Biotechnology for Biofuels published a feasibility study to produce bioethanol from sweet potato residues (SPR) using enzymatic hydrolysis that has a large potential of being adopted by industry.
China is the largest sweet potato producer and exporter in the world, with more than 71 million tons of sweet potatoes being produced each year. SPRs separated after extracting starch account for more than 10 % of the total dry matter of sweet potatoes. In China, more than 2 million tons of SPRs cannot be utilized, mostly due to their high viscosity. In addition, these unutilized SPRs are perishable, and release methane. Thus, it causes a serious environmental problem; since methane is the second-most common greenhouse gas, on climate change is more than 25 times greater than that of CO2 over a 100-year period.
This research paper demonstrates that using high-gravity fermentation to convert SPR to bioethanol decreases energy consumption for ethanol distillation and waste distillation treatment. The strategy adopted was to use different enzyme systems (cellulose and pectinase) during high-gravity SPRs hydrolysis. Following this strategy the researchers obtained the highest concentrations of glucose and ethanol produced from potato wastes compared to former studies. Therefore, the processes described in this article have a potential for industrial-scale production of bioethanol from potato waste because it’s environmentally friendly, highly productive, of low cost, and easily manipulated.
Read it _ Open Access Article.