Nylon 5 and nylon 6,5 are recently explored as new commercial polyamides, of which the monomer includes delta-valerolactam. In this study, a novel catalytic activity of lysine 2-monooxygenase (DavB) was explored to produce delta-valerolactam froml-pipecolic acid (L-PA), functioning as oxidative decarboxylase on a cyclic compound. RecombinantEscherichia coliBS01 strain expressing DavB fromPseudomonas putidacould synthesize delta-valerolactam froml-pipecolic acid with a concentration of 90.3 mg/L. Through the co-expression of recombinant apoptosis-inducing protein (rAIP) fromScomber japonicus, glucose dehydrogenase (GDH) fromBacillus subtilis, Delta(1)-piperideine-2-carboxylae reductase (DpkA) fromP. putidaand lysine permease (LysP) fromE. coliwith DavB, delta-valerolactam was produced with the highest concentration of 242 mg/L. alpha-Dioxygenases (alpha Dox) fromOryza sativacould act as a similar catalyst onl-pipecolic acid. A novel delta-valerolactam synthesis pathway was constructed entirely via microbial conversion from feedstock lysine in this study. Our system has great potential in the development of a bio-nylon production process.