Extremophiles

, Volume 17, Issue 2, pp 339–348

Purification and biochemical characterization of an acidophilic amylase from a newly isolated Bacillus sp. DR90

  • Ahmad Asoodeh
  • Ashraf Alemi
  • Akbar Heydari
  • Jafar Akbari
Original Paper

DOI: 10.1007/s00792-013-0520-1

Cite this article as:
Asoodeh, A., Alemi, A., Heydari, A. et al. Extremophiles (2013) 17: 339. doi:10.1007/s00792-013-0520-1

Abstract

An acidophilic and Ca2+-independent amylase was purified from a newly isolated Bacillus sp. DR90 by ion-exchange chromatography, and exhibited a molecular weight of 68.9 kDa by SDS-PAGE. The optimum pH and temperature of the enzyme were found to be 4.0 and 45 °C, respectively. The enzyme activity was increased by Ba2+, Fe2+ and Mg2+, and decreased by Hg2+ and Zn2+, while it was not affected by Na+, K+, phenylmethylsulfonyl fluoride and β-mercaptoethanol. Ca2+ and EDTA did not have significant effect on the enzyme activity and thermal stability. The values of Km and Vmax for starch as substrate were 4.5 ± 0.13 mg/ml and 307 ± 12 μM/min/mg, respectively. N,N-dialkylimidazolium-based ionic liquids such as 1-hexyl-3-methylimidazolium bromide [HMIM][Br] have inhibitory effect on the enzyme activity. Thin layer chromatography analyses displayed that maltose and glucose are the main products of the enzyme reaction on starch. Regarding the features of the enzyme, it may be utilized as a novel candidate for industrial applications.

Keywords

Bacillus sp. DR90Acidophilic amylaseStarch industryCharacterizationIonic liquids

Supplementary material

792_2013_520_MOESM1_ESM.doc (139 kb)
Supplementary material 1 (DOC 139 kb)

Copyright information

© Springer Japan 2013

Authors and Affiliations

  • Ahmad Asoodeh
    • 1
    • 2
  • Ashraf Alemi
    • 1
  • Akbar Heydari
    • 3
  • Jafar Akbari
    • 3
  1. 1.Department of Chemistry, Faculty of SciencesFerdowsi University of MashhadMashhadIran
  2. 2.Institute of BiotechnologyFerdowsi University of MashhadMashhadIran
  3. 3.Department of ChemistryTarbiat Modares UniversityTehranIran