Production of low (C1 to C3) and high carbon content (C4 + ) alcohols under aerobic conditions using total reducing sugar from mixed Agro-Waste

Abstract

In the biofuels industries, agro-waste has been recommended as the most promising feedstock for the production of bioalcohols. However, the challenge of utilizing agro-waste as a feedstock is due to its highly recalcitrant structure, which limits cellulolytic enzymes to convert the holocelluloses into fermentable sugars. Different pre-treatments such as dilute acid, alkaline, thermal, hot water and enzymatic, have been used in previous studies. The challenge with these pre-treatment methods is the residual toxicants, which inhibits a high bioalcohol yield, by reducing the microbial populations’ ability to be metabolically proficient during fermentation. Engineered strains have been developed to reduce the inhibition and toxicity of the alcohols produced or by-products produced during pre-treatment, while enhancing the alcohol production. In the present study, a common method for the degradation of the mixed agro-waste was used, which consisted of hot water pre-treatment followed by dilute acid (H2SO4 ) pre-treatment. To further pretreat the mixed agro-waste residue, cellulases were used to further hydrolyse the pre-treated agro-waste. A commercial strain was used to produce low (C1 to C3 ) and high carbon content (C4 + ) alcohols under aerobic conditions for the benefit of the biorefinery industry