Fermentation production of L-methionine and regulation of L-methionine biosynthesis on Corynebacterium glutamicum. I. Production of O-acetyl-L-homoserine by methionine analogresisttant mutants and regulation of homoserine-O-transacetylase in Corynebacterium glutamicum.

• KASE Hiroshi

  Tokyo Research Laboratory, Kyowa Hakko Kogyo Co., Ltd.

• NAKAYAMA Kiyoshi

  Tokyo Research Laboratory, Kyowa Hakko Kogyo Co., Ltd.

抄録

A large amount of O-acetyl-L-homoserine (OAH) was found to be produced by trifluoromethionine-resistant mutants derived from Corynebacterium glutamicum ESLR-146 (Thr^-, ethionine^R, selenomethionine^R) and ET_zR-606 (Thr^-, ethionine^R, 1, 2, 4-triazole^R) by mutational treatment with ethyl methanesulfonate. Some cultural conditions for OAH production were examined with one of the mutants, ESLFR-736, which was derived from ESLR-146. Addition of L-methionine or L-serine decreased OAR production. Optimal level of L-threonine, a growth factor in ESLFR-736, for OAH production was about 200μg/ml, and further addition of excess L-threonine repressed OAH production. Corn steep liquor (CSL) and yeast extract added simultaneously enhanced OAH production to a great extent. Thus, the amount of OAH production reached to a level of 10.5mg/ml with a medium containing 10% glucose and 0.01% of both CSL and yeast extract after 2 days incubation.<br> Cell-free extract of C. glutamicum catalyzed the formation of OAH from acetyl CoA and L-homoserine, while a corresponding reaction with succinyl CoA was hardly detected. These observations indicate that OAH but not O-succinyl-L-homoserine is an intermediate of L-methionine biosynthesis in C. glutamicum.<br> The regulation of homoserine-O-transacetylase was examined in a methionine requiring mutant of C. glutamicum. The enzyme activity was not inhibited by L-methionine, S-adenosylmethionine and S-adenosylhomocysteine, separately or in combination. The synthesis of homoserine-O-transacetylase was strongly repressed by L-methionine. The enzyme level in an OAH producer, ESLFR-736, increased to about 2-fold of that in ESLR-146, the parental strain.

収録刊行物

• Agricultural and Biological Chemistry

  Agricultural and Biological Chemistry 38 (10), 2021-2030, 1974

  公益社団法人 日本農芸化学会

キーワード

• General Agricultural and Biological Sciences
• General Biochemistry, Genetics and Molecular Biology

詳細情報

• CRID: 1390001206466474496
• NII論文ID: 130003524417
• DOI: 10.1271/bbb1961.38.2021
• COI: 1:CAS:528:DyaE2MXosVequw%3D%3D
• ISSN: 18811280
• ISSN: 00021369
• 本文言語コード: en
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可