a b s t r a c t
An energy-saving ethanol fermentation technology was developed using uncooked fresh sweet potato as
raw material. A mutant strain of Aspergillus niger isolated from mildewed sweet potato was used to produce
abundant raw starch saccharification enzymes for treating uncooked sweet potato storage roots.
The viscosity of the fermentation paste of uncooked sweet potato roots was lower than that of the cooked
roots. The ethanol fermentation was carried out by Zymomonas mobilis, and 14.4 g of ethanol (87.2% of the
theoretical yield) was produced from 100 g of fresh sweet potato storage roots. Based on this method, an
energy-saving, high efficient and environment-friendly technology can be developed for large-scale production
of fuel ethanol from sweet potato roots.