Production of gluconic acid by Aspergillus niger immobilized on polyurethane foam.
Production of gluconic acid by cells of Aspergillus niger immobilized on polyurethane foam was studied in repeated-batch shake-flask and bubble-column fermentations. For passive immobilization, various amounts of polyurethane foam and spore suspension were tested in order to obtain a suitable combination for optimal concentration of immobilized biomass. Immobilized cells were successfully reused with higher levels of product formation being maintained for longer period (65-70 h) than free cells. The highest gluconic acid concentration of about 143 g l-1 was reached on hydrol-based production medium with 0.3-cm3 foam cubes in the bubble column, where the effect of more suitable aeration and particle volume: medium volume ratio scheme was also investigated.
Vassilev
N B
NB
Institute of Microbiology, Bulgarian Academy of Sciences, Sofia.
Vassileva
M C
MC
Spassova
D I
DI
D001234:Aspergillus niger / Q000378:metabolism* / Q000648:ultrastructure; D001709:Biotechnology; D005069:Evaluation Studies as Topic; D005285:Fermentation; D005942:Gluconates / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D011140:Polyurethanes; D013499:Surface Properties
D005942:Gluconates; D011140:Polyurethanes; C028279:polyurethane foam; C030691:gluconic acid