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Munar-Palmer M, Santamaría-Hernando S, Liedtke J, Ortega DR, López-Torrejón G, Rodríguez-Herva JJ, Briegel A, López-Solanilla E. Chemosensory systems interact to shape relevant traits for bacterial plant pathogenesis. mBio 2024; 15:e0087124. [PMID: 38899869 PMCID: PMC11253619 DOI: 10.1128/mbio.00871-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 05/01/2024] [Indexed: 06/21/2024] Open
Abstract
Chemosensory systems allow bacteria to respond and adapt to environmental conditions. Many bacteria contain more than one chemosensory system, but knowledge of their specific roles in regulating different functions remains scarce. Here, we address this issue by analyzing the function of the F6, F8, and alternative (non-motility) cellular functions (ACF) chemosensory systems of the model plant pathogen Pseudomonas syringae pv. tomato. In this work, we assign PsPto chemoreceptors to each chemosensory system, and we visualize for the first time the F6 and F8 chemosensory systems of PsPto using cryo-electron tomography. We confirm that chemotaxis and swimming motility are controlled by the F6 system, and we demonstrate how different components from the F8 and ACF systems also modulate swimming motility. We also determine how the kinase and response regulators from the F6 and F8 chemosensory systems do not work together in the regulation of biofilm, whereas both components from the ACF system contribute together to regulate these traits. Furthermore, we show how the F6, F8, and ACF kinases interact with the ACF response regulator WspR, supporting crosstalk among chemosensory systems. Finally, we reveal how all chemosensory systems play a role in regulating virulence. IMPORTANCE Chemoperception through chemosensory systems is an essential feature for bacterial survival, as it allows bacterial interaction with its surrounding environment. In the case of plant pathogens, it is especially relevant to enter the host and achieve full virulence. Multiple chemosensory systems allow bacteria to display a wider plasticity in their response to external signals. Here, we perform a deep characterization of the F6, F8, and alternative (non-motility) cellular functions chemosensory systems in the model plant pathogen Pseudomonas syringae pv. tomato DC3000. These chemosensory systems regulate key virulence-related traits, like motility and biofilm formation. Furthermore, we unveil an unexpected crosstalk among these chemosensory systems at the level of the interaction between kinases and response regulators. This work shows novel results that contribute to the knowledge of chemosensory systems and their role in functions alternative to chemotaxis.
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Affiliation(s)
- Martí Munar-Palmer
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)–Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
| | - Saray Santamaría-Hernando
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)–Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
| | - Janine Liedtke
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Davi R. Ortega
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Gema López-Torrejón
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)–Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), Madrid, Spain
| | - José Juan Rodríguez-Herva
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)–Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), Madrid, Spain
| | - Ariane Briegel
- Institute of Biology, Leiden University, Leiden, The Netherlands
| | - Emilia López-Solanilla
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM)–Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA-CSIC), Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM), Madrid, Spain
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2
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Barbey C, Latour X. Molecular Mechanisms of Bacterial Communication and Their Biocontrol. Int J Mol Sci 2024; 25:5443. [PMID: 38791481 PMCID: PMC11121524 DOI: 10.3390/ijms25105443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 05/14/2024] [Indexed: 05/26/2024] Open
Abstract
A bacterium's ability to colonize and adapt to an ecological niche is highly dependent on its capacity to perceive and analyze its environment and its ability to interact with its hosts and congeners [...].
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Affiliation(s)
- Corinne Barbey
- Laboratory of Bacterial Communication and Anti-Infectious Strategies (CBSA UR4312, Formerly LMSM EA4312), University Rouen Normandie, Université Caen Normandie, Normandie University, F-76000 Rouen, France;
- Research Federation NORVEGE Fed4277, Normandie University, F-76000 Rouen, France
- International Research Federation NOR-SEVE, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
| | - Xavier Latour
- Laboratory of Bacterial Communication and Anti-Infectious Strategies (CBSA UR4312, Formerly LMSM EA4312), University Rouen Normandie, Université Caen Normandie, Normandie University, F-76000 Rouen, France;
- Research Federation NORVEGE Fed4277, Normandie University, F-76000 Rouen, France
- International Research Federation NOR-SEVE, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada
- Biocontrol and Biostimulation for Agroecology Association (ABBA), F-75000 Paris, France
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3
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Romero-Cuadrado L, Picos MC, Camacho M, Ollero FJ, Capote N. Biocontrol of almond canker diseases caused by Botryosphaeriaceae fungi. PEST MANAGEMENT SCIENCE 2024; 80:1839-1848. [PMID: 38050948 DOI: 10.1002/ps.7919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/27/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
BACKGROUND Botryosphaeria dieback is a canker disease caused by fungal species of the Botryosphaeriaceae family that threatens almond productivity. The most common control measure to prevent canker development is the application of fungicides which are being phased out by European Union regulations. In the present study, two sets of bacterial strains were evaluated for their antifungal activity against pathogenic Botryosphaeriaceae species through in vitro and in vivo antagonism assays. RESULTS The rhizospheric bacteria Pseudomonas aeruginosa AC17 and Bacillus velezensis ACH16, as well as the endophytic bacteria Bacillus mobilis Sol 1-2, respectively inhibited 87, 95, and 63% of the mycelial growth of Neofusicoccum parvum, Botryosphaeria dothidea, Diplodia seriata, and Macrophomina phaseolina. Additionally, they significantly reduced the length of lesions caused by N. parvum and B. dothidea in artificially inoculated detached almond twigs. All these bacterial strains produce hydrolytic enzymes that are able to degrade the fungal cell wall. P. aeruginosa AC17 also produces toxic volatile compounds, such as hydrogen cyanide. This strain was the most effective in controlling Botryosphaeria dieback in planta under controlled conditions at a level similar to the biocontrol agent Trichoderma atroviride and standard chemical fungicide treatments. CONCLUSION Pseudomonas aeruginosa AC17 is the best candidate to be considered as a potential biocontrol agent against Botryosphaeriaceae fungi affecting almond. © 2023 Society of Chemical Industry.
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Affiliation(s)
- Laura Romero-Cuadrado
- Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Center Las Torres, Seville, Spain
| | - María Cinta Picos
- Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Center Las Torres, Seville, Spain
| | - María Camacho
- Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Center Las Torres, Seville, Spain
| | | | - Nieves Capote
- Andalusian Institute of Agricultural and Fisheries Research and Training (IFAPA), Center Las Torres, Seville, Spain
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4
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Anand A, Falquet L, Abou-Mansour E, L'Haridon F, Keel C, Weisskopf L. Biological hydrogen cyanide emission globally impacts the physiology of both HCN-emitting and HCN-perceiving Pseudomonas. mBio 2023; 14:e0085723. [PMID: 37650608 PMCID: PMC10653877 DOI: 10.1128/mbio.00857-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 07/11/2023] [Indexed: 09/01/2023] Open
Abstract
IMPORTANCE Bacteria communicate by exchanging chemical signals, some of which are volatile and can remotely reach other organisms. HCN was one of the first volatiles discovered to severely impact exposed organisms by inhibiting their respiration. Using HCN-deficient mutants in two Pseudomonas strains, we demonstrate that HCN's impact goes beyond the sole inhibition of respiration and affects both emitting and receiving bacteria in a global way, modulating their motility, biofilm formation, and production of antimicrobial compounds. Our data suggest that bacteria could use HCN not only to control their own cellular functions, but also to remotely influence the behavior of other bacteria sharing the same environment. Since HCN emission occurs in both clinically and environmentally relevant Pseudomonas, these findings are important to better understand or even modulate the expression of bacterial traits involved in both virulence of opportunistic pathogens and in biocontrol efficacy of plant-beneficial strains.
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Affiliation(s)
- Abhishek Anand
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Laurent Falquet
- Department of Biology, University of Fribourg, Fribourg, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | | | | | - Christoph Keel
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Laure Weisskopf
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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5
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Carrau A, Tano J, Moyano L, Ripa MB, Petrocelli S, Piskulic L, Moreira LM, Patané JSL, Setubal JC, Orellano EG. A novel BLUF photoreceptor modulates the Xanthomonas citri subsp. citri-host plant interaction. Photochem Photobiol Sci 2023; 22:1901-1918. [PMID: 37209300 DOI: 10.1007/s43630-023-00420-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/05/2023] [Indexed: 05/22/2023]
Abstract
Plant-pathogen interaction is influenced by multiple environmental factors, including temperature and light. Recent works have shown that light modulates not only the defense response of plants but also the pathogens virulence. Xanthomonas citri subsp. citri (Xcc) is the bacterium responsible for citrus canker, an important plant disease worldwide. The Xcc genome presents four genes encoding putative photoreceptors: one bacteriophytochrome and three blue light photoreceptors, one LOV and two BLUFs (bluf1: XAC2120 and bluf2: XAC3278). The presence of two BLUFs proteins is an outstanding feature of Xcc. In this work we show that the bluf2 gene is functional. The mutant strain, XccΔbluf2, was constructed demonstrating that BLUF2 regulates swimming-type motility, adhesion to leaves, exopolysaccharide production and biofilm formation, features involved in the Xcc virulence processes. An important aspect during the plant-pathogen interaction is the oxidative response of the host and the consequent reaction of the pathogen. We observed that ROS detoxification is regulated by Xcc bluf2 gene. The phenotypes of disease in orange plants produced by WT and XccΔbluf2 strains were evaluated, observing different phenotypes. Altogether, these results show that BLUF2 negatively regulates virulence during citrus canker. This work constitutes the first report on BLUF-like receptors in plant pathogenic bacteria.
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Affiliation(s)
- Analía Carrau
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina
| | - Josefina Tano
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina
| | - Laura Moyano
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Biodiversidad y Biología Experimental, Buenos Aires, Argentina
- Instituto de Biodiversidad y Biología Experimental y Aplicada, Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires (IBBEA, CONICET-UBA), Buenos Aires, Argentina
| | - María Belén Ripa
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina
| | - Silvana Petrocelli
- Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina
| | - Laura Piskulic
- Área Estadística y Procesamiento de Datos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Leandro Marcio Moreira
- Programa de Pós-Graduação em Biotecnologia, Núcleo de Pesquisas em Ciências Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
- Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil
| | | | | | - Elena Graciela Orellano
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, S2002LRK, Rosario, Argentina.
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6
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Bhattacharyya A, Mavrodi O, Bhowmik N, Weller D, Thomashow L, Mavrodi D. Bacterial biofilms as an essential component of rhizosphere plant-microbe interactions. METHODS IN MICROBIOLOGY 2023; 53:3-48. [PMID: 38415193 PMCID: PMC10898258 DOI: 10.1016/bs.mim.2023.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Affiliation(s)
- Ankita Bhattacharyya
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Olga Mavrodi
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - Niladri Bhowmik
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
| | - David Weller
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA, United States
| | - Linda Thomashow
- USDA-ARS Wheat Health, Genetics and Quality Research Unit, Pullman, WA, United States
| | - Dmitri Mavrodi
- School of Biological, Environmental and Earth Sciences, The University of Southern Mississippi, Hattiesburg, MS, United States
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7
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Carezzano ME, Paletti Rovey MF, Cappellari LDR, Gallarato LA, Bogino P, Oliva MDLM, Giordano W. Biofilm-Forming Ability of Phytopathogenic Bacteria: A Review of its Involvement in Plant Stress. PLANTS (BASEL, SWITZERLAND) 2023; 12:plants12112207. [PMID: 37299186 DOI: 10.3390/plants12112207] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 05/24/2023] [Accepted: 06/01/2023] [Indexed: 06/12/2023]
Abstract
Phytopathogenic bacteria not only affect crop yield and quality but also the environment. Understanding the mechanisms involved in their survival is essential to develop new strategies to control plant disease. One such mechanism is the formation of biofilms; i.e., microbial communities within a three-dimensional structure that offers adaptive advantages, such as protection against unfavorable environmental conditions. Biofilm-producing phytopathogenic bacteria are difficult to manage. They colonize the intercellular spaces and the vascular system of the host plants and cause a wide range of symptoms such as necrosis, wilting, leaf spots, blight, soft rot, and hyperplasia. This review summarizes up-to-date information about saline and drought stress in plants (abiotic stress) and then goes on to focus on the biotic stress produced by biofilm-forming phytopathogenic bacteria, which are responsible for serious disease in many crops. Their characteristics, pathogenesis, virulence factors, systems of cellular communication, and the molecules implicated in the regulation of these processes are all covered.
