Comparison of different lignocellulosic biomass for Solvent production by Clostridium beijerinckii strains

Abstract

The aim of the present study was to compare the effect of lignocellulosic sugar hydrolysate, obtained after acid pretreatment of different lignocellulosic biomass on production of solvents by two different Clostridium beijerinckii strains. C. beijerinckii C-01 produced solvents via the isopropanol-butanol-ethanol (IBE) pathway and C. beijerinckii B-17 via the acetone-butanol-ethanol (ABE). The hydrolysate was obtained after acid pretreatment of rice-husk, rice-straw and sugarcane-bagasse. Solvent production was observed from all the three substrates by both the strains. However, the highest solvent production of 9.2 gL− 1 similar to medium supplemented with commercial sugars was observed in sugarcane-bagasse hydrolysate by C. beijerinckii B-17. Degradation products i.e. 5-Hydroxy-methyl-furfural, levulinic acid, furfural and formic acid were found in different concentrations during acid pretreatments. The highest amount of formic acid (3.5 gL− 1), along with significant amounts of levulinic acid and furfural, was found to be present in rice-husk hydrolysate. The study shows that rice-straw and sugarcane-bagasse obtained after acid pretreatment are better substrates in comparison to rice-husk for butanol production by Clostridium beijerinckii strains.