Production
of Cellulase by Trichoderma reesei from Dairy Manure
Zhiyou Wen*, Wei Liao and Shulin Chen
Department
of Biological System Engineering
Phone:
(509)335-3743
Fax:
(509)335-2722
Email:
zwen@wsu.edu)
Animal manure represents a large
potential bioresource for producing bio-based chemicals. Currently, about 90%
of collected manures are disposed through direct land application, which can
cause severe environmental problems such as stream and groundwater
contamination (from nitrate), air pollution (from ammonia), and ecological
system eutrophication (from phosphorus).
This work provided an alternative
for animal manure treatment and disposal. A cellulase production by the fungi Trichoderma
reesei was studied using dairy manure as a substrate. Data showed that T.
reesei RUT-C30 had higher cellulase production than T. reesei QM
9414 and that a homogenized manure, treated by a blender to reduce fiber size,
led to higher cellulase production The cellulase production was further
optimized by growing T. reesei RUT-C30 on homogenized manure. The
effects of manure concentration, pH, and temperature on cellulase production
were investigated with optimal parameter values determined to be 10 g /L manure
(dry basis), 25.5 oC, and pH 5.7, respectively. Elimination of CaCl2,
MgSO4, nitrogen sources (NH4+ and urea) and
trace elements (Fe2+, Zn2+, Co2+ and Mn2+)
from the original salt solution had no negative influence on the cellulase
production, while phosphate elimination did reduce cellulase production. Based
on above results, the final medium composition was simplified with manure
additives being KH2PO4, tween-80 and CoCl2
only. Using this medium composition and a reaction time of 6~8 days, a maximum
cellulose production activity of 1.74 IU/mL of filter paper activity, 12.22
IU/mL of CMCase activity, and 0.0978 IU/mL of b-glucosidase
was obtained. This filter paper activity is the highest ever reported in
cellulase production from agricultural wastes.