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Affiliation(s)
- María Evangelina Carezzano
- Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Córdoba X5804BYA, Argentina
- Departamento de Biología Molecular; Universidad Nacional de Río Cuarto (UNRC), Río Cuarto, Córdoba X5804BYA, Argentina
- Departamento de Microbiología e Inmunología, UNRC, Río Cuarto, Córdoba X5804BYA, Argentina
| | - María Fernanda Paletti Rovey
- Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Córdoba X5804BYA, Argentina
- Departamento de Microbiología e Inmunología, UNRC, Río Cuarto, Córdoba X5804BYA, Argentina
| | - Lorena Del Rosario Cappellari
- Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Córdoba X5804BYA, Argentina
- Departamento de Biología Molecular; Universidad Nacional de Río Cuarto (UNRC), Río Cuarto, Córdoba X5804BYA, Argentina
| | | | - Pablo Bogino
- Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Córdoba X5804BYA, Argentina
- Departamento de Biología Molecular; Universidad Nacional de Río Cuarto (UNRC), Río Cuarto, Córdoba X5804BYA, Argentina
| | - María de Las Mercedes Oliva
- Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Córdoba X5804BYA, Argentina
- Departamento de Microbiología e Inmunología, UNRC, Río Cuarto, Córdoba X5804BYA, Argentina
| | - Walter Giordano
- Instituto de Biotecnología Ambiental y Salud (INBIAS-CONICET), Córdoba X5804BYA, Argentina
- Departamento de Biología Molecular; Universidad Nacional de Río Cuarto (UNRC), Río Cuarto, Córdoba X5804BYA, Argentina
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8
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Williams DE, Nesbitt NM, Muralidharan S, Hossain S, Boon EM. H-NOX Regulates Biofilm Formation in Agrobacterium Vitis in Response to NO. Biochemistry 2023; 62:912-922. [PMID: 36746768 DOI: 10.1021/acs.biochem.2c00639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Transitions between motile and biofilm lifestyles are highly regulated and fundamental to microbial pathogenesis. H-NOX (heme-nitric oxide/oxygen-binding domain) is a key regulator of bacterial communal behaviors, such as biofilm formation. A predicted bifunctional cyclic di-GMP metabolizing enzyme, composed of diguanylate cyclase and phosphodiesterase (PDE) domains (avi_3097), is annotated downstream of an hnoX gene in Agrobacterium vitis S4. Here, we demonstrate that avH-NOX is a nitric oxide (NO)-binding hemoprotein that binds to and regulates the activity of avi_3097 (avHaCE; H-NOX-associated cyclic di-GMP processing enzyme). Kinetic analysis of avHaCE indicates a ∼four-fold increase in PDE activity in the presence of NO-bound avH-NOX. Biofilm analysis with crystal violet staining reveals that low concentrations of NO reduce biofilm growth in the wild-type A. vitis S4 strain, but the mutant ΔhnoX strain has no NO phenotype, suggesting that H-NOX is responsible for the NO biofilm phenotype in A. vitis. Together, these data indicate that avH-NOX enhances cyclic di-GMP degradation to reduce biofilm formation in response to NO in A. vitis.
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Affiliation(s)
- Dominique E Williams
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Natasha M Nesbitt
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Sandhya Muralidharan
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Sajjad Hossain
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
| | - Elizabeth M Boon
- Department of Chemistry and Institute of Chemical Biology and Drug Design, Stony Brook University, Stony Brook, New York 11794-3400, United States
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9
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Fessia A, Sartori M, García D, Fernández L, Ponzio R, Barros G, Nesci A. In vitro studies of biofilm-forming Bacillus strains, biocontrol agents isolated from the maize phyllosphere. Biofilm 2022; 4:100097. [PMID: 36504526 PMCID: PMC9731887 DOI: 10.1016/j.bioflm.2022.100097] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/08/2022] [Accepted: 11/18/2022] [Indexed: 12/12/2022] Open
Abstract
We aimed to assess how biofilm formation by three Bacillus isolates was affected by changes in temperature, water potential, growth media, time, and the combinations between these factors. The strains had been selected as potential biological control agents (BCAs) in earlier studies, and they were identified as B. subtilis and B. velezensis spp. through 16 rRNA sequencing and MALDI-TOF MS. Maize leaves (ML) were used as one of the growth media, since they made it possible to simulate the nutrient content in the maize phyllosphere, from which the bacteria were originally isolated. The strains were able to form biofilm both in ML and biofilm-inducing MSgg after 24, 48, and 72 h. Biofilm development in the form of pellicles and architecturally complex colonies varied morphologically from one strain to another and depended on the conditions mentioned above. In all cases, colonies and pellicles were less complex when both temperature and water potential were lower. Scanning electron microscopy (SEM) revealed that changing levels of complexity in pellicles were correlated with those in colonies. Statistical analyses found that the quantification of biofilm produced by the isolates was influenced by all the conditions tested. In terms of motility (which may contribute to biofilm formation), swimming and swarming were possible for all strains in 0.3 and 0.7% agar, respectively. A more in-depth understanding of how abiotic factors influence biofilm formation can contribute to a more effective use of these biocontrol strains against pathogens in the maize phyllosphere.
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Affiliation(s)
- Aluminé Fessia
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina,Corresponding author. Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina.
| | - Melina Sartori
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Daiana García
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Luciana Fernández
- Departamento de Física, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CONICET, X5804BYA, Río Cuarto, Argentina,Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Rodrigo Ponzio
- Departamento de Física, Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, CONICET, X5804BYA, Río Cuarto, Argentina,Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados (IITEMA), Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Germán Barros
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
| | - Andrea Nesci
- Laboratorio de Ecología Microbiana, Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional 36, Km 601, X5804ZAB, Río Cuarto, Córdoba, Argentina,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
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10
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Shaffique S, Imran M, Wani SH, Khan MA, Kang SM, Adhikari A, Lee IJ. Evaluating the adhesive potential of the newly isolated bacterial strains in research exploitation of plant microbial interaction. FRONTIERS IN PLANT SCIENCE 2022; 13:1004331. [PMID: 36340407 PMCID: PMC9634002 DOI: 10.3389/fpls.2022.1004331] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 10/06/2022] [Indexed: 05/26/2023]
Abstract
Bacterial adhesion potential constitutes the transition of bacteria from the planktonic to the static phase by promoting biofilm formation, which plays a significant role in plant-microbial interaction in the agriculture industry. In present study, the adhesion potential of five soil-borne bacterial strains belonging to different genera was studied. All bacterial strains were capable of forming colonies and biofilms of different levels of firmness on polystyrene. Significant variation was observed in hydrophobicity and motility assays. Among the five bacterial strains (SH-6, SH-8, SH-9, SH-10, and SH-19), SH-19 had a strong hydrophobic force, while SH-10 showed the most hydrophilic property. SH-6 showed great variability in motility; SH-8 had a swimming diffusion diameter of 70 mm, which was three times higher than that of SH-19. In the motility assay, SH-9 and SH-10 showed diffusion diameters of approximately 22 mm and 55 mm, respectively. Furthermore, among the five strains, four are predominately electron donors and one is electron acceptors. Overall, positive correlation was observed among Lewis acid base properties, hydrophobicity, and biofilm forming ability. However, no correlation of motility with bacterial adhesion could be found in present experimental work. Scanning electron microscopy images confirmed the adhesion potential and biofilm ability within extra polymeric substances. Research on the role of adhesion in biofilm formation of bacteria isolated from plants is potentially conducive for developing strategies such as plant-microbial interaction to mitigate the abiotic stress.
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Affiliation(s)
- Shifa Shaffique
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - Muhammad Imran
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - Shabir Hussain Wani
- Mountain Research for Field Crops Khudwani, Sher-e Kashmir University of Agricultural Sciences and Technology of Kashmir, Srinagar, Jamu and Kashmir, India
| | - Muhamad Aqil Khan
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - Sang-Mo Kang
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - Arjun Adhikari
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
| | - In-Jung Lee
- Department of Applied Biosciences, Kyungpook National University, Daegu, South Korea
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11
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Ehau‐Taumaunu H, Hockett KL. The plant host environment influences competitive interactions between bacterial pathogens. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:785-794. [PMID: 35700743 PMCID: PMC9796116 DOI: 10.1111/1758-2229.13103] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 05/31/2022] [Accepted: 06/02/2022] [Indexed: 06/15/2023]
Abstract
Bacteria compete for resources in diverse environments using an array of antagonistic strategies, including the production of narrow-spectrum protein antibacterials termed bacteriocins. Although significant research has focused on bacteriocin-mediated dynamics in culture environments, little research has explored bacteriocin-mediated dynamics within a host context, particularly in plant environments. Here, we show that a bacterial plant pathogen, Pseudomonas syringae pv. syringae (Psy), expresses a bacteriocin both in culture and in leaf apoplast when co-inoculated with a bacteriocin-sensitive competitor, P. syringae pv. phaseolicola (Pph). Although there is an observable negative effect of the bacteriocin on the Pph population at most time points both in culture and in the leaf apoplast, a bacteriocin-mediated benefit to Psy was only observed when the producing strain was co-infiltrated at a low population frequency (1:9) into the leaf apoplast. At 6 days post-infiltration, Psy achieved an eightfold population increase compared to a bacteriocin-deficient mutant in the apoplast. No bacteriocin-mediated benefit for Psy was observed under the culture conditions tested. Additionally, we found that the bacteriocin-mediated benefit for Psy was dependent on the Type III Secretion System. Taken together, our results demonstrate that the fitness benefit of bacteriocin-mediated antagonism is influenced by interactions within the host plant.
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Affiliation(s)
- Hanareia Ehau‐Taumaunu
- Department of Plant Pathology and Environmental MicrobiologyThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | - Kevin L. Hockett
- Department of Plant Pathology and Environmental MicrobiologyThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- Center for Infectious Diseases DynamicsThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
- The Huck Institutes of the Life SciencesThe Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
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12
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De La Fuente L, Merfa MV, Cobine PA, Coleman JJ. Pathogen Adaptation to the Xylem Environment. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:163-186. [PMID: 35472277 DOI: 10.1146/annurev-phyto-021021-041716] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
A group of aggressive pathogens have evolved to colonize the plant xylem. In this vascular tissue, where water and nutrients are transported from the roots to the rest of the plant, pathogens must be able to thrive under acropetal xylem sap flow and scarcity of nutrients while having direct contact only with predominantly dead cells. Nevertheless, a few bacteria have adapted to exclusively live in the xylem, and various pathogens may colonize other plant niches without causing symptoms unless they reach the xylem. Once established, the pathogens modulate its physicochemical conditions to enhance their growth and virulence. Adaptation to the restrictive lifestyle of the xylem leads to genome reduction in xylem-restricted bacteria, as they have a higher proportion of pseudogenes in their genome. The basis of xylem adaptation is not completely understood; therefore, a need still exists for model systems to advance the knowledge on this topic.
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Affiliation(s)
- Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA;
| | - Marcus V Merfa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA;
| | - Paul A Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama, USA
| | - Jeffrey J Coleman
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, USA;
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13
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Singh BSM, Dhal NK, Kumar M, Mohapatra D, Seshadri H, Rout NC, Nayak M. Phytoremediation of 137Cs: factors and consequences in the environment. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2022; 61:341-359. [PMID: 35869396 DOI: 10.1007/s00411-022-00985-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 06/27/2022] [Indexed: 06/15/2023]
Abstract
Radionuclide contamination is a concerning threat due to unexpected nuclear disasters and authorized discharge of radioactive elements, both in the past and in present times. Use of atomic power for energy generation is associated with unresolved issues concerning storage of residues and contaminants. For example, the nuclear accidents in Chernobyl 1986 and Fukushima 2011 resulted in considerable deposition of cesium (Cs) in soil, along with other radionuclides. Among Cs radioactive variants, the anthropogenic radioisotope 137Cs (t½ = 30.16 years) is of serious environmental concern, owing to its rapid incorporation into biological systems and emission of β and γ radiation during the decaying process. To remediate contaminated areas, mostly conventional techniques are applied that are not eco-friendly. Hence, an alternative green technology, i.e., phytoremediation, should in future be considered and implemented. This sustainable technology generates limited secondary waste and its objectives are to utilize hyper-accumulating plants to extract, stabilize, degrade, and filter the radionuclides. The review highlights plant mechanisms for up-taking radionuclides and influences of different environmental factors involved in the process, while considering its long-term effects.
