He wrote a PhD thesis on the German Petőfi translations.

After three years working as a research associate at the Finnish-Ugrish Department, University of Göttingen, Lossau graduated in 1996 and received the clerkship for the senior library service.

He then worked for the preparatory phase of the DFG-project retrospective digitization of library collections and in 1997 took over construction and management of the Göttinger Digitalisierungszentrum.

In 1998, he was also technical advisor for the special collections Hungary, Finland and Finnish-Ugrish.

In August 2002, he returned as director of the Bielefeld University Library in Germany.