The amino acid octamers (-Glu)8 and (Asp)8 were synthesized in order to screen for new microbial degraders of unnatural amino acid peptides. We have successfully isolated the microorganisms from soil acclimated to a medium containing the oligopeptides; they were classified as Klebsiella ornithinolytica, Delftia acidovorans, and α-Proteobacteria.