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Affiliation(s)
- B S Manisha Singh
- Environment and Sustainability Department, CSIR-IMMT, Bhubaneshwar, 751013, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Human Resource Development Centre, (CSIR-HRDC) Campus, Ghaziabad, Uttar Pradesh, 201002, India
| | - Nabin Kumar Dhal
- Environment and Sustainability Department, CSIR-IMMT, Bhubaneshwar, 751013, India.
| | - Manish Kumar
- Environment and Sustainability Department, CSIR-IMMT, Bhubaneshwar, 751013, India
| | | | | | - Nirad Chandra Rout
- Environment and Sustainability Department, CSIR-IMMT, Bhubaneshwar, 751013, India
| | - Monalisha Nayak
- Atomic Energy Regulatory Board, Niyamak Bhavan, Mumbai, Anushakti nagar, 400094, India
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14
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He C, Zheng L, Gao W, Ding J, Li C, Xu X, Han B, Li Q, Wang S. Diversity and functions of quorum sensing bacteria in the root environment of the Suaeda glauca and Phragmites australis coastal wetlands. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2022; 29:54619-54631. [PMID: 35305219 DOI: 10.1007/s11356-022-19564-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
The quorum sensing (QS) system plays a significant role in the bacteria-bacteria or plant-bacteria relationships through signal molecules. However, little is known about the distribution and functional diversity of QS bacteria in the root environment of Suaeda glauca and Phragmites australis in coastal wetlands. We explored the bacterial community by amplicon sequencing and isolated 1050 strains from the rhizosphere soil and root tissues of S. glauca and P. australis in northern China to investigate the bacterial community and AHL producers. AHL activity was found in 76 isolates, and 22 distinct strains were confirmed by 16S rRNA gene sequencing. A substantial number of AHL producers clustered in rhizobiales and sphingomonadale, which derived from the root tissues. AHL producers in the rhizosphere soil mostly belonged to rhodobacterales. The different taxa of AHL producers in the rhizosphere soil and root tissues resulted in a variation of AHL profiles that C6-HSL dominated the AHL profiles in root bacteria compared to the C8-HSL in rhizobacteria, implying different ecological roles for AHL producers in the rhizosphere soil and root tissues. Many AHL producers may form biofilms, and some can degrade DMSP and oil, demonstrating that QS bacteria in the root environment have a wide ecological roles. In our study, for one of the first times here, we explore the distribution and functional variety of AHL producers in the root environment of S. glauca-P. australis. This study expands current knowledge of the relationship between QS bacteria and coastal plants (S. glauca and P. australis), and vital roles of QS bacterial in maintaining the health of coastal wetlands.
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Affiliation(s)
- Changfei He
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Li Zheng
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China.
- Laboratory for Marine Ecology and Environmental Science, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266071, China.
| | - Wei Gao
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Jinfeng Ding
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Chengxuan Li
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Xiyuan Xu
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Bin Han
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Qian Li
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
| | - Shuai Wang
- Key Laboratory of Marine Eco-Environmental Science and Technology, First Institute of Oceanography, Ministry of Natural Resources, Qingdao, 266061, China
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15
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Effects of Volatile Organic Compounds on Biofilms and Swimming Motility of Agrobacterium tumefaciens. Microorganisms 2022; 10:microorganisms10081512. [PMID: 35893570 PMCID: PMC9394263 DOI: 10.3390/microorganisms10081512] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/22/2022] [Accepted: 07/25/2022] [Indexed: 11/29/2022] Open
Abstract
Volatile organic compounds (VOCs) emitted by bacteria play an important role in the interaction between microorganisms and other organisms. They can inhibit the growth of phytopathogenic microorganisms, modulate plant growth, and serve as infochemicals. Here, we investigated the effects of ketones, alcohols, and terpenes on the colony biofilms of plant pathogenic Agrobacterium tumefaciens strains and swimming motility, which can play an important role in the formation of biofilms. It was shown that 2-octanone had the greatest inhibitory effect on biofilm formation, acting in a small amount (38.7 g/m3). Ketone 2-butanone and unsaturated ketone β-ionone reduced the formation of biofilms at higher doses (145.2–580.6 and 387.1–1548.3 g/m3, respectively, up to 2.5–5 times). Isoamyl alcohol and 2-phenylethanol decreased the formation of biofilms at doses of 88.7 and 122.9 g/m3 by 1.7 and 5 times, respectively, with an increased effect at 177.4 and 245.9 g/m3, respectively. The agrobacteria cells in mature biofilms were more resistant to the action of ketones and alcohols. These VOCs also suppressed the swimming motility of agrobacteria; the radius of swimming zones decreased ~from 2 to 5 times. Terpenes (−)-limonene and (+)-α-pinene had no significant influence on the colony biofilms and swimming motility at the doses used. The results obtained represent new information about the effect of VOCs on biofilms and the motility of bacteria.
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16
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Shao Y, Yin C, Lv F, Jiang S, Wu S, Han Y, Xue W, Ma Y, Zheng J, Zhan Y, Ke X, Lu W, Lin M, Shang L, Yan Y. The Sigma Factor AlgU Regulates Exopolysaccharide Production and Nitrogen-Fixing Biofilm Formation by Directly Activating the Transcription of pslA in Pseudomonas stutzeri A1501. Genes (Basel) 2022; 13:genes13050867. [PMID: 35627252 PMCID: PMC9141998 DOI: 10.3390/genes13050867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 05/06/2022] [Accepted: 05/10/2022] [Indexed: 11/29/2022] Open
Abstract
Pseudomonas stutzeri A1501, a plant-associated diazotrophic bacterium, prefers to conform to a nitrogen-fixing biofilm state under nitrogen-deficient conditions. The extracytoplasmic function (ECF) sigma factor AlgU is reported to play key roles in exopolysaccharide (EPS) production and biofilm formation in the Pseudomonas genus; however, the function of AlgU in P. stutzeri A1501 is still unclear. In this work, we mainly investigated the role of algU in EPS production, biofilm formation and nitrogenase activity in A1501. The algU mutant ΔalgU showed a dramatic decrease both in the EPS production and the biofilm formation capabilities. In addition, the biofilm-based nitrogenase activity was reduced by 81.4% in the ΔalgU mutant. The transcriptional level of pslA, a key Psl-like (a major EPS in A1501) synthesis-related gene, was almost completely inhibited in the algU mutant and was upregulated by 2.8-fold in the algU-overexpressing strain. A predicted AlgU-binding site was identified in the promoter region of pslA. The DNase I footprinting assays indicated that AlgU could directly bind to the pslA promoter, and β-galactosidase activity analysis further revealed mutations of the AlgU-binding boxes drastically reduced the transcriptional activity of the pslA promoter; moreover, we also demonstrated that AlgU was positively regulated by RpoN at the transcriptional level and negatively regulated by the RNA-binding protein RsmA at the posttranscriptional level. Taken together, these data suggest that AlgU promotes EPS production and nitrogen-fixing biofilm formation by directly activating the transcription of pslA, and the expression of AlgU is controlled by RpoN and RsmA at different regulatory levels.
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Affiliation(s)
- Yahui Shao
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Changyan Yin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Fanyang Lv
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Shanshan Jiang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Shaoyu Wu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Yueyue Han
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Wei Xue
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Yiyuan Ma
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Juan Zheng
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Yuhua Zhan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Xiubin Ke
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Wei Lu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Min Lin
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
| | - Liguo Shang
- School of Basic Medicine, GuangXi University of Chinese Medicine, Nanning 530200, China
- Correspondence: (L.S.); (Y.Y.)
| | - Yongliang Yan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; (Y.S.); (C.Y.); (F.L.); (S.J.); (S.W.); (Y.H.); (W.X.); (Y.M.); (J.Z.); (Y.Z.); (X.K.); (W.L.); (M.L.)
- Correspondence: (L.S.); (Y.Y.)
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Afonso AC, Sousa M, Simões LC, Simões M. Phytochemicals Against Drug-Resistant Bacterial Biofilms and Use of Green Extraction Solvents to Increase Their Bioactivity. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022. [DOI: 10.1007/5584_2022_723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Šantl-Temkiv T, Amato P, Casamayor EO, Lee PKH, Pointing SB. OUP accepted manuscript. FEMS Microbiol Rev 2022; 46:6524182. [PMID: 35137064 PMCID: PMC9249623 DOI: 10.1093/femsre/fuac009] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 01/31/2022] [Accepted: 02/06/2022] [Indexed: 11/30/2022] Open
Abstract
The atmosphere connects habitats across multiple spatial scales via airborne dispersal of microbial cells, propagules and biomolecules. Atmospheric microorganisms have been implicated in a variety of biochemical and biophysical transformations. Here, we review ecological aspects of airborne microorganisms with respect to their dispersal, activity and contribution to climatic processes. Latest studies utilizing metagenomic approaches demonstrate that airborne microbial communities exhibit pronounced biogeography, driven by a combination of biotic and abiotic factors. We quantify distributions and fluxes of microbial cells between surface habitats and the atmosphere and place special emphasis on long-range pathogen dispersal. Recent advances have established that these processes may be relevant for macroecological outcomes in terrestrial and marine habitats. We evaluate the potential biological transformation of atmospheric volatile organic compounds and other substrates by airborne microorganisms and discuss clouds as hotspots of microbial metabolic activity in the atmosphere. Furthermore, we emphasize the role of microorganisms as ice nucleating particles and their relevance for the water cycle via formation of clouds and precipitation. Finally, potential impacts of anthropogenic forcing on the natural atmospheric microbiota via emission of particulate matter, greenhouse gases and microorganisms are discussed.
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Affiliation(s)
- Tina Šantl-Temkiv
- Department of Biology, Aarhus University, DK-8000 Aarhus, Denmark
- Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus, Denmark
| | - Pierre Amato
- Institut de Chimie de Clermont-Ferrand, SIGMA Clermont, CNRS, Université Clermont Auvergne, 63178, Clermont-Ferrand, France
| | - Emilio O Casamayor
- Centre for Advanced Studies of Blanes, Spanish Council for Research (CSIC), 17300, Blanes, Spain
| | - Patrick K H Lee
- School of Energy and Environment, City University of Hong Kong, Hong Kong, China
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Stephen B Pointing
- Corresponding author: Yale-NUS College, National University of Singapore, 16 College Avenue West, Singapore 138527. Tel: +65 6601 1000; E-mail:
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19
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Peng J, Liu H, Shen M, Chen R, Li J, Dong Y. The inhibitory effects of different types of Brassica seed meals on the virulence of Ralstonia solanacearum. PEST MANAGEMENT SCIENCE 2021; 77:5129-5138. [PMID: 34251090 DOI: 10.1002/ps.6552] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 07/12/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Understanding the specific inhibitory effects of different Brassica seed meals (BSMs) on soilborne pathogens is important for their application as biocontrol agents for controlling plant disease. In this study, the seed meals of Brassica napus L. (BnSM), Brassica campestris L. (BcSM), and Brassica juncea L. (BjSM), and the combined seed meal of BcSM and BjSM (CSM, 1:1), were selected for investigation. The inhibitory effects of these seed meals on the plant pathogen Ralstonia solanacearum (Smith) and tomato bacterial wilt, were assessed and compared. RESULTS All the BSMs significantly inhibited the growth of R. solanacearum in vitro. Furthermore, the BSMs could effectively suppress R. solanacearum virulence traits, including motility, exopolysaccharide production, dehydrogenase activity, virulence-related gene expression, and colonization in the soil. Among them, BjSM showed the best inhibiting effects, and CSM displayed synergic toxicity against R. solanacearum. In addition, the predominant antibacterial compounds in BcSM and BjSM were identified as the volatile compounds, 3-butenyl isothiocyanate and allyl isothiocyanate, respectively. Finally, pot experiment verified that the control effects of BjSM and CSM on tomato wilt reached more than 90%. CONCLUSION This is the first study to report on the ability of different kinds of BSMs to suppress the virulence of R. solanacearum and biocontrol efficiencies against bacterial wilt in tomato plants. Furtherly, the main antibacterial compounds in the BSMs were identified. The results demonstrated that CSM may possess potential for controlling bacterial wilt caused by R. solanacearum. The results provide a fresh perspective for comprehending the mechanism underlying BSM suppression of pathogens and plant disease.
