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BioMed Research International
Volume 2015 (2015), Article ID 245649, 8 pages
http://dx.doi.org/10.1155/2015/245649
Research Article

Purification and Characterization of a Polyextremophilic α-Amylase from an Obligate Halophilic Aspergillus penicillioides Isolate and Its Potential for Souse with Detergents

1Plant Biomass Utilization Research Unit, Department of Botany, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
2Institute of Biochemistry, University of Balochistan, Quetta 87300, Pakistan
3Department of Microbiology, University of Balochistan, Quetta 87300, Pakistan

Received 13 October 2014; Revised 25 December 2014; Accepted 25 December 2014

Academic Editor: Subash C. B. Gopinath

Copyright © 2015 Imran Ali et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

An extracellular α-amylase from the obligate halophilic Aspergillus penicillioides TISTR3639 strain was produced and enriched to apparent homogeneity by ammonium sulfate precipitation and Sephadex G100 gel filtration column chromatography. The mass of the purified amylase was estimated to be 42 kDa by SDS-PAGE. With soluble starch as the substrate it had a specific activity of 118.42 Umg−1 and and values of 1.05 µmolmin−1mg−1 and 5.41 mgmL−1, respectively. The enzyme was found to have certain polyextremophilic characteristics, with an optimum activity at pH 9, 80°C, and 300 gL−1 NaCl. The addition of CaCl2 at 2 mM was found to slightly enhance the amylase activity, while ZnCl2, FeCl2, or EDTA at 2 mM was strongly or moderately inhibitory, respectively, suggesting the requirement for a (non-Fe2+ or Zn2+) divalent cation. The enzyme retained more than 80% of its activity when incubated with three different laundry detergents and had a better performance compared to a commercial amylase and three detergents in the presence of increasing NaCl concentrations up to 300 gL−1. Accordingly, it has a good potential for use as an α-amylase in a low water activity (high salt concentration) and at high pH and temperatures.