Continuous bioethanol production from fermentation of hydrolysed sago starch using the 'Ishizaki Process'

Continous fermentation of hydrolysed sago starch based on the 'Ishizaki process' was studied. Sago starch (20% DS) were hydrolyzed by the enzymes termamyl - 120L and dextrozyme to yield fermentable sugars at 97.6+0.6%. At a larger scale (50L), a reduction of hydrolysis yield to 62.5% was observed. Batch ethanol fermentations using saccharomyces cerevisiae CSI-1 was studied, employing commercial glucose and various nitrogen sources (yeast extract, mieki and corn steep liquor). It was observed that yeast extract exhibited the highest fermentation efficiency at 98.4=0.2% compared to CSL (4% v/v) and Mieki (2% v/v) at 97.02= 1.05% and 93.0 = 1.1%, respectively.