Enhanced production of l-serine by deleting sdaA combined with modifying and overexpressing serA in a mutant of Corynebacterium glutamicum SYPS-062 from sucrose

Journal of Industrial Microbiology and Biotechnology

et al. 2016

Self Cite

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.

“…1843 [28]. C. glutamicum SYPS-062-33a, derived from C. glutamicum SYPS-062 by random mutagenesis was deposited in CGMCC with the No.…”

Section: Strains and Plasmidsmentioning

confidence: 99%

Section: Strains and Plasmidsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Wen

Chen

Journal of Industrial Microbiology and Biotechnology

et al. 2016

Self Cite

Integration of ARTP mutagenesis with biosensor-mediated high-throughput screening to improve l-serine yield in Corynebacterium glutamicum

Appl Microbiol Biotechnol

et al. 2018

L-Serine is widely used in the pharmaceutical, food, and cosmetics industries. Although direct fermentative production of L-serine from sugar in Corynebacterium glutamicum has been achieved, the L-serine yield remains relatively low. In this study, atmospheric and room temperature plasma (ARTP) mutagenesis was used to improve the L-serine yield based on engineered C. glutamicum ΔSSAAI strain. Subsequently, we developed a novel high-throughput screening method using a biosensor constructed based on NCgl0581, a transcriptional factor specifically responsive to L-serine, so that L-serine concentration within single cell of C. glutamicum can be monitored via fluorescence-activated cell sorting (FACS). Novel L-serine-producing mutants were isolated from a large library of mutagenized cells. The mutant strain A36-pDser was screened from 1.2 × 10 cells, and the magnesium ion concentration in the medium was optimized specifically for this mutant. C. glutamicum A36-pDser accumulated 34.78 g/L L-serine with a yield of 0.35 g/g sucrose, which were 35.9 and 66.7% higher than those of the parent C. glutamicum ΔSSAAI-pDser strain, respectively. The L-serine yield achieved in this mutant was the highest of all reported L-serine-producing strains of C. glutamicum. Moreover, the whole-genome sequencing identified 11 non-synonymous mutations of genes associated with metabolic and transport pathways, which might be responsible for the higher L-serine production and better cell growth in C. glutamicum A36-pDser. This study explored an effective mutagenesis strategy and reported a novel high-throughput screening method for the development of L-serine-producing strains.

High-yield production of l-serine from glycerol by engineered Escherichia coli

Journal of Industrial Microbiology and Biotechnology

Zhu

et al. 2019

l-Serine is widely used in pharmaceutical, food and cosmetic industries, and the direct fermentation to produce l-serine from cheap carbon sources such as glycerol is greatly desired. The production of l-serine by engineered Escherichia coli from glycerol has not been achieved so far. In this study, E. coli was engineered to efficiently produce l-serine from glycerol. To this end, three l-serine deaminase genes were deleted in turn, and all of the deletions caused the maximal accumulation of l-serine at 0.06 g/L. Furthermore, removal of feedback inhibition by l-serine resulted in a titer of 1.1 g/L. Additionally, adaptive laboratory evolution was employed to improve glycerol utilization in combination with the overexpression of the cysteine/acetyl serine transporter gene eamA, leading to 2.36 g/L l-serine (23.6% of the theoretical yield). In 5-L bioreactor, l-serine titer could reach up to 7.53 g/L from glycerol, demonstrating the potential of the established strain and bioprocess.