Intensification of 2-phenylethanol production using an aerated system assisted by a membrane-based solvent extraction technique

Abstract

The production of 2-phenylethanol (2-PE), a high-valued aroma, has been performed naturally through the bioconversion of Lphenylalanine by the Ehrlich pathway in yeast. Nevertheless, one of the main limitations of this bioconversion is the inhibition of yeast growth by 2-PE. This work evaluated the intensification of 2-PE production in a batch culture using a conventional bioreactor coupled to an in-situ product removal (ISPR) process, by means of membrane-based solvent extraction (MBSE). The culture of the native yeast Kluyveromyces marxianus ITD0090, using a shaker flask stirred at 150 rpm, produced a maximum concentration of 2-PE of 0.7 g L-1 after 24 hours. When the yeast was cultivated in a controlled aerated-stirred bioreactor operated at 0.8 vvm and 350 rpm, the maximum production of 2-PE after 48 h reached 1.49 g L-1. Intensification of the bioprocess was achieved by coupling the controlled bioreactor with a MBSE system, which allowed the continuous recovery of the 2-PE produced, reaching a final titre of 3.02 g L-1 after 56 h.