kram-ul-Haq
Government College University, Pakistan
Posters & Accepted Abstracts: J Proteomics Bioinform
The growing demand of bioenergy has led to the emphasis on novel cellulases to improve efficiency of biodegradation process of plant biomass. Therefore, A Thermostable cellulolytic gene (CenC) with 3,675 bp was cloned from Clostridium thermocellum and over-expressed in Escherichia coli strain BL21 CodonPlus. It was attested that CenC belongs to glycoside hydrolase family 9 (GH9) with four binding domains, a Processive endoglucanase. CenC was purified to homogeneity, producing a single band on SDSPAGE corresponding to 137.11 kDa by purification steps of heat treatment combined with ion-exchange chromatography. Purified enzyme displayed optimal activity at pH 6.0 and 70 �°C. CenC had a half-life of 24 min at 74 �°C, was stable up to 2 hours at 60 �°C and over a pH range of 5.5-7.5. Enzyme showed high affinity towards various substrates and Processively released cellobiose from cellulosic substrates confirmed by using HPLC technique. It efficiently hydrolyzed carboxymethyl cellulose (30 U/mg), �²-glucan Barley (94 U/mg); also showed activity towards p-nitrophenyl-�²-D-cellobioside (18 U/mg), birch wood xylan (19 U/mg), beechwood xylan (17.5 U/mg), avicel (9 U/mg), Whatman filter paper (11 U/mg) and laminarin (3.3 U/mg). CenC exhibited Km, Vmax, Kcat, VmaxKm-1 and KcatKm-1 of 7.14 mM, 52.4 �¼mol mg-1min-1, 632.85 s-1, 7.34 min-1 and 88.63, respectively used CMC as substrate. Recombinant CenC saccharified pre-treated wheat straw and bagasse to 5.12% and 7.31%, respectively at pH 7.0 and 45 �°C after 2 hours incubation. Its thermostability, high catalytic efficiency and independence of inhibitors make CenC enzyme an appropriate candidate for industrial applications and cost-effective saccharification process.
Email: ikmhaq@yahoo.com
