
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | - Angélica Bianchini Sanchez
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | - Érica Barbosa Felestrino
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | | | - Isabella Ferreira Cordeiro
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | - Natasha Peixoto Fonseca
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | - Morghana Marina Villa
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | - Izadora Tabuso Vieira
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | - Lauro Ângelo Gonçalves Moraes
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | | | | | | | - Robson Soares Silva
- Faculdade de Computação (FACOM), Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Jesus Aparecido Ferro
- Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Universidade Estadual Paulista, Departamento de Tecnologia, SP, Brazil
| | - Maria Inês Tiraboschi Ferro
- Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Universidade Estadual Paulista, Departamento de Tecnologia, SP, Brazil
| | - Rafael Marini Ferreira
- Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Universidade Estadual Paulista, Departamento de Tecnologia, SP, Brazil
| | - Vera Lúcia Santos
- Departamento de Microbiologia, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | | | - Nalvo Franco Almeida
- Faculdade de Computação (FACOM), Universidade Federal de Mato Grosso do Sul, Campo Grande, MS, Brazil
| | - Alessandro de Mello Varani
- Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal, UNESP - Universidade Estadual Paulista, Departamento de Tecnologia, SP, Brazil
| | - Camila Carrião Machado Garcia
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
- Departamento de Ciências Biológicas (DECBI), Instituto de Ciências Exatas e Biológicas (ICEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | - João Carlos Setubal
- Departamento de Bioquímica (DB), Instituto de Química (IQ), Universidade de São Paulo (USP), São Paulo, SP, Brazil
- Biocomplexity Institute, Virginia Tech, Blacksburg, VA, USA
| | - Leandro Marcio Moreira
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil.
- Departamento de Ciências Biológicas (DECBI), Instituto de Ciências Exatas e Biológicas (ICEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil.
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12
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Bio-enzymes for inhibition and elimination of Escherichia coli O157:H7 biofilm and their synergistic effect with sodium hypochlorite. Sci Rep 2019; 9:9920. [PMID: 31289312 PMCID: PMC6616338 DOI: 10.1038/s41598-019-46363-w] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 06/21/2019] [Indexed: 12/17/2022] Open
Abstract
Escherichia coli O157:H7 is one of the most important pathogens worldwide. In this study, three different kinds of enzymes, DNase I, proteinase K and cellulase were evaluated for inhibitory or degrading activity against E. coli O157:H7 biofilm by targeting extracellular DNA, proteins, and cellulose, respectively. The cell number of biofilms formed under proteinase K resulted in a 2.43 log CFU/cm2 reduction with an additional synergistic 3.72 log CFU/cm2 reduction after NaClO post-treatment, while no significant reduction occurred with NaClO treatment alone. It suggests that protein degradation could be a good way to control the biofilm effectively. In preformed biofilms, all enzymes showed a significant reduction of 16.4–36.7% in biofilm matrix in 10-fold diluted media (p < 0.05). The sequential treatment with proteinase K, cellulase, and NaClO showed a significantly higher synergistic inactivation of 2.83 log CFU/cm2 compared to 1.58 log CFU/cm2 in the sequence of cellulase, proteinase K, and NaClO (p < 0.05). It suggests that the sequence of multiple enzymes can make a significant difference in the susceptibility of biofilms to NaClO. This study indicates that the combination of extracellular polymeric substance-degrading enzymes with NaClO could be useful for the efficient control of E. coli O157:H7 biofilms.
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13
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Lorite MJ, Estrella MJ, Escaray FJ, Sannazzaro A, Videira e Castro IM, Monza J, Sanjuán J, León-Barrios M. The Rhizobia- Lotus Symbioses: Deeply Specific and Widely Diverse. Front Microbiol 2018; 9:2055. [PMID: 30258414 PMCID: PMC6144797 DOI: 10.3389/fmicb.2018.02055] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/13/2018] [Indexed: 11/13/2022] Open
Abstract
The symbiosis between Lotus and rhizobia has been long considered very specific and only two bacterial species were recognized as the microsymbionts of Lotus: Mesorhizobium loti was considered the typical rhizobia for the L. corniculatus complex, whereas Bradyrhizobium sp. (Lotus) was the symbiont for L. uliginosus and related species. As discussed in this review, this situation has dramatically changed during the last 15 years, with the characterization of nodule bacteria from worldwide geographical locations and from previously unexplored Lotus spp. Current data support that the Lotus rhizobia are dispersed amongst nearly 20 species in five genera (Mesorhizobium, Bradyrhizobium, Rhizobium, Ensifer, and Aminobacter). As a consequence, M. loti could be regarded an infrequent symbiont of Lotus, and several plant-bacteria compatibility groups can be envisaged. Despite the great progress achieved with the model L. japonicus in understanding the establishment and functionality of the symbiosis, the genetic and biochemical bases governing the stringent host-bacteria compatibility pairships within the genus Lotus await to be uncovered. Several Lotus spp. are grown for forage, and inoculation with rhizobia is a common practice in various countries. However, the great diversity of the Lotus rhizobia is likely squandered, as only few bacterial strains are used as inoculants for Lotus pastures in very different geographical locations, with a great variety of edaphic and climatic conditions. The agroecological potential of the genus Lotus can not be fully harnessed without acknowledging the great diversity of rhizobia-Lotus interactions, along with a better understanding of the specific plant and bacterial requirements for optimal symbiotic nitrogen fixation under increasingly constrained environmental conditions.
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Affiliation(s)
- María J. Lorite
- Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - María J. Estrella
- Instituto Tecnológico de Chascomús, IIB-INTECH, UNSAM-CONICET, Chascomús, Argentina
| | - Francisco J. Escaray
- Instituto Tecnológico de Chascomús, IIB-INTECH, UNSAM-CONICET, Chascomús, Argentina
| | - Analía Sannazzaro
- Instituto Tecnológico de Chascomús, IIB-INTECH, UNSAM-CONICET, Chascomús, Argentina
| | | | - Jorge Monza
- Facultad de Agronomia, Universidad de la República, Montevideo, Uruguay
| | - Juan Sanjuán
- Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Granada, Spain
| | - Milagros León-Barrios
- Departamento de Bioquímica, Microbiología, Biología Celular y Genética, Universidad de la Laguna, Santa Cruz de Tenerife, Spain
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14
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Gómez-Aldapa CA, Rangel-Vargas E, Torres-Vitela MR, Villarruel-López A, Acevedo-Sandoval OA, Gordillo-Martínez AJ, Godínez-Oviedo A, Castro-Rosas J. Antibacterial Activities of Hibiscus sabdariffa Extracts and Chemical Sanitizers Directly on Green Leaves Contaminated with Foodborne Pathogens. J Food Prot 2018; 81:209-217. [PMID: 29320233 DOI: 10.4315/0362-028x.jfp-17-053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Leafy greens have been associated with foodborne disease outbreaks in different countries. To decrease microbial contamination of leafy greens, chemical agents are commonly used; however, a number of studies have shown these agents to have limited antimicrobial effect against pathogenic bacteria on vegetables. The objective of this study was to compare the antibacterial effect of Hibiscus sabdariffa calyx extracts (water, methanol, acetone, and ethyl acetate), sodium hypochlorite, acetic acid, and colloidal silver against foodborne bacteria on leafy greens. Thirteen foodborne bacteria were used in the study: Listeria monocytogenes, Shigella flexneri, Salmonella serotypes Typhimurium Typhi, and Montevideo, Staphylococcus aureus, Escherichia coli O157:H7, five E. coli pathotypes (Shiga toxin-producing, enteropathogenic, enterotoxigenic, enteroinvasive, and enteroaggregative), and Vibrio cholerae O1. Each foodborne bacterium was separately inoculated on romaine lettuce, spinach, and coriander leaves. Separately, contaminated leafy greens were immersed in four hibiscus extracts and in sanitizers for 5 min. Next, green leaves were washed with sterile tap water. Separately, each green leaf was placed in a bag that contained 0.1% sterile peptone water and was rubbed for 2 min. Counts were done by plate count using appropriate dilutions (in sterile peptone water) of the bacterial suspensions spread on Trypticase soy agar plates and incubated at 35 ± 2°C for 48 h. Statistically significant differences ( P < 0.05) were calculated with an analysis of variance and Duncan's test. All 13 foodborne bacteria attached to leafy greens. Roselle calyx extracts caused a significantly greater reduction ( P < 0.05) in concentration of all foodborne bacteria on contaminated romaine lettuce, spinach, and coriander than did the sodium hypochlorite, colloidal silver, and acetic acid. Dry roselle calyx extracts may potentially be a useful addition to disinfection procedures for romaine lettuce, spinach, and coriander.
