α-L-rhamnosidase of Aspergillus terreus immobilized on ferromagnetic supports.
Appl Microbiol Biotechnol
; 93(3): 1127-34, 2012 Feb.
Article
em En
| MEDLINE
| ID: mdl-21779843
α-L-rhamnosidase from Aspergillus terreus was covalently immobilized on the following ferromagnetic supports: polyethylene terephthalate (Dacron-hydrazide), polysiloxane/polyvinyl alcohol (POS/PVA), and chitosan. The powdered supports were magnetized by thermal coprecipitation method using ferric and ferrous chlorides, and the immobilization was carried out via glutaraldehyde. The activity of the Dacron-hydrazide (0.53 nkat/µg of protein) and POS/PVA (0.59 nkat/µg of protein) immobilized enzyme was significantly higher than that found for the chitosan derivative (0.06 nkat/µg of protein). The activity-pH and activity-temperature profiles for all immobilized enzymes did not show difference compared to the free enzyme, except the chitosan derivative that presented higher maximum temperature at 65 °C. The Dacron-hydrazide derivative thermal stability showed a similar behavior of the free enzyme in the temperature range of 40-70 °C. The POS/PVA and chitosan derivatives were stable up to 60 °C, but were completely inactivated at 70 °C. The activity of the preparations did not appreciably decrease after ten successive reuses. Apparent K (m) of α-L-rhamnosidase immobilized on magnetized Dacron-hydrazide (1.05 ± 0.22 mM), POS/PVA (0.57 ± 0.09 mM), and chitosan (1.78 ± 0.24 mM) were higher than that estimated for the soluble enzyme (0.30 ± 0.03 mM). The Dacron-hydrazide enzyme derivative showed better performance than the free enzyme to hydrolyze 0.3% narigin (91% and 73% after 1 h, respectively) and synthesize rhamnosides (0.116 and 0.014 mg narirutin after 1 h, respectively).
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Aspergillus
/
Biotecnologia
/
Enzimas Imobilizadas
/
Imãs
/
Glicosídeo Hidrolases
Tipo de estudo:
Evaluation_studies
Idioma:
En
Revista:
Appl Microbiol Biotechnol
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Argentina
País de publicação:
Alemanha