Improving enzymatic digestibility of sugarcane bagasse from different varieties of sugarcane using deep eutectic solvent pretreatment

Sugarcane bagasse, a fundamental by-product of the sugar industry, was utilised to improve its digestibility for bioenergy applications. Choline chloride based deep eutectic solvents (DESs) were used for pretreatment of five different varieties of sugarcane bagasse (SRA1, SRA5, Q208, MA239, ISB) and a comparative study of compositional and morphological changes was performed. Three eutectic mixtures - choline chloride: malonic acid (1:1), choline chloride: glycerol (1:2) and choline chloride: lactic acid (1:5) were used to selectively remove lignin and improve saccharification efficiency. Physico-chemical characterizations performed using FE-SEM, FTIR, TGA and XRD analysis consistently indicated disruption of bagasse structure after DES pretreatment. Glucose recovery was predominantly influenced by the glucose content, as SRA1 variety showed the highest recovery of 92.8% for choline chloride: glycerol DES pretreatment. Choline chloride: lactic acid DES pretreatment demonstrated the most efficient lignin removal of 81.6% for ISB variety and the enzyme amenability was prominently increased to 98.5%.

Automated summary

This study focused on pretreating sugarcane bagasse with choline chloride-based deep eutectic solvents to improve its digestibility for bioenergy applications. The experiment showed that different varieties of sugarcane bagasse exhibited changes in composition and morphology after pretreatment, leading to increased glucose recovery and efficient lignin removal. The use of choline chloride-based deep eutectic solvents demonstrated promising results in enhancing saccharification efficiency and enzyme accessibility.