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Affiliation(s)
- Carlos A Gómez-Aldapa
- 1 Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Carretera Pachuca-Tulancingo kilometro 4.5, 42183 Mineral de la Reforma, Hidalgo, México
| | - Esmeralda Rangel-Vargas
- 1 Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Carretera Pachuca-Tulancingo kilometro 4.5, 42183 Mineral de la Reforma, Hidalgo, México
| | - Ma Refugio Torres-Vitela
- 2 Laboratorio de Microbiología Sanitaria, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Marcelino García Barragán no. 1421, 44430, Guadalajara, Jalisco, México; and
| | - Angélica Villarruel-López
- 2 Laboratorio de Microbiología Sanitaria, Centro Universitario de Ciencias Exactas e Ingenierías, Universidad de Guadalajara, Marcelino García Barragán no. 1421, 44430, Guadalajara, Jalisco, México; and
| | - Otilio A Acevedo-Sandoval
- 3 Instituto de Ciencias Agropecuarias, Rancho Universitario, UAEH, Avenida Universidad kilometro 1, Ex Hacienda Aquetzalpa, Apartado Postal no. 32, Tulancingo, Hidalgo, México
| | - Alberto J Gordillo-Martínez
- 1 Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Carretera Pachuca-Tulancingo kilometro 4.5, 42183 Mineral de la Reforma, Hidalgo, México
| | - Angélica Godínez-Oviedo
- 3 Instituto de Ciencias Agropecuarias, Rancho Universitario, UAEH, Avenida Universidad kilometro 1, Ex Hacienda Aquetzalpa, Apartado Postal no. 32, Tulancingo, Hidalgo, México
| | - Javier Castro-Rosas
- 1 Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH), Carretera Pachuca-Tulancingo kilometro 4.5, 42183 Mineral de la Reforma, Hidalgo, México
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15
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Abstract
Rhizobia are some of the best-studied plant microbiota. These oligotrophic Alphaproteobacteria or Betaproteobacteria form symbioses with their legume hosts. Rhizobia must exist in soil and compete with other members of the microbiota before infecting legumes and forming N2-fixing bacteroids. These dramatic lifestyle and developmental changes are underpinned by large genomes and even more complex pan-genomes, which encompass the whole population and are subject to rapid genetic exchange. The ability to respond to plant signals and chemoattractants and to colonize nutrient-rich roots are crucial for the competitive success of these bacteria. The availability of a large body of genomic, physiological, biochemical and ecological studies makes rhizobia unique models for investigating community interactions and plant colonization.
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16
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Gómez‐Aldapa CA, Portillo‐Torres LA, Villagómez‐Ibarra JR, Rangel‐Vargas E, Téllez‐Jurado A, Cruz‐Gálvez AM, Castro‐Rosas J. Survival of foodborne bacteria on strawberries and antibacterial activities of
Hibiscus sabdariffa
extracts and chemical sanitizers on strawberries. J Food Saf 2017. [DOI: 10.1111/jfs.12378] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Carlos A. Gómez‐Aldapa
- Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH)Carretera Pachuca‐Tulancingo Km. 4.5, C.P. 42183 Mineral de la Reforma, Hidalgo México
| | - Lizbeth A. Portillo‐Torres
- Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH)Carretera Pachuca‐Tulancingo Km. 4.5, C.P. 42183 Mineral de la Reforma, Hidalgo México
| | - José R. Villagómez‐Ibarra
- Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH)Carretera Pachuca‐Tulancingo Km. 4.5, C.P. 42183 Mineral de la Reforma, Hidalgo México
| | - Esmeralda Rangel‐Vargas
- Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH)Carretera Pachuca‐Tulancingo Km. 4.5, C.P. 42183 Mineral de la Reforma, Hidalgo México
| | - Alejandro Téllez‐Jurado
- Universidad Politécnica de PachucaCarretera Pachuca–Cd. Sahagún Km. 20, C.P. 43830, Rancho Luna, Ex‐Hacienda Santa Barbara, Zempoala, Hidalgo Mexico
| | - Andrés M. Cruz‐Gálvez
- Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH)Carretera Pachuca‐Tulancingo Km. 4.5, C.P. 42183 Mineral de la Reforma, Hidalgo México
- Universidad Politécnica de PachucaCarretera Pachuca–Cd. Sahagún Km. 20, C.P. 43830, Rancho Luna, Ex‐Hacienda Santa Barbara, Zempoala, Hidalgo Mexico
| | - Javier Castro‐Rosas
- Área Académica de Química, Instituto de Ciencias Básicas e Ingeniería, Ciudad del Conocimiento, Universidad Autónoma del Estado de Hidalgo (UAEH)Carretera Pachuca‐Tulancingo Km. 4.5, C.P. 42183 Mineral de la Reforma, Hidalgo México
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17
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Velmourougane K, Prasanna R, Singh SB, Kumar R, Saha S. Sequence of inoculation influences the nature of extracellular polymeric substances and biofilm formation in Azotobacter chroococcum and Trichoderma viride. FEMS Microbiol Ecol 2017; 93:3814244. [DOI: 10.1093/femsec/fix066] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 05/10/2017] [Indexed: 11/13/2022] Open
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18
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Velmourougane K, Prasanna R, Saxena AK. Agriculturally important microbial biofilms: Present status and future prospects. J Basic Microbiol 2017; 57:548-573. [PMID: 28407275 DOI: 10.1002/jobm.201700046] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 03/17/2017] [Accepted: 03/19/2017] [Indexed: 11/07/2022]
Abstract
Microbial biofilms are a fascinating subject, due to their significant roles in the environment, industry, and health. Advances in biochemical and molecular techniques have helped in enhancing our understanding of biofilm structure and development. In the past, research on biofilms primarily focussed on health and industrial sectors; however, lately, biofilms in agriculture are gaining attention due to their immense potential in crop production, protection, and improvement. Biofilms play an important role in colonization of surfaces - soil, roots, or shoots of plants and enable proliferation in the desired niche, besides enhancing soil fertility. Although reports are available on microbial biofilms in general; scanty information is published on biofilm formation by agriculturally important microorganisms (bacteria, fungi, bacterial-fungal) and their interactions in the ecosystem. Better understanding of agriculturally important bacterial-fungal communities and their interactions can have several implications on climate change, soil quality, plant nutrition, plant protection, bioremediation, etc. Understanding the factors and genes involved in biofilm formation will help to develop more effective strategies for sustainable and environment-friendly agriculture. The present review brings together fundamental aspects of biofilms, in relation to their formation, regulatory mechanisms, genes involved, and their application in different fields, with special emphasis on agriculturally important microbial biofilms.
