Method for producing ergothioneine
A method for producing ergothioneine at a low cost in large quantities and a bacterium for use in said method are provided. A method for producing ergothioneine or a related substance thereof, or a mixture thereof, comprising culturing a bacterium belonging to the family Enterobacteriaceae having the ergothioneine-producing ability in a culture medium, and collecting ergothioneine or a related substance thereof, or a mixture thereof, from the culture medium or from the cells obtained by culture, wherein said bacterium is the one which is modified so as to have a reduced activity of a protein comprising a core sequence region comprising 5 amino acid residues: Ser-Arg-Gly-Arg-Thr (SEQ ID NO:7) as a part thereof; and a bacterium belonging to the family Enterobacteriaceae having the ergothioneine-producing ability modified so as to have a reduced activity of a protein comprising a core sequence region comprising 5 amino acid residues: Ser-Arg-Gly-Arg-Thr (SEQ ID NO:7) as a part thereof.
1. A method for producing ergothioneine or a related substance thereof having functionally related activity, or a mixture thereof, the method comprising:
culturing a bacterium belonging to the family Enterobacteriaceae having an ergothioneine-producing ability in a culture medium, and
collecting ergothioneine or a related substance thereof having functionally related activity, or a mixture thereof, from the culture medium or from cells obtained by culture,
wherein the bacterium is modified so as to have a reduced activity of a BetT protein comprising an amino acid sequence having 90% or more identity to the amino acid sequence shown in SEQ ID NO: 10,
wherein the bacterium produces ergothioneine or a related substance thereof having functionally related activity, and
wherein the reduction of the activity is 50% or less than the activity of a corresponding protein of a parent strain of the bacterium.
2. The method of claim 1 , wherein the
amino acid sequence has 95% or more identity to the amino acid sequence shown in SEQ ID NO: 10.
3. The method of claim 1 , wherein the bacterium belonging to the family Enterobacteriaceae having the ergothioneine-producing ability is a bacterium modified so as to enhance expression of ergothioneine biosynthesis genes.
4. The method of claim 3 , wherein the ergothioneine biosynthesis genes comprise any one or more of a gene corresponding to egtA, egtB, egtC, egtD or egtE of Mycobacterium smegmatis , a gene corresponding to Egt1 Egt2 of Schizosaccaromyces pombe , a gene corresponding to Egt1 or Egt2 of Neurospora crassa and a gene corresponding to eanA or eanB of Chlorobium limicola.
5. The method of claim 1 , wherein the bacterium belonging to the family Enterobacteriaceae having the ergothioneine-producing ability is a bacterium belonging to the genus Escherichia.
6. The method of claim 5 , wherein the bacterium belonging to the family Enterobacteriaceae having the ergothioneine-producing ability is Escherichia coli.
7. The method of claim 4 , wherein the ergothioneine biosynthesis genes comprise one or more genes corresponding to eanA or eanB of Chlorobium limicola.