Simultaneous Enzymatic Transesterification and Esterification of an Acid Oil Using Fermented Solid as Biocatalyst

This work studied the enzymatic synthesis of fatty acid ethyl esters (FAEE) for potential use as biodiesel via simultaneous esterification and transesterification of acid oil from macaúba in a solvent-free system. A fermented and dry babassu cake with lipase activity from Rhizomucor miehei was used as biocatalyst. FAEE content above 85% was achieved after 96 h of reaction with enzyme loading of 13 U per g of oil, 120 mmol of hydrous ethanol (95% ethanol and 5% water)/20 mmol of oil (molar ratio ethanol:oil of 6:1), at 40 °C. After two consecutive enzymatic reactions, 90.8 wt% FAEE content was obtained. These results demonstrate a promising transesterification/esterification method for FAEE production from an acid and low-cost oil and the process has potential to decrease the costs of enzymatic biodiesel production.