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Affiliation(s)
| | - Radha Prasanna
- Division of Microbiology, ICAR-Indian Agricultural Research Institute, New Delhi, India
| | - Anil Kumar Saxena
- ICAR-National Bureau of Agriculturally Important Microorganisms (NBAIM), Mau Nath Bhanjan, Uttar Pradesh, India
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19
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Draft genome and description of Orrella dioscoreae gen. nov. sp. nov., a new species of Alcaligenaceae isolated from leaf acumens of Dioscorea sansibarensis. Syst Appl Microbiol 2017; 40:11-21. [DOI: 10.1016/j.syapm.2016.10.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 10/17/2016] [Accepted: 10/28/2016] [Indexed: 01/31/2023]
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20
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Ghosh PK, Maiti TK. Structure of Extracellular Polysaccharides (EPS) Produced by Rhizobia and their Functions in Legume–Bacteria Symbiosis: — A Review. ACTA ACUST UNITED AC 2016. [DOI: 10.1016/j.als.2016.11.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Rachwał K, Boguszewska A, Kopcińska J, Karaś M, Tchórzewski M, Janczarek M. The Regulatory Protein RosR Affects Rhizobium leguminosarum bv. trifolii Protein Profiles, Cell Surface Properties, and Symbiosis with Clover. Front Microbiol 2016; 7:1302. [PMID: 27602024 PMCID: PMC4993760 DOI: 10.3389/fmicb.2016.01302] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/08/2016] [Indexed: 11/13/2022] Open
Abstract
Rhizobium leguminosarum bv. trifolii is capable of establishing a symbiotic relationship with plants from the genus Trifolium. Previously, a regulatory protein encoded by rosR was identified and characterized in this bacterium. RosR possesses a Cys2-His2-type zinc finger motif and belongs to Ros/MucR family of rhizobial transcriptional regulators. Transcriptome profiling of the rosR mutant revealed a role of this protein in several cellular processes, including the synthesis of cell-surface components and polysaccharides, motility, and bacterial metabolism. Here, we show that a mutation in rosR resulted in considerable changes in R. leguminosarum bv. trifolii protein profiles. Extracellular, membrane, and periplasmic protein profiles of R. leguminosarum bv. trifolii wild type and the rosR mutant were examined, and proteins with substantially different abundances between these strains were identified. Compared with the wild type, extracellular fraction of the rosR mutant contained greater amounts of several proteins, including Ca(2+)-binding cadherin-like proteins, a RTX-like protein, autoaggregation protein RapA1, and flagellins FlaA and FlaB. In contrast, several proteins involved in the uptake of various substrates were less abundant in the mutant strain (DppA, BraC, and SfuA). In addition, differences were observed in membrane proteins of the mutant and wild-type strains, which mainly concerned various transport system components. Using atomic force microscopy (AFM) imaging, we characterized the topography and surface properties of the rosR mutant and wild-type cells. We found that the mutation in rosR gene also affected surface properties of R. leguminosarum bv. trifolii. The mutant cells were significantly more hydrophobic than the wild-type cells, and their outer membrane was three times more permeable to the hydrophobic dye N-phenyl-1-naphthylamine. The mutation of rosR also caused defects in bacterial symbiotic interaction with clover plants. Compared with the wild type, the rosR mutant infected host plant roots much less effectively and its nodule occupation was disturbed. At the ultrastructural level, the most striking differences between the mutant and the wild-type nodules concerned the structure of infection threads, release of bacteria, and bacteroid differentiation. This confirms an essential role of RosR in establishment of successful symbiotic interaction of R. leguminosarum bv. trifolii with clover plants.
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Affiliation(s)
- Kamila Rachwał
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
| | - Aleksandra Boguszewska
- Department of Molecular Biology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
| | - Joanna Kopcińska
- Department of Botany, Faculty of Agriculture and Biology, Warsaw University of Life Sciences Warsaw, Poland
| | - Magdalena Karaś
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
| | - Marek Tchórzewski
- Department of Molecular Biology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
| | - Monika Janczarek
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University Lublin, Poland
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22
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Muszyński A, Heiss C, Hjuler CT, Sullivan JT, Kelly SJ, Thygesen MB, Stougaard J, Azadi P, Carlson RW, Ronson CW. Structures of Exopolysaccharides Involved in Receptor-mediated Perception of Mesorhizobium loti by Lotus japonicus. J Biol Chem 2016; 291:20946-20961. [PMID: 27502279 DOI: 10.1074/jbc.m116.743856] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Indexed: 11/06/2022] Open
Abstract
In the symbiosis formed between Mesorhizobium loti strain R7A and Lotus japonicus Gifu, rhizobial exopolysaccharide (EPS) plays an important role in infection thread formation. Mutants of strain R7A affected in early exopolysaccharide biosynthetic steps form nitrogen-fixing nodules on L. japonicus Gifu after a delay, whereas mutants affected in mid or late biosynthetic steps induce uninfected nodule primordia. Recently, it was shown that a plant receptor-like kinase, EPR3, binds low molecular mass exopolysaccharide from strain R7A to regulate bacterial passage through the plant's epidermal cell layer (Kawaharada, Y., Kelly, S., Nielsen, M. W., Hjuler, C. T., Gysel, K., Muszyński, A., Carlson, R. W., Thygesen, M. B., Sandal, N., Asmussen, M. H., Vinther, M., Andersen, S. U., Krusell, L., Thirup, S., Jensen, K. J., et al. (2015) Nature 523, 308-312). In this work, we define the structure of both high and low molecular mass exopolysaccharide from R7A. The low molecular mass exopolysaccharide produced by R7A is a monomer unit of the acetylated octasaccharide with the structure (2,3/3-OAc)β-d-RibfA-(1→4)-α-d-GlcpA-(1→4)-β-d-Glcp-(1→6)-(3OAc)β-d-Glcp-(1→6)-*[(2OAc)β-d-Glcp-(1→4)-(2/3OAc)β-d-Glcp-(1→4)-β-d-Glcp-(1→3)-β-d-Galp]. We propose it is a biosynthetic constituent of high molecular mass EPS polymer. Every new repeating unit is attached via its reducing-end β-d-Galp to C-4 of the fourth glucose (asterisked above) of the octasaccharide, forming a branch. The O-acetylation occurs on the four glycosyl residues in a non-stoichiometric ratio, and each octasaccharide subunit is on average substituted with three O-acetyl groups. The availability of these structures will facilitate studies of EPR3 receptor binding of symbiotically compatible and incompatible EPS and the positive or negative consequences on infection by the M. loti exo mutants synthesizing such EPS variants.