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Affiliation(s)
- Junwei Peng
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Hong Liu
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Minchong Shen
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ruihuan Chen
- University of Chinese Academy of Sciences, Beijing, China
- College of Life and Environmental Science, Wenzhou University, Wenzhou, China
| | - Jiangang Li
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Yuanhua Dong
- CAS Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
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20
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Sentenac H, Loyau A, Leflaive J, Schmeller DS. The significance of biofilms to human, animal, plant and ecosystem health. Funct Ecol 2021. [DOI: 10.1111/1365-2435.13947] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Hugo Sentenac
- Laboratoire Ecologie Fonctionnelle et Environnement UMR 5245 Université de Toulouse CNRS INPT UPS Castanet‐Tolosan Cedex France
| | - Adeline Loyau
- Laboratoire Ecologie Fonctionnelle et Environnement UMR 5245 Université de Toulouse CNRS INPT UPS Castanet‐Tolosan Cedex France
- Department of Experimental Limnology Leibniz‐Institute of Freshwater Ecology and Inland Fisheries (IGB) Stechlin Germany
| | - Joséphine Leflaive
- Laboratoire Ecologie Fonctionnelle et Environnement UMR 5245 Université de Toulouse CNRS INPT UPS Castanet‐Tolosan Cedex France
| | - Dirk S. Schmeller
- Laboratoire Ecologie Fonctionnelle et Environnement UMR 5245 Université de Toulouse CNRS INPT UPS Castanet‐Tolosan Cedex France
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21
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Mansoor S, Zahoor I, Baba TR, Padder SA, Bhat ZA, Koul AM, Jiang L. Fabrication of Silver Nanoparticles Against Fungal Pathogens. FRONTIERS IN NANOTECHNOLOGY 2021. [DOI: 10.3389/fnano.2021.679358] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The use of silver nanoparticles (AgNPs) against various pathogens is now being well recognized in the agriculture and health sector. Nanoparticles have been shown to exhibit various novel properties and these properties, on other hand, rely upon the size, shape, and morphology of these particles. Moreover, these physical characteristics enable them to interact with microbes, plants, and animals. Smaller-sized particles have shown more toxicity than larger-sized nanoparticles. AgNPs have shown growth inhibition of many fungi like Aspergillus fumigates, A. niger, A. flavus, Trichophyton rubrum, Candida albicans, and Penicillium species. According to the current hypothesis, AgNPs act by producing reactive oxygen species and free radicals, which cause protein denaturation, nucleic acid and proton pump damage, lipid peroxidation, and cell wall damage. Therefore, they alter the cell membrane permeability, causing cell death. This mini-review summarizes the use of silver nanoparticles against fungal pathogens and fungal biofilm in the agricultural sector.
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Wang H, Cai XY, Xu M, Tian F. Enhanced Biocontrol of Cucumber Fusarium Wilt by Combined Application of New Antagonistic Bacteria Bacillus amyloliquefaciens B2 and Phenolic Acid-Degrading Fungus Pleurotus ostreatus P5. Front Microbiol 2021; 12:700142. [PMID: 34512576 PMCID: PMC8425394 DOI: 10.3389/fmicb.2021.700142] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/27/2021] [Indexed: 11/25/2022] Open
Abstract
Continuous monoculture of cucumber (Cucumis sativus L.) typically leads to the frequent incidence of Fusarium wilt caused by Fusarium oxysporum f. sp. cucumerinum (FOC). As potent allelochemicals, phenolic acids are believed to be associated with soilborne diseases. This study aimed to investigate the effect of single or co-inoculation of antagonistic bacteria Bacillus amyloliquefaciens B2 and phenolic acid-degrading fungus Pleurotus ostreatus P5 on the suppression of cucumber Fusarium wilt. The strain B2 was identified as B. amyloliquefaciens based on biochemical, physiological, and 16S rDNA and gyrB gene sequence analyses. Strain B2 showed indole-3-acetic acid (IAA) and siderophore production and phosphate solubilization in in vitro assays. Scanning electron microscope (SEM) imaging showed the ability of strain B2 to adhere to the root surface of cucumber. P. ostreatus P5 could effectively degrade mixed phenolic acids as its sole source of carbon and energy for growth in liquid medium. In a pot experiment, four treatments were established as follows: (1) CK, uninoculated control; (2) B2, inoculation of strain B2; (3) P5, inoculation of strain P5; and (4) B2 + P5, co-inoculation of strain B2 and strain P5. At the end of the 60-day pot experiment, the B2, P5, and B2 + P5 treatments significantly reduced disease incidence by 48.1, 22.2, and 63.0%, respectively, compared to the CK treatment (p < 0.05). All three inoculation treatments significantly increased the growth of cucumber seedlings and suppressed the FOC population compared to the control (p < 0.05). High-performance liquid chromatography (HPLC) analysis showed that total phenolic acids were decreased by 18.9, 35.9, and 63.2% in the B2, P5, and B2 + P5 treatments, respectively. The results from this study suggest that combined application of B. amyloliquefaciens B2 and P. ostreatus P5 could be a promising strategy for suppressing Fusarium wilt and improving plant growth of cucumber seedlings under continuous cropping conditions.
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Affiliation(s)
- Hongwei Wang
- Nanjing Institute of Environmental Science, Ministry of Ecology and Environment of China, Nanjing, China
| | - Xiao-Yu Cai
- Nanjing Institute of Environmental Science, Ministry of Ecology and Environment of China, Nanjing, China
| | - Man Xu
- Nanjing Institute of Environmental Science, Ministry of Ecology and Environment of China, Nanjing, China
| | - Feng Tian
- Nanjing Institute of Environmental Science, Ministry of Ecology and Environment of China, Nanjing, China
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23
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Biofilm formation by strains of Burkholderia cenocepacia lineages IIIA and IIIB and B. gladioli pv. alliicola associated with onion bacterial scale rot. Braz J Microbiol 2021; 52:1665-1675. [PMID: 34351603 DOI: 10.1007/s42770-021-00564-6] [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: 02/25/2021] [Accepted: 06/27/2021] [Indexed: 10/20/2022] Open
Abstract
The Burkholderia genus has high ecological and nutritional versatility, having species capable of causing diseases in animals, humans, and plants. During chronic infections in humans, biofilm formation is a characteristic often associated with strains from different species of this genus. However, there is still no information on the formation of biofilms by plant pathogenic strains of B. cenocepacia (Bce) lineages IIIA and IIIB and B. gladioli pv. alliicola (Bga), which are associated with onion bacterial scale rot in the semi-arid region of northeast Brazil. In this study, we performed an in vitro characterization of biofilm formation ability in different culture media by the phytopathogenic strains of Bce and Bga and investigated its relationship with swarming motility. Our results indicated the existence of an intraspecific variation in biofilm formation capacity in vitro by these bacteria and the existence of a negative correlation between swarming motility and biofilm formation for strains of Bce lineage IIIB. In addition, histopathological analyses performed using optical microscopy and scanning electron microscopy revealed the formation of biofilm in vivo by Bce strains in onion tissues.
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24
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Bourigault Y, Rodrigues S, Crépin A, Chane A, Taupin L, Bouteiller M, Dupont C, Merieau A, Konto-Ghiorghi Y, Boukerb AM, Turner M, Hamon C, Dufour A, Barbey C, Latour X. Biocontrol of Biofilm Formation: Jamming of Sessile-Associated Rhizobial Communication by Rhodococcal Quorum-Quenching. Int J Mol Sci 2021; 22:ijms22158241. [PMID: 34361010 PMCID: PMC8347015 DOI: 10.3390/ijms22158241] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/02/2021] [Accepted: 07/07/2021] [Indexed: 11/16/2022] Open
Abstract
Biofilms are complex structures formed by a community of microbes adhering to a surface and/or to each other through the secretion of an adhesive and protective matrix. The establishment of these structures requires a coordination of action between microorganisms through powerful communication systems such as quorum-sensing. Therefore, auxiliary bacteria capable of interfering with these means of communication could be used to prevent biofilm formation and development. The phytopathogen Rhizobium rhizogenes, which causes hairy root disease and forms large biofilms in hydroponic crops, and the biocontrol agent Rhodococcus erythropolis R138 were used for this study. Changes in biofilm biovolume and structure, as well as interactions between rhizobia and rhodococci, were monitored by confocal laser scanning microscopy with appropriate fluorescent biosensors. We obtained direct visual evidence of an exchange of signals between rhizobia and the jamming of this communication by Rhodococcus within the biofilm. Signaling molecules were characterized as long chain (C14) N-acyl-homoserine lactones. The role of the Qsd quorum-quenching pathway in biofilm alteration was confirmed with an R. erythropolis mutant unable to produce the QsdA lactonase, and by expression of the qsdA gene in a heterologous host, Escherichia coli. Finally, Rhizobium biofilm formation was similarly inhibited by a purified extract of QsdA enzyme.
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Affiliation(s)
- Yvann Bourigault
- Laboratory of Microbiology Signals and Microenvironment (LMSM EA 4312), University of Rouen Normandy, F-27000 Evreux, France; (Y.B.); (A.C.); (M.B.); (C.D.); (A.M.); (Y.K.-G.); (A.M.B.); (C.B.)
- Research Federations NORVEGE Fed4277 & NORSEVE, Normandy University, F-76821 Mont-Saint-Aignan, France
| | - Sophie Rodrigues
- Laboratoire de Biotechnologie et Chimie Marines, LBCM IUEM, EA 3884, Université de Bretagne-Sud, F-56100 Lorient, France; (S.R.); (L.T.); (A.D.)
| | - Alexandre Crépin
- Laboratoire Ecologie et Biologie des Interactions, UMR CNRS 7267, F-86073 Poitiers, France;
| | - Andrea Chane
- Laboratory of Microbiology Signals and Microenvironment (LMSM EA 4312), University of Rouen Normandy, F-27000 Evreux, France; (Y.B.); (A.C.); (M.B.); (C.D.); (A.M.); (Y.K.-G.); (A.M.B.); (C.B.)
| | - Laure Taupin
- Laboratoire de Biotechnologie et Chimie Marines, LBCM IUEM, EA 3884, Université de Bretagne-Sud, F-56100 Lorient, France; (S.R.); (L.T.); (A.D.)
| | - Mathilde Bouteiller
- Laboratory of Microbiology Signals and Microenvironment (LMSM EA 4312), University of Rouen Normandy, F-27000 Evreux, France; (Y.B.); (A.C.); (M.B.); (C.D.); (A.M.); (Y.K.-G.); (A.M.B.); (C.B.)
- Research Federations NORVEGE Fed4277 & NORSEVE, Normandy University, F-76821 Mont-Saint-Aignan, France
| | - Charly Dupont
- Laboratory of Microbiology Signals and Microenvironment (LMSM EA 4312), University of Rouen Normandy, F-27000 Evreux, France; (Y.B.); (A.C.); (M.B.); (C.D.); (A.M.); (Y.K.-G.); (A.M.B.); (C.B.)
- Research Federations NORVEGE Fed4277 & NORSEVE, Normandy University, F-76821 Mont-Saint-Aignan, France
| | - Annabelle Merieau
- Laboratory of Microbiology Signals and Microenvironment (LMSM EA 4312), University of Rouen Normandy, F-27000 Evreux, France; (Y.B.); (A.C.); (M.B.); (C.D.); (A.M.); (Y.K.-G.); (A.M.B.); (C.B.)
- Research Federations NORVEGE Fed4277 & NORSEVE, Normandy University, F-76821 Mont-Saint-Aignan, France
| | - Yoan Konto-Ghiorghi
- Laboratory of Microbiology Signals and Microenvironment (LMSM EA 4312), University of Rouen Normandy, F-27000 Evreux, France; (Y.B.); (A.C.); (M.B.); (C.D.); (A.M.); (Y.K.-G.); (A.M.B.); (C.B.)
- Research Federations NORVEGE Fed4277 & NORSEVE, Normandy University, F-76821 Mont-Saint-Aignan, France
| | - Amine M. Boukerb
- Laboratory of Microbiology Signals and Microenvironment (LMSM EA 4312), University of Rouen Normandy, F-27000 Evreux, France; (Y.B.); (A.C.); (M.B.); (C.D.); (A.M.); (Y.K.-G.); (A.M.B.); (C.B.)
| | - Marie Turner
- Vegenov, F-29250 Saint-Pol-de-Léon, France; (M.T.); (C.H.)
- Biocontrol Consortium, F-75007 Paris, France
| | - Céline Hamon
- Vegenov, F-29250 Saint-Pol-de-Léon, France; (M.T.); (C.H.)
| | - Alain Dufour
- Laboratoire de Biotechnologie et Chimie Marines, LBCM IUEM, EA 3884, Université de Bretagne-Sud, F-56100 Lorient, France; (S.R.); (L.T.); (A.D.)
| | - Corinne Barbey
- Laboratory of Microbiology Signals and Microenvironment (LMSM EA 4312), University of Rouen Normandy, F-27000 Evreux, France; (Y.B.); (A.C.); (M.B.); (C.D.); (A.M.); (Y.K.-G.); (A.M.B.); (C.B.)
- Research Federations NORVEGE Fed4277 & NORSEVE, Normandy University, F-76821 Mont-Saint-Aignan, France
| | - Xavier Latour
- Laboratory of Microbiology Signals and Microenvironment (LMSM EA 4312), University of Rouen Normandy, F-27000 Evreux, France; (Y.B.); (A.C.); (M.B.); (C.D.); (A.M.); (Y.K.-G.); (A.M.B.); (C.B.)
