The Production of Ethanol and Hydrogen from Pineapple Peel by Saccharomyces cerevisiae and Enterobacter aerogenes

The production of biofuels including ethanol and hydrogen from agricultural waste is being concern as a renewable energy. Pineapple peel, a by-product of the pineapple processing industry, account for 29-40% (w/w) of total pineapple weight. 36.25 +/- 2.87% of cellulose was achieved from pineapple peel after pretreatment with water and heat at 100 degrees C for 4 h. Afterwards, 0.5% (w/w) cellulase from Aspergillus niger (Sigma) was added for enzymatic hydrolysis. The maximum sugar production (34.03 +/- 1.30 g/L) was obtained after 24 h of incubation time. The enzyme hydrolysate was utilized as fermentation medium, with no nutritional addition to produce ethanol and hydrogen by Saccharomyces cerevisiae TISTR 5048 and Enterobacter aerogenes TISTR 1468. The maximum yield of ethanol (9.69 g/L) with no hydrogen production by S. cerevisiae was achieved after 72 h. However, the maximum ethanol and hydrogen from E. aerogenes were 1.38 g/L and 1,416 mL/L after 72 h and 12 h of cultivation, respectively. In addition, the 1.2-folds of biofuel production were increased when immobilized bacterial cell in matrix of loofah. (C) 2014 Published by Elsevier Ltd.