Overexpression of sADH gene in C. acetobutylicum Rh8. (a) Plasmid for expression of sADH gene in C. acetobutylicum Rh8. (b) SDS-PAGE analysis of overexpressing sADH gene in strain Rh8. The overexpressed protein sADH (theoretical molecular weight 37.65 kDa) is indicated by the arrow on the right. Strain Rh8(pIMP1) is the control strain containing empty vector. (c) Detection of sADH acitivty. C. acetobutylicum Rh8(psADH) and C. acetobutylicum Rh8(pIMP1) cells were cultured in RCM culture medium adding 5 g/l acetone when cells grow into exponential stage (OD600 = 0.8). The concentrations of acetone (solid squares/open squares) and isopropanol (open triangle /solid squares) in strain Rh8(pIMP1)/Rh8(psADH) were determined by HPLC.