Properties of polysaccharide produced by Azotobacter vinelandii cultured on 4-hydroxybenzoic acid.
OBJECTIVE
Characterization of the exopolysaccharide produced by Azotobacter vinelandii grown on 4-hydroxybenzoic acid (EPS I), and the comparison between this exopolysaccharide and commercial alginate, constituted the main objective of this work.


RESULTS
Total carbohydrates, uronic acids, acetyl and pyruvyl groups and proteins were determined by colorimetric methods and composition was confirmed by Nuclear Magnetic Resonance studies. Rheological properties were analysed under different physical and chemical conditions. Results showed differences between EPS I and commercial alginate, in relation to both composition and viscosity. Higher amount of guluronnosyl residues were found in EPS I, whereas commercial alginate contained the same proportion of mannuronosyl and guluronnosyl residues. In accordance with this result, EPS I gave rise to solutions of higher viscosity than commercial alginate, although solutions of this polysaccharide showed greater stability when conditions were altered.


CONCLUSIONS
The exopolysaccharide produced by A. vinelandii grown on 4-hydroxybenzoic acid showed a different composition in comparison with commercial alginate, which leads to higher viscosity values for the aqueous solutions of EPS I.


CONCLUSIONS
This work describes for the first time the characteristics of an exopolysaccharide produced by A. vinelandii from 4-hydroxybenzoic acid, a substrate rarely used as sole carbon source.
Vargas-Garcia
M C
MC
Departamento de Biologia Aplicada, Escuela Politecnica Superior, Universidad de Almeria, Almeria, Spain.
Lopez
M J
MJ
Elorrieta
M A
MA
Suarez
F
F
Moreno
J
J
D000085:Acetates / Q000032:analysis; D000464:Alginates / Q000494:pharmacology; D016948:Azotobacter vinelandii / Q000187:drug effects / Q000378:metabolism*; D001426:Bacterial Proteins / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D003470:Culture Media; D005947:Glucose / Q000494:pharmacology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D010226:Parabens / Q000494:pharmacology*; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis* / Q000737:chemistry; D011773:Pyruvates / Q000032:analysis; D014574:Uronic Acids / Q000032:analysis; D014783:Viscosity
D000085:Acetates; D000464:Alginates; D001426:Bacterial Proteins; D002241:Carbohydrates; D003470:Culture Media; D010226:Parabens; D011135:Polysaccharides, Bacterial; D011773:Pyruvates; D014574:Uronic Acids; D005947:Glucose; C038193:4-hydroxybenzoic acid