Ethanol Production from Pineapple Waste by Co-culture of Saccharomyces cerevisiae TISTR 5339 and Candida shehatae KCCM 11422

The ethanol production from alkaline pretreated pineapple waste (core and peel) by using co-culture process of S. cerevisiae TISTR 5339 and C. shehatae KCCM 11422  was evaluated. The potential of ultrasound-assisted alkaline pretreatment was applied to enhance total reducing sugar concentration. The highest yield of total reducing sugar was obtained at 21.84 g/g dried sample after pretreatment by 2% NaOH with ultrasonic-assistance for 60 min subsequently by enzymatic hydrolysis. The compositions  of pretreated pineapple waste were 40.52±0.99% cellulose, 24.03±1.52% hemicellulose and 2.27±0.23% lignin. However, the dry matter loss reached to 44.67±3.21% after pretreatment. The structural changes of pretreated pineapple waste were observed by scanning electron microscopy (SEM). The maximum ethanol concentration and ethanol yield after 24 h fermentation were 9.73±0.15g/L and 0.45±0.01 g/g, respectively.