Intensification of 1-phenylethanol production by periodical membrane extraction of the product from fermentation broth

BACKGROUND: Enantioselective bioreduction of acetophenone to S-(-)-1-phenylethanol by Saccharomyces cerevisiae under non-growth conditions is inhibited by the product created. This study investigated the possibility of intensification and mathematical simulation of 1-phenylethanol production using periodic product removal carried out by membrane extraction in a hollow fiber membrane module. RESULTS: The highest reaction rate was observed at the beginning of the biotransformation. With increased product concentration in the reaction medium, the reaction rate gradually decreased by about 50% after 20 h of biotransformation. The low concentration of product maintained in the reaction medium using membrane extraction had positive influence on the 1-phenylethanol production with a high yield (96%) and mean reaction rate of 0.226 mg h-1g-1, 35% higher than biotransformation without product removal. The equilibrium change and membrane fouling caused by biomass were not significant. It was possible to mathematically simulate the whole course of the extractive biotransformation with good agreement with experimental data. CONCLUSION: Bioreductive production of 1-phenylethanol is more effective when using periodic membrane extraction of the product from the fermentation broth, which gives higher reaction rate, higher yield and simpler downstream process than biotransformation without product removal. Copyright (c) 2012 Society of Chemical Industry