Fig. 1

Metabolic engineering of M. alcaliphilum 20Z for putrescine production. Red arrows indicate expression reactions. Green arrows indicate overexpression reactions. Yellow X indicates gene deletion. ack, acetate kinase; argA, N-acetylglutamate synthase; argB, N-acetylglutamate kinase; argC, N-acetylglutamylphosphate reductase; argD, acetylornithine aminotransferase; argJ, ornithine acetyltransferase; ldh, lactate dehydrogenase; potE, putrescine transporter; speC, constitutive ornithine decarboxylase; speE, spermidine synthase; speF, inducible ornithine decarboxylase; Agm, agmatine; Glut, glutamate; l-Arg, l-arginine; l-Orn, l-ornithine; N-Acglu, N-acetylglutamate; N-AcGluAld, N-acetylglutamate semialdehyde; N-AcGluP, N-acetylglutamylphosphate; N-AcOrn, N-acetylornithine; N-CbmP, N-carbamoylputrescine