Amin Fatoni and Zusfahair

pp. 525 - 531

Abstract

Limited reserves of fossil energy stimulate researchers to explore for a new alternative energy, such as bioethanol.
A thermophilic amylase producing bacterium was isolated from local hot-springs and its characteristic and potential application for bioethanol production was determined. The obtained amylase was studied to determine its optimum temperature, pH,
enzymatic reaction time, and substrate concentration. Tapioca waste was used as the substrate to find the potential of the
amylase for degrading starch into glucose, and then the process was continued by fermentation to produce bioethanol. The
amylase producer bacterium was proposed as genus Thermus sp. The crude amylase that was obtained has the optimum
temperature of 60°C and optimum pH of 8.0, optimum substrate concentration at 10% (w/w) and optimum enzymatic reaction
time of 45 minutes. These enzymes convert the starches of waste tapioca at optimum conditions, with the result of 2.9%
ethanol produced from raw materials.