Development of probiotic E. coli Nissle 1917 for ß-alanine production by using protein and metabolic engineering.
Appl Microbiol Biotechnol
; 107(7-8): 2277-2288, 2023 Apr.
Article
em En
| MEDLINE
| ID: mdl-36929190
ABSTRACT
ß-alanine has been used in food and pharmaceutical industries. Although Escherichia coli Nissle 1917 (EcN) is generally considered safe and engineered as living therapeutics, engineering EcN for producing industrial metabolites has rarely been explored. Here, by protein and metabolic engineering, EcN was engineered for producing ß-alanine from glucose. First, an aspartate-α-decarboxylase variant ADCK43Y with improved activity was identified and over-expressed in EcN, promoting the titer of ß-alanine from an undetectable level to 0.46 g/L. Second, directing the metabolic flux towards L-aspartate increased the titer of ß-alanine to 0.92 g/L. Third, the yield of ß-alanine was elevated to 1.19 g/L by blocking conversion of phosphoenolpyruvate to pyruvate, and further increased to 2.14 g/L through optimizing culture medium. Finally, the engineered EcN produced 11.9 g/L ß-alanine in fed-batch fermentation. Our work not only shows the potential of EcN as a valuable industrial platform, but also facilitates production of ß-alanine via fermentation. KEY POINTS ⢠Escherichia coli Nissle 1917 (EcN) was engineered as a ß-alanine producing cell factory ⢠Identification of a decarboxylase variant ADCK43Y with improved activity ⢠Directing the metabolic flux to L-ASP and expressing ADCK43Y elevated the titer of ß-alanine to 11.9 g/L.
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1
Base de dados:
MEDLINE
Assunto principal:
Probióticos
/
Engenharia Metabólica
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2023
Tipo de documento:
Article