Screening of microorganisms secreted high efficient enzymes and properties of enzymatic deinking for old newsprint(III) - Production of bacterial cellulase and xylanase for enzymatic deinking of old newsprint

This study was carried out to examine the optimal cultural condition in enzyme activities of CMCase, FPase and xylanase in selected strains which secret extracellular enzymes for using deinking agent to old newsprint. The results of this study were as follow: The production of enzyme by Bacillus pumilus I was maximal as grown on the medium, containing of rice bran⁺xylan 2.0%, peptone 0.8%, K₂HPO₄ 0.1% and CaCl₂ 0.06% at pH 8.0 and 28°C for 72 hours. Optimal cultural condition of B. subtilis I was avicel-xylan 3.5%, urea 0.4%, K₃PO₄ 0.1% and CaCl ₂ 0.015% at pH 9.0 and 28°C for 36 hours. The maximal enzyme production was observed in the medium, containing of avicel⁺xylan 3.5%, urea 1.6% and K₂HPO₄ 0.125% with pH 9.0 when B. pumilus II was cultured at 28°C for 60 hours. The production of enzyme by B. subtilis II was maximal as grown on the medium, containing of xylan 2.0%, yeast extract 0.6%, K₂HPO₄ 0.1% and ZnSO₄ 0.04% at pH 8.0 and 34°C for 36 hours. The activities of FPase and xylanase in tested 4 strains were not much different with Thermomonospora fusca.