- Research Federations NORVEGE Fed4277 & NORSEVE, Normandy University, F-76821 Mont-Saint-Aignan, France
- Biocontrol Consortium, F-75007 Paris, France
- Correspondence: ; +33-235-146-000
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A regulatory network involving Rpo, Gac and Rsm for nitrogen-fixing biofilm formation by Pseudomonas stutzeri. NPJ Biofilms Microbiomes 2021; 7:54. [PMID: 34210981 PMCID: PMC8249394 DOI: 10.1038/s41522-021-00230-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
Biofilm and nitrogen fixation are two competitive strategies used by many plant-associated bacteria; however, the mechanisms underlying the formation of nitrogen-fixing biofilms remain largely unknown. Here, we examined the roles of multiple signalling systems in the regulation of biofilm formation by root-associated diazotrophic P. stutzeri A1501. Physiological analysis, construction of mutant strains and microscale thermophoresis experiments showed that RpoN is a regulatory hub coupling nitrogen fixation and biofilm formation by directly activating the transcription of pslA, a major gene involved in the synthesis of the Psl exopolysaccharide component of the biofilm matrix and nifA, the transcriptional activator of nif gene expression. Genetic complementation studies and determination of the copy number of transcripts by droplet digital PCR confirmed that the regulatory ncRNA RsmZ serves as a signal amplifier to trigger biofilm formation by sequestering the translational repressor protein RsmA away from pslA and sadC mRNAs, the latter of which encodes a diguanylate cyclase that synthesises c-di-GMP. Moreover, RpoS exerts a braking effect on biofilm formation by transcriptionally downregulating RsmZ expression, while RpoS expression is repressed posttranscriptionally by RsmA. These findings provide mechanistic insights into how the Rpo/Gac/Rsm regulatory networks fine-tune nitrogen-fixing biofilm formation in response to the availability of nutrients.
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26
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Pashang R, Gilbride KA. From individual response to population ecology: Environmental factors restricting survival of vegetative bacteria at solid-air interfaces. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 773:144982. [PMID: 33592458 DOI: 10.1016/j.scitotenv.2021.144982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/06/2020] [Accepted: 01/02/2021] [Indexed: 06/12/2023]
Abstract
Combating microbial survival on dry surfaces contributes to improving public health in indoor environments (clinical and industrial settings) and extends to the natural environment. For vegetative bacteria at solid-air interfaces, lack of water impacts cellular response, and acclimation depends on community support in response to ecological processes. Gaining insights about important ecological processes leading to inhibition of microbial survival under extreme conditions, such as vicinity of highly radioactive nuclear waste, is key for improving engineering designs. Canada plans to store used nuclear fuel and radioactive waste in a deep geological repository (DGR) with a multiple-barrier system constructed at an approximate depth of 500 m. Microorganisms in highly compacted bentonite surrounding used fuel containers will be challenged by high pressure, temperature, and radiation, as well as limited water and nutrients. Thus, it is difficult to estimate microbial activities, given that the prime concern for a microbial community is survival, and energy expenditure is regulated. To enable preventive measures and for risk evaluation, a deeper understanding of community-based survival strategies of bacterial cells exposed to air (gaseous phase) during prolonged periods of desiccation is required. An in-depth review of collective studies that assess microbial survival and persistence during desiccation is presented here to augment and direct our prior knowledge about tactics used by bacteria for survival at interfaces in hostile natural environments including and similar to a DGR.
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Affiliation(s)
- Rosha Pashang
- Department of Chemistry and Biology, Ryerson University, Toronto, Canada; Department of Chemical Engineering, University of Bath, Bath, United Kingdom
| | - Kimberley A Gilbride
- Department of Chemistry and Biology, Ryerson University, Toronto, Canada; Ryerson Urban Water Group, Ryerson University, Toronto, Canada.
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Rajamma SB, Raj A, Kalampalath V, Eapen SJ. Elucidation of antibacterial effect of calcium chloride against Ralstonia pseudosolanacearum race 4 biovar 3 infecting ginger (Zingiber officinale Rosc.). Arch Microbiol 2021; 203:663-671. [PMID: 33029663 DOI: 10.1007/s00203-020-02052-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 08/25/2020] [Accepted: 09/15/2020] [Indexed: 11/25/2022]
Abstract
Bacterial wilt incited by Ralstonia pseudosolanacearum (Rps) race 4 biovar 3 is a serious threat to ginger (Zingiber officinale Rosc.) cultivation throughout the ginger growing tracts and warrants effective remedial measures since most of the strategies failed at field level implementation. After a series of experiments, calcium chloride was found to be effective against Rps both in vitro and in planta and its prophylactic effect has been successfully demonstrated under field conditions. CaCl2 at a concentration of > 2% significantly inhibited Rps under in vitro conditions. Calcium is an important nutritional element imparts a major role in plant disease resistance, and numerous studies have demonstrated the mitigating effect of calcium for disease management. CaCl2 being inhibitory to Rps, the mechanism of inhibition by CaCl2 against Rps was elucidated by a series of in vitro assays including swarming motility and biofilm formation. Direct inhibition was also studied using Scanning Electron Microscopy (SEM). The minimum bactericidal concentration and minimum inhibitory concentration were found to be around 3% while the EC 90 value was found to be 2.25%. The SEM analysis revealed the destruction of cell structure by making perforations on the cell surface. CaCl2 at the targeted concentrations inhibited biofilm formation as well as swarming motility of Rps. These findings suggest that CaCl2 exhibits strong antibacterial activity against Rps and has the potential to be used as an effective bactericide for Rps in managing bacterial wilt in ginger.
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Affiliation(s)
- Suseela Bhai Rajamma
- ICAR-Indian Institute of Spices Research, Marikunnu P O, Kozhikode, Kerala, 673012, India.
| | - Ammu Raj
- ICAR-Indian Institute of Spices Research, Marikunnu P O, Kozhikode, Kerala, 673012, India
| | - Vincy Kalampalath
- ICAR-Indian Institute of Spices Research, Marikunnu P O, Kozhikode, Kerala, 673012, India
| | - Santhosh J Eapen
- ICAR-Indian Institute of Spices Research, Marikunnu P O, Kozhikode, Kerala, 673012, India
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28
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Purahong W, Hossen S, Nawaz A, Sadubsarn D, Tanunchai B, Dommert S, Noll M, Ampornpan LA, Werukamkul P, Wubet T. Life on the Rocks: First Insights Into the Microbiota of the Threatened Aquatic Rheophyte Hanseniella heterophylla. FRONTIERS IN PLANT SCIENCE 2021; 12:634960. [PMID: 34194446 PMCID: PMC8238419 DOI: 10.3389/fpls.2021.634960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Accepted: 04/15/2021] [Indexed: 05/15/2023]
Abstract
Little is known about microbial communities of aquatic plants despite their crucial ecosystem function in aquatic ecosystems. Here, we analyzed the microbiota of an aquatic rheophyte, Hanseniella heterophylla, growing at three areas differing in their degree of anthropogenic disturbance in Thailand employing a metabarcoding approach. Our results show that diverse taxonomic and functional groups of microbes colonize H. heterophylla. Proteobacteria, Actinobacteria, Dothideomycetes, and Sordariomycetes form the backbone of the microbiota. Surprisingly, the beneficial microbes reported from plant microbiomes in terrestrial habitats, such as N-fixing bacteria and ectomycorrhizal fungi, were also frequently detected. We showed that biofilms for attachment of H. heterophylla plants to rocks may associate with diverse cyanobacteria (distributed in eight families, including Chroococcidiopsaceae, Coleofasciculaceae, Leptolyngbyaceae, Microcystaceae, Nostocaceae, Phormidiaceae, Synechococcaceae, and Xenococcaceae) and other rock biofilm-forming bacteria (mainly Acinetobacter, Pseudomonas, and Flavobacterium). We found distinct community compositions of both bacteria and fungi at high and low anthropogenic disturbance levels regardless of the study areas. In the highly disturbed area, we found strong enrichment of Gammaproteobacteria and Tremellomycetes coupled with significant decline of total bacterial OTU richness. Bacteria involved with sulfamethoxazole (antibiotic) degradation and human pathogenic fungi (Candida, Cryptococcus, Trichosporon, and Rhodotorula) were exclusively detected as indicator microorganisms in H. heterophylla microbiota growing in a highly disturbed area, which can pose a major threat to human health. We conclude that aquatic plant microbiota are sensitive to anthropogenic disturbance. Our results also unravel the potential use of this plant as biological indicators in remediation or treatment of such disturbed ecosystems.
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Affiliation(s)
- Witoon Purahong
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, Halle, Germany
- *Correspondence: Witoon Purahong, ;
| | - Shakhawat Hossen
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, Halle, Germany
- Institute of Ecology and Evolution, Friedrich-Schiller-Universität Jena, Jena, Germany
| | - Ali Nawaz
- Department of Community Ecology, UFZ-Helmholtz Centre for Environmental Research, Halle, Germany
- Department of Civil, Geo and Environmental Engineering, Technical University of Munich, Garching, Germany
| | - Dolaya Sadubsarn
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, Halle, Germany
| | - Benjawan Tanunchai
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, Halle, Germany
| | - Sven Dommert
- Department of Soil Ecology, UFZ-Helmholtz Centre for Environmental Research, Halle, Germany
| | - Matthias Noll
- Institute for Bioanalysis, Coburg University of Applied Sciences and Arts, Coburg, Germany
| | - La-aw Ampornpan
- Department of Biology, Srinakharinwirot University, Bangkok, Thailand
| | - Petcharat Werukamkul
- Faculty of Science and Technology, Rajamangala University of Technology Phra Nakhon, Bangkok, Thailand
- Petcharat Werukamkul,
| | - Tesfaye Wubet
- Department of Community Ecology, UFZ-Helmholtz Centre for Environmental Research, Halle, Germany
- German Centre for Integrative Biodiversity Research, Halle-Jena-Leipzig, Leipzig, Germany
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29
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Heredia-Ponce Z, Gutiérrez-Barranquero JA, Purtschert-Montenegro G, Eberl L, de Vicente A, Cazorla FM. Role of extracellular matrix components in the formation of biofilms and their contribution to the biocontrol activity of Pseudomonas chlororaphis PCL1606. Environ Microbiol 2020; 23:2086-2101. [PMID: 33314481 DOI: 10.1111/1462-2920.15355] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/09/2020] [Accepted: 12/10/2020] [Indexed: 12/15/2022]
Abstract
Pseudomonas chlororaphis PCL1606 (PcPCL1606) displays plant-colonizing features and exhibits antagonistic traits against soil-borne phytopathogenic fungi. Biofilm formation could be relevant for the PcPCL1606 lifestyle, and in this study the role of some putative extracellular matrix components (EMC; Fap-like fibre, alginate and Psl-like polysaccharides) in the biofilm architecture and biocontrol activity of this bacterium were determined. EMC such as the Fap-like fibre and alginate polysaccharide play secondary roles in biofilm formation in PcPCL1606, because they are not fundamental to its biofilm architecture in flow cell chamber, but synergistically they have shown to favour bacterial competition during biofilm formation. Conversely, studies on Psl-like polysaccharide have revealed that it may contain mannose, and that it is strongly involved in the PcPCL1606 biofilm architecture and niche competition. Furthermore, the Fap-like fibre and Psl-like exopolysaccharide play roles in early surface attachment and contribute to biocontrol activity against the white root rot disease caused by Rosellinia necatrix in avocado plants. These results constitute the first report regarding the study of the extracellular matrix of the PcPCL1606 strain and highlight the importance of a putative Fap-like fibre and Psl-like exopolysaccharide produced by PcPCL1606 in the biofilm formation process and interactions with the host plant root.
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Affiliation(s)
- Zaira Heredia-Ponce
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
| | - José Antonio Gutiérrez-Barranquero
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
| | | | - Leo Eberl
- Department of Plant and Microbial Biology, University of Zurich, Zollikerstrasse 107, Zurich, CH-8008, Switzerland
| | - Antonio de Vicente
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
| | - Francisco M Cazorla
- Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora" (IHSM-UMA-CSIC) - Departamento de Microbiología, Universidad de Málaga, Bulevar Louis Pasteur, 31 (Campus Universitario de Teatinos), Málaga, 29071, Spain
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30
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Thambugala KM, Daranagama DA, Phillips AJL, Kannangara SD, Promputtha I. Fungi vs. Fungi in Biocontrol: An Overview of Fungal Antagonists Applied Against Fungal Plant Pathogens. Front Cell Infect Microbiol 2020; 10:604923. [PMID: 33330142 PMCID: PMC7734056 DOI: 10.3389/fcimb.2020.604923] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 10/23/2020] [Indexed: 11/21/2022] Open
Abstract
Plant pathogens cause severe losses or damage to crops worldwide and thereby significantly reduce the quality and quantity of agricultural commodities. World tendencies are shifting towards reducing the usage of chemically synthesized pesticides, while various biocontrol methods, strategies and approaches are being used in plant disease management. Fungal antagonists play a significant role in controlling plant pathogens and diseases and they are used as Biocontrol Agents (BCAs) throughout the world. This review provides a comprehensive list of fungal BCAs used against fungal plant pathogens according to modern taxonomic concepts, and clarifies their phylogenetic relationships because thewrong names are frequently used in the literature of biocontrol. Details of approximately 300 fungal antagonists belonging to 13 classes and 113 genera are listed together with the target pathogens and corresponding plant diseases. Trichoderma is identified as the genus with greatest potential comprising 25 biocontrol agents that have been used against a number of plant fungal diseases. In addition to Trichoderma, nine genera are recognized as significant comprising five or more known antagonistic species, namely, Alternaria, Aspergillus, Candida, Fusarium, Penicillium, Pichia, Pythium, Talaromyces, and Verticillium. A phylogenetic analysis based on partial sequences of the 28S nrRNA gene (LSU) of fungal antagonists was performed to establish their phylogenetic relationships.