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Affiliation(s)
- Artur Muszyński
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602,
| | - Christian Heiss
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Christian T Hjuler
- the Department of Chemistry, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - John T Sullivan
- the Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand
| | - Simon J Kelly
- the Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand
| | - Mikkel B Thygesen
- the Department of Chemistry, University of Copenhagen, 1871 Frederiksberg C, Denmark
| | - Jens Stougaard
- the Department of Molecular Biology and Genetics, Aarhus University, 8000 Aarhus C, Denmark, and
| | - Parastoo Azadi
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Russell W Carlson
- From the Complex Carbohydrate Research Center, University of Georgia, Athens, Georgia 30602
| | - Clive W Ronson
- the Department of Microbiology and Immunology, University of Otago, Dunedin 9016, New Zealand,
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23
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Augimeri RV, Varley AJ, Strap JL. Establishing a Role for Bacterial Cellulose in Environmental Interactions: Lessons Learned from Diverse Biofilm-Producing Proteobacteria. Front Microbiol 2015; 6:1282. [PMID: 26635751 PMCID: PMC4646962 DOI: 10.3389/fmicb.2015.01282] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Accepted: 10/31/2015] [Indexed: 01/21/2023] Open
Abstract
Bacterial cellulose (BC) serves as a molecular glue to facilitate intra- and inter-domain interactions in nature. Biosynthesis of BC-containing biofilms occurs in a variety of Proteobacteria that inhabit diverse ecological niches. The enzymatic and regulatory systems responsible for the polymerization, exportation, and regulation of BC are equally as diverse. Though the magnitude and environmental consequences of BC production are species-specific, the common role of BC-containing biofilms is to establish close contact with a preferred host to facilitate efficient host-bacteria interactions. Universally, BC aids in attachment, adherence, and subsequent colonization of a substrate. Bi-directional interactions influence host physiology, bacterial physiology, and regulation of BC biosynthesis, primarily through modulation of intracellular bis-(3'→5')-cyclic diguanylate (c-di-GMP) levels. Depending on the circumstance, BC producers exhibit a pathogenic or symbiotic relationship with plant, animal, or fungal hosts. Rhizobiaceae species colonize plant roots, Pseudomonadaceae inhabit the phyllosphere, Acetobacteriaceae associate with sugar-loving insects and inhabit the carposphere, Enterobacteriaceae use fresh produce as vehicles to infect animal hosts, and Vibrionaceae, particularly Aliivibrio fischeri, colonize the light organ of squid. This review will highlight the diversity of the biosynthesis and regulation of BC in nature by discussing various examples of Proteobacteria that use BC-containing biofilms to facilitate host-bacteria interactions. Through discussion of current data we will establish new directions for the elucidation of BC biosynthesis, its regulation and its ecophysiological roles.
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Affiliation(s)
| | | | - Janice L. Strap
- Molecular Microbial Biochemistry Laboratory, Faculty of Science, University of Ontario Institute of TechnologyOshawa, ON, Canada
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Receptor-mediated exopolysaccharide perception controls bacterial infection. Nature 2015; 523:308-12. [DOI: 10.1038/nature14611] [Citation(s) in RCA: 282] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 06/03/2015] [Indexed: 02/06/2023]
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Römling U, Galperin MY. Bacterial cellulose biosynthesis: diversity of operons, subunits, products, and functions. Trends Microbiol 2015; 23:545-57. [PMID: 26077867 DOI: 10.1016/j.tim.2015.05.005] [Citation(s) in RCA: 310] [Impact Index Per Article: 34.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Revised: 05/05/2015] [Accepted: 05/18/2015] [Indexed: 12/30/2022]
Abstract
Recent studies of bacterial cellulose biosynthesis, including structural characterization of a functional cellulose synthase complex, provided the first mechanistic insight into this fascinating process. In most studied bacteria, just two subunits, BcsA and BcsB, are necessary and sufficient for the formation of the polysaccharide chain in vitro. Other subunits - which differ among various taxa - affect the enzymatic activity and product yield in vivo by modulating (i) the expression of the biosynthesis apparatus, (ii) the export of the nascent β-D-glucan polymer to the cell surface, and (iii) the organization of cellulose fibers into a higher-order structure. These auxiliary subunits play key roles in determining the quantity and structure of resulting biofilms, which is particularly important for the interactions of bacteria with higher organisms - leading to rhizosphere colonization and modulating the virulence of cellulose-producing bacterial pathogens inside and outside of host cells. We review the organization of four principal types of cellulose synthase operon found in various bacterial genomes, identify additional bcs genes that encode components of the cellulose biosynthesis and secretion machinery, and propose a unified nomenclature for these genes and subunits. We also discuss the role of cellulose as a key component of biofilms and in the choice between acute infection and persistence in the host.
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Affiliation(s)
- Ute Römling
- Department of Microbiology, Tumor and Cell Biology (MTC), Karolinska Institutet, Stockholm, Sweden.
| | - Michael Y Galperin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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Suzaki T, Yoro E, Kawaguchi M. Leguminous plants: inventors of root nodules to accommodate symbiotic bacteria. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 316:111-58. [PMID: 25805123 DOI: 10.1016/bs.ircmb.2015.01.004] [Citation(s) in RCA: 95] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Legumes and a few other plant species can establish a symbiotic relationship with nitrogen-fixing rhizobia, which enables them to survive in a nitrogen-deficient environment. During the course of nodulation, infection with rhizobia induces the dedifferentiation of host cells to form primordia of a symbiotic organ, the nodule, which prepares plants to accommodate rhizobia in host cells. While these nodulation processes are known to be genetically controlled by both plants and rhizobia, recent advances in studies on two model legumes, Lotus japonicus and Medicago truncatula, have provided great insight into the underlying plant-side molecular mechanism. In this chapter, we review such knowledge, with particular emphasis on two key processes of nodulation, nodule development and rhizobial invasion.
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Affiliation(s)
- Takuya Suzaki
- National Institute for Basic Biology, Okazaki, Japan; School of Life Science, Graduate University for Advanced Studies, Okazaki, Japan
| | - Emiko Yoro
- National Institute for Basic Biology, Okazaki, Japan; School of Life Science, Graduate University for Advanced Studies, Okazaki, Japan
| | - Masayoshi Kawaguchi
- National Institute for Basic Biology, Okazaki, Japan; School of Life Science, Graduate University for Advanced Studies, Okazaki, Japan
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Castellane TCL, Persona MR, Campanharo JC, de Macedo Lemos EG. Production of exopolysaccharide from rhizobia with potential biotechnological and bioremediation applications. Int J Biol Macromol 2015; 74:515-22. [PMID: 25592842 DOI: 10.1016/j.ijbiomac.2015.01.007] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 11/21/2014] [Accepted: 01/05/2015] [Indexed: 11/16/2022]
Abstract
The potential use of rhizobia under controlled fermentation conditions may result in the production of new extracellular polymeric substances (EPS) having novel and superior properties that will open up new areas of industrial applications and thus increase their demand. The production of EPS and the stability of emulsions formed with soybean oil, diesel oil and toluene using different concentrations of purified EPS derived from wild-type and mutant strains of Rhizobium tropici SEMIA 4077 was investigated. The EPS was defined as a heteropolysaccharide composed of six constituent monosaccharides that displayed higher intrinsic viscosity and pseudoplastic non-Newtonian fluid behavior in an aqueous solution. The ratio between the total EPS production and the cellular biomass was 76.70 for the 4077::Z04 mutant strain and only 8.10 for the wild-type strain. The EPS produced by the wild-type R. tropici SEMIA 4077 resulted in more stable emulsions with the tested toluene than xanthan gum, and the emulsification indexes with hydrocarbons and soybean oil were higher than 50%, indicating strong emulsion-stabilizing capacity. These results demonstrate that the EPS of R. tropici strains could be attractive for use in industrial and environmental applications, as it had higher intrinsic viscosity and good emulsification activity.
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Affiliation(s)
- Tereza Cristina Luque Castellane
- Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil.
| | - Michelli Romanoli Persona
- Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil.
| | - João Carlos Campanharo
- Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil.
| | - Eliana Gertrudes de Macedo Lemos
- Departamento de Tecnologia, UNESP - Univ Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, Rod. Prof. Paulo Donato Castellane km 5, CEP 14884-900 Jaboticabal, SP, Brazil.
