The use of non- treated starch for butanol production by Clostridium acetobutylicum

Introduction: Greenhouse effect problems, environmental pollution, global increase in oil demand, and reduced fossil fuel resources have boosted research on the production of renewable energies such as bioenegries in recent years. Amongst various biofuels, biobutanol has been recently introduced as a replacement liquid fuel for gasoline and gas oil. Anaerobic bacteria such as Clostridium acetobutylicum are able to produce acetone, butanol, and ethanol using different sugar sources. This bacterium exhibits amylolytic activity and therefore is able to hydrolyzes starch to glucose and use it directly as carbon source. Materials and methods: In this study, three substrates including glucose, treated starch and starch were used in different concentrations to produce butanol by Clostridium acetobutylicum PTCC 1492. Results: For all three carbon sources, 60 g/ l of substrate was found as the optimum concentration. The results revealed that this bacterium is capable of producing butanol using all three carbon sources without any treatment. Butanol concentrations of 6.45, 5.81, and 4.64 g/ l were obtained using non-treated starch, treated starch, and glucose as carbon sources, respectively. Discussion and conclusion: The results suggested the possibility of using non-hydrolyzed starch as carbon source for butanol production. Also it was shown that non-treated starch produces more butanol compared to the treated starch