The keywords focus on the introduction of foreign genes and specific enzyme variants to drive the production of O-acetyl homoserine and L-methionine. This indicates that native metabolic pathways suffer from bottlenecks or inadequate conversion rates of intermediate precursors.

The wild-type O-acylhomoserine sulfhydrylase enzyme exhibits insufficient catalytic activity and substrate specificity for industrial-scale synthesis of cysteine and its derivatives. Improving these variants overcomes the kinetic bottlenecks that limit high-yield amino acid production.

The keywords indicate a need to modify enzymes to improve the synthesis of L-glufosinate and homoserine derivatives. This addresses the bottleneck of insufficient metabolic flux or poor substrate conversion rates in industrial amino acid production.