PENGARUH PENAMBAHAN VOLUME MIKROBA DAN ENZIM TERHADAP PEMBUATAN BIOETANOL DARI SINGKONG KARET (MANIHOT GLAZIOVII M.A.)

Manihot glaziovii is a tuber that non-food corps, because it contains cyanide acid (HCN) which are toxic. Carbohydrat content in cassava tubers is 98,5% so it worth to be converted to bioethanol. Bioethanol is a product of hydrolysis of starch glucose, followed by enzymatic fermentation of glucose using yeast pichia stipitis to ethanol. This research aims to find out the influence variation of yeast and enzyme volume to bioethanol from resulting product. The enzyme:starch rasio used was 0.2 ; 0,4 and 0,6 ml/gr with variation of yeast 10 ml, 15 ml and 20 ml. Material cassava (manihot glaziovii, M.A) starch used was 25 gram. The research was carried out in several stages, including the enzymatic hydrolysis ofcassava starch to gucose and continued fermentation of glucose to ethanol. The bioethanol purity is chacked by means of gas cromatography, refraktometer (to check its indeks bias). The optimum result obtained at yeast 20 ml using enzyme volume 15 ml. The purity obtained was 27,9005%, indeks bias 1,3365 and bioethanol volume 6 ml. Keywords: manihot glaziovii M.A, Hydrolysis, Fermentation, Bioethanol