Here are badges that appear to match the shoulder badges of your tunic, and they're apparently from the German Army 110th Infantry Regiment prior to World War 1 according to this site.

The tunic appears very similar to the one in this auction lot, described as WW1 officer's dress tunic.

Whether you can safely say this is a World War One German tunic from that particular regiment or not, I'll defer to someone who knows; I was just exercising my Google-fu here.