Yuan et al. [26] reported the
shortening of fermentation from 84 h to 48 h from under oxygen
limited conditions, and correspondingly an increase in ethanol productivity from 0.99 to 1.58 g/l h. However, the ethanol yield
as percent of the theoretical value achieved under the aeration
condition was only 77.1% compared with that of 86.9% achieved
under the oxygen limited condition