Biobutanol production from high sugar content wastewaters

Over the last decade, the depletion of oil resources and concerns regarding both economic and environmental issues associated with petroleum-based fuels have renewed interests in biofuel production from renewable resources . Industrial and academic researches have paid attention to the development of (bio)sustainable processes and to the produce biofuels by conversion of renewable feedstoks. The spectrum of biofuels includes the butanol, a simple four carbon alcohol characterized by interesting features. A biotechnological route to produce butanol is based on the fermentation of clostridia: saccharolytic butyric acid-producing bacteria able to produce acetone-butanol-ethanol (ABE) by fermentation adopting a wide spectrum of carbohydrates, typically present in renewable unexpensive feedstocks. This contribution reports about a study on the feasibility of bio-butanol production by fermentation of high-sugar content beverages (HSCBs). The anaerobic solventogenic bacterium Clostridium acetobutylicum DSM 792 was adopted for the fermentation process. Commercial pineapple juice, lemon syrup and tonic water were tested as substrate for the fermentation. Preliminary tests pointed out that: i) the microorganism did not grow on any of the HSBCs investigated without complex medium supplementation; ii) the conversion degree of sucrose was quite low. Therefore, tests were carried out with broth made of the complex medium and HSCB pre-idrolized (sucrose idrolized to glucose and fructose).