Please use this identifier to cite or link to this item:
http://nopr.niscpr.res.in/handle/123456789/28693| Title: | A novel pullulanase from a fungus Hypocrea jecorina QM9414: production and biochemical characterization |
| Authors: | Orhan, Nurdagul Kiymaz, Nilay Altas Peksel, Aysegul |
| Keywords: | Hypocrea jecorina QM9414;Culture conditions;Induction;Type II pullulanase;Purification |
| Issue Date: | Apr-2014 |
| Publisher: | NISCAIR-CSIR, India |
| Abstract: | Pullulanase production from a fungus Hypocrea jecorina QM9414 that produces native extracellular hydrolases having industrial applications was carried out in a shaking flask culture containing 0.5% amylopectin at a pH of 6.50 at 30°C. The enzyme was purified 11-fold by ammonium sulfate fractionation, anion-exchange and gel-filtration chromatographies with a yield of 10.12% and a specific activity of 1.36 ± 0.14 U/mg protein. The molecular mass of pullulanase was estimated to be 130.56 kDa by PAGE and SDS-PAGE, indicating that the native enzyme was a monomer. The optimum pH and temperature for purified enzyme was 6.5 and between 35°-65°C, respectively. The Km values for amylopectin, starch and pullulan as substrates were 10.7, 15.5 and 38.4 mg/mL, respectively. The Vmax values were found to be 3.32, 3.32 and 3.82 ΔA/min for amylopectin, starch and pullulan, respectively. The enzyme was stable at 40-70°C for 30 min, but lost about 33% of its activity at 80°C and about 43% of activity at 90°C and 100°C for the same incubation period. Pullulanase activity was stimulated by CoCl2, NiCl2, KI, NaCl, MgCl2, and LiSO4. The enzyme was slightly inhibited by urea, CaCl2 and b-mercaptoethanol. The enyzmatic characteristics, substrate specificity and the products of hydrolysis indicated that the enzyme was similar to those of type II pullulanases. |
| Page(s): | 149-155 |
| ISSN: | 0975-0959 (Online); 0301-1208 (Print) |
| Appears in Collections: | IJBB Vol.51(2) [April 2014] |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| IJBB 51(2) 149-155.pdf | 172.73 kB | Adobe PDF | View/Open |
Items in NOPR are protected by copyright, with all rights reserved, unless otherwise indicated.