Fermentative Production of the Diamine Putrescine: System Metabolic Engineering of Corynebacterium Glutamicum

摘要: Corynebacterium glutamicum shows great potential for the production of glutamate-derived diamine putrescine, a monomeric compound polyamides. A genome-scale stoichiometric model C. strain with reduced ornithine transcarbamoylase activity, derepressed arginine biosynthesis, and an anabolic plasmid-addiction system heterologous expression E. coli decarboxylase gene speC was investigated by flux balance analysis respect to its putrescine potential. Based on these simulations, enhancing glycolysis anaplerosis plasmid-borne overexpression genes glyceraldehyde 3-phosphate dehydrogenase pyruvate carboxylase as well reducing 2-oxoglutarate activity were chosen targets metabolic engineering. Changing translational start codon chromosomal subunit E1o less preferred TTG changing threonine 15 OdhI alanine about five fold improved titers 28%. Additional engineering steps further largest contributions from preventing formation by-product N-acetylputrescine deletion spermi(di)ne N-acetyltransferase snaA feedback-resistant N-acetylglutamate kinase variant. The resulting NA6 obtained systems accumulated two more than base strain, i.e., 58.1 ± 0.2 mM, showed specific productivity 0.045 g·g−1·h−1 yield glucose 0.26 g·g−1.