Journal of Cell Science & Therapy
Open Access
ISSN: 2157-7013
+44 1300 500008
ISSN: 2157-7013
+44 1300 500008
Ikramul Haq, Fatima Akram and Ali Nawaz
Government College University, Pakistan
Posters & Accepted Abstracts: J Cell Sci Ther
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 overexpressed in Escherichia coli strain BL21 Codon Plus. 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 SDS-PAGE 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 70oC. CenC had a half life of 24 min at 74oC, was stable up to 2 hours at 60oC and over a pH range of 5.5-7.5. Enzyme showed high affinity towards various substrates and processively released cellobiose from cellulosic substrates. 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), birchwood 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 pretreated wheat straw and bagasse to 5.12% and 7.31%, respectively at pH 7.0 and 45oC 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