Ethanol is a form of renewable energy. That can be used as fuel. Can replace gasoline or diesel. Fuel is an important factor driving the countrys economy. Ethanol can be produced from agricultural products garbage and various waste. his research uses watermelon rind. Which is waste from the community as a raw material for the production of ethanol by the fermentation process the microorganisms used in the fermentation process are ball flour. After fermentation for 6 hours it was found that the watermelon rind weighing 10 grams measured the concentration of alcohol. The concentration was 9.3 % VOL 18 Brix %. 20 grams of watermelon rind measuring the concentration of alcohol The concentration of 8.1 % VOL 16 Brix % of watermelon rind at 30 grams measured the concentration of alcohol. Get the concentration 8 % VOL 16 Brix % watermelon rind at 40 grams measure the concentration of alcohol get the concentration of 7.9 % VOL 15.1 Brix % and watermelon rind at 50 grams measure the concentration of alcohol the concentration of 7 % VOL 15 Brix %. Therefore it can be said that the watermelon rind which is waste from the community. Is a raw material with high potential for ethanol production to be used as a renewable energy source Instead of using raw materials from food plants and other energy crops.

Most of ethanol production processes are limited by low ethanol production rate and recyclable problem of ethanologenic organisms. In the present study Saccharomyces cerevisiae TISTR 5339 entrapped in an aqueous mixture of alginate and pretreated-bagasse was used for ethanol production of immobilization parameter of yeast cells consisting of amount of bagasse and alginate concentration on ethanol production were investigated. The results showed that increase in alginate concentration and the amount of bagasse can increase structural strength and reduce deterioration of bead. The optimal condition of immobilization was 1.0% (w/v) bagasse and 2.5% alginate. Ethanol yield (Yp/s) ethanol production rate (Qp) and efficiency of fermentation (Ey) obtained from the bagasse-alginate immobilized yeast cell was 3.39±0.72 g/l0.14±0.03 g/l/h and 70.98±14.08% respectively. The ultrastructure obtained from SEM illustrated that S. cerevisiae TISTR 5339 was well incorporated within the bagasse-alginate matrix. Moreover the bagasse-alginate immobilized yeast cells were reusable at least 5 times with Ey higher than 50% of 1st round of fermentation. Therefore the pretreated bagasse-alginate immobilized yeast cells is an alternatively interesting techniques with effiiciency for ethanol production in the future.