HYDROLYSIS OF SOME AGRICULTURAL CELLULOSIC WASTES BY Aspergillus awamor; CELLULASES PRODUCED BY SOLID-STATE FERMENTATION

Document Type : Original Article

Authors

1 Microbiol. Dept., Soil, Water and Environ. Res. Institute, Agric. Res. Center, Giza, Egypt.

2 Home Economics, Fac. of Specific Education, Mansoura Univ., Mansoura, Egypt.

Abstract

The use of purified cellulose for bioconversion into cellulases increases the
cost of enzyme production. Consequently, there have been attempts to develop a
bioprocess to produce such enzymes using different lignocellulosic wastes. The
results revealed that: High extracellular cellulases activities were observed after 4
days incubation. Com stalk (1.5%). sugar cane molasse (1 %), corn steep liquor (at
0.056% as nitrogen content) were found as the best inducers for these enzymes
biosynthesis. pH 6.5 and 4.5 were found as the favourable pH for p-glucosidase and
CMC-ase & FP-ase synthesis. respectively. 35°C. 40 and 35 & 50°C were found as
the optimum temperature for these enzymes production, respectively. PH S.O and 5.5
, 50 and 60°C were found as the pH and temperature optima for p-glucosidase and
CMC-ase & FP-ase activities, respectively. These enzymes were completely stable in
the pH range between 5.0 - S.O, outside this pH range, all enzymes lost highest
amount of their maximum activities. P-Glucosidase was completely stable up to 50·C.
Some deleterious effects were happened to enzyme protein over this temperature
degree. CMC-ase and FP-ase were highest stable up to 70·C, above, enzymes
activities decreased sharply, This means that these enzymes were thermostable
enzymes. Ca+2 and Mg+2 stimulated these enzymes activities. Others such as HG+2
and Fe +2 inhibited their activities with much more inhibition. These enzyme mixtures
were successful to hydrolyzed untreated and treated cellulosic wastes. Alkali treated
materials were hydrolyzed with higher extent ranged between 1.8 to 3.24 times than
other untreated ones indicating that these enzymes play an important role for
hydrolysis similar materials and recycling such materials to an important
biotechnological substances.

Keywords