Kinetic parameters are summarized in Table 1.
Maximum values for volumetric and specific
ethanol productivities were 42.8 g1 l1 h1 and,
1.2 g1 dry weight cell h1, respectively, at a
dilution rate of 1.5 h1. Two main factors contributing
to the relatively high ethanol productivities
are the bead size and cell loading. Small beads
provide high solid–liquid interfacial areas per unit
reactor volume and minimizes mass-transfer limitation
problems of sugar, ethanol, and CO2. Similar
observations were reported by Margaritis and
Bajpai (1982).