Assessment of kinetics for butanol production by Clostridium Acetobutylicum

Preliminary results of a research activity aiming at investigating the feasibility of the acetone-butanol-ethanol (ABE) production by Clostridium acetobutylicum ATCC824 are reported. The contribution regards the characterization of the kinetics related to the ABE production process by free C. acetobutylicum ATCC824. Lactose solutions were adopted as medium with the aim of emulating cheese whey. The conversion process is characterized in terms of cells, acids, solvents, pH and total organic compounds as a function of time. Tests carried out under batch conditions show that: i) cells growth is constant for lactose concentration (CL) smaller than 100 g/L; ii) the butanol specific production rate as a function of CL may be represented by a Monod-like kinetics; iii) the lactose conversion - measured at the end of the solventogenesis phase - decreases with CL; iv) the selectivity of butanol with respect to total solvents increases with CL and stabilizes at about 72%W for CL larger than 30 g/L.