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Affiliation(s)
- Kasun M Thambugala
- Department of Plant and Molecular Biology, Faculty of Science, University of Kelaniya, Kelaniya, Sri Lanka.,Genetics and Molecular Biology Unit, Faculty of Applied Sciences, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Dinushani A Daranagama
- Department of Plant and Molecular Biology, Faculty of Science, University of Kelaniya, Kelaniya, Sri Lanka
| | - Alan J L Phillips
- Faculdade de Ciências, Biosystems and Integrative Sciences Institute (BioISI), Universidade de Lisboa, Lisbon, Portugal
| | - Sagarika D Kannangara
- Department of Plant and Molecular Biology, Faculty of Science, University of Kelaniya, Kelaniya, Sri Lanka
| | - Itthayakorn Promputtha
- Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand.,Research Center in Bioresources for Agriculture, Industry and Medicine, Chiang Mai University, Chiang Mai, Thailand
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31
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He D, Ren L, Wu QL. Growing season drives the compositional changes and assembly processes of epiphytic bacterial communities of two submerged macrophytes in Taihu Lake. FEMS Microbiol Ecol 2020; 96:5736013. [PMID: 32055830 DOI: 10.1093/femsec/fiaa025] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Accepted: 02/13/2020] [Indexed: 11/12/2022] Open
Abstract
Large amounts of epiphytic bacteria live on the leaf surfaces of submerged macrophytes in freshwater lakes. Despite their important roles in affecting host plant's health and biogeochemical cycling, knowledge about epiphytic bacteria assembly is not sufficient. We studied epiphytic bacteria on two cohabiting plant species in Taihu Lake, China. In comparison with plant identity and geographic distance, the plant-growing season played a prominent role in driving alpha and beta diversity (compositional variations) of epiphytic bacterial communities. Phylogeny-based null model analysis revealed that the growing season also drove the relative importance of deterministic versus stochastic processes underlying bacterial community assembly. In May when both plants start growth, the deterministic processes were most prominent, while in months later than June, the stochastic processes' effects increased substantially. In addition, we found a significant positive relationship between alpha diversity and compositional stochasticity, implying that stochastic processes may have great effects on the maintenance of diversity and functioning of epiphytic bacteria in aquatic ecosystems. In summary, the growing season overwhelmed plant identity and spatial site in shaping epiphytic bacterial communities in Taihu Lake, which may suggest new clues in understanding the dynamics of epiphytic communities and their roles in large shallow lacustrine ecosystems.
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Affiliation(s)
- Dan He
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Microbial Culture Collection Center, Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China.,State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Lijuan Ren
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.,Department of Ecology, Institute of Hydrobiology, Jinan University, Guangzhou, 510632, China
| | - Qinglong L Wu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
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32
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Zhang B, Yu P, Wang Z, Alvarez PJJ. Hormetic Promotion of Biofilm Growth by Polyvalent Bacteriophages at Low Concentrations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:12358-12365. [PMID: 32886494 DOI: 10.1021/acs.est.0c03558] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Interactions between bacteriophages (phages) and biofilms are poorly understood despite their broad ecological and water quality implications. Here, we report that biofilm exposure to lytic polyvalent phages at low concentrations (i.e., 102-104 phages/mL) can counterintuitively promote biofilm growth and densification (corroborated by confocal laser scanning microscopy (CLSM)). Such exposure hormetically upregulated quorum sensing genes (by 4.1- to 24.9-fold), polysaccharide production genes (by 3.7- to 9.3-fold), and curli synthesis genes (by 4.5- to 6.5-fold) in the biofilm-dwelling bacterial hosts (i.e., Escherichia coli and Pseudomonas aeruginosa) relative to unexposed controls. Accordingly, the biofilm matrix increased its polysaccharide and extracellular DNA content relative to unexposed controls (by 41.8 ± 2.3 and 81.4 ± 2.2%, respectively), which decreased biofilm permeability and increased structural integrity. This contributed to enhanced resistance to disinfection with chlorine (bacteria half-lives were 6.08 ± 0.05 vs 3.91 ± 0.03 min for unexposed controls) and to subsequent phage infection (biomass removal was 18.2 ± 1.2 vs 32.3 ± 1.2% for unexposed controls), apparently by mitigating diffusion of these antibacterial agents through the biofilm. Overall, low concentrations of phages reaching a biofilm may result in unintended biofilm stimulation, which might accelerate biofouling, biocorrosion, or other biofilm-related water quality problems.
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Affiliation(s)
- Bo Zhang
- School of Environment, Harbin Institute of Technology, Harbin 150090, China
| | - Pingfeng Yu
- Department of Civil and Environmental Engineering, Rice University, Houston 77005, United States
| | - Zijian Wang
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14853, United States
| | - Pedro J J Alvarez
- Department of Civil and Environmental Engineering, Rice University, Houston 77005, United States
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33
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Iasur Kruh L, Bari VK, Abu-Nassar J, Lidor O, Aly R. Characterization of an endophytic bacterium ( Pseudomonas aeruginosa), originating from tomato ( Solanum lycopersicum L.), and its ability to inhabit the parasitic weed Phelipanche aegyptiaca. PLANT SIGNALING & BEHAVIOR 2020; 15:1766292. [PMID: 32425100 PMCID: PMC8570727 DOI: 10.1080/15592324.2020.1766292] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 04/16/2020] [Accepted: 04/17/2020] [Indexed: 06/11/2023]
Abstract
is an obligate holo-parasitic weedlacking a functional photosynthetic system, which subsists on roots of a wide range of host crops, causing severe losses in yield quality and quantity. The parasite and its host are connected through their vascular system, forming a unique ecological system that enables the exchange of various substances. In a previous study, it was suggested that endophytic bacteria, which naturally inhabit the internal tissues of plants, can also be transmitted from the parasitic weed to its host and vice versa. In the current study, we investigate the characteristics of a previously isolated Pseudomonas sp. PhelS10 strain using both biochemical and molecular methods. This isolate was obtained from tomato plant tissue and was able to reduce P. aegyptiaca parasitism, and thus it may serve as a biocontrol agent. Our results revealed that production of Pseudomonas aeruginosa quinolone signal (PQS) was 2.1 times higher than that of the standard Pseudomonas aeruginosa strain (PAO1), which contributed to a 22% higher biofilm formation capability. PhelS10 strain was detected in the xylem of tomato plants using FISH analysis. In addition, PhelS10 strain was found in the parasitic weed's inner tissues, confirming the hypothesis that endophytic bacteria traffic between the host plant and its parasitic weed.
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Affiliation(s)
- Lilach Iasur Kruh
- Department of Biotechnology Engineering, ORT Braude College, Karmiel, Israel
| | - Vinay Kumar Bari
- Department of Weed Science, NeweYa’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Jacline Abu-Nassar
- Department of Weed Science, NeweYa’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Ofir Lidor
- Department of Weed Science, NeweYa’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
| | - Radi Aly
- Department of Weed Science, NeweYa’ar Research Center, Agricultural Research Organization, Ramat Yishay, Israel
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34
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Toju H, Abe MS, Ishii C, Hori Y, Fujita H, Fukuda S. Scoring Species for Synthetic Community Design: Network Analyses of Functional Core Microbiomes. Front Microbiol 2020; 11:1361. [PMID: 32676061 PMCID: PMC7333532 DOI: 10.3389/fmicb.2020.01361] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 05/27/2020] [Indexed: 11/16/2022] Open
Abstract
Constructing biological communities is a major challenge in both basic and applied sciences. Although model synthetic communities with a few species have been constructed, designing systems consisting of tens or hundreds of species remains one of the most difficult goals in ecology and microbiology. By utilizing high-throughput sequencing data of interspecific association networks, we here propose a framework for exploring “functional core” species that have great impacts on whole community processes and functions. The framework allows us to score each species within a large community based on three criteria: namely, topological positions, functional portfolios, and functional balance within a target network. The criteria are measures of each species’ roles in maximizing functional benefits at the community or ecosystem level. When species with potentially large contributions to ecosystem-level functions are screened, the framework also helps us design “functional core microbiomes” by focusing on properties of species groups (modules) within a network. When embedded into agroecosystems or human gut, such functional core microbiomes are expected to organize whole microbiome processes and functions. An application to a plant-associated microbiome dataset actually highlighted potential functional core microbes that were known to control rhizosphere microbiomes by suppressing pathogens. Meanwhile, an example of application in mouse gut microbiomes called attention to poorly investigated bacterial species, whose potential roles within gut microbiomes deserve future experimental studies. The framework for gaining “bird’s-eye” views of functional cores within networks is applicable not only to agricultural and medical data but also to datasets produced in food processing, brewing, waste water purification, and biofuel production.
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Affiliation(s)
- Hirokazu Toju
- Center for Ecological Research, Kyoto University, Kyoto, Japan.,Precursory Research for Embryonic Science and Technology, Japan Science and Technology Agency, Kawaguchi, Japan
| | - Masato S Abe
- Center for Advanced Intelligence Project, RIKEN, Tokyo, Japan
| | - Chiharu Ishii
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan
| | - Yoshie Hori
- Center for Ecological Research, Kyoto University, Kyoto, Japan
| | - Hiroaki Fujita
- Center for Ecological Research, Kyoto University, Kyoto, Japan
| | - Shinji Fukuda
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan.,Intestinal Microbiota Project, Kanagawa Institute of Industrial Science and Technology, Kawasaki, Japan.,Transborder Medical Research Center, University of Tsukuba, Tsukuba, Japan
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35
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Zhu M, He Y, Li Y, Ren T, Liu H, Huang J, Jiang D, Hsiang T, Zheng L. Two New Biocontrol Agents Against Clubroot Caused by Plasmodiophora brassicae. Front Microbiol 2020; 10:3099. [PMID: 32038545 PMCID: PMC6986203 DOI: 10.3389/fmicb.2019.03099] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 12/20/2019] [Indexed: 01/26/2023] Open
Abstract
Clubroot disease caused by Plasmodiophora brassicae can lead to serious yield losses in crucifers such as Brassica napus. In this study, 323 bacterial strains were isolated from the rhizosphere of severely diseased B. napus in Dangyang county, Hubei province, China. Antagonistic strains were first identified based on dual culture inhibition zones with Fusarium oxysporum and Magnaporthe oryzae. These were then further screened in germination inhibition and viability assays of resting spores of P. brassicae. Finally, eight of the antagonistic strains were found to significantly reduce the disease severity of clubroot by more than 40% under greenhouse conditions, and two strains, F85 and T113, were found to have efficacy of more than 80%. Root hair infection experiments showed that F85 and T113 can inhibit early infection of root hairs, reduce the differentiation of primary plasmodia of P. brassicae, and inhibit formation of secondary zoosporangia. Based on sequence analysis of 16S rDNA gene, gyrA gene and 22 housekeeping genes as well as carbon source utilization analysis, the F85 was identified as Bacillus velezensis and T113 as Bacillus amyloliquefaciens. Genome analysis, PCR and RT-PCR detection revealed that both F85 and T113 harbor various antibiotic biosynthesis gene clusters required to form peptides with antimicrobial activity. To our knowledge, this is the first report of B. velezensis as a biocontrol agent against clubroot disease.
