Rachana Bhatt - Purification and properties of extracellular poly (3-hydroxybutyrate) depolymerase produced by A. fumigatus 202.

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      Publication Details (including relevant citation   information):

      J.   Polym. Environ. 2010

        Rachana Bhatt - Google Scholar Citations

      Abstract:

        An extracellular poly(3-hydroxybutyrate) (PHB) depolymerase   produced by a thermotolerant fungal soil isolate,    Aspergillus fumigatus   202, was purified and characterized. Maximum PHB depolymerase   production was obtained at the end of 48 h with initial medium pH   7.0 and 45 °C in Bushnell Haas Minerals medium containing PHB as   sole source of carbon. The PHB depolymerase was purified using   size exclusion chromatography to a fold purification of 20.62 and   61.62% yield. SDS-PAGE and isoelectric focusing revealed the   molecular weight and pI of the purified enzyme as 63,744 Da and   4.2, respectively. N-terminal amino acid sequence of purified   enzyme was HAXDAYLVK. This non-glycosylated enzyme was most   active at pH 9.0 and 45 °C. Purified enzyme was inactivated by   N-bromosuccinimide and dithiothreitol suggesting the involvement   of tryptophan residues and disulfide bonds at its active site.   Nonionic detergents like Tween 20, Tween 80 and Triton X-100   inhibited the enzyme activity. Ions like Ca+2    and Mg+2    (5 mM) increased the enzyme activity 1.5 times.   Fe+2    effectively inhibited the enzyme activity to 88% whereas   Hg+2    completely inhibited the enzyme.

      Address (URL): http://link.springer.com/article/10.1007/s10924-010-0176-1