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Indian Journal of Biotechnology (IJBT) >
IJBT Vol.05 [2006] >
IJBT Vol.05(2) [April 2006] >
| Title: | Purification and immobilization of an Aspergillus terreus xylanase: Use of continuous fluidized bed column reactor |
| Authors: | Pal, Anju
Ray, Lalitagauri
Chattopadhyay, Parimal |
| Keywords: | xylanase
purification
immobilization
continuous conversion |
| Issue Date: | Apr-2006 |
| Publisher: | CSIR |
| IPC Code: | Int. Cl.8 A01N63/02, C12N9/24, C12N11/04 |
| Abstract: | An Aspergillus terreus extracellular xylanase produced by solid state fermentation was purified and characterized. A 6.4 fold purified xylanase was obtained by ammonium sulphate (in 30-40% saturation) precipitation followed by dialysis. Molecular weight of the xylanase was 67.0 kDa as estimated by SDS-PAGE. The enzyme was immobilized in barium alginate gel. Both free and immobilized enzyme showed maximum activity at pH 5.5 and 60°C (8.0 IU/mg & 5.25 IU/mg, respectively) and were most stable at pH 5.5 and thermostable up to 55°C. Co2+ stimulated free enzyme activity (9.27 IU/mg) and Mg2+ stimulated activity of immobilized enzyme (5.54 IU/mg). Vmax and Km for free and immobilized xylanases were 6.6  mole/mg/min, 0.75% and 1.25 mole/mg/min, 0.625%, respectively. 23.4% conversion of substrate (0.1% birchwood xylan) was possible in 7 h using a continuous fluidized bed column reactor under the following conditions: bed height 16 cm, temperature 40°C, and dilution rate 4.09 h-1. |
| Page(s): | 163-168 |
| ISSN: | 0975-0967 (Online); 0972-5849 (Print) |
| Source: | IJBT Vol.05(2) [April 2006]
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