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Affiliation(s)
- Manli Zhu
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Youwei He
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Yi Li
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Tirong Ren
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Hao Liu
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Junbin Huang
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Daohong Jiang
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Tom Hsiang
- School of Environmental Sciences, University of Guelph, Guelph, ON, Canada
| | - Lu Zheng
- The Key Lab of Plant Pathology of Hubei Province, Huazhong Agricultural University, Wuhan, China
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36
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Flemming HC, Wuertz S. Bacteria and archaea on Earth and their abundance in biofilms. Nat Rev Microbiol 2020; 17:247-260. [PMID: 30760902 DOI: 10.1038/s41579-019-0158-9] [Citation(s) in RCA: 695] [Impact Index Per Article: 173.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Biofilms are a form of collective life with emergent properties that confer many advantages on their inhabitants, and they represent a much higher level of organization than single cells do. However, to date, no global analysis on biofilm abundance exists. We offer a critical discussion of the definition of biofilms and compile current estimates of global cell numbers in major microbial habitats, mindful of the associated uncertainty. Most bacteria and archaea on Earth (1.2 × 1030 cells) exist in the 'big five' habitats: deep oceanic subsurface (4 × 1029), upper oceanic sediment (5 × 1028), deep continental subsurface (3 × 1029), soil (3 × 1029) and oceans (1 × 1029). The remaining habitats, including groundwater, the atmosphere, the ocean surface microlayer, humans, animals and the phyllosphere, account for fewer cells by orders of magnitude. Biofilms dominate in all habitats on the surface of the Earth, except in the oceans, accounting for ~80% of bacterial and archaeal cells. In the deep subsurface, however, they cannot always be distinguished from single sessile cells; we estimate that 20-80% of cells in the subsurface exist as biofilms. Hence, overall, 40-80% of cells on Earth reside in biofilms. We conclude that biofilms drive all biogeochemical processes and represent the main way of active bacterial and archaeal life.
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Affiliation(s)
- Hans-Curt Flemming
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Singapore, Singapore. .,Biofilm Centre, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany.
| | - Stefan Wuertz
- Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Singapore, Singapore. .,School of Civil and Environmental Engineering, Nanyang Technological University, Singapore, Singapore.
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37
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Soffe R, Bernach M, Remus-Emsermann MNP, Nock V. Replicating Arabidopsis Model Leaf Surfaces for Phyllosphere Microbiology. Sci Rep 2019; 9:14420. [PMID: 31595008 PMCID: PMC6783459 DOI: 10.1038/s41598-019-50983-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 09/23/2019] [Indexed: 12/20/2022] Open
Abstract
Artificial surfaces are commonly used in place of leaves in phyllosphere microbiology to study microbial behaviour on plant leaf surfaces. These surfaces enable a reductionist approach to be undertaken, to enable individual environmental factors influencing microorganisms to be studied. Commonly used artificial surfaces include nutrient agar, isolated leaf cuticles, and reconstituted leaf waxes. Recently, replica surfaces mimicking the complex topography of leaf surfaces for phyllosphere microbiology studies are appearing in literature. Replica leaf surfaces have been produced in agar, epoxy, polystyrene, and polydimethylsiloxane (PDMS). However, none of these protocols are suitable for replicating fragile leaves such as of the model plant Arabidopsis thaliana. This is of importance, as A. thaliana is a model system for molecular plant genetics, molecular plant biology, and microbial ecology. To overcome this limitation, we introduce a versatile replication protocol for replicating fragile leaf surfaces into PDMS. Here we demonstrate the capacity of our replication process using optical microscopy, atomic force microscopy (AFM), and contact angle measurements to compare living and PDMS replica A. thaliana leaf surfaces. To highlight the use of our replica leaf surfaces for phyllosphere microbiology, we visualise bacteria on the replica leaf surfaces in comparison to living leaf surfaces.
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Affiliation(s)
- Rebecca Soffe
- Department of Electrical and Computer Engineering, University of Canterbury, Christchurch, New Zealand.
| | - Michal Bernach
- Department of Electrical and Computer Engineering, University of Canterbury, Christchurch, New Zealand
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | | | - Volker Nock
- Department of Electrical and Computer Engineering, University of Canterbury, Christchurch, New Zealand.
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38
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Chemoperception of Specific Amino Acids Controls Phytopathogenicity in Pseudomonas syringae pv. tomato. mBio 2019; 10:mBio.01868-19. [PMID: 31575767 PMCID: PMC6775455 DOI: 10.1128/mbio.01868-19] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
There is substantive evidence that chemotaxis is a key requisite for efficient pathogenesis in plant pathogens. However, information regarding particular bacterial chemoreceptors and the specific plant signal that they sense is scarce. Our work shows that the phytopathogenic bacterium Pseudomonas syringae pv. tomato mediates not only chemotaxis but also the control of pathogenicity through the perception of the plant abundant amino acids Asp and Glu. We describe the specificity of the perception of l- and d-Asp and l-Glu by the PsPto-PscA chemoreceptor and the involvement of this perception in the regulation of pathogenicity-related traits. Moreover, a saturating concentration of d-Asp reduces bacterial virulence, and we therefore propose that ligand-mediated interference of key chemoreceptors may be an alternative strategy to control virulence. Chemotaxis has been associated with the pathogenicity of bacteria in plants and was found to facilitate bacterial entry through stomata and wounds. However, knowledge regarding the plant signals involved in this process is scarce. We have addressed this issue using Pseudomonas syringae pv. tomato, which is a foliar pathogen that causes bacterial speck in tomato. We show that the chemoreceptor P. syringae pv. tomato PscA (PsPto-PscA) recognizes specifically and with high affinity l-Asp, l-Glu, and d-Asp. The mutation of the chemoreceptor gene largely reduced chemotaxis to these ligands but also altered cyclic di-GMP (c-di-GMP) levels, biofilm formation, and motility, pointing to cross talk between different chemosensory pathways. Furthermore, the PsPto-PscA mutant strain showed reduced virulence in tomato. Asp and Glu are the most abundant amino acids in plants and in particular in tomato apoplasts, and we hypothesize that this receptor may have evolved to specifically recognize these compounds to facilitate bacterial entry into the plant. Infection assays with the wild-type strain showed that the presence of saturating concentrations of d-Asp also reduced bacterial virulence.
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Saleem H, Arslan M, Rehman K, Tahseen R, Afzal M. Phragmites australis - a helophytic grass - can establish successful partnership with phenol-degrading bacteria in a floating treatment wetland. Saudi J Biol Sci 2019; 26:1179-1186. [PMID: 31516347 PMCID: PMC6733312 DOI: 10.1016/j.sjbs.2018.01.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 01/25/2018] [Accepted: 01/28/2018] [Indexed: 11/19/2022] Open
Abstract
Helophytic plants contribute significantly in phytoremediation of a variety of pollutants due to their physiological or biochemical mechanisms. Phenol, which is reported to have negative/deleterious effects on plant metabolism at concentrations higher than 500 mg/L, remains hard to be removed from the environmental compartments using conventional phytoremediation procedures. The present study aims to investigate the feasibility of using P. australis (a helophytic grass) in combination with three bacterial strains namely Acinetobacter lwofii ACRH76, Bacillus cereus LORH97, and Pseudomonas sp. LCRH90, in a floating treatment wetland (FTW) for the removal of phenol from contaminated water. The strains were screened based on their phenol degrading and plant growth promoting activities. We found that inoculated bacteria were able to colonize in the roots and shoots of P. australis, suggesting their potential role in the successful removal of phenol from the contaminated water. Pseudomonas sp. LCRH90 dominated the bacterial community structure followed by A. lowfii ACRH76 and B. cereus LORH97. The removal rate was significantly high when compared with the individual partners, i.e., plants and bacteria separately. The plant biomass, which was drastically reduced in the presence of phenol, recovered significantly with the inoculation of bacterial consortia. Likewise, highest reduction in chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total organic carbon (TOC) is achieved when both plants and bacteria were employed. The study, therefore, suggests that P. australis in combination with efficient bacteria can be a suitable choice to FTWs for phenol-degradation in water.
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Affiliation(s)
- Hamna Saleem
- Deparment Molecular Life Sciences, Friedrich-Schiller-University Jena, Jena, Germany
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
| | - Muhammad Arslan
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
- Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany
| | - Khadeeja Rehman
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
| | - Razia Tahseen
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
| | - Muhammad Afzal
- Soil and Environmental Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan
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40
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Mendis HC, Ozcan A, Santra S, De La Fuente L. A novel Zn chelate (TSOL) that moves systemically in citrus plants inhibits growth and biofilm formation of bacterial pathogens. PLoS One 2019; 14:e0218900. [PMID: 31233560 PMCID: PMC6590827 DOI: 10.1371/journal.pone.0218900] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 06/11/2019] [Indexed: 11/19/2022] Open
Abstract
Ternary solution (TSOL) is a novel Zn chelate-based systemic antimicrobial formulation designed for treating citrus bacterial pathogens 'Candidatus Liberibacter asiaticus' and Xanthomonas citri subsp. citri. TSOL is a component of MS3T, a novel multifunctional surface/sub-surface/systemic therapeutic formulation. Antimicrobial activity of TSOL was compared with the antimicrobial compound ZnO against X. citri subsp. citri and 'Ca. L. asiaticus' surrogate Liberibacter crescens in batch cultures. X. citri subsp. citri and L. crescens were also introduced into microfluidic chambers, and the inhibitory action of TSOL against biofilm formation was evaluated. The minimum inhibitory concentration of TSOL for both X. citri subsp. citri and L. crescens was 40ppm. TSOL was bactericidal to X. citri subsp. citri and L. crescens above 150 ppm and 200 ppm, respectively. On the contrary, ZnO was more effective as a bactericidal agent against L. crescens than X. citri subsp. citri. TSOL was more effective in controlling growth and biofilm formation of X. citri subsp. citri in batch cultures compared to ZnO. Time-lapse video imaging microscopy showed that biofilm formation of X. citri subsp. citri was inhibited in microfluidic chambers treated with 60 ppm TSOL. TSOL also inhibited further growth of already formed X. citri subsp. citri and L. crescens biofilms in microfluidic chambers. Leaf spraying of TSOL showed higher plant uptake and systemic movement in citrus (Citrus reshni) plants compared to that of ZnO, suggesting that TSOL is a promising antimicrobial compound to control vascular plant pathogens such as 'Ca. L. asiaticus'.
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Affiliation(s)
- Hajeewaka C. Mendis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States of America
- NanoScience Technology Center, University of Central Florida, Orlando, FL, United States of America
| | - Ali Ozcan
- NanoScience Technology Center, University of Central Florida, Orlando, FL, United States of America
- Department of Chemistry, University of Central Florida, Orlando, FL, United States of America
| | - Swadeshmukul Santra
- NanoScience Technology Center, University of Central Florida, Orlando, FL, United States of America
- Department of Chemistry, University of Central Florida, Orlando, FL, United States of America
- Department of Materials Science and Engineering, University of Central Florida, Orlando, FL, United States of America
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, FL, United States of America
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States of America
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41
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Comparison of replica leaf surface materials for phyllosphere microbiology. PLoS One 2019; 14:e0218102. [PMID: 31170240 PMCID: PMC6553772 DOI: 10.1371/journal.pone.0218102] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 05/27/2019] [Indexed: 12/25/2022] Open
Abstract
Artificial surfaces are routinely used instead of leaves to enable a reductionist approach in phyllosphere microbiology, the study of microorganisms residing on plant leaf surfaces. Commonly used artificial surfaces include, flat surfaces, such as metal and nutrient agar, and microstructured surfaces, such as isolate leaf cuticles or reconstituted leaf waxes. However, interest in replica leaf surfaces as an artificial surface is growing, as replica surfaces provide an improved representation of the complex topography of leaf surfaces. To date, leaf surfaces have predominantly been replicated for their superhydrophobic properties. In contrast, in this paper we investigated the potential of agarose, the elastomer polydimethylsiloxane (PDMS), and gelatin as replica leaf surface materials for phyllosphere microbiology studies. Using a test pattern of pillars, we investigated the ability to replicate microstructures into the materials, as well as the degradation characteristics of the materials in environmental conditions. Pillars produced in PDMS were measured to be within 10% of the mold master and remained stable throughout the degradation experiments. In agarose and gelatin the pillars deviated by more than 10% and degraded considerably within 48 hours in environmental conditions. Furthermore, we investigated the surface energy of the materials, an important property of a leaf surface, which influences resource availability and microorganism attachment. We found that the surface energy and bacterial viability on PDMS was comparable to isolated Citrus × aurantium and Populus × canescens leaf cuticles. Hence indicating that PDMS is the most suitable material for replica leaf surfaces. In summary, our experiments highlight the importance of considering the inherent material properties when selecting a replica leaf surface for phyllosphere microbiology studies. As demonstrated, a PDMS replica leaf offers a control surface that can be used for investigating microbe-microbe and microbe-plant interactions in the phyllosphere, which will enable mitigation strategies against pathogens to be developed.
