Cellulase enzyme produced from difkferent fungi has been immobilized
on two different supports, i.e. gel fertilizer and chitin. Thc immobilized enzyme
with chum as a support had retention activity lower than that of gel fertilizer.
The retention activities of immobilized enzyme on chitin were found to be 89%.
6OY0 and 72% for T. reesci, T harzianun and A . niger. respectively. Whilc.
these values were 97 95 and 96% for the aboveementioned enzymes which were
immobilized on gel fertilizer as a support. The optimum temperature for
immobilized enzyme on chitin was established at 55°C for T reesel, T.
harzianum and A. niger. But the optimum temperature of immobilized enzyme
on gel fertilizer was 60°C for T. reesei and A. niger and 55°C for 7’. harzianuin.
On the other hand. the optimum pH in case ofgel fertilizer support was 5.0 for
T reesei and A. niger and 4.8 for T harzianum.While. the optimum pH for
immobilized enzyme on chitin was 4.8 for either T. reesel. orA. niger. But T
harzianurn showed that the maximum activity at pH 4:6. Kinetic behavior of the
immobilized enzyme with different supports was studied. MichaeLis constant
(Km) of inunobilized cellulase enzyme from T. reesel were determined to be 0.42
and 0.22 g/100 ml CMC in case of gel fertilizer and chitin support, respectively.
On the other hand. Km values of immobilized cellulase dnzyinC produced from T
harzianurn were calculated to be O. 1 8 and 0.2 gIl 00 ml CMC for gcleccllulase
complex and chitin-cellulase complex. respectively. While, Km of immobilized
cellulase enzyme produced from A. niger was 0.2 g/100 nil in case of gel
fertilizer and 0.52 g/100 ml for chitin-cellulase enzyme complex.
The stability of immobilized cellulase enzymes forms were found to be
more stable in comparison with native form. The immobilized cellulase enzyme
on gel fertilizer from different studied sources of fungi (T. reesel, T. harzianum
and A. niger) lost 40% of its original activity after 4 cycles. While, the
immobilized enzyme on chifin lost 70% of its activity after 4 times. |
