from J. Cuccui, R.H. Langdon, M.G. Moule and Brendan W. Wren writing in Bacterial Glycomics: Current Research, Technology and Applications:
Once thought to be restricted to eukaryotes and archaea, N-linked glycosylation has now been discovered in prokarytoes. Over the past decade, our understanding of bacterial N-linked glycosylations systems and their abundance has been expanding. This type of protein modification was first demonstrated in Campylobacter jejuni, a human gut pathogen, and we now know that N-linked glycosylation also exists in other &episilon;-proteobacteria ranging from the deep-sea vent Nitratiruptor spp. and Sulfurovum spp. to sulfate reducing δ-proteobacteria. A greater understanding of these systems is necessary in order to comprehend the evolutionary reasons for their development and maintenance. In addition, this knowledge may also be exploited for glycoengineering purposes to produce cheaper subunit vaccines as well as humanized proteins.
Further reading: Bacterial Glycomics: Current Research, Technology and Applications