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Indian Journal of Biochemistry and Biophysics (IJBB) >
IJBB Vol.45 [2008] >
IJBB Vol.45(5) [October 2008] >
| Title: | Enzymatic characteristics of quercetinases from some indigenous Aspergillus flavus strains |
| Authors: | Yadav, R S S
Yadav, K D S |
| Keywords: | Quercetinase
Aspergillus flavus
Dioxygenase
Copper enzyme |
| Issue Date: | Oct-2008 |
| Publisher: | CSIR |
| Abstract: | Five indigenous Aspergillus flavus strains MTCC-2206,
1884, 1883, 1783 and 2456 were screened for the secretion of
quercetinase. Fungal strains MTCC-2206, 1884, 1883, and 1783
were found to secrete the quercetinase in the range of 0.24-0.36
enzyme unit/mL of the culture medium, while MTCC-2456
secreted only 0.04 enzyme unit/mL. The enzymatic characteristics
of quercetinase were determined. The Km values using quercetin
as the substrate were 12.5 μM, 14.0 μM, 12.5 μM and 13.0 μM for
the quercetinase produced by MTCC-2206, 1884, 1883 and 1783,
respectively. The pH optima for the above enzymes were 6.5, 6.5,
6.0 and 6.0 and temperature optima were 45, 40, 45 and 50ºC,
respectively. The partial purification from only one strain MTCC-
2206 was achieved (nearly 3-fold purification). |
| Page(s): | 345-349 |
| ISSN: | 0301-1208 |
| Source: | IJBB Vol.45(5) [October 2008]
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