1 Department of Biotechnology, Indian Institute of Technology Guwahati, North Guwahati, Assam, 781 039, India
2 CIISA-Faculdade de Medicina Veterinária, Rua Prof. Cid dos Santos, Lisbon, 1300 477, Portugal
*Corresponding author; E-mail: arungoyl@iitg.ernet.in Tel. 91-(361) 258 2208, Fax: 91-(361) 269 0762
Glycoside hydrolase (GH5) of family5, of the bi-functional cellulase from Clostridium thermocellum was amplified through PCR and cloned into an expression vector pET21a. The 35 kDa protein was over-expressed in cells of Escherichin coli BL-21 and purified to homogeneity by a single step purification method using immobilised metal ion affinity-chromatography. The purified enzyme showed high activity towards soluble substrates like carboxymethyl cellulose, β-glucan, lichenan, and weak activity towards hydroxymethyl cellulose and oat splet xylan. GH5 also hydrolysed the insoluble polysaccharide such as avicel. The optimum temperature for GH5 was 50°C and optimum pH was 4.2 with carboxymethyl cellulase as substrate.
Glycoside hydrolase, Clostridium thermocellum, cellulase, E. Coli, PCR
