L-Methionine production in 21st century: A paradigm shift from chemistry to microbiology

Abstract

Japan began large-scale fermentation production of amino acids more than 75 years ago. However, L-methionine is an exception that cannot be produced on a large scale by fermentation, and hence no successful production plant has been established. It is most likely due to a lack of knowledge about its bacterial biosynthesis, including feedback regulation. Due to its huge market demands, several trials have been made but have been unsuccessful. This review tries to give an overview of how it was discovered, how it is made on a large scale, how the global market works, the metabolic pathways for bacterial synthesis of stereospecific production of L-methionine, how it is exported outside of cells, recent progress, recovery from production media, problems, and possible futures in this century.