1
|
Blanco-Romero E, Garrido-Sanz D, Durán D, Rybtke M, Tolker-Nielsen T, Redondo-Nieto M, Rivilla R, Martín M. Role of extracellular matrix components in biofilm formation and adaptation of Pseudomonas ogarae F113 to the rhizosphere environment. Front Microbiol 2024; 15:1341728. [PMID: 38333580 PMCID: PMC10850567 DOI: 10.3389/fmicb.2024.1341728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/11/2024] [Indexed: 02/10/2024] Open
Abstract
Regulating the transition of bacteria from motile to sessile lifestyles is crucial for their ability to compete effectively in the rhizosphere environment. Pseudomonas are known to rely on extracellular matrix (ECM) components for microcolony and biofilm formation, allowing them to adapt to a sessile lifestyle. Pseudomonas ogarae F113 possesses eight gene clusters responsible for the production of ECM components. These gene clusters are tightly regulated by AmrZ, a major transcriptional regulator that influences the cellular levels of c-di-GMP. The AmrZ-mediated transcriptional regulation of ECM components is primarily mediated by the signaling molecule c-di-GMP and the flagella master regulator FleQ. To investigate the functional role of these ECM components in P. ogarae F113, we performed phenotypic analyses using mutants in genes encoding these ECM components. These analyses included assessments of colony morphology, dye-staining, static attachment to abiotic surfaces, dynamic biofilm formation on abiotic surfaces, swimming motility, and competitive colonization assays of the rhizosphere. Our results revealed that alginate and PNAG polysaccharides, along with PsmE and the fimbrial low molecular weight protein/tight adherence (Flp/Tad) pilus, are the major ECM components contributing to biofilm formation. Additionally, we found that the majority of these components and MapA are needed for a competitive colonization of the rhizosphere in P. ogarae F113.
Collapse
Affiliation(s)
- Esther Blanco-Romero
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Daniel Garrido-Sanz
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - David Durán
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Morten Rybtke
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Miguel Redondo-Nieto
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Rafael Rivilla
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| | - Marta Martín
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Madrid, Spain
| |
Collapse
|
2
|
González E, Zuleta C, Zamora G, Maturana N, Ponce B, Rivero MV, Rodríguez A, Soto JP, Scott F, Díaz-Barrera Á. Production of poly (3-hydroxybutyrate) and extracellular polymeric substances from glycerol by the acidophile Acidiphilium cryptum. Extremophiles 2023; 27:30. [PMID: 37847335 DOI: 10.1007/s00792-023-01313-3] [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: 04/20/2023] [Accepted: 09/26/2023] [Indexed: 10/18/2023]
Abstract
Acidiphilium cryptum is an acidophilic, heterotrophic, and metallotolerant bacteria able to use dissolved oxygen or Fe(III) as an electron sink. The ability of this extremophile to accumulate poly(3-hydroxybutyrate) (PHB) and secrete extracellular polymeric substances (EPS) has also been reported. Hence, the aim of this work is to characterize the production of PHB and EPS by the wild strain DSM2389 using glycerol in shaken flasks and bioreactor. Results showed that maximum PHB accumulation (37-42% w/w) was obtained using glycerol concentrations of 9 and 15 g L-1, where maximum dry cell weight titers reached 3.6 and 3.9 g L-1, respectively. The culture in the bioreactor showed that PHB accumulation takes place under oxygen limitation, while the redox potential of the culture medium could be used for online monitoring of the PHB production. Recovered EPS was analyzed by Fourier-transform infrared spectroscopy and subjected to gas chromatography-mass spectrometry after cleavage and derivatization steps. These analyses showed the presence of sugars which were identified as mannose, rhamnose and glucose, in a proportion near to 3.2:2.3:1, respectively. Since glycerol had not been used in previous works, these findings suggest the potential of A. cryptum to produce biopolymers from this compound at a large scale with a low risk of microbial contamination due to the low pH of the fermentation process.
Collapse
Affiliation(s)
- Ernesto González
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Av. Brasil, 2085, Valparaíso, Chile.
- Department of Chemical and Materials Engineering, Faculty of Chemistry, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid, Spain.
| | - Camila Zuleta
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Av. Brasil, 2085, Valparaíso, Chile
| | - Guiselle Zamora
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Av. Brasil, 2085, Valparaíso, Chile
| | - Nataly Maturana
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Av. Brasil, 2085, Valparaíso, Chile
| | - Belén Ponce
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Av. Brasil, 2085, Valparaíso, Chile
| | - María Virginia Rivero
- Polymer Biotechnology Lab, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
- Interdisciplinary Platform for Sustainable Plastics Towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), Madrid, Spain
| | - Alberto Rodríguez
- Polymer Biotechnology Lab, Centro de Investigaciones Biológicas Margarita Salas (CIB-CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
- Interdisciplinary Platform for Sustainable Plastics Towards a Circular Economy-Spanish National Research Council (SusPlast-CSIC), Madrid, Spain
| | - Juan Pablo Soto
- Instituto de Química, Pontificia Universidad Católica de Valparaíso, Av. Universidad 330, Curauma, Valparaíso, Chile
| | - Felipe Scott
- Green Technologies Research Group, Facultad de Ingeniería y Ciencias Aplicadas, Universidad de los Andes, Av. Mons. Álvaro del Portillo, Las Condes, 12455, Santiago, Chile
| | - Álvaro Díaz-Barrera
- Escuela de Ingeniería Bioquímica, Pontificia Universidad Católica de Valparaíso, Av. Brasil, 2085, Valparaíso, Chile
| |
Collapse
|
3
|
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.
Collapse
|
4
|
Beyond the Wall: Exopolysaccharides in the Biofilm Lifestyle of Pathogenic and Beneficial Plant-Associated Pseudomonas. Microorganisms 2021; 9:microorganisms9020445. [PMID: 33670010 PMCID: PMC7926942 DOI: 10.3390/microorganisms9020445] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/12/2021] [Accepted: 02/18/2021] [Indexed: 11/16/2022] Open
Abstract
The formation of biofilms results from a multicellular mode of growth, in which bacteria remain enwrapped by an extracellular matrix of their own production. Many different bacteria form biofilms, but among the most studied species are those that belong to the Pseudomonas genus due to the metabolic versatility, ubiquity, and ecological significance of members of this group of microorganisms. Within the Pseudomonas genus, biofilm studies have mainly focused on the opportunistic human pathogen Pseudomonas aeruginosa due to its clinical importance. The extracellular matrix of P. aeruginosa is mainly composed of exopolysaccharides, which have been shown to be important for the biofilm architecture and pathogenic features of this bacterium. Notably, some of the exopolysaccharides recurrently used by P. aeruginosa during biofilm formation, such as the alginate and polysaccharide synthesis loci (Psl) polysaccharides, are also used by pathogenic and beneficial plant-associated Pseudomonas during their interaction with plants. Interestingly, their functions are multifaceted and seem to be highly dependent on the bacterial lifestyle and genetic context of production. This paper reviews the functions and significance of the exopolysaccharides produced by plant-associated Pseudomonas, particularly the alginate, Psl, and cellulose polysaccharides, focusing on their equivalents produced in P. aeruginosa within the context of pathogenic and beneficial interactions.
