Ethanol fermentation from solid waste of tapioca (onggok) by Aspergillus niger and Zymomonas mobilis

Abstract

The aims of this research were to know the concentration of arrowroot flour which produced the highest reducing sugar in saccharification process by A. niger, as well as to know the efficiency of ethanol production by Z. mobilis. The framework of this research was the increasing needs of ethanol; meanwhile ethanol could be obtained from the fermentation arrowroot. This research was carried out in two stages. In the saccharification stage, there are four concentrations, namely: 10%, 20%, 30% and 40%, and A. niger concentration of 10% (v/v) for each arrowroot flour concentration with spores amount 3,3x106/mL. The parametric measurement includes: starch concentration in the starting day and the sixth day, while the reducing sugar concentration and pH was measured every 24 hours during 6 days. In the ethanol fermentation, Z. mobilis concentration have been used 10% (v/v) with cells amount 5,1x107/mL and it was used in solution product of arrowroot starch saccharification and parametric measurement carried out during 72 hours includes: ethanol and reducing sugar concentration and the growth of Z. mobilis cells. The data resulted from parametric measurement. The result of the research showed that arrowroot flour concentration of 10% produced the highest reducing sugar in process of saccharification with reducing sugar concentration was 1,230 g/100 mL in four days and the efficiency of ethanol production by Z. mobilis during 72 hours was 83,03%.