Construction and screening of L-valine high-yielding Escherichia coli using an artificial screening marker.

ABSTRACT: L-valine is commonly utilized in cosmetics, pharmaceuticals, food additives, and animal feeds. The selection and breeding of high-yielding, low-cost, and genetically stable production strains have become a key objective in the L-valine production industry. Using Escherichia coli DB-1-1, we developed a screening marker LESG associated with intracellular L-valine levels by choosing GTC, a less common codon for L-valine, in place of all L-valine codons. The artificial LESG was then ligated into pUC-57 and transformed into competent E. coli DB-1-1 cells with the rare L-valine codon. After conducting atmospheric and room-temperature plasma mutagenesis cultures, mutants that displayed elevated fluorescence were sorted using flow cytometry. After sorting the 240 strains. We sorted out 143 highly

SUBMITTER: Du B 

PROVIDER: S-EPMC12369413 | biostudies-literature | 2025

REPOSITORIES: biostudies-literature