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Title
Isolation and biochemical characterization of crude xylanase from Coprinus cinereus AT-1 MTCC 9695 and its effectiveness in biodeinking of SOP
Authors
DHARM DUTT C. H. TYAGI R. P. SINGH ARCHANA GAUTAM SWARNIMA AGNOHOTRI and A. KUMAR
Received
August 2, 2012
Published
Volume 47 Issue 3-4 March-April
Keywords
Coprinus cinereus, xylanase, cellulase, deinking, brightness, dirt counts
Abstract
Out of 10 fungal strains isolated from various sources, Coprinus cinereus AT-1 MTCC 9695 produced the highest
xylanase (698.75 IU/mL), cellulase (1.01 IU/mL) and laccase (25.6±3.2 IU/mL) activities, using wheat bran and yeast
extract as the carbon and nitrogen sources at incubation period of 7days, incubation temperature of 37 °C, pH 6.4 and
solid substrate to NSS ratio of 1:3. The SSF was more effective, yielding 54.55% higher xylanase activity, compared to
SmF. Biochemical characterization revealed that crude xylanase was active in the pH range of 6.0 to 8.0 with the
maximum xylanase activity at pH 6.4 (699.60 IU/mL). At neutral and 7.5 pH levels, xylanase retained about 64 and
56% xylanase activity, respectively. At a temperature of 65 °C, xylanase retained about 74% of its optimum xylanase
activity and at higher temperatures (75 and 85 °C), it retained 17 and 11% of its optimum activity, respectively. SDS–
PAGE and zymogram analysis indicated that the molecular weights of xylanase produced by Coprinus cinereus AT-1
MTCC 9695 were of 50 kDa and 83 kDa. The effectiveness of crude xylanase was assessed by adding it along with
cellulase in equal amounts (6 IU/mL) during deinking of SOP. It mitigated ERIC values and dirt counts by 11.34 and
2.20% and improved brightness, DB and DE by 3.07, 8.73 and 4.90%, respectively, compared to deinking with cellulase
only.
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