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Lipopolysaccharide O-chain core region required for cellular cohesion and compaction of in vitro and root biofilms developed by Rhizobium leguminosarum. Appl Environ Microbiol 2014; 81:1013-23. [PMID: 25416773 DOI: 10.1128/aem.03175-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The formation of biofilms is an important survival strategy allowing rhizobia to live on soil particles and plant roots. Within the microcolonies of the biofilm developed by Rhizobium leguminosarum, rhizobial cells interact tightly through lateral and polar connections, forming organized and compact cell aggregates. These microcolonies are embedded in a biofilm matrix, whose main component is the acidic exopolysaccharide (EPS). Our work shows that the O-chain core region of the R. leguminosarum lipopolysaccharide (LPS) (which stretches out of the cell surface) strongly influences bacterial adhesive properties and cell-cell cohesion. Mutants defective in the O chain or O-chain core moiety developed premature microcolonies in which lateral bacterial contacts were greatly reduced. Furthermore, cell-cell interactions within the microcolonies of the LPS mutants were mediated mostly through their poles, resulting in a biofilm with an altered three-dimensional structure and increased thickness. In addition, on the root epidermis and on root hairs, O-antigen core-defective strains showed altered biofilm patterns with the typical microcolony compaction impaired. Taken together, these results indicate that the surface-exposed moiety of the LPS is crucial for proper cell-to-cell interactions and for the formation of robust biofilms on different surfaces.
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Yaron S, Römling U. Biofilm formation by enteric pathogens and its role in plant colonization and persistence. Microb Biotechnol 2014; 7:496-516. [PMID: 25351039 PMCID: PMC4265070 DOI: 10.1111/1751-7915.12186] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 09/16/2014] [Indexed: 12/28/2022] Open
Abstract
The significant increase in foodborne outbreaks caused by contaminated fresh produce, such as alfalfa sprouts, lettuce, melons, tomatoes and spinach, during the last 30 years stimulated investigation of the mechanisms of persistence of human pathogens on plants. Emerging evidence suggests that Salmonella enterica and Escherichia coli, which cause the vast majority of fresh produce outbreaks, are able to adhere to and to form biofilms on plants leading to persistence and resistance to disinfection treatments, which subsequently can cause human infections and major outbreaks. In this review, we present the current knowledge about host, bacterial and environmental factors that affect the attachment to plant tissue and the process of biofilm formation by S. enterica and E. coli, and discuss how biofilm formation assists in persistence of pathogens on the plants. Mechanisms used by S. enterica and E. coli to adhere and persist on abiotic surfaces and mammalian cells are partially similar and also used by plant pathogens and symbionts. For example, amyloid curli fimbriae, part of the extracellular matrix of biofilms, frequently contribute to adherence and are upregulated upon adherence and colonization of plant material. Also the major exopolysaccharide of the biofilm matrix, cellulose, is an adherence factor not only of S. enterica and E. coli, but also of plant symbionts and pathogens. Plants, on the other hand, respond to colonization by enteric pathogens with a variety of defence mechanisms, some of which can effectively inhibit biofilm formation. Consequently, plant compounds might be investigated for promising novel antibiofilm strategies.
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Affiliation(s)
- Sima Yaron
- Faculty of Biotechnology and Food Engineering, Technion – Israel Institute of TechnologyHaifa, 32000, Israel
| | - Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska InstitutetStockholm, Sweden
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Frederix M, Edwards A, Swiderska A, Stanger A, Karunakaran R, Williams A, Abbruscato P, Sanchez-Contreras M, Poole PS, Downie JA. Mutation of praR in Rhizobium leguminosarum enhances root biofilms, improving nodulation competitiveness by increased expression of attachment proteins. Mol Microbiol 2014; 93:464-78. [PMID: 24942546 PMCID: PMC4149787 DOI: 10.1111/mmi.12670] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2014] [Indexed: 11/27/2022]
Abstract
In Rhizobium leguminosarum bv. viciae, quorum-sensing is regulated by CinR, which induces the cinIS operon. CinI synthesizes an AHL, whereas CinS inactivates PraR, a repressor. Mutation of praR enhanced biofilms in vitro. We developed a light (lux)-dependent assay of rhizobial attachment to roots and demonstrated that mutation of praR increased biofilms on pea roots. The praR mutant out-competed wild-type for infection of pea nodules in mixed inoculations. Analysis of gene expression by microarrays and promoter fusions revealed that PraR represses its own transcription and mutation of praR increased expression of several genes including those encoding secreted proteins (the adhesins RapA2, RapB and RapC, two cadherins and the glycanase PlyB), the polysaccharide regulator RosR, and another protein similar to PraR. PraR bound to the promoters of several of these genes indicating direct repression. Mutations in rapA2, rapB, rapC, plyB, the cadherins or rosR did not affect the enhanced root attachment or nodule competitiveness of the praR mutant. However combinations of mutations in rapA, rapB and rapC abolished the enhanced attachment and nodule competitiveness. We conclude that relief of PraR-mediated repression determines a lifestyle switch allowing the expression of genes that are important for biofilm formation on roots and the subsequent initiation of infection of legume roots.
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Affiliation(s)
| | | | | | - Andrew Stanger
- Department of Molecular Microbiology, John Innes CentreNorwich Research Park, Norwich, NR4 7UH, UK
| | - Ramakrishnan Karunakaran
- Department of Molecular Microbiology, John Innes CentreNorwich Research Park, Norwich, NR4 7UH, UK
| | | | | | | | | | - J Allan Downie
- Department of Molecular Microbiology, John Innes CentreNorwich Research Park, Norwich, NR4 7UH, UK
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Synthesis of Microbial Signaling Molecules and Their Stereochemistry-Activity Relationships. Biosci Biotechnol Biochem 2014; 75:1418-29. [DOI: 10.1271/bbb.110283] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Pérez-Mendoza D, Aragón IM, Prada-Ramírez HA, Romero-Jiménez L, Ramos C, Gallegos MT, Sanjuán J. Responses to elevated c-di-GMP levels in mutualistic and pathogenic plant-interacting bacteria. PLoS One 2014; 9:e91645. [PMID: 24626229 PMCID: PMC3953490 DOI: 10.1371/journal.pone.0091645] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 02/13/2014] [Indexed: 11/18/2022] Open
Abstract
Despite a recent burst of research, knowledge on c-di-GMP signaling pathways remains largely fragmentary and molecular mechanisms of regulation and even c-di-GMP targets are yet unknown for most bacteria. Besides genomics or bioinformatics, accompanying alternative approaches are necessary to reveal c-di-GMP regulation in bacteria with complex lifestyles. We have approached this study by artificially altering the c-di-GMP economy of diverse pathogenic and mutualistic plant-interacting bacteria and examining the effects on the interaction with their respective host plants. Phytopathogenic Pseudomonas and symbiotic Rhizobium strains with enhanced levels of intracellular c-di-GMP displayed common free-living responses: reduction of motility, increased production of extracellular polysaccharides and enhanced biofilm formation. Regarding the interaction with the host plants, P. savastanoi pv. savastanoi cells containing high c-di-GMP levels formed larger knots on olive plants which, however, displayed reduced necrosis. In contrast, development of disease symptoms in P. syringae-tomato or P. syringae-bean interactions did not seem significantly affected by high c-di-GMP. On the other hand, increasing c-di-GMP levels in symbiotic R. etli and R. leguminosarum strains favoured the early stages of the interaction since enhanced adhesion to plant roots, but decreased symbiotic efficiency as plant growth and nitrogen contents were reduced. Our results remark the importance of c-di-GMP economy for plant-interacting bacteria and show the usefulness of our approach to reveal particular stages during plant-bacteria associations which are sensitive to changes in c-di-GMP levels.
