Increasing methionine production by overexpressing succinate dehydrogenase

摘要

The present invention relates to a process for improving the production of methionine by culturing a microorganism modified for enhancing the expression of genes involved in succinate dehydrogenase synthesis. The microorganisms were modified in a way that the methionine/carbon source yield is increased. The isolation of methionine from the fermentation medium is also claimed.

主权项

1. A method for the production of methionine, in a fermentative process comprising:
(a) culturing a microorganism modified for an improved production of methionine in an appropriate culture medium comprising a source of carbon and a source of sulfur, and (b) recovering methionine from the culture medium, wherein said microorganism presents at least one of the following modifications:
overexpression of the genes cysP, cysU, cysW, cysA, cysM, cysJ, cysI, cysH, cysE gcvT, gcvH, gcvP, metF, metA, thrA, metH, serA, serB, serC, glyA, and/orattenuation of the genes pykA, pykF, metJ, and purU, and wherein said microorganism is further modified by enhancing the expression of gene(s) encoding a succinate dehydrogenase enzyme by inserting into the microorganism at least one supplementary copy of the four genes sdhA, sdhB, sdhC, and sdhD of E. coli.