title: Impact of glycerol and nitrogen concentration on Enterobacter A47 growth and exopolysaccharide production.
abstract: Enterobacter A47 produces a fucose-containing exopolysaccharide (EPS) by cultivation in mineral medium supplemented with glycerol. EPS synthesis by Enterobacter A47 was shown to be influenced by both the initial glycerol and nitrogen concentrations and by the nutrients' feeding rate during the fed-batch phase. Initial nitrogen concentrations above 1.05g/L were detrimental for EPS synthesis: the productivity was reduced to 0.35-0.62g/Ld (compared to 1.89-2.04g/Ld under lower nitrogen concentrations) and the polymer had lower fucose content (14-17%mol, compared to 36-38%mol under lower nitrogen concentrations). On the other hand, EPS productivity was improved to 5.66g/Ld by increasing the glycerol and nitrogen feeding rates during the fed-batch phase. However, the EPS thus obtained had lower fucose (26%mol) and higher galactose (34%mol) contents, as well as lower average molecular weight (7.2×10(5)). The ability of Enterobacter A47 to synthesize EPS with different physico-chemical characteristics may be useful for the generation of biopolymers with distinct functional properties suitable for different applications.
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Cristiana A V
authors.initials: CA
authors.lastname: Torres
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Marques
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Ana R V
authors.initials: AR
authors.lastname: Ferreira
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Sílvia
authors.initials: S
authors.lastname: Antunes
authors.affiliation: Interfacultary Research Centre of Biomaterials (CEIB), University of Liège, B-4000 Liège, Belgium.
authors.forename: Christian
authors.initials: C
authors.lastname: Grandfils
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal. Electronic address: a4406@fct.unl.pt.
authors.forename: Filomena
authors.initials: F
authors.lastname: Freitas
authors.affiliation: REQUIMTE/CQFB, Chemistry Department, FCT/Universidade Nova de Lisboa, 2829-516 Caparica, Portugal.
authors.forename: Maria A M
authors.initials: MA
authors.lastname: Reis
mesh_terms: D061249:Batch Cell Culture Techniques; D019149:Bioreactors; D003470:Culture Media / Q000737:chemistry; D004754:Enterobacter / Q000378:metabolism*; D005285:Fermentation; D005990:Glycerol / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*
chemical_list: D003470:Culture Media; D011135:Polysaccharides, Bacterial; D009584:Nitrogen; D005990:Glycerol
keywords: Enterobacter; Exopolysaccharide (EPS); Fucose