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Affiliation(s)
- Daniel Pérez-Mendoza
- Dpto. Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Granada, Spain
| | - Isabel M. Aragón
- Área de Genética, Universidad de Málaga, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-CSIC (IHSM-UMA-CSIC), Málaga, Spain
| | - Harold A. Prada-Ramírez
- Dpto. Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Granada, Spain
| | - Lorena Romero-Jiménez
- Dpto. Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Granada, Spain
| | - Cayo Ramos
- Área de Genética, Universidad de Málaga, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora”, Universidad de Málaga-CSIC (IHSM-UMA-CSIC), Málaga, Spain
| | - María-Trinidad Gallegos
- Dpto. Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Granada, Spain
| | - Juan Sanjuán
- Dpto. Microbiología del Suelo y Sistemas Simbióticos, Estación Experimental del Zaidín, CSIC, Granada, Spain
- * E-mail:
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Freitas F, Alves VD, Reis MAM. Bacterial Polysaccharides: Production and Applications in Cosmetic Industry. POLYSACCHARIDES 2014. [DOI: 10.1007/978-3-319-03751-6_63-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Garg N, Manchanda G, Kumar A. Bacterial quorum sensing: circuits and applications. Antonie Van Leeuwenhoek 2013; 105:289-305. [DOI: 10.1007/s10482-013-0082-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 11/16/2013] [Indexed: 11/28/2022]
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Cellulose as an architectural element in spatially structured Escherichia coli biofilms. J Bacteriol 2013; 195:5540-54. [PMID: 24097954 DOI: 10.1128/jb.00946-13] [Citation(s) in RCA: 235] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Morphological form in multicellular aggregates emerges from the interplay of genetic constitution and environmental signals. Bacterial macrocolony biofilms, which form intricate three-dimensional structures, such as large and often radially oriented ridges, concentric rings, and elaborate wrinkles, provide a unique opportunity to understand this interplay of "nature and nurture" in morphogenesis at the molecular level. Macrocolony morphology depends on self-produced extracellular matrix components. In Escherichia coli, these are stationary phase-induced amyloid curli fibers and cellulose. While the widely used "domesticated" E. coli K-12 laboratory strains are unable to generate cellulose, we could restore cellulose production and macrocolony morphology of E. coli K-12 strain W3110 by "repairing" a single chromosomal SNP in the bcs operon. Using scanning electron and fluorescence microscopy, cellulose filaments, sheets and nanocomposites with curli fibers were localized in situ at cellular resolution within the physiologically two-layered macrocolony biofilms of this "de-domesticated" strain. As an architectural element, cellulose confers cohesion and elasticity, i.e., tissue-like properties that-together with the cell-encasing curli fiber network and geometrical constraints in a growing colony-explain the formation of long and high ridges and elaborate wrinkles of wild-type macrocolonies. In contrast, a biofilm matrix consisting of the curli fiber network only is brittle and breaks into a pattern of concentric dome-shaped rings separated by deep crevices. These studies now set the stage for clarifying how regulatory networks and in particular c-di-GMP signaling operate in the three-dimensional space of highly structured and "tissue-like" bacterial biofilms.
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Bogino PC, de las Mercedes Oliva M, Sorroche FG, Giordano W. The role of bacterial biofilms and surface components in plant-bacterial associations. Int J Mol Sci 2013; 14:15838-59. [PMID: 23903045 PMCID: PMC3759889 DOI: 10.3390/ijms140815838] [Citation(s) in RCA: 223] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 06/18/2013] [Accepted: 06/28/2013] [Indexed: 01/09/2023] Open
Abstract
The role of bacterial surface components in combination with bacterial functional signals in the process of biofilm formation has been increasingly studied in recent years. Plants support a diverse array of bacteria on or in their roots, transport vessels, stems, and leaves. These plant-associated bacteria have important effects on plant health and productivity. Biofilm formation on plants is associated with symbiotic and pathogenic responses, but how plants regulate such associations is unclear. Certain bacteria in biofilm matrices have been found to induce plant growth and to protect plants from phytopathogens (a process termed biocontrol), whereas others are involved in pathogenesis. In this review, we systematically describe the various components and mechanisms involved in bacterial biofilm formation and attachment to plant surfaces and the relationships of these mechanisms to bacterial activity and survival.
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Affiliation(s)
- Pablo C. Bogino
- Department of Molecular Biology, National University of Río Cuarto, Ruta 36 Km 601, Río Cuarto, Córdoba X5804BYA, Argentina; E-Mails: (P.C.B.); (F.G.S.)
| | - María de las Mercedes Oliva
- Department of Microbiology and Immunology, National University of Río Cuarto, Ruta 36 Km 601, Córdoba X5804BYA, Argentina; E-Mail:
| | - Fernando G. Sorroche
- Department of Molecular Biology, National University of Río Cuarto, Ruta 36 Km 601, Río Cuarto, Córdoba X5804BYA, Argentina; E-Mails: (P.C.B.); (F.G.S.)
| | - Walter Giordano
- Department of Molecular Biology, National University of Río Cuarto, Ruta 36 Km 601, Río Cuarto, Córdoba X5804BYA, Argentina; E-Mails: (P.C.B.); (F.G.S.)
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Kelly SJ, Muszyński A, Kawaharada Y, Hubber AM, Sullivan JT, Sandal N, Carlson RW, Stougaard J, Ronson CW. Conditional requirement for exopolysaccharide in the Mesorhizobium-Lotus symbiosis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:319-29. [PMID: 23134480 DOI: 10.1094/mpmi-09-12-0227-r] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Rhizobial surface polysaccharides are required for nodule formation on the roots of at least some legumes but the mechanisms by which they act are yet to be determined. As a first step to investigate the function of exopolysaccharide (EPS) in the formation of determinate nodules, we isolated Mesorhizobium loti mutants affected in various steps of EPS biosynthesis and characterized their symbiotic phenotypes on two Lotus spp. The wild-type M. loti R7A produced both high molecular weight EPS and lower molecular weight (LMW) polysaccharide fractions whereas most mutant strains produced only LMW fractions. Mutants affected in predicted early biosynthetic steps (e.g., exoB) formed nitrogen-fixing nodules on Lotus corniculatus and L. japonicus 'Gifu', whereas mutants affected in mid or late biosynthetic steps (e.g., exoU) induced uninfected nodule primordia and, occasionally, a few infected nodules following a lengthy delay. These mutants were disrupted at the stage of infection thread (IT) development. Symbiotically defective EPS and Nod factor mutants functionally complemented each other in co-inoculation experiments. The majority of full-length IT observed harbored only the EPS mutant strain and did not show bacterial release, whereas the nitrogen-fixing nodules contained both mutants. Examination of the symbiotic proficiency of the exoU mutant on various L. japonicus ecotypes revealed that both host and environmental factors were linked to the requirement for EPS. These results reveal a complex function for M. loti EPS in determinate nodule formation and suggest that EPS plays a signaling role at the stages of both IT initiation and bacterial release.
