To evaluate the potential application of the xylanase from culture
OM3 in biofuel application, a separate hydrolysis and fermentation
process was carried out using 40 g/L of birchwood xylan
with 4 U/mL xylanse at 60 C. During the enzymatic saccharification
of birchwood xylan, a regular increase of reducing sugars
was observed till 24 h of incubation, which remained almost constant
(9.5 g/L), thereafter, strain BOH3 was inoculated to initiate
fermentation (Fig. 2). Fermentation was essentially completed
after 72 h with 1.7 g/L butanol produced, which demonstrates the
feasibility of using the xylanase and butanol-generating microbes
for biofuel production from hemicellulose. The butanol production
can be improved by addition of more enzymes in order to hydrolyze
birchwood xylan more efficiently for higher reducing sugar
production. However, a disadvantage is the expense of enzymes
during the production and purification process, which covers a
big part of biofuel cost.