Pseudomonas aeruginosa biofilms: role of the alginate exopolysaccharide.
Pseudomonas aeruginosa synthesizes an exopolysaccharide called alginate in response to environmental conditions. Alginate serves to protect the bacteria from adversity in its surroundings and also enhances adhesion to solid surfaces. Transcription of the alginate biosynthetic genes is induced upon attachment to the substratum and this leads to increased alginate production. As a result, biofilms develop which are advantageous to the survival and growth of the bacteria. In certain circumstances, P. aeruginosa produces an alginate lyase enzyme which cleaves the polymer into short oligosaccharides. This negates the anchoring properties of the alginate and results in increased detachment of the bacteria away from the surface, allowing them to spread and colonize new sites. Thus, both alginate biosynthetic and degradative enzymes are important for the development, maintenance and spread of P. aeruginosa biofilms.
Department of Microbiology and Immunology, University of Illinois, Chicago College of Medicine 60612, USA.
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Boyd
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Chakrabarty
D000464:Alginates / Q000737:chemistry / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D002240:Carbohydrate Sequence; D003550:Cystic Fibrosis / Q000150:complications; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006801:Humans; D008969:Molecular Sequence Data; D009894:Opportunistic Infections / Q000209:etiology; D018410:Pneumonia, Bacterial / Q000209:etiology; D011135:Polysaccharides, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*
D000464:Alginates; D006603:Hexuronic Acids; D011135:Polysaccharides, Bacterial; C064841:exopolysaccharide, Pseudomonas; D020723:Glucuronic Acid