Feasibility of bioethanol production from tubers of Dioscorea sansibarensis and Pyrenacantha kaurabassana

Diluted acid hydrolysis yielded ca. 100% of total reducing sugars. Ethanol yield ca. 56 and 35 g/L was obtained at high efficiency through batch fermentation of acid hydrolysate (25% w/v) of DS and PK, respectively. A simple technique of recording and monitoring ethanol through CO2 generated during fermentation correlated strongly with HPLC measurement R2 = 0.99. Thus, tubers from these plants are potential feedstocks for bioethanol production with no competing uses.