Collapse
|
5
|
Kim MK, Lee SM, Seuk SW, Ryu JS, Kim HD, Kwon JH, Choi YJ, Yun HD. Characterization of the rcsA Gene from Pantoea sp. Strain PPE7 and Its Influence on Extracellular Polysaccharide Production and Virulence on Pleurotus eryngii. THE PLANT PATHOLOGY JOURNAL 2017; 33:276-287. [PMID: 28592946 PMCID: PMC5461046 DOI: 10.5423/ppj.oa.08.2016.0177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 02/23/2017] [Accepted: 02/27/2017] [Indexed: 06/07/2023]
Abstract
RcsA is a positive activator of extracellular polysaccharide (EPS) synthesis in the Enterobacteriaceae. The rcsA gene of the soft rot pathogen Pantoea sp. strain PPE7 in Pleurotus eryngii was cloned by PCR amplification, and its role in EPS synthesis and virulence was investigated. The RcsA protein contains 3 highly conserved domains, and the C-terminal end of the open reading frame shared significant amino acid homology to the helix-turn-helix DNA binding motif of bacterial activator proteins. The inactivation of rcsA by insertional mutagenesis created mutants that had decreased production of EPS compared to the wild-type strain and abolished the virulence of Pantoea sp. strain PPE7 in P. eryngii. The Pantoea sp. strain PPE7 rcsA gene was shown to strongly affect the formation of the disease symptoms of a mushroom pathogen and to act as the virulence factor to cause soft rot disease in P. eryngii.
Collapse
Affiliation(s)
- Min Keun Kim
- Environment-Friendly Research Division, Gyeongsangnam-do Agricultural Research & Extension Services, Jinju 52733,
Korea
| | - Sun Mi Lee
- Environment-Friendly Research Division, Gyeongsangnam-do Agricultural Research & Extension Services, Jinju 52733,
Korea
| | - Su Won Seuk
- Environment-Friendly Research Division, Gyeongsangnam-do Agricultural Research & Extension Services, Jinju 52733,
Korea
| | - Jae San Ryu
- Environment-Friendly Research Division, Gyeongsangnam-do Agricultural Research & Extension Services, Jinju 52733,
Korea
| | - Hee Dae Kim
- Environment-Friendly Research Division, Gyeongsangnam-do Agricultural Research & Extension Services, Jinju 52733,
Korea
| | - Jin Hyeuk Kwon
- Environment-Friendly Research Division, Gyeongsangnam-do Agricultural Research & Extension Services, Jinju 52733,
Korea
| | - Yong Jo Choi
- Environment-Friendly Research Division, Gyeongsangnam-do Agricultural Research & Extension Services, Jinju 52733,
Korea
| | - Han Dae Yun
- Department of Applied Life Chemistry, College of Agriculture and Life Science, Gyeongsang National University, JinJu 52828,
Korea
| |
Collapse
|
6
|
Multifunctional Exopolysaccharides from Pseudomonas aeruginosa PF23 Involved in Plant Growth Stimulation, Biocontrol and Stress Amelioration in Sunflower Under Saline Conditions. Curr Microbiol 2014; 69:484-94. [DOI: 10.1007/s00284-014-0612-x] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Accepted: 03/28/2014] [Indexed: 11/26/2022]
|
7
|
Bartoli C, Berge O, Monteil CL, Guilbaud C, Balestra GM, Varvaro L, Jones C, Dangl JL, Baltrus DA, Sands DC, Morris CE. ThePseudomonas viridiflavaphylogroups in theP. syringaespecies complex are characterized by genetic variability and phenotypic plasticity of pathogenicity-related traits. Environ Microbiol 2014; 16:2301-15. [DOI: 10.1111/1462-2920.12433] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 02/13/2014] [Indexed: 11/29/2022]
Affiliation(s)
- Claudia Bartoli
- Department of Science and Technology for Agriculture, Forestry, Nature and Energy (DAFNE); Tuscia University; Viterbo Italy
- UR0407 Pathologie Végétale; INRA; Montfavet France
| | - Odile Berge
- UR0407 Pathologie Végétale; INRA; Montfavet France
| | | | | | - Giorgio M. Balestra
- Department of Science and Technology for Agriculture, Forestry, Nature and Energy (DAFNE); Tuscia University; Viterbo Italy
| | - Leonardo Varvaro
- Department of Science and Technology for Agriculture, Forestry, Nature and Energy (DAFNE); Tuscia University; Viterbo Italy
| | - Corbin Jones
- Department of Biology; Carolina Center for Genome Sciences; Chapel Hill NC 29599 USA
| | - Jeffery L. Dangl
- Department of Biology; Howard Hughes Medical Institute; University of North Carolina; Chapel Hill NC 29599 USA
| | - David A. Baltrus
- School of Plant Sciences; University of Arizona; Tucson AZ 85721 USA
| | - David C. Sands
- Department Plant Sciences and Plant Pathology; Montana State University; Bozeman MT 59717-3150 USA
| | - Cindy E. Morris
- UR0407 Pathologie Végétale; INRA; Montfavet France
- Department Plant Sciences and Plant Pathology; Montana State University; Bozeman MT 59717-3150 USA
| |
Collapse
|
8
|
Razack SA, Velayutham V, Thangavelu V. Medium optimization and in vitro antioxidant activity of exopolysaccharide produced by Bacillus subtilis. KOREAN J CHEM ENG 2013. [DOI: 10.1007/s11814-013-0217-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
9
|
Isolation and characterization of drought-tolerant ACC deaminase and exopolysaccharide-producing fluorescent Pseudomonas sp. ANN MICROBIOL 2013. [DOI: 10.1007/s13213-013-0680-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
|
10
|
Lee BU, Baek H, Oh KH. Use of an algD promoter-driven expression system for the degradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by Pseudomonas sp. HK-6. Curr Microbiol 2013; 67:480-6. [PMID: 23715665 DOI: 10.1007/s00284-013-0387-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Accepted: 04/18/2013] [Indexed: 10/26/2022]
Abstract
Pseudomonas sp. HK-6 is able to utilize hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) as a sole nitrogen source. The HK-6 strain was stimulated to produce an exopolymer, mainly alginate, as a stress response when grown in LB broth containing RDX, synthesizing ~230 μg/mL after 48 h. The algA mRNA levels in HK-6 increased by 7-8-fold after 2-6 h of exposure to 0.1 mM RDX, as measured by RT-qPCR. HK-6 was able to degrade ~25 % of 0.1 mM RDX after 20 days and 60 % after 50 days, whereas the pnrB null mutant only degraded less than 1 % after 50 days. The introduction of an algD promoter-pnrB gene fusion into the pnrB mutant fully restored RDX-degradation capability. To facilitate a study of PnrB action on RDX, a His6-PnrB fusion protein was heterologously expressed in E. coli BL21 cells, and the enzymatic activity on RDX was assayed by measuring the decrease in absorbance at 340 nm due to NADH oxidation. At the fixed condition of 0.1 mM RDX, 0.2 mM NADH, and 1 μg His6-PnrB, the absorbance at 340 nM gradually decreased and reached to its minimum value after 30 min. However, calculating the V max and K m values of PnrB for RDX was challenging due to extremely low solubility of RDX in water. The results clearly indicate the potential use of the algD promoter in studies of some genes in Pseudomonas species.
