Fermentative production of fumaric acid from Eucalyptus globulus wood hydrolyzates

Fumaric acid (FA) was produced from Eucalyptus globulus wood by successive steps of hydrothermal processing (to solubilize hemicelluloses and to increase the susceptibility of solids to enzymatic hydrolysis), enzymatic hydrolysis and fermentation with Rhizopus arrhizus DSM 5772. For comparative purposes, additional fermentations were carried out using synthetic media. Single stage fermentation of synthetic media led to a medium containing 11.8 g FA L-1 (YP/S = 0.60 g g-1). Operating in fed batch mode, the fourth stage increased the FA concentration from 19.7 up to 43.6 g L-1 (YP/S = 0.71 g g-1). Hydrolyzate fermentation in a single stage resulted in lower fumaric acid concentration (9.65 g L-1) and yield (0.35 g g-1). Additional fermentations were carried out in media made with hydrolyzates subjected to membrane processing, adsorption or ion exchange. The highest yield (YP/S = 0.44 g g-1) was reached in media made up of ion-exchange treated hydrolyzates and a commercial glucose solution in proportion 85/15 w/w. Copyright (c) 2011 Society of Chemical Industry