BIOTRANSFORMATION OF BENZALDEHYDE BY SACCHAROMYCES-CEREVISIAE - CHARACTERIZATION OF THE FERMENTATION AND TOXICITY EFFECTS OF SUBSTRATES AND PRODUCTS

Although higher initial rates of phenylacetyl carbinol formation were observed in fermentations containing a high starting benzaldehyde level, a massive reduction in yeast viability was observed resulting in early cessation of production formation. Pulse feeding to maintain lower benzaldehyde concentrations resulted in a lower initial reaction rate, but prolonged yeast viability and the biotransformation. This resulted in higher overall product titers. As benzaldehyde concentration was increased, yeast growth rate was reduced (0.5 g/L), inhibited (1-2 g/L), or cell viability reduced (3 g/L).