Abstract

Cellulases along with proteases and lipases account for a significant share in the globalenzyme market. Microbial cellulases have important applications in industries like fodder, food,  textile,  brewery,  pulp  and  paper.  The  present  study,  therefore,  was  undertaken  to purify  and  characterize  callulase  enzyme  from  the  cellulolytic  microbes  isolated  from  a waste dumping site. Of the 28 microbial isolates, five isolates produced cellulase on LB agar plates containing 1% CMC. The PCS-22 isolate, representing Pseudomonas sp. was selected for further purification and characterization of cellulase produced. The enzyme was purified using anion exchange chromatography. The molecular weight of the purified enzyme was approximately 60 kDa. The purified enzyme showed maximum activity and stability at 50°C and pH 7.0. Inhibition of enzymatic activity was observed in the presence of  Zn²⁺,  Cu²⁺ and Fe²⁺  ions  while  the  presence  of  Mn²⁺ ions caused a three-fold increase in the activity. The effect of inhibitors (PMSF, EDTA, β-mercaptoethanol), surfactants (TritonX-100 and SDS) and commercial detergents (Tide and Surf Excel) on the stability of the purified enzyme was also studied.

Keywords

hdrolysis, enzyme assay , cellulase, cellulolytic bacteria, 16S rRNA gene, Pseudomonas sp., enzyme characterization, substrate concentration, enzyme activity, stability