Collapse
Affiliation(s)
- Bheong-Uk Lee
- Divison of Biological Sciences, Kosin University, Busan 606-701, Republic of Korea
| | | | | |
Collapse
|
11
|
Mi L, Giarmarco MM, Shao Q, Jiang S. Divalent cation-mediated polysaccharide interactions with zwitterionic surfaces. Biomaterials 2012; 33:2001-6. [DOI: 10.1016/j.biomaterials.2011.11.071] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2011] [Accepted: 11/25/2011] [Indexed: 10/14/2022]
|
12
|
Fones H, Preston GM. Reactive oxygen and oxidative stress tolerance in plant pathogenic Pseudomonas. FEMS Microbiol Lett 2011; 327:1-8. [PMID: 22092667 DOI: 10.1111/j.1574-6968.2011.02449.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 10/22/2011] [Indexed: 11/29/2022] Open
Abstract
Reactive oxygen species (ROS) are a key feature of plant (and animal) defences against invading pathogens. As a result, plant pathogens must be able to either prevent their production or tolerate high concentrations of these highly reactive chemicals. In this review, we focus on plant pathogenic bacteria of the genus Pseudomonas and the ways in which they overcome the challenges posed by ROS. We also explore the ways in which pseudomonads may exploit plant ROS generation for their own purposes and even produce ROS directly as part of their infection mechanisms.
Collapse
Affiliation(s)
- Helen Fones
- Department of Plant Sciences, University of Oxford, Oxford, UK
| | | |
Collapse
|
13
|
Sandhya V, Ali SZ, Venkateswarlu B, Reddy G, Grover M. Effect of osmotic stress on plant growth promoting Pseudomonas spp. Arch Microbiol 2010; 192:867-76. [DOI: 10.1007/s00203-010-0613-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2009] [Revised: 07/09/2010] [Accepted: 07/30/2010] [Indexed: 11/28/2022]
|
14
|
McLaughlin RJ, Wilson CL, Chalutz E, Kurtzman CP, Fett WF, Osman SF. Characterization and reclassification of yeasts used for biological control of postharvest diseases of fruits and vegetables. Appl Environ Microbiol 2010; 56:3583-6. [PMID: 16348361 PMCID: PMC185026 DOI: 10.1128/aem.56.11.3583-3586.1990] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In previous studies workers have shown that three yeast strains (strains US-7, 82, and 101) have biological control activity against various postharvest fungal pathogens of fruits and vegetables, including Penicillium rots of apples and citrus and Botrytis rot of apples. In these reports the researchers have described these strains as Debaryomyces hansenii (anamorph, Candida famata) or Candida sp. strains. In this study we performed additional physiological, DNA reassociation, and mannan characterization tests that clearly established a new taxonomic classification for these strains, Candida guilliermondii. We also propose amendment of the physiological test profile in the taxonomic description of C. guilliermondii.
Collapse
Affiliation(s)
- R J McLaughlin
- Appalachian Fruit Research Station, Agricultural Research Service, United States Department of Agriculture, Kearneysville, West Virginia 25430
| | | | | | | | | | | |
Collapse
|
15
|
Lee BU, Park SC, Cho YS, Oh KH. Exopolymer biosynthesis and proteomic changes of Pseudomonas sp. HK-6 under stress of TNT (2,4,6-trinitrotoluene). Curr Microbiol 2008; 57:477-83. [PMID: 18810534 DOI: 10.1007/s00284-008-9272-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2008] [Accepted: 07/01/2008] [Indexed: 10/21/2022]
Abstract
Scanning electron microscopy revealed pores and wrinkles on the surface of Pseudomonas sp. HK-6 cells grown in Luria Bertani (LB) medium containing 0.5 mM TNT (2,4,6-trinitrotoluene). Exopolymer connections were also observed on the wild-type HK-6 cells but not on the algA mutant cells. In addition, the amount of exopolymer from HK strain increased from 90 to 210 microg/mL under TNT stress, whereas the algA mutant produced approximately 30 microg/mL, and its exopolymer production was little increased by TNT stress. These results indicate that TNT stress induced exopolymer production with alginate as a major component. The algA mutant degraded TNT more slowly than the wild-type HK-6 strain. HK-6 was able to completely degrade 0.5 mM TNT within 8 days, whereas algA mutant only achieved approximately 40% within the same time period. Even after 20 days, no more than 80% of TNT was degraded. According to analyses of proteomes of HK-6 and algA mutant cells grown under TNT stress or no stress, several proteins (KinB, AlgB, Alg8, and AlgL) in alginate biosynthesis were only highly induced by both strains under TNT stress. Interestingly, two stress-shock proteins (SSPs), GroEL and RpoH, were more highly expressed in the algA mutant than the HK-6 strain. The algA mutant was rendered more vulnerable to environmental stress and had reduced ability to metabolize TNT in the absence of alginate synthesis.
