Very High Gravity Fermentation of Ethanol with Fresh Sweet Potato

Ethanol can be utilized as fuel to improve energy consumption structure and reduce dependence on oil.Very high gravity fermentation,as a kind of emerging technique,can greatly reduce the costs of ethanol production.The very high gravity fermentation of ethanol with fresh sweet potato by Saccharomyces cerevisiae was studied.The impact factors of this fermentation technique were investigated,including fermentation stimulant,inorganic salt,vitamin and initial sugar concentration.As a result,the optimal fermentation culture was determined:1.20 g kg-1 fermentation stimulant B,270 g kg-1 initial sugar concentration and no inorganic salt and vitamin.Under the optimum medium conditions,132.86 g kg-1 ethanol was produced within 28 hours and the ethanol production rate reached 4.74 g kg-1 h-1.In 10 L fermentor,131.71 g kg-1 ethanol was produced within 28 hours and the ethanol production rate reached 4.70 g kg-1 h-1.Fig 3,Tab 3,Ref 16