Bioconversion using immobilized recombinant flocculent yeast cells carrying a fused enzyme gene in an `intelligent' bioreactor
✍ Scribed by Yan Liu; Akihiko Kondo; Hideo Ohkawa; Noriaki Shiota; Hideki Fukuda
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 280 KB
- Volume
- 2
- Category
- Article
- ISSN
- 1369-703X
No coin nor oath required. For personal study only.
✦ Synopsis
Immobilized recombinant cells of the ¯occulent yeast Saccharomyces diastaticus carrying an expression plasmid for a fused enzyme between rat cytochrome P4501A1 and yeast NADPH-cytochrome P450 reductase were used in the bioconversion reaction from acetanilide (AA) to p-acetaminophene (p-AAP). Immobilization of the strain within reticulated polyurethane foam biomass support particles (BSPs) was effected passively in situ in a ¯uidized-bed bioreactor using draw and ®ll' operation. In repeated batch reactions both the ®nal product concentration and the production rate were notably improved compared with the results obtained using freely suspended cells without BSPs. Cells immobilized within BSPs exhibited a signi®cantly high level of expression of the fused enzyme. In addition, a high proportion of plasmid-carrying cells was maintained among the immobilized cells, in contrast to a much lower proportion among freely suspended cells released from the BSPs. Since the bioreactor became packed with highly expressing cells immobilized within BSPs as a consequence of spontaneous screening, it was termed an intelligent' bioreactor, and is believed to offer signi®cant potential for the further development of ef®cient production processes.