After the fermentations of different ratios between corncob and
PM described in 3.1, 400 g corncob and about 30% inoculum of the
ratio 3:2 between corncob and PM were added into glass bottles
with working volume 4 L for anaerobic digestion. The fermentation
conditions were controlled as Section 2.2 described above. The
experiment continued for 29 days.