Production and characterization of extracellular α-amylase produced by Wickerhamia sp. X-Fep

Appl Biochem Biotechnol. 2012 Aug;167(7):2117-29. doi: 10.1007/s12010-012-9736-2. Epub 2012 Jun 8.

Abstract

A yeast isolate able to produce high levels of extracellular α-amylase was selected from a collection of 385 yeasts and identified as Wickerhamia sp. by the sequence of the D1/D2 domain of the 26 S rDNA gene. Part of the nucleotide sequence of the amy1-W gene was cloned, and a sequence of 191 amino acids deduced from this gene was analyzed. The peptide contains three characteristic well-conserved regions in the active sites of α-amylases (EC 3.2.1.1). The enzyme was purified and in situ activity showed only one band with amylolytic activity. The molecular mass of the α-amylase was estimated at 54 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Enzymatic activity on soluble starch as substrate was optimal at pH 5-6 and 50 °C. This thermostable enzyme was inhibited by EDTA-Na(2) and 1,10-phenanthroline; the activity of the dialyzed enzyme was reactivated with Ca(2+) and Mg(2+) cations, which indicates that the α-amylase is a metalloenzyme. α-Amylase production was induced by starch and maltose and repressed by glucose. The high yield and productivity found in this work makes this Wickerhamia sp. strain a promising candidate for the biotechnological production of α-amylase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Ascomycota / cytology
  • Ascomycota / enzymology*
  • Ascomycota / genetics
  • Ascomycota / growth & development
  • Bioreactors / microbiology
  • Extracellular Space / enzymology*
  • Genes, Fungal / genetics
  • Kinetics
  • Molecular Sequence Data
  • Phylogeny
  • Sequence Alignment
  • Substrate Specificity
  • alpha-Amylases / biosynthesis*
  • alpha-Amylases / chemistry

Substances

  • alpha-Amylases