Production of glucose oxidase and catalase by Aspergillus niger free and immobilized in alginate-polyvinyl alcohol beads.
The production of glucose oxidase (GOX) and catalase (CAT) by submerged fermentation of the free and immobilized xerophytic fungus Aspergillus niger under equal conditions was compared. To immobilize fungal spores, entrapment in PVA/alginate beads treated with NaNO3/CaCl2 was performed. The yield of immobilization in the beads with a diameter less than 1mm was equal to 100%. Fungus growth and substrate consumption were evaluated in both fermentation systems, demonstrating the lag-period presence in the case of the first cycle of immobilized fungus use. The enzyme production by immobilized fungus reuse was carried out. In these cases, greater enzymatic GOX activity was detected, while CAT activity decreased. SEM micrographs for the beads with immobilized fungus applied in the first and second fermentation cycles were obtained, presenting fungus spreading inside the sphere, spore presence and branching hyphae. Immobilization of A. niger on PVA/alginate beads is effective for GOX and CAT production at least on 2-3 repeated fermentative cycles. Thus, immobilization enables repeated use of microbial cells.
Coahuila Autonomous University, Nanobioscience Group of Chemistry Faculty and Medical School.
Rocio
R
V Garay-Flores
Elda
E
P Segura-Ceniceros
Rosalba
R
De León-Gámez
Cecilia
C
Balvantín-García
José
J
L Martínez-Hernández
Rebeca
R
Betancourt-Galindo
Alma
A
Rosa Paredes Ramírez
Cristóbal
C
Noé Aguilar
Anna
A
Ilyina
D000464:Alginates; D001234:Aspergillus niger / Q000201:enzymology* / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism*; D018914:Cells, Immobilized / Q000378:metabolism; D005285:Fermentation; D005949:Glucose Oxidase / Q000378:metabolism*; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011142:Polyvinyl Alcohol
D000464:Alginates; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D011142:Polyvinyl Alcohol; D005949:Glucose Oxidase; D002374:Catalase