The impact of different physicochemical parameters of fermentation on extracellular cellulolytic enzyme production by Trichoderma harzianum

This study was undertaken to find out the optimum physicochemical parameters of fermentation, i.e. pH, incubation temperature and incubation time for the cellulase enzyme production of Trichoderma harzianum. The extracellular protein content was estimated by the dye binding method of Bradford. Endo-glucanase (EG), exoglucanase (or Cellobiohydrolase; CBH), β-glucosidase and total cellulase activity were investigated. The molecular weight of cellulase enzymes was studied using SDS-PAGE. To identify the predominant catalytic components in optimum conditions of enzyme production, cellulases were separated by an adapted two-dimensional electrophoresis technique. Estimated optimum conditions for cellulase enzyme were found as: pH ۶.۵, incubation temperature ۲۸°C and incubation time ۷۲ h. The SDS-PAGE profiles showed several enzyme bonds such as CBHs, EGs and BGLs. The T. harzianumhad both enzyme bonds of Cel۷A (CBHI) and Cel۷B (EG). Finally, the results of the ۲D PAGE analysis showed that the profile of protein in optimium conditions of enzyme production had several enzymes such as CBHs, EGs and the high values of cellulose activity due to synergism that occurred between the CBH and EG.

Keywords:

Trichoderma harzianum , Cellulase enzyme , SDS-PAGE , ۲D-PAGE