title: Cellulose as an extracellular matrix component present in Enterobacter sakazakii biofilms.
abstract: Cellulose was identified and characterized as an extracellular matrix component present in the biofilm of an Enterobacter sakazakii clinical isolate grown in nutrient-deficient (M9) medium. Using a bacterial artificial cloning approach in Escherichia coli and subsequent screening of transformants for fluorescence on calcofluor plates, nine genes organized in two operons were identified as putatively responsible for the biosynthesis of cellulose. In addition to the genes already described for cellulose production, two more genes were identified, putatively transcribed together with the genes from the first operon. Putative cellulose in E. sakazakii ES5 biofilm grown on glass coverslips was visualized by calcofluor staining and confocal fluorescence laser scanning microscopy. For the first time, the presence of cellulose in biofilms produced by E. sakazakii was confirmed by methylation analysis.
authors.affiliation: Institute for Food Safety and Hygiene, Vetsuisse Faculty, University of Zurich, CH-8057 Zurich, Switzerland.
authors.forename: Maya
authors.initials: M
authors.lastname: Grimm
authors.forename: Roger
authors.initials: R
authors.lastname: Stephan
authors.forename: Carol
authors.initials: C
authors.lastname: Iversen
authors.forename: Giuseppe G G
authors.initials: GG
authors.lastname: Manzardo
authors.forename: Thomas
authors.initials: T
authors.lastname: Rattei
authors.forename: Kathrin
authors.initials: K
authors.lastname: Riedel
authors.forename: Andreas
authors.initials: A
authors.lastname: Ruepp
authors.forename: Dmitrij
authors.initials: D
authors.lastname: Frishman
authors.forename: Angelika
authors.initials: A
authors.lastname: Lehner
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D002482:Cellulose / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D044083:Cronobacter sakazakii / Q000502:physiology*; D003470:Culture Media / Q000737:chemistry; D005109:Extracellular Matrix / Q000737:chemistry*; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D018613:Microscopy, Confocal; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D003470:Culture Media; D002482:Cellulose