Catalyzes the decarboxylation of D-ornithine and D-lysine (PubMed:29024617, PubMed:30699288). Ornithine is likely the physiological substrate (PubMed:29024617). Has no detectable diaminopimelate decarboxylase activity in vitro (PubMed:29024617). D-ornithine + H(+) = CO2 + putrescine D-lysine + H(+) = cadaverine + CO2 kcat is 1.8 sec(-1) with D-ornithine as substrate. kcat is 4.4 sec(-1) with D-lysine as substrate. Optimum pH is 6.5-8. Homodimer. Belongs to the Orn/Lys/Arg decarboxylase class-II family.