Provided are a microorganism producing an L-amino acid or a precursor thereof, and a method of producing an L-amino acid or a precursor thereof using the microorganism.

A method of the bio-production of methionine and/or of its derivatives thereof from a reduced source of sulfur, such as MeSH or MeSNa including genetically modified yeasts, having an increased ability to produce methionine and/or its derivatives thereof, as compared to the parent yeasts.

A method of the bio-production of methionine and/or of its derivatives thereof from a reduced source of sulfur, such as MeSH or MeSNa including genetically modified yeasts, having an increased ability to produce methionine and/or its derivatives thereof, as compared to the parent yeasts.

The present application is related to a recombinant microorganism optimized for the fermentative production of methionine and/or its derivatives, wherein in said recombinant microorganism, the cobalamin-dependent methionine synthase activity and the methionine efflux are enhanced. The application is also related to a method for optimizing the fermentative production of methionine and/or its derivatives comprising the steps of: c. culturing a recombinant microorganism wherein in said microorganism, the cobalamin-dependent methionine synthase activity and the methionine efflux are enhanced, in an appropriate culture medium comprising a fermentable source of carbon and a source of sulphur, and d. recovering methionine and/or its derivatives from the culture medium.

Provided are a microorganism producing an L-amino acid or a precursor thereof, and a method of producing an L-amino acid or a precursor thereof using the microorganism.