title: An improved Bacillus subtilis cell factory for producing scyllo-inositol, a promising therapeutic agent for Alzheimer's disease.
abstract: BACKGROUND
  Bacillus subtilis 168 possesses an efficient pathway to metabolize some of the stereoisomers of inositol, including myo-inositol (MI) and scyllo-inositol (SI). Previously we reported a prototype of a B. subtilis cell factory with modified inositol metabolism that converts MI into SI in the culture medium. However, it wasted half of initial 1.0% (w/v) MI, and the conversion was limited to produce only 0.4% (w/v) SI. To achieve a more efficient SI production, we attempted additional modifications.
  
  
  RESULTS
  All "useless" genes involved in MI and SI metabolism were deleted. Although no elevation in SI production was observed in the deletion strain, it did result in no wastage of MI anymore. Thus additionally, overexpression of the key enzymes, IolG and IolW, was appended to demonstrate that simultaneous overexpression of them enabled complete conversion of all MI into SI.
  
  
  CONCLUSIONS
  The B. subtilis cell factory was improved to yield an SI production rate of 10 g/L/48 h at least. The improved conversion was achieved only in the presence of enriched nutrition in the form of 2% (w/v) Bacto soytone in the medium, which may be due to the increasing demand for regeneration of cofactors.
authors: Kosei
authors: K
authors: Tanaka
authors: Shintaro
authors: S
authors: Tajima
authors: Shinji
authors: S
authors: Takenaka
authors: Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodai, Nada, Kobe 657 8501, Japan. kenyoshi@kobe-u.ac.jp.
authors: Ken-ichi
authors: K
authors: Yoshida
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy / Q000628:therapy; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007294:Inositol / Q000235:genetics / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: C009217:scyllitol; D007294:Inositol