Stable high-titer n-butanol production from sucrose and sugarcane juice by Clostridium acetobutylicum JB200 in repeated batch fermentations

The production of n-butanol, a widely used industrial chemical and promising transportation fuel, from abundant, low-cost substrates, such as sugarcane juice, in acetone–butanol–ethanol (ABE) fermentation was studied with Clostridium acetobutylicum JB200, a mutant with high butanol tolerance and capable of producing high-titer (>20 g/L) n-butanol from glucose. Although JB200 is a favorable host for industrial bio-butanol production, its fermentation performance with sucrose and sugarcane juice as substrates has not been well studied. In this study, the long-term n-butanol production from sucrose by JB200 was evaluated with cells immobilized in a fibrous-bed bioreactor (FBB), showing stable performance with high titer (16–20 g/L), yield (∼0.21 g/g sucrose) and productivity (∼0.32 g/L h) for 16 consecutive batches over 800 h. Sugarcane thick juice as low-cost substrate was then tested in 3 consecutive batches, which gave similar n-butanol production, demonstrating that JB200 is a robust and promising strain for industrial ABE fermentation.