The effect of (NH4)2SO4 as a nitrogen source at a concentration of 0–0.1% on ethanol fermentation of DMKU 3-1042 was determined in a sugar cane juice medium composed of sugar cane juice supplemented with sucrose to 22% total sugars and adjusted to pH 4.5. At 37 C, the highest ethanol concentration, 7.8% (w/v), was obtained with 0.07% (NH4)2SO4 supplementation (Table 2); the productivity was 1.08 g/l/h and the yield was the highest: 69.5% of theoretical yield