A cell factory of Bacillus subtilis engineered for the simple bioconversion of myo-inositol to scyllo-inositol, a potential therapeutic agent for Alzheimer's disease

BACKGROUND: A stereoisomer of inositol, scyllo-inositol, is known as a promising therapeutic agent for Alzheimer's disease, since it prevents the accumulation of beta-amyloid deposits, a hallmark of the disease. However, this compound is relatively rare in nature, whereas another stereoisomer of inositol, myo-inositol, is abundantly available. RESULTS: Bacillus subtilis possesses a unique inositol metabolism involving both stereoisomers. We manipulated the inositol metabolism in B. subtilis to permit the possible bioconversion from myo-inositol to scyllo-inositol. Within 48 h of cultivation, the engineered strain was able to convert almost half of 10 g/L myo-inositol to scyllo-inositol that accumulated in the culture medium. CONCLUSIONS: The engineered B. subtilis serves as a prototype of cell factory enabling a novel and inexpensive supply of scyllo-inositol.