Main content area

A novel aceE mutation leading to a better growth profile and a higher L-serine production in a high-yield L-serine-producing Corynebacterium glutamicum strain

Guo, Wen, Chen, Ziwei, Zhang, Xiaomei, Xu, Guoqiang, Zhang, Xiaojuan, Shi, Jinsong, Xu, Zhenghong
Journal of industrial microbiology & biotechnology 2016 v.43 no.9 pp. 1293-1301
Corynebacterium glutamicum, alanine, byproducts, genes, genetic variation, genomics, metabolic engineering, mutagenesis, mutants, point mutation, serine, valine
A comparative genomic analysis was performed to study the genetic variations between the L-serine-producing strain Corynebacterium glutamicum SYPS-062 and the mutant strain SYPS-062-33a, which was derived from SYPS-062 by random mutagenesis with enhanced L-serine production. Some variant genes between the two strains were reversely mutated or deleted in the genome of SYPS-062-33a to verify the influences of the gene mutations introduced by random mutagenesis. It was found that a His-594 → Tyr mutation in aceE was responsible for the more accumulation of by-products, such as L-alanine and L-valine, in SYPS-062-33a. Furthermore, the influence of this point mutation on the L-serine production was investigated, and the results suggested that this point mutation led to a better growth profile and a higher L-serine production in the high-yield strain 33a∆SSAAI, which was derived from SYPS-062-33a by metabolic engineering with the highest L-serine production to date.