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Affiliation(s)
- Simon J Kelly
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
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Robledo M, Rivera L, Jiménez-Zurdo JI, Rivas R, Dazzo F, Velázquez E, Martínez-Molina E, Hirsch AM, Mateos PF. Role of Rhizobium endoglucanase CelC2 in cellulose biosynthesis and biofilm formation on plant roots and abiotic surfaces. Microb Cell Fact 2012; 11:125. [PMID: 22970813 PMCID: PMC3520766 DOI: 10.1186/1475-2859-11-125] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 09/06/2012] [Indexed: 02/02/2023] Open
Abstract
Background The synthesis of cellulose is among the most important but poorly understood biochemical processes, especially in bacteria, due to its complexity and high degree of regulation. In this study, we analyzed both the production of cellulose by all known members of the Rhizobiaceae and the diversity of Rhizobium celABC operon predicted to be involved in cellulose biosynthesis. We also investigated the involvement in cellulose production and biofilm formation of celC gene encoding an endoglucanase (CelC2) that is required for canonical symbiotic root hair infection by Rhizobium leguminosarum bv. trifolii. Results ANU843 celC mutants lacking (ANU843ΔC2) or overproducing cellulase (ANU843C2+) produced greatly increased or reduced amounts of external cellulose micro fibrils, respectively. Calcofluor-stained cellulose micro fibrils were considerably longer when formed by ANU843ΔC2 bacteria rather than by the wild-type strain, in correlation with a significant increase in their flocculation in batch culture. In contrast, neither calcofluor-stained extracellular micro fibrils nor flocculation was detectable in ANU843C2+ cells. To clarify the role of cellulose synthesis in Rhizobium cell aggregation and attachment, we analyzed the ability of these mutants to produce biofilms on different surfaces. Alteration of wild-type CelC2 levels resulted in a reduced ability of bacteria to form biofilms both in abiotic surfaces and in planta. Conclusions Our results support a key role of the CelC2 cellulase in cellulose biosynthesis by modulating the length of the cellulose fibrils that mediate firm adhesion among Rhizobium bacteria leading to biofilm formation. Rhizobium cellulose is an essential component of the biofilm polysaccharidic matrix architecture and either an excess or a defect of this “building material” seem to collapse the biofilm structure. These results position cellulose hydrolytic enzymes as excellent anti-biofilm candidates.
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Affiliation(s)
- M Robledo
- Departamento de Microbiología y Genética and CIALE, Universidad de Salamanca, Salamanca, Spain
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Lon protease of Azorhizobium caulinodans ORS571 is required for suppression of reb gene expression. Appl Environ Microbiol 2012; 78:6251-61. [PMID: 22752172 DOI: 10.1128/aem.01039-12] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacterial Lon proteases play important roles in a variety of biological processes in addition to housekeeping functions. In this study, we focused on the Lon protease of Azorhizobium caulinodans, which can fix nitrogen both during free-living growth and in stem nodules of the legume Sesbania rostrata. The nitrogen fixation activity of an A. caulinodans lon mutant in the free-living state was not significantly different from that of the wild-type strain. However, the stem nodules formed by the lon mutant showed little or no nitrogen fixation activity. By microscopic analyses, two kinds of host cells were observed in the stem nodules formed by the lon mutant. One type has shrunken host cells containing a high density of bacteria, and the other type has oval or elongated host cells containing a low density or no bacteria. This phenotype is similar to a praR mutant highly expressing the reb genes. Quantitative reverse transcription-PCR analyses revealed that reb genes were also highly expressed in the lon mutant. Furthermore, a lon reb double mutant formed stem nodules showing higher nitrogen fixation activity than the lon mutant, and shrunken host cells were not observed in these stem nodules. These results suggest that Lon protease is required to suppress the expression of the reb genes and that high expression of reb genes in part causes aberrance in the A. caulinodans-S. rostrata symbiosis. In addition to the suppression of reb genes, it was found that Lon protease was involved in the regulation of exopolysaccharide production and autoagglutination of bacterial cells.
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Smol’kina ON, Shishonkova NS, Yurasov NA, Ignatov VV. Capsular and extracellular polysaccharides of the diazotrophic rhizobacterium Herbaspirillum seropedicae Z78. Microbiology (Reading) 2012. [DOI: 10.1134/s0026261712030113] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Abstract
To allow rhizobial infection of legume roots, plant cell walls must be locally degraded for plant-made infection threads (ITs) to be formed. Here we identify a Lotus japonicus nodulation pectate lyase gene (LjNPL), which is induced in roots and root hairs by rhizobial nodulation (Nod) factors via activation of the nodulation signaling pathway and the NIN transcription factor. Two Ljnpl mutants produced uninfected nodules and most infections arrested as infection foci in root hairs or roots. The few partially infected nodules that did form contained large abnormal infections. The purified LjNPL protein had pectate lyase activity, demonstrating that this activity is required for rhizobia to penetrate the cell wall and initiate formation of plant-made infection threads. Therefore, we conclude that legume-determined degradation of plant cell walls is required for root infection during initiation of the symbiotic interaction between rhizobia and legumes.
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Huang KH, Chen BY, Shen FT, Young CC. Optimization of exopolysaccharide production and diesel oil emulsifying properties in root nodulating bacteria. World J Microbiol Biotechnol 2011; 28:1367-73. [DOI: 10.1007/s11274-011-0936-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Accepted: 10/27/2011] [Indexed: 11/28/2022]
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Oldroyd GED, Murray JD, Poole PS, Downie JA. The rules of engagement in the legume-rhizobial symbiosis. Annu Rev Genet 2011; 45:119-44. [PMID: 21838550 DOI: 10.1146/annurev-genet-110410-132549] [Citation(s) in RCA: 646] [Impact Index Per Article: 49.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Rhizobial bacteria enter a symbiotic association with leguminous plants, resulting in differentiated bacteria enclosed in intracellular compartments called symbiosomes within nodules on the root. The nodules and associated symbiosomes are structured for efficient nitrogen fixation. Although the interaction is beneficial to both partners, it comes with rigid rules that are strictly enforced by the plant. Entry into root cells requires appropriate recognition of the rhizobial Nod factor signaling molecule, and this recognition activates a series of events, including polarized root-hair tip growth, invagination associated with bacterial infection, and the promotion of cell division in the cortex leading to the nodule meristem. The plant's command of the infection process has been highlighted by its enforcement of terminal differentiation upon the bacteria within nodules of some legumes, and this can result in a loss of bacterial viability while permitting effective nitrogen fixation. Here, we review the mechanisms by which the plant allows bacterial infection and promotes the formation of the nodule, as well as the details of how this intimate association plays out inside the cells of the nodule where a complex interchange of metabolites and regulatory peptides force the bacteria into a nitrogen-fixing organelle-like state.
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Affiliation(s)
- Giles E D Oldroyd
- John Innes Center, Norwich Research Park, Norwich NR4 7UH, United Kingdom.
