Azizan A H Syahadah’s scientific contributions

A two-stage acid hydrolysis was carried out with different concentrations of perchloric acid using date palm frond. In the first stage, most of hemicellulose and crystalline cellulose were hydrolyzed, as well as lignin, which was partially decomposed.In the second stage, the hydrolysis of crystalline cellulose and some additional decomposition of lignin were observed. The combined hydrolysates from the two-stage acid hydrolysis were concentrated by vacuum evaporation to increase the concentration of fermentable sugars and detoxified by over liming and activated charcoal adsorption to decrease concentration of fermentation inhibitors. A higher ethanol yield was obtained with the co-culture of Saccharomyces cerevisiae and Pichiastipitis, than the ethanol produced with a monoculture of Saccharomyces cerevisiae. The ethanol concentration reached 10.32 g/l in 66 h of incubation, with a yield, productivity and fermentation efficiency of 0.45 g/g, 0.16 g/l.h and 88.6%, respectively by using a co-culture of Saccharomyces cerevisiae and Pichiastipitis.