Patent 7148047 was granted and assigned to AJINOMOTO CO., INC. on December, 2006 by the United States Patent and Trademark Office.
L-cysteine is produced by culturing a coryneform bacterium in which intracellular serine acetyltransferase activity is increased by transformation with a gene coding for serine acetyltransferase, such modification of an expression control sequence of a gene coding for serine acetyltransferase that expression of the gene in a cell should be enhanced and for forth, preferably in which L-cysteine decomposition system is further suppressed, in a medium to produce and accumulate L-cysteine in culture and collecting the L-cysteine from the culture.