Continuous production of acetone and butanol with shear-activated Clostridium acetobutylicum

Modeling and optimization of anaerobic digested sludge converting starch to hydrogen

“…Such a phenomenon is similar to that of Jones and co-workers (1982), who reported that VFAs (i.e., acetate and butyrate), but not solvents (i.e., butanol and acetone), are produced by Clostridium acetobutylicum during exponential growth. Obviously, the growth response of hydrogen-producing microorganisms obtained from the chemostat reactor was in general good agreement with that of Clostridium sp.-consuming carbohydrates in normal-batch culture (Afschar et al, 1986;Brosseau et al, 1986;Jones et al, 1982;). As a result, it must be concluded that both influences of pH and HRT in starchhydrogen fermentation corresponded closely to its metabolic control.…”

“…3A, C, D) show that the production trends of hydrogen/VFA were clearly opposite to that of alcohols. This mechanism is remarkably similar to that of Clostridium sp.-consuming carbohydrates, such as glucose and sucrose (Afschar et al, 1986;Brosseau et al, 1986;Jones et al, 1982;). Previous studies (Lay et al, 1999a(Lay et al, , 1999b(Lay et al, , 1999c have demonstrated that the boiling of sludge can readily deactivate hydrogentrophic bacteria and has a great potential to enhance the sludge's clostridial characteristics.…”

“…form VFAs during the exponential-growth phase. Only during the late-growth phase does the metabolism shift to rapid alcohol production in normal-batch culture (Afschar et al, 1986;Brosseau et al, 1986;Jones et al, 1982).…”

Modeling of the Performance of Industrial Bioreactors with a Dynamic Microenvironmental Approach: A Critical Review

“…Such studies could even lead to the definition of models considering the interaction between the biological and physical environments. Theses models could then be used to increase the activity of the cells in cultivation, as was done by Afschar et al [29]. These authors reported that cell growth and product formation rates, concerning Clostridium acetobutylicum, were considerably increased when the inoculum was shear-activated before cultivation.…”

Biobutanol from Renewable Agricultural and Lignocellulose Resources and Its Perspectives as Alternative of Liquid Fuels

“…The shear-activated continous culture growth is affected already at a butanol concentration lower than 1.6 g L -1 [83], Afschar et al (1986) [80]. The effect of viscosity on the ABE fermentation was studied by Korneeva et al [84].…”