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Abstract
Bacteria are often found living in aggregated multicellular communities known as biofilms. Biofilms are three-dimensional structures that confer distinct physical and biological properties to the collective of cells living within them. We used agent-based modeling to explore whether local cellular interactions were sufficient to give rise to global structural features of biofilms. Specifically, we asked whether chemorepulsion from a self-produced quorum-sensing molecule, autoinducer-2 (AI-2), was sufficient to recapitulate biofilm growth and cellular organization observed for biofilms of Helicobacter pylori, a common bacterial resident of human stomachs. To carry out this modeling, we modified an existing platform, Individual-based Dynamics of Microbial Communities Simulator (iDynoMiCS), to incorporate three-dimensional chemotaxis, planktonic cells that could join or leave the biofilm structure, and cellular production of AI-2. We simulated biofilm growth of previously characterized H. pylori strains with various AI-2 production and sensing capacities. Using biologically plausible parameters, we were able to recapitulate both the variation in biofilm mass and cellular distributions observed with these strains. Specifically, the strains that were competent to chemotax away from AI-2 produced smaller and more heterogeneously spaced biofilms, whereas the AI-2 chemotaxis-defective strains produced larger and more homogeneously spaced biofilms. The model also provided new insights into the cellular demographics contributing to the biofilm patterning of each strain. Our analysis supports the idea that cellular interactions at small spatial and temporal scales are sufficient to give rise to larger-scale emergent properties of biofilms.IMPORTANCE Most bacteria exist in aggregated, three-dimensional structures called biofilms. Although biofilms play important ecological roles in natural and engineered settings, they can also pose societal problems, for example, when they grow in plumbing systems or on medical implants. Understanding the processes that promote the growth and disassembly of biofilms could lead to better strategies to manage these structures. We had previously shown that Helicobacter pylori bacteria are repulsed by high concentrations of a self-produced molecule, AI-2, and that H. pylori mutants deficient in AI-2 sensing form larger and more homogeneously spaced biofilms. Here, we used computer simulations of biofilm formation to show that local H. pylori behavior of repulsion from high AI-2 could explain the overall architecture of H. pylori biofilms. Our findings demonstrate that it is possible to change global biofilm organization by manipulating local cell behaviors, which suggests that simple strategies targeting cells at local scales could be useful for controlling biofilms in industrial and medical settings.
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Big Impact of the Tiny: Bacteriophage-Bacteria Interactions in Biofilms. Trends Microbiol 2019; 27:739-752. [PMID: 31128928 DOI: 10.1016/j.tim.2019.04.006] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 04/10/2019] [Accepted: 04/19/2019] [Indexed: 01/17/2023]
Abstract
Bacteriophages (phages) have been shaping bacterial ecology and evolution for millions of years, for example, by selecting for defence strategies. Evidence supports that bacterial biofilm formation is one such strategy and that biofilm-mediated protection against phage infection depends on maturation and composition of the extracellular matrix. Interestingly, studies have revealed that phages can induce and strengthen biofilms. Here we review interactions between bacteria and phages in biofilms, discuss the underlying mechanisms, the potential of phage therapy for biofilm control, and emphasize the importance of considering biofilms in future phage research. This is especially relevant as biofilms are associated with increased tolerance towards antibiotics and are implicated in the majority of chronic infections.
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Srinivasan S, Vladescu ID, Koehler SA, Wang X, Mani M, Rubinstein SM. Matrix Production and Sporulation in Bacillus subtilis Biofilms Localize to Propagating Wave Fronts. Biophys J 2019; 114:1490-1498. [PMID: 29590605 DOI: 10.1016/j.bpj.2018.02.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 01/31/2018] [Accepted: 02/02/2018] [Indexed: 12/31/2022] Open
Abstract
Bacterial biofilms are surface-attached microbial communities encased in self-produced extracellular polymeric substances. Here we demonstrate that during the development of Bacillus subtilis biofilms, matrix production is localized to an annular front propagating at the periphery and sporulation to a second front at a fixed distance at the interior. We show that within these fronts, cells switch off matrix production and transition to sporulation after a set time delay of ∼100 min. Correlation analyses of fluctuations in fluorescence reporter activity reveal that the fronts emerge from a pair of gene-expression waves of matrix production and sporulation. The localized expression waves travel across cells that are immobilized in the biofilm matrix in contrast to active cell migration or horizontal colony spreading. Our results suggest that front propagation arises via a local developmental program occurring at the level of individual bacterial cells, likely driven by nutrient depletion and metabolic by-product accumulation. A single-length scale and timescale couples the spatiotemporal propagation of both fronts throughout development. As a result, gene expression patterns within the advancing fronts collapse to self-similar expression profiles. Our findings highlight the key role of the localized cellular developmental program associated with the propagating front in describing biofilm growth.
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Affiliation(s)
- Siddarth Srinivasan
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts.
| | - Ioana D Vladescu
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
| | - Stephan A Koehler
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
| | - Xiaoling Wang
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts; School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China
| | - Madhav Mani
- Department of Engineering Sciences and Applied Mathematics, Northwestern University, Evanston, Illinois
| | - Shmuel M Rubinstein
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts; School of Engineering and Applied Sciences and Kavli Institute for Bionano Science and Technology, Harvard University, Cambridge, Massachusetts.
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Assessment of Water Quality Parameters Using Temporal Remote Sensing Spectral Reflectance in Arid Environments, Saudi Arabia. WATER 2019. [DOI: 10.3390/w11030556] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Remote sensing applications in water resources management are quite essential in watershed characterization, particularly when mega basins are under investigation. Water quality parameters help in decision making regarding the further use of water based on its quality. Water quality parameters of chlorophyll a concentration, nitrate concentration, and water turbidity were used in the current study to estimate the water quality parameters in the dam lake of Wadi Baysh, Saudi Arabia. Water quality parameters were collected daily over 2 years (2017–2018) from the water treatment station located within the dam vicinity and were correspondingly tested against remotely sensed water quality parameters. Remote sensing data were collected from Sentinel-2 sensor, European Space Agency (ESA) on a satellite temporal resolution basis. Data were pre-processed then processed to estimate the maximum chlorophyll index (MCI), green normalized difference vegetation index (GNDVI) and normalized difference turbidity index (NDTI). Zonal statistics were used to improve the regression analysis between the spatial data estimated from the remote sensing images and the nonspatial data collected from the water treatment plant. Results showed different correlation coefficients between the ground truth collected data and the corresponding indices conducted from remote sensing data. Actual chlorophyll a concentration showed high correlation with estimated MCI mean values with an R2 of 0.96, actual nitrate concentration showed high correlation with the estimated GNDVI mean values with an R2 of 0.94, and the actual water turbidity measurements showed high correlation with the estimated NDTI mean values with an R2 of 0.94. The research findings support the use of remote sensing data of Sentinel-2 to estimate water quality parameters in arid environments.
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Genome sequence of Xanthomonas fuscans subsp. fuscans strain Xff49: a new isolate obtained from common beans in Southern Brazil. Braz J Microbiol 2019; 50:357-367. [PMID: 30850979 DOI: 10.1007/s42770-019-00050-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 01/21/2019] [Indexed: 01/22/2023] Open
Abstract
The genus Xanthomonas comprises Gram-negative bacteria, many of which are phytopathogens. Xanthomonas fuscans subsp. fuscans is one of the most devastating pathogens affecting the bean plant, resulting in the common bacterial blight of bean (CBB). The disease is mainly foliar and affects a wide variety of bean species, thus acting as the yield-limiting factor for the bean crop. Here, we report the whole-genome sequencing of a new strain of X. fuscans subsp. fuscans, named Xff49, isolated from the infected and symptomatic beans from Capão do Leão, Southern Brazil. The genetic analysis demonstrated the presence of single-nucleotide variants (SNVs) in this strain, potentially affecting the mobilome, cell mobility, and inorganic ion metabolism. In addition, the analysis resulted in the identification of a new plasmid similar to the pAX22 derived from Achromobacter denitrificans, which was named plX, along with plA and plC, previously reported in other strains of X. fuscans subsp. fuscans. Xff49 represents the first Brazilian genome of X. fuscans subsp. fuscans and might provide useful information applicable to the studies of phylogenetics, evolution, and pathogenomics, thereby allowing a better understanding of the genomic features present in the Brazilian strains.
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Zheng J, Xia Y, Liu Q, He X, Yu J, Feng Y. Extracellular DNA enhances the formation and stability of symplasmata in Pantoea agglomerans YS19. J GEN APPL MICROBIOL 2019; 65:11-17. [PMID: 30185735 DOI: 10.2323/jgam.2018.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Extracellular DNA (eDNA) is an important polymeric substance that plays essential roles in cell aggregation and nutrient provision for the sessile bacteria. eDNA in bacterial biofilms was extensively studied. Here we found that eDNA also exists in symplasmata, a bacterial cell aggregate, which is different to a biofilm, in the rice enophyte Pantoea agglomerans YS19. We found that exogenous eDNA enhanced the formation and stability of symplasmata significantly, and that, exogenous eDNA also improved the stress resistance and colonization ability of the bacterium on host rice. These results strongly indicate novel roles of the eDNA in Pantoea agglomerans YS19, showing its special relation to the stress-resistance and endophyte-host association of the strain.
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Affiliation(s)
- Jing Zheng
- School of Life Science, Beijing Institute of Technology
| | - Yifan Xia
- School of Life Science, Beijing Institute of Technology
| | - Qi Liu
- School of Life Science, Beijing Institute of Technology
| | - Xinyu He
- School of Life Science, Beijing Institute of Technology
| | - Jiajia Yu
- School of Life Science, Beijing Institute of Technology
| | - Yongjun Feng
- School of Life Science, Beijing Institute of Technology
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Corzo-Ariyama HA, García-Heredia A, Heredia N, García S, León J, Jaykus L, Solís-Soto L. Phylogroups, pathotypes, biofilm formation and antimicrobial resistance of Escherichia coli isolates in farms and packing facilities of tomato, jalapeño pepper and cantaloupe from Northern Mexico. Int J Food Microbiol 2019; 290:96-104. [DOI: 10.1016/j.ijfoodmicro.2018.10.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 08/15/2018] [Accepted: 10/05/2018] [Indexed: 01/05/2023]
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Chhetri VS, Fontenot K, Strahan R, Yemmireddy VK, Cason C, Kharel K, Adhikari A. Attachment strength and on-farm die-off rate of Escherichia coli on watermelon surfaces. PLoS One 2019; 14:e0210115. [PMID: 30620744 PMCID: PMC6324798 DOI: 10.1371/journal.pone.0210115] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 12/17/2018] [Indexed: 01/10/2023] Open
Abstract
Pre-harvest contamination of produce has been a major food safety focus. Insight into the behavior of enteric pathogens on produce in pre-harvest conditions will aid in developing pre-harvest and post-harvest risk management strategies. In this study, the attachment strength (SR) and die-off rate of E. coli on the surface of watermelon fruits and the efficacy of aqueous chlorine treatment against strongly attached E. coli population were investigated. Watermelon seedlings were transplanted into eighteen plots. Prior to harvesting, a cocktail of generic E. coli (ATCC 23716, 25922 and 11775) was inoculated on the surface of the watermelon fruits (n = 162) and the attachment strength (SR) values and the daily die-off rates were examined up to 6 days by attachment assay. After 120 h, watermelon samples were treated with aqueous chlorine (150 ppm free chlorine for 3 min). The SR value of the E. coli cells on watermelon surfaces significantly increased (P<0.05) from 0.04 to 0.99 in the first 24 h, which was primarily due to the decrease in loosely attached population, given that the population of strongly attached cells was constant. Thereafter, there was no significant change in SR values, up to 120 h. The daily die-off rate of E. coli ranged from -0.12 to 1.3 log CFU/cm2. The chlorine treatment reduced the E. coli level by 4.2 log CFU/cm2 (initial level 5.6 log CFU/cm2) and 0.62 log CFU/cm2 (initial level 1.8 log CFU/cm2), on the watermelons that had an attachment time of 30 min and 120 h respectively. Overall, our findings revealed that the population of E. coli on watermelon surfaces declined over time in an agricultural environment. Microbial contamination during pre-harvest stages may promote the formation of strongly attached cells on the produce surfaces, which could influence the efficacy of post-harvest washing and sanitation techniques.
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Affiliation(s)
- Vijay Singh Chhetri
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Kathryn Fontenot
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Ronald Strahan
- School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Veerachandra K. Yemmireddy
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Cameron Cason
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Karuna Kharel
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
| | - Achyut Adhikari
- School of Nutrition and Food Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA, United States of America
- * E-mail:
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50
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Begum JF, Tamilarasi M, Pushpakanth P, Balachandar D. A simple method for direct isolation of N-acyl-L-homoserine lactone mediated biofilm-forming rhizobacteria from roots. J Microbiol Methods 2019; 156:34-39. [DOI: 10.1016/j.mimet.2018.11.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2018] [Revised: 11/20/2018] [Accepted: 11/20/2018] [Indexed: 10/27/2022]
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