Sweet sorghum bagasse as an immobilized carrier for ABE fermentation by using Clostridium acetobutylicum ABE 1201

Abstract

In this study, sweet sorghum bagasse was used as an immobilized carrier for acetone–butanol–ethanol (ABE) fermentation production. Scanning electron microscopy revealed the relationship between Clostridium cells and the sorghum bagasse in terms of adsorption and embedding. The ABE productivity and yield of ABE solvents in batch fermentation were 0.37 g L⁻¹ h⁻¹ and 0.41 g g⁻¹, with 68% and 24% improvement than free cells, respectively. Repeated batch fermentation was carried out under optimized conditions, plus a total of 970 h of continuous fermentation at different dilution rates. A maximum ABE concentration of 16.5 g L⁻¹ was obtained at a dilution rate of 0.08 per h, with optimized yield and productivity. This novel immobilization method using sweet sorghum bagasse offers an attractive prospect for the industrial production of bio-based butanol.