Effect of process parameters on production of a biopolymer by Rhizobium sp.
The production of biopolymers by a Rhizobium strain was studied under batch and bioreactor conditions. The best viscosity levels were obtained under low mannitol concentrations as well as low agitation and aeration conditions. Infrared spectra indicated the presence of chemical groups characteristic of microbially produced biopolymers, including C = O and O-acetyl groups. Thermogravimetric analysis showed the characteristic degradation profiles of the exopolysaccharide produced (T(onset) = 290degreesC). The experimental design showed that a low substrate concentration (10.0 g/L), and low aeration (0.2 vvm) and agitation (200 rpm) levels should be used. The maximum yield of the process was a Yp/s (g/g) of 0.19 +/- 0.1, obtained under optimized conditions.
Duta
Flávia Pereira
FP
Universidade Federal do Rio de Janeiro, Departamento de Engenharia Bioquímica, Bloco E, Ilha do Fundão, Rio de Janeiro, RJ CEP: 21949-900 Brazil.
De França
Francisca Pessôa
FP
Sérvulo
Eliana Flávia Camporese
EF
De Almeida Lopes
Léa Maria
LM
Da Costa
Antonio Carlos Augusto
AC
Barros
Ana
A
D000362:Agar / Q000737:chemistry; D018533:Biomass; D001704:Biopolymers / Q000737:chemistry*; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D003470:Culture Media; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D008353:Mannitol / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D012231:Rhizobium / Q000378:metabolism*; D013055:Spectrophotometry, Infrared; D013223:Statistics as Topic; D013696:Temperature; D014783:Viscosity
D001704:Biopolymers; D003470:Culture Media; D011134:Polysaccharides; D008353:Mannitol; D000362:Agar