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Ahmad M, Zahir ZA, Asghar HN, Asghar M. Inducing salt tolerance in mung bean through coinoculation with rhizobia and plant-growth-promoting rhizobacteria containing 1-aminocyclopropane-1-carboxylate deaminase. Can J Microbiol 2011; 57:578-89. [PMID: 21770816 DOI: 10.1139/w11-044] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Twenty-five strains of plant-growth-promoting rhizobacteria (PGPR) containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase and 10 strains of rhizobia were isolated from rhizosphere soil samples and nodules of mung bean. They were screened in separate trials under salt-stressed axenic conditions. The three most effective strains of PGPR (Mk1, Pseudomonas syringae ; Mk20, Pseudomonas fluorescens ; and Mk25, Pseudomonas fluorescens biotype G) and Rhizobium phaseoli strains M1, M6, and M9 were evaluated in coinoculation for their growth-promoting activity at three salinity levels (original, 4 dS·m(-1), and 6 dS·m(-1)) under axenic conditions. The results showed that salinity stress significantly reduced plant growth but inoculation with PGPR containing ACC deaminase and rhizobia enhanced plant growth, thus reducing the inhibitory effect of salinity. However, their combined application was more effective under saline conditions, and the combination Mk20 × M6 was the most efficient for improving seedling growth and nodulation. The effect of high ethylene concentrations on plant growth and the performance of these strains for reducing the negative impact of saline stress was also evaluated by conducting a classical triple-response bioassay. The intensity of the classical triple response decreased owing to inoculation with these strains, with the root and shoot lengths of inoculated mung bean seedlings increasing and stem diameter decreasing, which is a typical response to the dilution in a classical triple response bioassay. Thus, coinoculation with PGPR containing ACC deaminase and Rhizobium spp. could be a useful approach for inducing salt tolerance and thus improving growth and nodulation in mung bean under salt-affected conditions.
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Affiliation(s)
- Maqshoof Ahmad
- Institute of Soil and Environmental Sciences, University of Agriculture, Faisalabad, Pakistan
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47
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Frederix M, Edwards A, McAnulla C, Downie JA. Co-ordination of quorum-sensing regulation in Rhizobium leguminosarum by induction of an anti-repressor. Mol Microbiol 2011; 81:994-1007. [PMID: 21732996 DOI: 10.1111/j.1365-2958.2011.07738.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Analysis of quorum-sensing (QS) regulation in Rhizobium leguminosarum revealed an unusual type of gene regulation that relies on the population density-dependent accumulation of an anti-repressor. The cinS gene, which is co-transcribed with the N-acyl-homoserine-lactone synthase gene cinI, is required to fully induce rhiR and raiR, whose products, together with their partner AHL synthases, regulate other genes in a QS-regulated hierarchy. Purified CinS bound to the R. leguminosarum transcriptional regulator PraR, which repressed rhiR and raiR expression. PraR bound to the rhiR and raiR promoters and CinS displaced PraR from these promoters, thereby inducing their expression. Although induction of cinS required CinI-made AHL, it appears CinS does not require the AHL for its anti-repressor function. The LuxR-type regulator ExpR was also required for normal induction of rhiR and raiR and it appears that this occurs by ExpR repressing the transcription of praR. Therefore ExpR and CinS act independently to attenuate PraR action, ExpR by repressing its transcription and CinS by attenuating its repressive activity. Thus, as CinS accumulates in a population density-dependent manner it induces the QS hierarchy by relieving PraR-mediated repression of rhiR and raiR.
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Affiliation(s)
- Marijke Frederix
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich NR47UH, UK
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48
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Vanderlinde EM, Harrison JJ, Muszyński A, Carlson RW, Turner RJ, Yost CK. Identification of a novel ABC transporter required for desiccation tolerance, and biofilm formation in Rhizobium leguminosarum bv. viciae 3841. FEMS Microbiol Ecol 2010; 71:327-40. [PMID: 20030718 PMCID: PMC2868943 DOI: 10.1111/j.1574-6941.2009.00824.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Rhizobium leguminosarum is a soil bacterium with the ability to form nitrogen-fixing nodules on the roots of leguminous plants. Soil-dwelling, free-living R. leguminosarum often encounters desiccation stress, which impacts its survival within the soil. The mechanisms by which soil bacteria resist the effects of desiccation stress have been described. However, the role of the cell envelope in the desiccation tolerance mechanisms of rhizobia is relatively uncharacterized. Using a transposon mutagenesis approach, a mutant of R. leguminosarum bv. viciae was isolated that was highly sensitive to desiccation. The mutation is located in the ATP-binding protein of an uncharacterized ATP-binding cassette transporter operon (RL2975-RL2977). Exopolysaccharide accumulation was significantly lower in the mutant and the decrease in desiccation tolerance was attributed to the decreased accumulation of exopolysaccharide. In addition to desiccation sensitivity, the mutant was severely impaired in biofilm formation, an important adaptation used by soil bacteria for survival. This work has identified a novel transporter required for physiological traits that are important for the survival of R. leguminosarum in the rhizosphere environment.
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Affiliation(s)
| | - Joe J. Harrison
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
| | - Artur Muszyński
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Russell W. Carlson
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - Raymond J. Turner
- Department of Biological Sciences, University of Calgary, Calgary, AB, Canada
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Downie JA. The roles of extracellular proteins, polysaccharides and signals in the interactions of rhizobia with legume roots. FEMS Microbiol Rev 2009; 34:150-70. [PMID: 20070373 DOI: 10.1111/j.1574-6976.2009.00205.x] [Citation(s) in RCA: 219] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Rhizobia adopt many different lifestyles including survival in soil, growth in the rhizosphere, attachment to root hairs and infection and growth within legume roots, both in infection threads and in nodules where they fix nitrogen. They are actively involved in extracellular signalling to their host legumes to initiate infection and nodule morphogenesis. Rhizobia also use quorum-sensing gene regulation via N-acyl-homoserine lactone signals and this can enhance their interaction with legumes as well as their survival under stress and their ability to induce conjugation of plasmids and symbiotic islands, thereby spreading their symbiotic capacity. They produce several surface polysaccharides that are critical for attachment and biofilm formation; some of these polysaccharides are specific for their growth on root hairs and can considerably enhance their ability to infect their host legumes. Different rhizobia use several different types of protein secretion mechanisms (Types I, III, IV, V and VI), and many of the secreted proteins play an important role in their interaction with plants. This review summarizes many of the aspects of the extracellular biology of rhizobia, in particular in relation to their symbiotic interaction with legumes.
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50
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Janczarek M, Jaroszuk-Sciseł J, Skorupska A. Multiple copies of rosR and pssA genes enhance exopolysaccharide production, symbiotic competitiveness and clover nodulation in Rhizobium leguminosarum bv. trifolii. Antonie van Leeuwenhoek 2009; 96:471-86. [PMID: 19588265 DOI: 10.1007/s10482-009-9362-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2009] [Accepted: 06/24/2009] [Indexed: 11/24/2022]
Abstract
Rhizobium leguminosarum bv. trifolii exopolysaccharide (EPS) plays an important role in determining symbiotic competence. The pssA gene encoding the first glucosyl-IP-transferase and rosR encoding a positive transcriptional regulator are key genes involved in the biosynthesis and regulation of EPS production. Mutation in pssA resulted in deficiency in EPS production and rosR mutation substantially decreased the amount of EPS. Both mutants induced nodules but the bacteria were unable to fix nitrogen. Defective functions of pssA and rosR mutants were fully restored by wild type copies of the respective genes. Introduction of multiple rosR and pssA gene copies on the plasmid vector pBBR1MCS-2 into five R. leguminosarum bv. trifolii nodule isolates resulted in significantly increased growth rates, EPS production and the number of nodules on clover roots. Increase in fresh and dry shoot mass of clovers and nodule occupation was also statistically significant. Interestingly, additional copies of pssA but particularly rosR gene, increased strains' competitiveness in relation to the wild type parental strains nearly twofold. Overall, experimental evidence is provided that increased amount of EPS beneficially affects R. leguminosarum bv. trifolii competitiveness and symbiosis with clover.
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Affiliation(s)
- Monika Janczarek
- Department of Genetics and Microbiology, Institute of Microbiology and Biotechnology, University of M. Curie-Skłodowska, Akademicka 19, 20-033 Lublin, Poland.
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