title: High production of polysialic acid [Neu5Ac alpha(2-8)-Neu5Ac alpha(2-9)]n by Escherichia coli K92 grown in a chemically defined medium. Regulation of temperature.
abstract: The capsular polysaccharide of Escherichia coli K92 consists of a linear polymer of Neu5Ac with alternating alpha(2-8) and alpha(2-9) linkages. It accumulates when the bacterium is grown at 37 degrees C in a defined medium containing D-xylose and L-asparagine as carbon and nitrogen sources. Release of the capsular polymer into the medium was maximal (450 micrograms x ml-1) in the stationary phase of growth (76 h). This medium could be useful for obtaining sufficient polymer to develop effective vaccines. The enzyme, CMP-Neu5Ac synthetase, was not detected in cells grown at 20 degrees C. The lack of this enzyme explains the absence of polymer biosynthesis when the bacterium was grown at 20 degrees C.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Universidad de León, Espana.
authors.forename: C
authors.initials: C
authors.lastname: González-Clemente
authors.forename: J M
authors.initials: JM
authors.lastname: Luengo
authors.forename: L B
authors.initials: LB
authors.lastname: Rodríguez-Aparicio
authors.forename: M A
authors.initials: MA
authors.lastname: Ferrero
authors.forename: A
authors.initials: A
authors.lastname: Reglero
mesh_terms: D000942:Antigens, Bacterial / Q000276:immunology; D001216:Asparagine; D001428:Bacterial Vaccines; D002236:Carbohydrate Conformation; D003470:Culture Media; D004926:Escherichia coli / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D007700:Kinetics; D000216:N-Acylneuraminate Cytidylyltransferase / Q000378:metabolism; D009584:Nitrogen; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000276:immunology; D012794:Sialic Acids / Q000276:immunology / Q000378:metabolism*; D013696:Temperature; D014994:Xylose
chemical_list: D000942:Antigens, Bacterial; D001428:Bacterial Vaccines; D003470:Culture Media; D011135:Polysaccharides, Bacterial; D012794:Sialic Acids; C021319:polysialic acid; D001216:Asparagine; D014994:Xylose; D000216:N-Acylneuraminate Cytidylyltransferase; D009584:Nitrogen