Collapse
Affiliation(s)
- Bheong-Uk Lee
- Division of Biological Sciences, Kosin University, Busan, 606-701, Republic of Korea
| | | | | | | |
Collapse
|
16
|
Marutani M, Taguchi F, Ogawa Y, Hossain MM, Inagaki Y, Toyoda K, Shiraishi T, Ichinose Y. Gac two-component system in Pseudomonas syringae pv. tabaci is required for virulence but not for hypersensitive reaction. Mol Genet Genomics 2008; 279:313-22. [PMID: 18080141 DOI: 10.1007/s00438-007-0309-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 11/28/2007] [Indexed: 11/28/2022]
Abstract
Pseudomonas syringae pv. tabaci 6605 causes wildfire disease on host tobacco plants. To investigate the regulatory mechanism of the expression of virulence, Gac two-component system-defective mutants, DeltagacA and DeltagacS, and a double mutant, DeltagacADeltagacS, were generated. These mutants produced smaller amounts of N-acyl homoserine lactones required for quorum sensing, had lost swarming motility, and had reduced expression of virulence-related hrp genes and the algT gene required for exopolysaccharide production. The ability of the mutants to cause disease symptoms in their host tobacco plant was remarkably reduced, while they retained the ability to induce hypersensitive reaction (HR) in the nonhost plants. These results indicated that the Gac two-component system of P. syringae pv. tabaci 6605 is indispensable for virulence on the host plant, but not for HR induction in the nonhost plants.
Collapse
Affiliation(s)
- Mizuri Marutani
- Laboratory of Plant Pathology and Genetic Engineering, Graduate School of Natural Science and Technology, Okayama University, Tsushima-naka 1-1-1, Okayama, 700-8530, Japan
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Muhammadi, Ahmed N. Genetics of bacterial alginate: alginate genes distribution, organization and biosynthesis in bacteria. Curr Genomics 2007; 8:191-202. [PMID: 18645604 PMCID: PMC2435354 DOI: 10.2174/138920207780833810] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Revised: 02/26/2007] [Accepted: 03/21/2007] [Indexed: 11/22/2022] Open
Abstract
Bacterial alginate genes are chromosomal and fairly widespread among rRNA homology group I Pseudomonads and Azotobacter. In both genera, the genetic pathway of alginate biosynthesis is mostly similar and the identified genes are identically organized into biosynthetic, regulatory and genetic switching clusters. In spite of these similarities,still there are transcriptional and functional variations between P. aeruginosa and A. vinelandii. In P. aeruginosa all biosynthetic genes except algC transcribe in polycistronic manner under the control of algD promoter while in A. vinelandii, these are organized into many transcriptional units. Of these, algA and algC are transcribed each from two different and algD from three different promoters. Unlike P. aeruginosa, the promoters of these transcriptional units except one of algC and algD are algT-independent. Both bacterial species carry homologous algG gene for Ca(2+)-independent epimerization. But besides algG, A. vinelandii also has algE1-7 genes which encode C-5-epimerases involved in the complex steps of Ca(2+)-dependent epimerization. A hierarchy of alginate genes expression under sigma(22)(algT) control exists in P. aeruginosa where algT is required for transcription of the response regulators algB and algR, which in turn are necessary for expression of algD and its downstream biosynthetic genes. Although algTmucABCD genes cluster play similar regulatory roles in both P. aeruginosa and A. vinelandii but unlike, transcription of A. vinelandii, algR is independent of sigma(22). These differences could be due to the fact that in A. vinelandii alginate plays a role as an integrated part in desiccation-resistant cyst which is not found in P. aeruginosa.
Collapse
Affiliation(s)
| | - Nuzhat Ahmed
- Centre for Molecular Genetics, University of Karachi, Karachi-75270,
Pakistan
| |
Collapse
|
18
|
Li H, Schenk A, Srivastava A, Zhurina D, Ullrich MS. Thermo-responsive expression and differential secretion of the extracellular enzyme levansucrase in the plant pathogenic bacterium Pseudomonas syringae pv. glycinea. FEMS Microbiol Lett 2006; 265:178-85. [PMID: 17147762 DOI: 10.1111/j.1574-6968.2006.00486.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
In the plant pathogen Pseudomonas syringae, production of the exopolysaccharide levan is mediated by extracellular levansucrase (Lsc), which is encoded by two functional genes, lscB and lscC. Comparison of extracellular protein profiles of P. syringae pv. glycinea PG4180 grown at 18 and 28 degrees C and Western blots revealed that Lsc was predominantly found in the supernatant at 18 degrees C, a temperature fostering virulence of this pathogen. Northern blot analysis indicated that transcription of lscB and lscC was temperature-dependent. Quantification of Lsc in supernatants and cellular protein samples of mutants defective in either lscB or lscC confirmed that LscB secretion at low temperature was due to a combination of thermo-regulated transcription and secretion. In contrast, LscC accumulated in the periplasmic space. LscB and LscC differ in only five amino acid residues, one of which is a cysteine residue. Temperature shift experiments suggested that de novo synthesized protein(s) at 18 degrees C might be responsible for differential LscB secretion and that the presumed secretory machinery was stable when cells were shifted to 28 degrees C. Our results imply that Lsc export and secretion may occur by yet-to-be identified novel mechanism(s).
Collapse
Affiliation(s)
- Hongqiao Li
- School of Engineering and Sciences, International University Bremen, Bremen, Germany
| | | | | | | | | |
Collapse
|
19
|
Shankar S, Ye RW, Schlictman D, Chakrabarty AM. Exopolysaccharide alginate synthesis in Pseudomonas aeruginosa: enzymology and regulation of gene expression. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 70:221-55. [PMID: 8638483 DOI: 10.1002/9780470123164.ch4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- S Shankar
- Department of Microbiology and Immunology, University of Illinois, College of Medicine, Chicago, USA
| | | | | | | |
Collapse
|
20
|
Kives J, Orgaz B, Sanjosé C. Polysaccharide differences between planktonic and biofilm-associated EPS from Pseudomonas fluorescens B52. Colloids Surf B Biointerfaces 2006; 52:123-7. [PMID: 16757156 DOI: 10.1016/j.colsurfb.2006.04.018] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2006] [Accepted: 04/27/2006] [Indexed: 11/20/2022]
Abstract
The polysaccharides associated with free (planktonic) and surface-attached (biofilm) cells from cultures of Pseudomonas fluorescens strain B52 were compared. Variations in the attached matrix due to surface material (glass or stainless steel) were also analyzed. Two digestion methods were used to optimize the recoveries of sugars, uronic acids and acidic substituents. The yield of analyzable material after digestion reached 90% for the material associated to the biofilms, though only 20-30% for that bound to planktonic cells. The polysaccharide(s) in the biofilm had glucuronic and guluronic acids as main components, besides rhamnose, glucose and glucosamine. The proportion of glucuronic to guluronic acid was higher in the polysaccharide(s) found in biofilms formed on stainless steel than in those on glass.
