Microbial production of 2-phenylethanol by an integrated bioprocess

Investigations are underway to develop an efficient bioprocess for the production of the aroma chemical 2-phenylethanol. Certain yeasts are known for their ability to synthesise 2-phenylethanol via the Ehrlich pathway if L-phenylalanine is provided as precursor, but they are also known for being sensitive to the product. For a technically feasible process, product inhibition has to be minimised. Yeasts were screened for their ability to produce 2-phenylethanol in shake-flask experiments with and without in situ product removal (ISPR) by an organic solvent as a second liquid phase. On the lab scale ISPR was carried out by coupling a pervaporation module directly to a bioreactor.