Ajinomoto Co., Ltd.

Nara Institute of Science and Technology

National University Corporation Nara Institute of Science and Technology

Iwao Ohtsu

Hiroshi Takagi

Gen Nonaka

Takeshi Nakatani

Ai Tamakoshi

Sayo Takahashi

Natthawut Wiriyathanawudhiwong

L-cysteine can be produced inexpensively and efficiently by using a bacterium belonging to the family Enterobacteriaceae modified to reduce activity of O-acetylserine sulfhydrylase B thereof, the bacterium being modified so that the C terminal region of its thiosulfate-binding protein is deleted, and the bacterium having an increased ability to produce L-cysteine in the presence of a sulfate.

Enterobacteriaceae bacteria exhibiting increased L-cysteine producing ability

The present invention provides a bacterium belonging to the family Enterobacteriaceae, which is able to produce L-cysteine and has been modified to increase the activity of the protein encoded by the dsbA gene. This bacterium is cultured in a medium, and L-cysteine, L-cystine, a derivative or precursor thereof or a mixture thereof can be collected from the medium.

L-cysteine-producing bacterium and a method for producing L-cysteine

L-Cysteine, L-cystine, a derivative or precursor thereof, or a mixture thereof is produced by culturing a bacterium belonging to the family Enterobacteriaceae, which has L-cysteine-producing ability and has been modified so that the activity of a protein encoded by a tolC gene, for example, a protein defined in the following (a) or (b), is increased in a medium, and by collecting L-cysteine, L-cystine, a derivative or precursor thereof, or a mixture thereof from the medium:

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Ikoma, Japan

Iwao Ohtsu