The productivity in the medium supplemented with 0.05% (NH4)2SO4 was 1.37 g/l/h, which was the highest among all treatments, while in the medium without nitrogen supplementation, productivity was only 1.15 g/l/h; in media supplemented with 0.07% and 0.1% (NH4)2SO4, the productivities were 1.05 and 1.07 g/l/h, respectively. Fermentation yield obtained in media with and without supplementation with a nitrogen source were in the range of 55.4–58.8% of theoretical yield