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. | Journal of Science andTechnology 54 (4A) (2016) 115-122 CHARACTERIZATION OF CELLULASE PREPARATION OF BACILLUS ISOLATED FROM THE TERMITES GUT Đào Thị Thanh Xuân1, 2, *, Phí Quyết Tiến3, Lê Thanh Hà2 1 Vinh University, 182 Le Duan, Vinh city, Nghe An 2 Hanoi University of Science and Technology, 1 Dai Co Viet, Hanoi 3 Institute of Biotechnology, VAST, 18 Hoang Quoc Viet, Hanoi * Email: Thanhxuan7879na@ Received: 15 August 2016; Accepted for publication: 5 October 2016 ABSTRACT 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 but the yield was only %, whereas acetone at 90 % concentration gave highest yield % with purification factor . CMCase activity of cellulasepreparation obtained by acetone precipitation at 90 % was optimum at pH 7 and 60 °C. Furthermore, CMCase was stable at pH - 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. Keywords: Bacillus, Cellulase, CMCase, isolation, EDTA, SDS, Tween 80, termite gut. 1. INTRODUCTION Cellulose is the most abundant renewable biopolymer in nature. In the near future, the processes using cellulase could lead to new environmentally friendly technologies. Cellulases hydrolyze theb-1,4-glycosidic linkages of cellulose. Traditionally, they are divided into two classes referred to as endoglucanases andcellobiohydrolases. Endoglucanases (endo-1,4-bglucanases, EGs), which is .
