Ethanol Production from Non Food Tubers of Iles-iles (Amorphophallus campanulatus) using Hydrolyzes by Commercial Enzymes (α and β amylase) and Fermentation by Saccharomices cereviseae

Abstract

The decrease of oil production caused the increase on the price of fossil fuels. This paper was investigated the possibility of Amorphophallus campanulatus or known as “iles-iles” by Javanese people, which is known have a high carbohydrate content, as a raw material to produce bioethanol. The first stage of the process was hydrolyzes the starch, combined by liquefaction and saccharification of the starch from “iles-iles” using α and β amylase. The process was followed by fermentation of glucose with the help of S. cerevisiae. To obtain the maximum ethanol content, several parameter had been studied, such as the type S. cerevisiae (pure, dry, wet and instant), the dosage of α-amylase, β-amylase and also DAP dosage as a nutrient support for S. cerevisiae. The result shows that the highest ethanol concentration obtained in fermentation using dry S. cereviseae for 72 h with 10.2% (v/v) of ethanol. The highest total sugar content by hydrolysis was achieved by 0.0032 mL α-amylase/g, while β-amylase was 0.0064 mL β-amylase/g (12.5% of glucose). This is show that with increasing of α and β amylase dosages, the total sugar formed was increased. The DAP (Diammonium phosphate) was used as a Nitrogen supply which is needed by S. cerevisiae to growth and as a results can increase the level of ethanol produced. The additional of DAP in the fermentation prove that it can enhance 8.45% (v/v) of ethanol. Therefore, it can be concluded that the highest levels of ethanol with conventional methods of “iles-iles” was obtained at 72 h using the dry S. cerevisiae, with 0.0032 and 0.0064 mL enzyme/g of α and β amylase, respectively. This result shows that the plant seems to be a potential raw material for bioethanol.