Production of L-phenylacetyl carbinol by immobilized yeast cells: II. Semicontinuous fermentation

✍ Scribed by Wafaa M. Mahmoud; Abdel-Halim M. M. El-Sayed; Robert W. Coughlin

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 566 KB
• Volume: 36
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.260360108

✦ Synopsis

The cyclic, semicontinuous production of L-phenylacetyl carbinol (L-PAC) from a benzaldehyde substrate by Saccharomyces cerevisiae ATCC 834 immobilized in calcium alginate beads w a s substantially enhanced to about 4.5 g/L in a second cycle by reactivation in fresh medium for 24 h, following an earlier 24-h period of production from substrate. Intermittent feeding of benzaldehyde was employed (four doses in 3 h). In subsequent similar cycles, however, the production returned to that produced in the first cycle, viz. L-PAC concentration of 2-3 g/L in the medium. Production of L-PAC was also increased by adaptation of the cells over 200 h of exposure to the benzaldehyde substrate (compared to wild-type cells) and by continuous (as compared to intermittent) feeding of the substrate. A titer a s great as 10 g/L was obtained with wild-type cells by continuous feeding of benzaldehyde over 6 h. Immobilization not only protected the cells from toxic effects of substrate but also permitted them to be used during 7 cycles of semicontinuous operation over more than 200 h.