ABSTRACT
Biological conversions are characterized by being performed in aqueous solutions, usually at low temperatures and pressures, and by leading to dilute product solutions and low productivities. Liquid-liquid extraction is one unit operation that effectively utilizes the partitioning of components between two immiscible solvents or the difference in the partition coefficients between components. Extractive bioconversions with nonaqueous solvents and aqueous two-phase systems have been used in the recovery of bioproducts. This chapter addresses the subject of product recovery from a biological reaction system by a novel effective extraction process of bioconversion end products utilizing liquid-liquid extraction and enzyme reaction to achieve both separation and enrichment of valuable substances. This novel approach enables the simultaneous production and extraction of hydrophilic compounds and their conversion into more lipophilic and valuable substances. Enzymes, such as lipases, can synthesize ester bonds in the presence of a high water content, which renders possible their use in the integration of biological conversion and recovery processes.
