ABSTRACT
Butanol or butyl alcohol has a great potential in the transportation sector for blending with fossil fuel–based existing engines and also for biodiesel blends that improve engine efficiency and performance. Carbohydrate-containing feedstocks are most suitable for the biochemical route of biobutanol production by acetone-butanol-ethanol fermentation with naturally occurring and genetically engineered bacteria and yeasts. Butanol-tolerant microbes, with their adaptation for butanol stress, have been found to be capable of improvement in fermentation efficiency. This chapter focuses on the discussion of the metabolism of the most common butanol-producing bacteria, Clostridium acetobutylicum, and the various improvement strategies in upstream and downstream processing to increase butanol productivity. Metabolic engineering techniques in searching for and developing alternate microbes for enhancing butanol productivity by different researchers are also deliberated. The current challenges in butanol commercialization may be definitely met by research progression with the advent of new and inexpensive substrates and efficient processes.
