Itaconic acid fermentation using activated charcoal-treated corn stover hydrolysate and process evaluation based on Aspen plus model

Itaconic acid production using lignocellulose materials is a promising approach to replace sugar substrates such as glucose that are expensive. However, the complicated detoxification of the hydrolysate is pre-requisite to remove the lignocellulose-derived inhibitors to enable high organic acid fermentation. In this study, the hydrolysate prepared using dry acid pretreated and biodetoxified corn stover was tested for itaconic acid production by the fungal strain Aspergillus terreus M69. Corn stover hydrolysate containing 0.85 g/L acetic acid severely inhibited the organic acid production, but a treatment on the hydrolysate with activated charcoal to remove partial acetic acid helped to produce 33.6 g/L itaconic acid at a yield of 0.56 g/g. Most acetic acid released during enzymatic hydrolysis other than pretreatment was responsible for the inhibition of itaconic acid production. The technol-economic analysis showed that the minimum itaconic acid selling price was $1.647 per kg, which was lower than its market price. This study demonstrates the great potential of itaconic acid production using lignocellulose.