Related Experiment Video
Updated: Apr 27, 2026

Identifying Amino Acid Overproducers Using Rare-Codon-Rich Markers
Published on: June 24, 2019
Introduction of two mutations into AroG increases phenylalanine production in Escherichia coli
Rui Ding1, Lifei Liu, Xuhui Chen
1College of Agronomy, Shenyang Agricultural University, Shenyang, Liaoning, People's Republic of China, mnidr7@gmail.com.
Abstract:
L-Phenylalanine is an important amino acid commercially, and therefore optimization of its manufacture is of interest. We constructed a range of mutant alleles of AroG, the enzyme involved in the first step of phenylalanine biosynthesis. Three single-site mutant alleles were constructed (aroG8, aroG15, and aroG29), which were then combined to generate three double-site aroG (fbr) mutant alleles (aroG8/15, aroG8/29, and aroG15/29). Enzymatic activity, feedback inhibition, and fermentation were analyzed in all of the mutants. All double-site mutants, except AroG15/29, showed higher enzymatic activity and greater resistance to feedback inhibition than their respective single-site mutants. The E. coli strain carrying the aroG8/15 allele produced a phenylalanine titer of 26.78 g/l, a 116 % improvement over the control phenylalanine overproducing strain (12.41 g/l). Our findings provide an effective method for modifying phenylalanine biosynthetic genes, which may be applied to optimize the commercial manufacture of phenylalanine.
Related Concept Videos
Mutations in Microorganisms
Production of Pharmaceuticals
Mutations
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...
Evolution of New Traits in Microbes
Epistasis Analysis

