However, the highest productivity, 1.36 g/l/l, was attained when the medium was supplemented with 0.05% (NH4)2SO4; the maximal ethanol concentration was 7.35% (w/v) and the yield was 65.5% of theoretical yield. In sugar cane juice media without supplementation with a nitrogen source, the ethanol concentration (6.85% w/v), productivity (0.95 g/l/h) and ethanol
yield (61.0% of theoretical yield) observed were lower