The Influence Of Metal Ions On Cellulolytic Activities Of Fungal Isolates From Palm Biomass

Abstract

Numerous metal ions and chemical compounds can influence the activity of some fungi. Some have inhibitory effects whereas others have enhancing effects. In this study, the effect of metallic chlorides; lead II chloride (PbCl₂), potassium chloride (KCl), copper II chloride (CuCl₂), calcium II chloride (CaCl₂), manganese II chloride (MnCl₂), iron III chloride (FeCl₃) and mercury II chloride (HgCl₂) were evaluated for their influence on the cellulolytic activity of seven (7) fungal isolates at a concentration of 0.005M at 30°C for four (4) days using 3, 5-dinitrosalicyclic acid (DNS) method. CaCl2 had the highest influence on the cellulolytic activity for all the fungal isolates as compared to the control. In the presence of CaCl₂, Trichoderma species (C) showed a high cellulolytic activity of 2.28x10^-5 mmol/min/ml, Rhizopus, Trichoderma and Aspergillus species (A, B and E) had activities of 1.72 x10^-5 ,1.65 x10^-5 and 1.68 x10^-5 mmol/min/ml respectively. HgCl₂ and CuCl₂ had the least influenced on the cellulolytic activity of all the fungal isolates. This, therefore, suggests that calcium ion activates the cellulase activity of the fungal species while HgCl₂, PbCl₂, KCl, CuCl₂, MnCl₂ and FeCl₃ had a retarding effect on the cellulolytic activity.