Butanol production by Clostridium beijerinckii BA101 using cassava flour as fermentation substrate: enzymatic versus chemical pretreatments
Cassava flour (CF), a cost-effective source of starch, was employed as a substrate for successful acetone-butanol-ethanol (ABE) production by batch-fermentation with Clostridium beijerinckii. The effect of temperature, initial concentration of CF and chemical/enzymatic hydrolysis were studied in a 23 factorial design. Results revealed that temperature and initial concentration of substrate exert a significant effect on ABE production, as well as interactions of temperature with the other variables. Solvent production was maximized when working at 40°C, 60 g l−1 CF and enzymatic pretreatment. An average of 31.38 g l−1 ABE was produced after 96 h, with a productivity of 0.33 g l−1 h−1. A posterior randomized block design (3 × 2) showed that enzymatic hydrolysis (with saccharification periods of 6 h at 60°C) enhances both reducing sugar and solvent production if compared to chemical pretreatments. Average ABE production in this case was 27.28 g l−1, with a productivity of 0.28 g l−1 h−1. Results suggest that CF may be a suitable substrate for industrial ABE production.
KeywordsCassava Butanol ABE fermentation Hydrolysis Clostridium beijerinckii
- Annous BA, Blaschek HP (1991) Isolation and characterization of Clostridium acetobutylicum mutants with enhanced amylolytic activity. Appl Environ Microbiol 57:2544–2548Google Scholar
- Formanek J, Mackie R, Blaschek HP (1997) Enhanced butanol production by Clostridium beijerinckii BA101 grown in semidefined P2 medium containing 6 percent maltodextrin or glucose. Appl Environ Microbiol 63:2306–2310Google Scholar
- Qureshi N, Blaschek HP (2000) Economics of butanol fermentation using hyper-butanol producing Clostridium beijerinckii BA101. Trans IChemE. Part C 78:139–144Google Scholar
- Sadavisam S, Manickam A (1996) Biochemical methods. New Age International, New DelhiGoogle Scholar