Collapse
Affiliation(s)
- Juliana Kives
- Departamento de Nutrición, Bromatología y Tecnología de Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | | | | |
Collapse
|
21
|
Gimmestad M, Steigedal M, Ertesvåg H, Moreno S, Christensen BE, Espín G, Valla S. Identification and characterization of an Azotobacter vinelandii type I secretion system responsible for export of the AlgE-type mannuronan C-5-epimerases. J Bacteriol 2006; 188:5551-60. [PMID: 16855245 PMCID: PMC1540039 DOI: 10.1128/jb.00236-06] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Alginate is a linear copolymer of beta-d-mannuronic acid and its C-5-epimer, alpha-l-guluronic acid. During biosynthesis, the polymer is first made as mannuronan, and various fractions of the monomers are then epimerized to guluronic acid by mannuronan C-5-epimerases. The Azotobacter vinelandii genome encodes a family of seven extracellular such epimerases (AlgE1 to AlgE7) which display motifs characteristic for proteins secreted via a type I pathway. Putative ATPase-binding cassette regions from the genome draft sequence of the A. vinelandii OP strain and experimentally verified type I transporters from other species were compared. This analysis led to the identification of one putative A. vinelandii type I system (eexDEF). The corresponding genes were individually disrupted in A. vinelandii strain E, and Western blot analysis using polyclonal antibodies against all AlgE epimerases showed that these proteins were present in wild-type culture supernatants but absent from the eex mutant supernatants. Consistent with this, the wild-type strain and the eex mutants produced alginate with about 20% guluronic acid and almost pure mannuronan (< or =2% guluronic acid), respectively. The A. vinelandii wild type is able to enter a particular desiccation-tolerant resting stage designated cyst. At this stage, the cells are surrounded by a rigid coat in which alginate is a major constituent. Such a coat was formed by wild-type cells in a particular growth medium but was missing in the eex mutants. These mutants were also found to be unable to survive desiccation. The reason for this is probably that continuous stretches of guluronic acid residues are needed for alginate gel formation to take place.
Collapse
Affiliation(s)
- Martin Gimmestad
- Department of Biotechnology, NTNU Norwegian University of Science and Technology, N-7491 Trondheim, Norway
| | | | | | | | | | | | | |
Collapse
|
22
|
Kemner KM, Kelly SD, Lai B, Maser J, O'loughlin EJ, Sholto-Douglas D, Cai Z, Schneegurt MA, Kulpa CF, Nealson KH. Elemental and redox analysis of single bacterial cells by x-ray microbeam analysis. Science 2004; 306:686-7. [PMID: 15499017 DOI: 10.1126/science.1103524] [Citation(s) in RCA: 151] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
High-energy x-ray fluorescence measurements were used to make elemental maps and qualitative chemical analyses of individual Pseudomonas fluorescens strain NCIMB 11764 cells. Marked differences between planktonic and adhered cells were seen in the morphology, elemental composition, and sensitivity to Cr(VI) of hydrated cells at spatial scales of 150 nm. This technology can be applied to natural geomicrobiological systems.
Collapse
Affiliation(s)
- Kenneth M Kemner
- Environmental Research Division and Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439-4843, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Porteous LA, Widmer F, Seidler RJ. Multiple enzyme restriction fragment length polymorphism analysis for high resolution distinction of Pseudomonas (sensu stricto) 16S rRNA genes. J Microbiol Methods 2002; 51:337-48. [PMID: 12223294 DOI: 10.1016/s0167-7012(02)00108-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Members of the genus Pseudomonas (sensu stricto) are important phytopathogens and agents of human infections, while other strains and species have beneficial bioremediation and biocontrol activities. Traditionally, these important species have been difficult to differentiate phenotypically; thus, rRNA lineage analyses have often been invoked. In this report, a newly developed approach is described to rapidly detect and distinguish fluorescent Pseudomonas isolates: PCR amplification of a Pseudomonas-specific 990-bp ribosomal RNA gene (rDNA) fragment [Appl. Environ. Microbiol. 64 (1998) 2545.] coupled with multiple enzyme restriction fragment length polymorphism (MERFLP) analysis using a single digestion mixture of AluI, HinfI, RsaI, and Tru9I incubated at 37 degrees C. The method distinguished 116 published sequences and 47 reference strains of authentic Pseudomonas representing 28 nomenspecies. A total of 55% (64/116) of the sequences analyzed by MERFLP were grouped into distinct phylogenetic clusters including Pseudomonas putida, P. syringae, P. aeruginosa, P. stutzeri, and P. fluorescens. The utility of the MERFLPs was confirmed when 100% (33/33) of the above named control reference strains were correctly placed into their phylogenetic clusters. The environmental relevance of the MERFLP method was confirmed when 67% of 28 forest and agricultural soil-derived presumptive Pseudomonas environmental clones and isolates were placed into the five major pseudomonad clusters, one clone fell into the P. agarici cluster, and five clones clustered near related pseudomonads. These data demonstrated that the PCR-MERFLP protocol provides an efficient and powerful tool for distinguishing isolates and rDNA gene libraries of environmental Pseudomonas species.
Collapse
Affiliation(s)
- L Arlene Porteous
- National Health and Ecological Effects Research Laboratory, Office of Research and Development, Western Ecology Division, US Environmental Protection Agency, 200 SW 35th Street, Corvallis, OR 97333, USA.
| | | | | |
Collapse
|
24
|
Li H, Ullrich MS. Characterization and mutational analysis of three allelic lsc genes encoding levansucrase in Pseudomonas syringae. J Bacteriol 2001; 183:3282-92. [PMID: 11344135 PMCID: PMC99625 DOI: 10.1128/jb.183.11.3282-3292.2001] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the plant pathogen Pseudomonas syringae pv. glycinea PG4180 and other bacterial species, synthesis of the exopolysaccharide levan is catalyzed by the extracellular enzyme levansucrase. The results of Southern blotting and PCR analysis indicated the presence of three levansucrase-encoding genes in strain PG4180: lscA, lscB, and lscC. In this study, lscB and lscC were cloned from a genomic library of strain PG4180. Sequence analysis of the two lsc genes showed that they were virtually identical to each other and highly similar to the previously characterized lscA gene. lscA and lscC had a chromosomal location, whereas lscB resided on an indigenous plasmid of PG4180. Mutants with impaired expression of individual lsc genes and double mutants were generated by marker exchange mutagenesis. Determination of levansucrase activities in these mutants revealed that the lscB gene product was secreted but not that of lscA or lscC. Our results indicated that lscB and lscC but not lscA contributed to periplasmic levan synthesis of PG4180. The lscB lscC double mutant was completely defective in levan formation and could be complemented by either lscB or lscC. Our data suggested a compartment-specific localization of two lsc gene products, with LscB being the secreted, extracellular enzyme and LscC being the predominantly periplasmic levansucrase. Results of Western blot analyses indicated that lscA was not expressed and that lscA was not associated with levansucrase activities in any particular protein fraction. LscA could be detected in PG4180 only when transcribed from the vector-borne P(lac) promoter. PCR screening in various P. syringae strains with primers derived from the three characterized lsc genes demonstrated the presence of multiple Lsc isoenzymes in other P. syringae pathovars.
