Residues, not food. Currently there is a trend to replace sugar by residue hydrolysates in fermenation processes. Although it is desirable to replace food by non-food biomass, it causes new challenges, such as the formation of inhibitors during the hydrolysis. Inhibitors can harm the fermenation process and reduce succinic acid formation. We are investigating the whole production system in ordert o optimise not just single process stgeps but the succinic acid production system by investigating interactions among hydro lysis and fermentation.