Considering glycerol as an inexpensive alternative carbon source, the optimal glycerol concentration for succinic acid production with Anaerobiospirillum succiniciproducens was identified in shake-flask trials. The addition of a defined amount of glucose improved the growth and succinic acid productivity significantly. In fed-batch processes with glycerol as sole substrate, a maximum succinic acid concentration and product substrate yield were obtained. The addition of glucose led to a 2.5-fold increased succinic acid concentration whereas the product substrate yield remained nearly constant.