Construction a metabolic engineering strain to produce succinic acid from Corynebacterium glutamicum by gene deletion mutation

Abstract:

[Objective] In order to improve the production of succinic acid and decrease the accumulation of by-products under the oxygen deprivation by Corynebacterium glutamicum 13032. [Methods] From the C. glutamicum ATCC13032, firstly, the gene of lactic dehydrogenase (ldh) was knocked-out and the single deletion mutation strain C. glutamicum ATCC13032Δldh was constructed. Secondly, we interrupted the pathway of pyruvic acid flux to acetic acid by marker-free deletion the E1p gene (aceE) which encode the essential part of the pyruvate dehydrogenase complex (PDHC). [Results] The production and yield of succinic acid of recombination strain improved 94.9% and 32%, respectively, compared to the parent strain C. glutamicum ATCC13032 and what’s more, the main by-product lactic acid was eliminated to none from 63.5 g/L. The inactive of the pyruvate dehydrogenase complex could not prevent the formation of acetic acid absolutely, but the production of acetic acid decreased 37.9%, compared to C. glutamicum ATCC13032Δldh and the production of succinic acid improved a little. [Conclusion] This recombination bacteria has a potential in industrial applications, and this study methods could provide reference for microbial metabolism breeding.