Collapse
Affiliation(s)
- H Li
- AG Okophysiologie, Max-Planck-Institut für Terrestrische Mikrobiologie, Karl-von-Frisch-Strasse, 35043 Marburg, Germany
| | | |
Collapse
|
25
|
Cheung HY, Sun SQ, Sreedhar B, Ching WM, Tanner PA. Alterations in extracellular substances during the biofilm development of Pseudomonas aeruginosa on aluminum plates. J Appl Microbiol 2000; 89:100-6. [PMID: 10945785 DOI: 10.1046/j.1365-2672.2000.01083.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The chemical moieties during biofilm formation of Pseudomonas aeruginosa on aluminium plates were examined for a period of 17 days. The effect of fluid shearing upon biofilm formation has also been investigated. The Fourier transform infrared (FTIR) spectrum of the biofilm taken on the fifth day showed significant differences compared with the spectrum of the unattached bacterial cells, indicating that structural changes or modifications of the cell envelope had taken place during the development of the biofilm. Major changes were also observed in the spectrum during the subsequent development of the biofilm from day 5 to day 17. The increasing intensity of a band corresponding to the symmetric stretching mode of the carboxyl group indicated interactions between the carboxyl group and the aluminium surface. Increased bacterial colonization was also observed at the air-water interface of the aluminium plates when compared with the middle and the bottom parts. Changes in FTIR spectra of the biofilm at the bottom, at the middle, and at the air-water interface suggest that the mechanisms of bacterial attachment differed by a -COO(-) interaction at the air-water interface, and by both -COO(-) and NH3(+) groups beneath the water surface.
Collapse
Affiliation(s)
- H Y Cheung
- Department of Biology and Chemistry, City University of Hong Kong.
| | | | | | | | | |
Collapse
|
26
|
Hettwer U, Jaeckel FR, Boch J, Meyer M, Rudolph K, Ullrich MS. Cloning, nucleotide sequence, and expression in Escherichia coli of levansucrase genes from the plant pathogens Pseudomonas syringae pv. glycinea and P. syringae pv. phaseolicola. Appl Environ Microbiol 1998; 64:3180-7. [PMID: 9726857 PMCID: PMC106707 DOI: 10.1128/aem.64.9.3180-3187.1998] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plant-pathogenic bacteria produce various extracellular polysaccharides (EPSs) which may function as virulence factors in diseases caused by these bacteria. The EPS levan is synthesized by the extracellular enzyme levansucrase in Pseudomonas syringae, Erwinia amylovora, and other bacterial species. The lsc genes encoding levansucrase from P. syringae pv. glycinea PG4180 and P. syringae pv. phaseolicola NCPPB 1321 were cloned, and their nucleotide sequences were determined. Heterologous expression of the lsc gene in Escherichia coli was found in four and two genomic library clones of strains PG4180 and NCPPB 1321, respectively. A 3. 0-kb PstI fragment common to all six clones conferred levan synthesis on E. coli when further subcloned. Nucleotide sequence analysis revealed a 1,248-bp open reading frame (ORF) derived from PG4180 and a 1,296-bp ORF derived from NCPPB 1321, which were both designated lsc. Both ORFs showed high homology to the E. amylovora and Zymomonas mobilis lsc genes at the nucleic acid and deduced amino acid sequence levels. Levansucrase was not secreted into the supernatant but was located in the periplasmic fraction of E. coli harboring the lsc gene. Expression of lsc was found to be dependent on the vector-based Plac promoter, indicating that the native promoter of lsc was not functional in E. coli. Insertion of an antibiotic resistance cassette in the lsc gene abolished levan synthesis in E. coli. A PCR screening with primers derived from lsc of P. syringae pv. glycinea PG4180 allowed the detection of this gene in a number of related bacteria.
Collapse
Affiliation(s)
- U Hettwer
- Institut für Phytopathologie und Pflanzenschutz der Universität Göttingen, 37077 Göttingen, Germany
| | | | | | | | | | | |
Collapse
|
27
|
Gacesa P. Bacterial alginate biosynthesis--recent progress and future prospects. MICROBIOLOGY (READING, ENGLAND) 1998; 144 ( Pt 5):1133-1143. [PMID: 9611788 DOI: 10.1099/00221287-144-5-1133] [Citation(s) in RCA: 137] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The extracellular polysaccharide alginate has been widely associated with chronic Pseudomonas aeruginosa infections in the cystic fibrosis lung. However, it is clear that alginate biosynthesis is a more widespread phenomenon. Alginate plays a key role as a virulence factor of plant-pathogenic pseudomonads, in the formation of biofilms and with the encystment process of Azotobacter spp.
