Ultrastructural and electron energy-loss spectroscopic analysis of an extracellular filamentous matrix of an environmental bacterial isolate.

2.50
Hdl Handle:
http://hdl.handle.net/10033/24432
Title:
Ultrastructural and electron energy-loss spectroscopic analysis of an extracellular filamentous matrix of an environmental bacterial isolate.
Authors:
Böckelmann, Uta; Lünsdorf, Heinrich; Szewzyk, Ulrich
Abstract:
Strain F8, a bacterial isolate from 'river snow', was found to produce extracellular fibres in the form of a filamentous network. These extracellular filaments, which were previously shown to be composed of DNA, have been studied for the first time by ultrastructural and electron energy-loss spectroscopy in the present work. 'Whole mount' preparations of strain F8 indicate these polymers are ultrastructurally homogeneous and form a network of elemental filaments, which have a width of 1.8-2.0 nm. When incubated at pH 3.5 with colloidal cationic ThO(2) tracers they become intensely stained (electron dense), affording direct evidence that the fibres are negatively charged and thus acidic chemically. Elemental analysis of the extracellular filaments by Energy-filtered Transmission Electron Microscopy revealed phosphorus to be the main element present and, because pretreatment of F8 cells with DNase prevented thorium labelling, the fibres must be composed of extracellular DNA (eDNA). Neither ultrathin sections nor 'whole mount negative stain' caused DNA release by general cell lysis. Additionally, cells infected with phages were never observed in ultrathin sections and phage particles were never detected in whole mount samples, which rules out the possibility of phages being directly involved in eDNA release.
Affiliation:
Department of Environmental Microbiology, Technical University Berlin, Franklin Str. 29, 10587 Berlin, Germany. uta.boeckelmann@tu-berlin.de
Citation:
Ultrastructural and electron energy-loss spectroscopic analysis of an extracellular filamentous matrix of an environmental bacterial isolate. 2007, 9 (9):2137-44 Environ. Microbiol.
Journal:
Environmental microbiology
Issue Date:
Sep-2007
URI:
http://hdl.handle.net/10033/24432
DOI:
10.1111/j.1462-2920.2007.01325.x
PubMed ID:
17686013
Type:
Article
Language:
en
ISSN:
1462-2912
Appears in Collections:
Publications of RG Environmental Microbiology (UMW)

Full metadata record

DC FieldValue Language
dc.contributor.authorBöckelmann, Uta-
dc.contributor.authorLünsdorf, Heinrich-
dc.contributor.authorSzewzyk, Ulrich-
dc.date.accessioned2008-04-29T13:38:06Z-
dc.date.available2008-04-29T13:38:06Z-
dc.date.issued2007-09-
dc.identifier.citationUltrastructural and electron energy-loss spectroscopic analysis of an extracellular filamentous matrix of an environmental bacterial isolate. 2007, 9 (9):2137-44 Environ. Microbiol.en
dc.identifier.issn1462-2912-
dc.identifier.pmid17686013-
dc.identifier.doi10.1111/j.1462-2920.2007.01325.x-
dc.identifier.urihttp://hdl.handle.net/10033/24432-
dc.description.abstractStrain F8, a bacterial isolate from 'river snow', was found to produce extracellular fibres in the form of a filamentous network. These extracellular filaments, which were previously shown to be composed of DNA, have been studied for the first time by ultrastructural and electron energy-loss spectroscopy in the present work. 'Whole mount' preparations of strain F8 indicate these polymers are ultrastructurally homogeneous and form a network of elemental filaments, which have a width of 1.8-2.0 nm. When incubated at pH 3.5 with colloidal cationic ThO(2) tracers they become intensely stained (electron dense), affording direct evidence that the fibres are negatively charged and thus acidic chemically. Elemental analysis of the extracellular filaments by Energy-filtered Transmission Electron Microscopy revealed phosphorus to be the main element present and, because pretreatment of F8 cells with DNase prevented thorium labelling, the fibres must be composed of extracellular DNA (eDNA). Neither ultrathin sections nor 'whole mount negative stain' caused DNA release by general cell lysis. Additionally, cells infected with phages were never observed in ultrathin sections and phage particles were never detected in whole mount samples, which rules out the possibility of phages being directly involved in eDNA release.en
dc.language.isoenen
dc.subject.meshBiofilmsen
dc.subject.meshCanadaen
dc.subject.meshDNAen
dc.subject.meshDNA, Bacterialen
dc.subject.meshIceen
dc.subject.meshMicroscopy, Energy-Filtering Transmission Electronen
dc.subject.meshPolymersen
dc.subject.meshRiversen
dc.titleUltrastructural and electron energy-loss spectroscopic analysis of an extracellular filamentous matrix of an environmental bacterial isolate.en
dc.typeArticleen
dc.contributor.departmentDepartment of Environmental Microbiology, Technical University Berlin, Franklin Str. 29, 10587 Berlin, Germany. uta.boeckelmann@tu-berlin.deen
dc.identifier.journalEnvironmental microbiologyen
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