The enzymatic hydrolysate was diluted to an initial glucose
concentration of 170 g L1. Glucose was completely consumed over
16 h of fermentation, reaching an ethanol concentration of 87 g L1.
These values correspond to a 99.8% fermentation efficiency based
on the theoretical value and a volumetric productivity of
5.4 g L1.h1 (Fig. 4). These results are similar to values obtained
industrially in sugarcane juice ethanol production, which according
to Zanin et al. [14] are 180 g L1 sugars, 87 g L1 ethanol and 92%
fermentation efficiency. Maltose present in the medium remained
constant throughout the process because glucose is preferentially
metabolized. Therefore, maltose consumption would begin after
the depletion of glucose in the medium.
3.4. Sweet sorghum bagasse: chemical composition and acid
pretreatment
Among biomass chemical pretreatments, dilute acid hydrolysis