The amount of bioethanol in the supernatant was determined
using HPLC (High Pressure Liquid Chromatography) equipped with
RI (refractive index) detector and an Aminex HPX-87H column with
an appropriate guard column (Bio-Rad, USA) at a flow rate of
0.6 mL/min. The temperatures of the column and detector were
60 C and 50 C, respectively. The mobile phase was 5 mM H2SO4
filtered through 0.2 mm filter and degassed.