The cellulase enzyme producing fungus Aspergillus niger was isolated and identified from hilly irrigated soil. The substrate concentration, pH, incubation temperature and carbon sources of the czapekdox medium were varied and maximum production of cellulase was studied. Cellulase activity was maximum on incubating them for 10 days. The optimum pH and temperature were found to be 5.0 and 50 ºC respectively for optimum enzyme production of 16 U/mL/min. Addition of 3% Carboxy Methyl Cellulase (CMC) showed maximum percentage of enzyme activity (17 U/mL/min). Sugarcane bagasse was found to be the cheaper source which enhanced cellulase production (20 U/mL/min). Partially purified cellulase enzyme was run on Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE); it showed two distinct bands—67 Kda and 43 Kda. The molecular weight of cellulase enzyme was found. The production of cellulase enzyme by Aspergillus niger (A. niger) was improved by optimizing the medium composition and cultural conditions.

Cellulose is the major polysaccharide constituent of plant cell wall and one of the most abundant available organic compounds in the biosphere and its estimated synthesis rate is 10¹⁰ tons per year (Schlesinger, 1991; Singh and Hayashi, 1995; and Lynd et al., 2002). Cellulose-rich plant biomass is one of the foreseeable and sustainable sources of fuels, animal feeds and feed stocks for chemical synthesis (Bhat, 2000). The utilization of cellulosic biomass continues to be a subject of worldwide interest in view of the fast depletion of our oil reserves and food shortages (Kuhad et al., 1997; and Gong et al., 1999). Cellulose serves as a vast reservoir of glucose residues linked by b-1, 4 glycosidic bonds. The conversion of cellulosic mass to fermentable sugars by saccharification through biocatalyst cellulase derived from cellulolytic organisms has been suggested as a feasible process and offers potential to reduce the use of fossil fuels and reduce environmental pollution (Dale, 1999; and Lynd et al., 1999). Lignocellulosic wastes are abundantly available in crop residues. The fungi, bacteria and actinomycetes degrade lignocellulosic material and cellulose into fermentable sugars by the production of cellulase enzyme. Cellulase is the major constituent of plant cell wall and is abundantly available in biopolymer of earth (Beguin and Auber, 1996). Cellulase is also applied in the malting process. It leads to a more economical and efficient technique for the removal of hemicellulase content of the pulp in paper and wood industries.

This study focuses on the optimization of pH, temperature and use of different carbon sources in czapekdox broth to enable high cellulase production and characterization of the enzyme. It also focuses on enzyme saccharification of industrial and municipal wastes which provide sugar syrup for human consumption. Materials and Methods

Biotechnology Journal, Aspergillus Niger, A. Niger, Cellulase, pH, Temperature, Carbon Sources, Lignocellulosic Material, Potato Dextrose Agar, PDA, Carboxy Methyl Cellulase, CMC, Lacto-Phenol Cotton Blue, LPCB, Bovine Serum Albumin, BSA, Cellulase Enzyme, Biocatalyst Cellulase, Carbonic Anhydrase.