Collapse
Affiliation(s)
- Peter Gacesa
- Faculty of Science and Engineering, Manchester Metropolitan University, John Dalton Extension, Chester Street, Manchester M1 5GD, UK
| |
Collapse
|
28
|
Peñaloza-Vázquez A, Kidambi SP, Chakrabarty AM, Bender CL. Characterization of the alginate biosynthetic gene cluster in Pseudomonas syringae pv. syringae. J Bacteriol 1997; 179:4464-72. [PMID: 9226254 PMCID: PMC179280 DOI: 10.1128/jb.179.14.4464-4472.1997] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Alginate, a copolymer of D-mannuronic acid and L-guluronic acid, is produced by a variety of pseudomonads, including Pseudomonas syringae. Alginate biosynthesis has been most extensively studied in P. aeruginosa, and a number of structural and regulatory genes from this species have been cloned and characterized. In the present study, an alginate-defective (Alg-) mutant of P. syringae pv. syringae FF5 was shown to contain a Tn5 insertion in algL, a gene encoding alginate lyase. A cosmid clone designated pSK2 restored alginate production to the algL mutant and was shown to contain homologs of algD, alg8, alg44, algG, algX (alg60), algL, algF, and algA. The order and arrangement of the structural gene cluster were virtually identical to those previously described for P. aeruginosa. Complementation analyses, however, indicated that the structural gene clusters in P. aeruginosa and P. syringae were not functionally interchangeable when expressed from their native promoters. A region upstream of the algD gene in P. syringae pv. syringae was shown to activate the transcription of a promoterless glucuronidase (uidA) gene and indicated that transcription initiated upstream of algD as described for P. aeruginosa. Transcription of the algD promoter from P. syringae FF5 was significantly higher at 32 degrees C than at 18 or 26 degrees C and was stimulated when copper sulfate or sodium chloride was added to the medium. Alginate gene expression was also stimulated by the addition of the nonionic solute sorbitol, indicating that osmolarity is a signal for algD expression in P. syringae FF5.
Collapse
Affiliation(s)
- A Peñaloza-Vázquez
- Department of Plant Pathology, Oklahoma State University, Stillwater 74078-3032, USA
| | | | | | | |
Collapse
|
29
|
Fishman ML, Cescutti P, Fett WF, Osman SF, Hoagland PD, Chau HK. Screening the physical properties of novel Pseudomonas exopolysaccharides by HPSEC with multi-angle light scattering and viscosity detection. Carbohydr Polym 1997. [DOI: 10.1016/s0144-8617(97)00012-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
30
|
Effects of external stimuli on environmental bacterial strains harboring analgD-lux bioluminescent reporter plasmid for the study of corrosive biofilms. ACTA ACUST UNITED AC 1995. [DOI: 10.1007/bf01569986] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
31
|
Kidambi SP, Sundin GW, Palmer DA, Chakrabarty AM, Bender CL. Copper as a signal for alginate synthesis in Pseudomonas syringae pv. syringae. Appl Environ Microbiol 1995; 61:2172-9. [PMID: 7793938 PMCID: PMC167489 DOI: 10.1128/aem.61.6.2172-2179.1995] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Plant-associated pseudomonads are commonly exposed to copper bactericides, which are applied to reduce the disease incidence caused by these bacteria. Consequently, many of these bacteria have acquired resistance or tolerance to copper salts. We recently conducted a survey of 37 copper-resistant (Cur) Pseudomonas spp., including P. cepacia, P. fluorescens, P. syringae, and P. viridiflava, and found that a subset of the P. syringae strains showed a dramatic increase in exopolysaccharide (EPS) production on mannitol-glutamate medium containing CuSO4 at 250 micrograms/ml. A modified carbazole assay indicated that the EPS produced on copper-amended media contained high levels of uronic acids, suggesting that the EPS was primarily alginic acid. Uronic acids extracted from selected strains were further confirmed to be alginate by demonstrating their sensitivity to alginate lyase and by descending paper chromatography following acid hydrolysis. Subinhibitory levels of arsenate, cobalt, lithium, rubidium, molybdenum, and mercury did not induce EPS production, indicating that alginate biosynthesis is not induced in P. syringae cells exposed to these heavy metals. A 200-kb plasmid designated pPSR12 conferred a stably mucoid phenotype to several P. syringae recipients and also increased their resistance to cobalt and arsenate. A cosmid clone constructed from pPSR12 which conferred a stably mucoid phenotype to several P. syringae strains but not to Pseudomonas aeruginosa was obtained. Results obtained in this study indicate that some of the signals and regulatory genes for alginate production in P. syringae differ from those described for alginate production in P. aeruginosa.
Collapse
Affiliation(s)
- S P Kidambi
- Department of Plant Pathology, Oklahoma State University, Stillwater 74078-9947, USA
| | | | | | | | | |
Collapse
|
32
|
Fett WF, Wells JM, Cescutti P, Wijey C. Identification of exopolysaccharides produced by fluorescent pseudomonads associated with commercial mushroom (Agaricus bisporus) production. Appl Environ Microbiol 1995; 61:513-7. [PMID: 7574589 PMCID: PMC167311 DOI: 10.1128/aem.61.2.513-517.1995] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The acidic exopolysaccharides (EPSs) from 63 strains of mushroom production-associated fluorescent pseudomonads which were mucoid on Pseudomonas agar F medium (PAF) were isolated, partially purified, and characterized. The strains were originally isolated from discolored lesion which developed postharvest on mushroom (Agaricus bisporus) caps or from commercial lots of mushroom casing medium. An acidic galactoglucan, previously named marginalan, was produced by mucoid strains of the saprophyte Pseudomonas putida and the majority of mucoid strains of saprophytic P. fluorescens (biovars III and V) isolated from casing medium. One biovar II strain (J1) of P. fluorescens produced alginate, a copolymer of mannuronic and guluronic acids, and one strain (H13) produced an apparently unique EPS containing neutral and amino sugars. Of 10 strains of the pathogen "P. gingeri," the causal agent of mushroom ginger blotch, 8 gave mucoid growth on PAF. The "P. gingeri" EPS also was unique in containing both neutral sugar and glucuronic acid. Mucoid, weakly virulent strains of "P. reactans" produced either alginate or marginalan. All 10 strains of the pathogen P. tolaasii, the causal agent of brown blotch of mushrooms were nonnmucoid on PAF. Production of EPS by these 10 strains plus the 2 nonmucoid strains of "P. gingeri" also was negative on several additional solid media as well as in two broth media tested. The results support our previous studies indicating that fluorescent pseudomonads are a rich source of novel EPSs.
