3. Results and discussion
3.1. Time course study
Xylanase production was checked by incubating the inoculated
flasks for various time periods and its was noted that
enzyme production was gradually increased with increase in
fermentation period and maximum production was achieved
after seven days of fermentation period as shown in Fig. 1. As
the fermentation period was increased decrease in enzyme
production was observed. Okafor, Emezue, Okochi,
Onyegeme-Okerenta, and Nwodo-Chinedu (2007) isolated a
strain of Penicillium chrysogenumPCL501 from wood wastes and
reported that highest xylanase activity of 6.47 units mL1 was
obtained with wheat bran after 96 h of fermentation period
and lowest activity of 0.79 U/ml after 120 h. Abdel-Satera and
El-Said (2001) obtained maximum production of xylanase
from Trichoderma harzianum after 8 days of fermentation
period. Goyal, Kalra, and Sareen (2008) achieved maximum
enzyme production for 14e17 days of fermentation period
using strain of T. viride. Increased fermentation time and
decreased enzyme synthesis might be due to the depletion of
macro- and micronutrients in the fermentation medium with
the passage of time, which altered the fungal physiology
resulting in the inactivation of secretary machinery of the
enzymes