CHARACTERIZATION OF CELLULASE PREPARATION OF BACILLUS SP.G4 ISOLATED FROM THE TERMITES GUT

The Bacillus sp. strain G4 isolated from termites gut can produce cellulase with high activity in rice bran medium after 72 h of incubation at 37 °C. The crude enzymewas collected by centrifugation at 6,000 rpmfor 15 minutes. The precipitation of cellulasewith ammonium sulfate 60 – 90 % saturation and acetone at the concentration 60 % – 90 % was studied. Results showed that ammonium sulfate 90 % saturation gave cellulase with highest purification factor 8.87 but the yield was only 59.9 %, whereas acetone at 90 % concentration gave highest yield 83.57 % with purification factor 4.38. CMCase activity of cellulasepreparation obtained by acetone precipitation at 90 % was optimum at pH 7 and 60 °C. Furthermore, CMCase was stable at pH 6.0 - 7.0 and at temperature lower than 50 °C. The CMCase was activated by ion Ca2+ but inhibited by Co2+, Zn2+, Cu2+, Fe2+, and was not affected by Mg2+ and Ba2+. The CMCase was inhibited by high concentration of SDS while EDTA and Tween 80 played activated role.