Collapse
Affiliation(s)
- W F Fett
- Eastern Regional Research Center, U.S. Department of Agriculture, Philadelphia, Pennsulvania 19118, USA
| | | | | | | |
Collapse
|
33
|
Deretic V, Schurr MJ, Boucher JC, Martin DW. Conversion of Pseudomonas aeruginosa to mucoidy in cystic fibrosis: environmental stress and regulation of bacterial virulence by alternative sigma factors. J Bacteriol 1994; 176:2773-80. [PMID: 8188579 PMCID: PMC205429 DOI: 10.1128/jb.176.10.2773-2780.1994] [Citation(s) in RCA: 173] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Affiliation(s)
- V Deretic
- Department of Microbiology, University of Texas Health Science Center at San Antonio 78284-7758
| | | | | | | |
Collapse
|
34
|
Fett WF, Wijey C, Lifson ER. Occurrence of alginate gene sequences among members of the pseudomonad rRNA homology groups IâIV. FEMS Microbiol Lett 1992. [DOI: 10.1111/j.1574-6968.1992.tb05558.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
|
35
|
Effect of osmolarity and dehydration on alginate production by fluorescent pseudomonads. Curr Microbiol 1992. [DOI: 10.1007/bf01577231] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
36
|
De Ruiter GA, Van Bruggen-van der Lugt AW, Nout MJ, Middelhoven WJ, Soentoro PS, Notermans SH, Rombouts FM. Formation of antigenic extracellular polysaccharides by selected strains of Mucor spp., Rhizopus spp., Rhizomucor spp., Absidia corymbifera and Syncephalastrum racemosum. Antonie Van Leeuwenhoek 1992; 62:189-99. [PMID: 1416915 DOI: 10.1007/bf00582579] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In this study, polyclonal IgG antibodies raised against extracellular polysaccharides (EPS) of Mucor racemosus were characterised as almost specific for moulds belonging to the order of Mucorales. Cross-reactivity in the ELISA could be observed only towards the yeast Pichia membranaefaciens. EPS were isolated from various cultures of M. hiemalis growing on six different carbon sources and two nitrogen sources, with ratios varying from 0.13 to 0.44 relative to the amount of biomass. Other strains including Mucor spp., Rhizopus spp., Rhizomucor spp., Absidia corymbifera and Syncephalastrum racemosum also excreted EPS, with ratios varying from 0.05 to 0.23. In all cases, the excreted EPS had similar antigenic properties as determined by ELISA. No enzymatic degradation of the antigenic parts of the polysaccharides could be observed upon prolonged incubation. Considering that all tested strains formed similar amounts of antigenic EPS there might be scope for the specific detection of biomass of Mucoralean moulds using ELISA techniques for example in food.
Collapse
Affiliation(s)
- G A De Ruiter
- Wageningen Agricultural University, Department of Food Science, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
37
|
Govan JR, Sarasola P, Taylor DJ, Tatnell PJ, Russell NJ, Gacesa P. Isolation of a mucoid alginate-producing Pseudomonas aeruginosa strain from the equine guttural pouch. J Clin Microbiol 1992; 30:595-9. [PMID: 1551975 PMCID: PMC265116 DOI: 10.1128/jcm.30.3.595-599.1992] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The isolation and characterization of a mucoid, alginate-producing strain of Pseudomonas aeruginosa from a nonhuman host, namely, in chondroids from an equine guttural pouch, is reported for the first time. Pure cultures of P. aeruginosa 12534 were isolated from a 17-month-old pony mare with a history of chronic bilateral mucopurulent nasal discharge from the right guttural pouch. Transmission electron microscopy of chondroids showed mucoid P. aeruginosa growing as microcolonies within a matrix of extracellular material. On the basis of expression of the mucoid phenotype under different growth conditions, P. aeruginosa 12534 belongs to group 1 and resembles other isolates carrying the muc-23 mutation. The bulk of the extracellular material was characterized as being alginate by chemical and 1H nuclear magnetic resonance analyses, which showed that it had a composition similar to that produced by isolates of P. aeruginosa from human patients with cystic fibrosis.
Collapse
Affiliation(s)
- J R Govan
- Department of Medical Microbiology, University of Edinburgh Medical School, Scotland, United Kingdom
| | | | | | | | | | | |
Collapse
|
38
|
Determinants of Epiphytic Fitness in Bacteria. BROCK/SPRINGER SERIES IN CONTEMPORARY BIOSCIENCE 1991. [DOI: 10.1007/978-1-4612-3168-4_15] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
39
|
Affiliation(s)
- M Fletcher
- Maryland Biotechnology Institute, University of Maryland, Baltimore
| |
Collapse
|
40
|
Osman SF, Fett WF. The structure of the acidic exopolysaccharide of Pseudomonas marginalis strains PF-05-2 and PM-LB-1. Carbohydr Res 1990; 199:77-82. [PMID: 2379201 DOI: 10.1016/0008-6215(90)84094-b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The structure of an acidic exopolysaccharide of two strains of Pseudomonas marginalis, a bacterium which causes soft rots of various vegetables, has been determined to consist of a repeating unit of: ----4) beta-D-Manp-(1----3)alpha-D-Glcp-(1----4)alpha-L-Rhap-(1-. The glucose is pyruvated at O-4 and O-6 and the mannose is acetylated at either O-2 or O-3.
Collapse
Affiliation(s)
- S F Osman
- Department of Agriculture, North Atlantic Area, Philadelphia, PA 19118
| | | |
Collapse
|
41
|
Fialho AM, Zielinski NA, Fett WF, Chakrabarty AM, Berry A. Distribution of alginate gene sequences in the Pseudomonas rRNA homology group I-Azomonas-Azotobacter lineage of superfamily B procaryotes. Appl Environ Microbiol 1990; 56:436-43. [PMID: 1689562 PMCID: PMC183358 DOI: 10.1128/aem.56.2.436-443.1990] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Chromosomal DNA from group I Pseudomonas species, Azotobacter vinelandii, Azomonas macrocytogens, Xanthomonas campestris, Serpens flexibilis, and three enteric bacteria was screened for sequences homologous to four Pseudomonas aeruginosa alginate (alg) genes (algA, pmm, algD, and algR1). All the group I Pseudomonas species tested (including alginate producers and nonproducers) contained sequences homologous to all the P. aeruginosa alg genes used as probes, with the exception of P. stutzeri, which lacked algD. Azotobacter vinelandii also contained sequences homologous to all the alg gene probes tested, while Azomonas macrocytogenes DNA showed homology to all but algD. X. campestris contained sequences homologous to pmm and algR1 but not to algA or algD. The helical bacterium S. flexibilis showed homology to the algR1 gene, suggesting that an environmentally responsive regulatory gene similar to algR1 exists in S. flexibilis. Escherichia coli showed homology to the algD and algR1 genes, while Salmonella typhimurium and Klebsiella pneumoniae failed to show homology with any of the P. aeruginosa alg genes. Since all the organisms tested are superfamily B procaryotes, these results suggest that within superfamily B, the alginate genes are distributed throughout the Pseudomonas group I-Azotobacter-Azomonas lineage, while only some alg genes have been retained in the Pseudomonas group V (Xanthomonas) and enteric lineages.
Collapse
Affiliation(s)
- A M Fialho
- Department of Microbiology and Immunology, University of Illinois College of Medicine, Chicago 60612
| | | | | | | | | |
Collapse
|