As the birth certificate is from 1927 you should also consider the possibility that he was not from Serbia at all but an ethnic Serbian from anywhere in the region - in US censuses and other documents a common mistake was that they recorded country of birth based on a persons ethnicity - under the assumption that Serbs are from Serbia, Slovaks from Slovakia and Hungarians from Hungary - which was very often not the case.
The list of possibilities of what the original surname was without more information is too long to be of any concrete use - I will post for you here only a few of the most phonetically similar ones found among Serbs:
If I alter the assumed spelling only to swap one sound with a similar other sound (Ž with DŽ or Š ) hundred or so surnames can be added to your possibilities list.
Try to narrow down your search and look for census data, possible records of employment, immigration records for him based on where your greatgrandmother lived or worked -your grandmother's parents paths had to have intersected somewhere. :)
"Rodoslovlje" Serbian Genealogy Societyhttp://www.rodoslovlje.com/en