title: Manipulating the molecular weight of alginate produced by Azotobacter vinelandii in continuous cultures.
abstract: Alginate production by Azotobacter vinelandii in chemostat cultures was evaluated at different dilution rates (D) and inlet sucrose concentrations of 5 and 20 g l(-1). At the low inlet sucrose concentration, the molecular weight of alginate increased from 800 to 1800 kDa when D increased from 0.05 to 0.10 h(-1), whereas the opposite trend was observed with the high inlet sucrose concentration. This behaviour can be explained by changes in specific sucrose uptake rate. Thus, a decrease in alginate molecular weight was dependent on the specific sucrose uptake rate when this rate was higher than 0.42 g g(-1) h(-1). The manipulation of the D can be used to select the molecular weight of alginate in continuous culture.
authors.affiliation: Escuela de Ingeniería Bioquímica, Pontificia Universidad Cato lica de Valparaíso, Av. Brasil 2147, Casilla 4059, Valparaíso, Chile. alvaro.diaz@ucv.cl
authors.forename: Alvaro
authors.initials: A
authors.lastname: Díaz-Barrera
authors.forename: Paulina
authors.initials: P
authors.lastname: Silva
authors.forename: Julio
authors.initials: J
authors.lastname: Berrios
authors.forename: Fernando
authors.initials: F
authors.lastname: Acevedo
mesh_terms: D000464:Alginates / Q000737:chemistry*; D016948:Azotobacter vinelandii / Q000166:cytology* / Q000378:metabolism*; D018533:Biomass; D018929:Cell Culture Techniques / Q000379:methods*; D020723:Glucuronic Acid / Q000096:biosynthesis / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D008970:Molecular Weight; D013395:Sucrose / Q000378:metabolism
chemical_list: D000464:Alginates; D006603:Hexuronic Acids; D013395:Sucrose; D020723:Glucuronic Acid