A new technology of fuel ethanol fermentation using fresh raw sweetpotato by Zymomonas mobilis

摘要

A new technology of ethanol fermentation was developed using uncooked fresh sweetpotato as raw material. A mutant strain of Aspergillus niger was used to produce raw starch lysis and saccharifica-tion enzymes,and the Gram negative bacterium Zymomonas mobilis,which has many advantages over Saccharomyces cerevisiae, was used to ferment ethanol from fresh and uncooked sweetpotato storage roots. The fermentation conditions, including the amount of inoculum, the age of inoculum,and the pH, temperature and duration of fermentation,were studied to develop an optimized protocol for ethanol fermentation. Under the optimized conditions,26.4 mL of ethanol (200 ml_ of 13.2% ethanol [v/v]) was produced from 100 grams of fresh sweetpotato storage roots and the media for growing microbial inocula (total dried biomass including sweetpotato about 50.6 grams). This method requires no heating or cooking of sweetpotato and produces high concentrations of ethanol at high energy conversion rates. Through the implementation of this method,an energy-saving,environment-friendly and highly efficient new technology can be developed for large-scale production of fuel ethanol from raw sweetpotato.