Studies of the extracellular glycocalyx of the anaerobic cellulolytic bacterium Ruminococcus albus 7

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dc.contributor.authorWeimer P.J.
dc.contributor.authorPrice N.P.J.
dc.contributor.authorKroukamp O.
dc.contributor.authorJoubert L.-M.
dc.contributor.authorWolfaardt G.M.
dc.contributor.authorVan Zyl W.H.
dc.date.accessioned2011-05-15T15:56:32Z
dc.date.available2011-05-15T15:56:32Z
dc.date.issued2006
dc.description.abstractAnaerobic cellulolytic bacteria are thought to adhere to cellulose via several mechanisms, including production of a glycocalyx containing extracellular polymeric substances (EPS). As the compositions and structures of these glycocalyces have not been elucidated, variable-pressure scanning electron microscopy (VP-SEM) and chemical analysis were used to characterize the glycocalyx of the ruminal bacterium Ruminococcus albus strain 7. VP-SEM revealed that growth of this strain was accompanied by the formation of thin cellular extensions that allowed the bacterium to adhere to cellulose, followed by formation of a ramifying network that interconnected individual cells to one another and to the unraveling cellulose microfibrils. Extraction of 48-h-old whole-culture pellets (bacterial cells plus glycocalyx [G] plus residual cellulose [C]) with 0.1 N NaOH released carbohydrate and protein in a ratio of 1:5. Boiling of the cellulose fermentation residue in a neutral detergent solution removed almost all of the adherent cells and protein while retaining a residual network of adhering noncellular material. Trifluoroacetic acid hydrolysis of this residue (G plus C) released primarily glucose, along with substantial amounts of xylose and mannose, but only traces of galactose, the most abundant sugar in most characterized bacterial exopolysaccharides. Linkage analysis and characterization by nuclear magnetic resonance suggested that most of the glucosyl units were not present as partially degraded cellulose. Calculations suggested that the energy demand for synthesis of the nonprotein fraction of EPS by this organism represents only a small fraction (<4%) of the anabolic ATP expenditure of the bacterium. Copyright © 2006, American Society for Microbiology. All Rights Reserved.
dc.description.versionArticle
dc.identifier.citationApplied and Environmental Microbiology
dc.identifier.citation72
dc.identifier.citation12
dc.identifier.issn992240
dc.identifier.other10.1128/AEM.01632-06
dc.identifier.urihttp://hdl.handle.net/10019.1/9902
dc.subjectAdhesion
dc.subjectCellulose
dc.subjectDetergents
dc.subjectFermentation
dc.subjectGlucose
dc.subjectHydrolysis
dc.subjectScanning electron microscopy
dc.subjectBacterial exopolysaccharides
dc.subjectExtracellular polymeric substances (EPS)
dc.subjectGlycocalyces
dc.subjectTrifluoroacetic acid hydrolysis
dc.subjectBacteria
dc.subjectadenosine triphosphate
dc.subjectbacterial polysaccharide
dc.subjectbacterial protein
dc.subjectcarbohydrate
dc.subjectcellulose
dc.subjectdetergent
dc.subjectexopolysaccharide
dc.subjectgalactose
dc.subjectmannose
dc.subjectpolymer
dc.subjectsodium hydroxide
dc.subjecttrifluoroacetic acid
dc.subjectxylose
dc.subjectacetic acid
dc.subjectbacterium
dc.subjectcellulose
dc.subjectglucose
dc.subjecthydrolysis
dc.subjectprotein
dc.subjectaqueous solution
dc.subjectarticle
dc.subjectbacterial growth
dc.subjectbacterial metabolism
dc.subjectbacterial strain
dc.subjectbacterium adherence
dc.subjectcell interaction
dc.subjectcell structure
dc.subjectchemical analysis
dc.subjectcontrolled study
dc.subjectenergy expenditure
dc.subjectextracellular matrix
dc.subjectfermentation
dc.subjectfiber
dc.subjectglycocalyx
dc.subjectlinkage analysis
dc.subjectnonhuman
dc.subjectnuclear magnetic resonance
dc.subjectrumen microorganism
dc.subjectRuminococcus albus
dc.subjectRuminococcus albus 7
dc.subjectsaccharification
dc.subjectscanning electron microscopy
dc.subjectvariable pressure scanning electron microscopy
dc.subjectAnaerobiosis
dc.subjectBacterial Adhesion
dc.subjectCellulose
dc.subjectCulture Media
dc.subjectGlycocalyx
dc.subjectMicroscopy, Electron, Scanning
dc.subjectRuminococcus
dc.subjectSpectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
dc.subjectAdhesion
dc.subjectBacteria
dc.subjectCellulose
dc.subjectDetergents
dc.subjectFermentation
dc.subjectGlucose
dc.subjectHydrolysis
dc.subjectScanning Electron Microscopy
dc.subjectBacteria (microorganisms)
dc.subjectRuminococcus albus
dc.titleStudies of the extracellular glycocalyx of the anaerobic cellulolytic bacterium Ruminococcus albus 7
dc.typeArticle
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