ISSN:
0006-3592
Schlagwort(e):
immobilization
;
plasmid stability
;
recombinant yeast
;
glucoamylase, bioreactor
;
Chemistry
;
Biochemistry and Biotechnology
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Biologie
,
Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
Notizen:
A recombinant Saccharomyces cerevisiae C468/pGAC9 (ATCC 20690), which expresses Aspergillus awamori glucoamylase gene under the control of the yeast enolase I (ENO1) promoter and secretes glucoamylase into the extracellular medium, was used as a model system to investigate the effect of cell immobilization on bioreactor culture performance. Free suspension cultures in stirred-tank and airlift bioreactors confirmed inherent genetic instability of the recombinant yeast. An immobilized-cell-film airlift bioreactor was developed by employing cotton cloth sheets to immobilize the yeast cells by attachment. Enhanced enzyme productivity and production stability in the immobilized-cell system were observed. Experimental data indicated that the immobilized cells maintained a higher proportion of plasmid-bearing cells for longer periods under continuous operation. The higher plasmid maintenance with immobilized cells is possibly due to reduced specific growth rate and increased plasmid copy number. Double-selection pressure was used to select and maintain the recombinant yeast. The selected strain showed better production performance than the original strain. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 55: 241-251, 1997.
Zusätzliches Material:
8 Ill.
Materialart:
Digitale Medien
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