ISSN:
0006-3592
Keywords:
calcium-alginate capsules
;
microencapsulation
;
invertase
;
recombinant Saccharomyces cerevisiae
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
As a means of integrating cell growth and immobilization, recombinant Saccharomyces cerevisiae cells with invertase activity were immobilized in liquid-core alginate capsules and cultured to a high density. S. cerevisiae cells of SEY 2102 (MAT α ura3-52 leu2-3, 112 his4-519) harboring plasmid pRB58 with the SUC2 gene coding for invertase were grown to 83 g/L of liquid-core volume inside the capsule on a dry weight basis. The cloned invertase was expressed well in the immobilized cells with slightly higher activity than the free cells in a batch culture. Invertase in the immobilized cells showed slightly more improved thermal stability than in the free cells. Storage in a Na-acetate buffer at 4°C and 10°C for 1 month resulted in 7% and 8% loss in activity, respectively. The sucrose hydrolysis reaction was stably maintained for 25 repeated batches for 7 days at 30°C. Continuous hydrolysis of 0.3 M sucrose was carried out in a packed bed reactor with a conversion of more than 90% at a maximum productivity of 55.5 g glucose/L per hour for 7 days. In a continuous stirred tank reactor, the maximum productivity of 80.8 g glucose/L per hour was achieved at a conversion of 59.1% using 1.0 M sucrose solution, and 0.5 M sucrose solution was hydrolyzed for 1 week with a 95% conversion at a productivity of 48.8 g/L per hour. © 1996 John Wiley & Sons, Inc.
Additional Material:
9 Ill.
Type of Medium:
Electronic Resource
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