Enhancing tryptophan production by balancing precursors in Escherichia coli.
Biotechnol Bioeng
; 119(3): 983-993, 2022 03.
Article
en En
| MEDLINE
| ID: mdl-34936092
ABSTRACT
Tryptophan, an essential aromatic amino acid, is widely used in animal feed, food additives, and pharmaceuticals. Although sustainable and environmentally friendly, microbial tryptophan production from renewable feedstocks is limited by low biosynthesis and transport rates. Here, an Escherichia coli strain capable of efficient tryptophan production was generated by improving and balancing the supply of precursors and by engineering membrane transporters. Tryptophan biosynthesis was increased by eliminating negative regulatory factors, blocking competing pathways, and preventing tryptophan degradation. Promoter engineering balanced the supply of the precursors erythrose-4-phosphate and phosphoenolpyruvate, as well as the availability of serine. Finally, the engineering of tryptophan transporters prevented feedback inhibition and growth toxicity. Fed-batch fermentation of the final strain (TRP12) in a 5 L bioreactor produced 52.1 g·L-1 of tryptophan, with a yield of 0.171 g·g-1 glucose and productivity of 1.45 g·L-1 ·h-1 . The metabolic engineering strategy described here paves the way for high-performance microbial cell factories aimed at the production of tryptophan as well as other valuable chemicals.
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Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Proteínas de Escherichia coli
/
Escherichia coli
Idioma:
En
Revista:
Biotechnol Bioeng
Año:
2022
Tipo del documento:
Article
País de afiliación:
China