LAUSR

A novel consolidated bioprocess was designed for processing of Parthenium hysterophorus biomass based on ultrasound-assisted deep eutectic solvent (DES) pretreatment followed by in situ enzymatic saccharification and fermentation of sugars to ethanol-biofuel. Among various DESs examined, choline chloride/sorbitol (CCS, molar ratio 1:5) pretreated P. hysterophorus biomass yielded maximum sugar (148.54 mg/g biomass) upon enzymatic saccharification. Furthermore, combined ultrasonic irradiation and CCS pretreatment resulted in substantially enhanced sugar yield as compared with either of the standalone pretreatment. A central composite design was employed for the optimization of combined ultrasound and choline chloride/sorbitol pretreatment that further aided in achieving increased reducing sugar yield (25.72%). The pretreated biomass was examined by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and proton nuclear magnetic resonance (1H-NMR) analysis to elucidate the functional mechanisms of combinative pretreatment. Understanding of pretreatment mechanisms may help custom designing of novel strategies for the efficient refining of biomass.