H2O + N(2)-acetyl-L-ornithine = acetate + L-ornithine Amino-acid biosynthesis; L-arginine biosynthesis; L-ornithine from N(2)-acetyl-L-ornithine (linear): step 1/1. Resembles portions of the beta' subunits of RNA polymerases from bacteria and chloroplasts. It was suggested that both the beta' subunit of RNA polymerases and L.biflexa ArgE-complementing activity possess N-acetylase or N-acetylornithinase activity. No homology with E.coli ArgE.