Open AccessAn alkaline β‐glucosidase isolated from an olive brine strain of Wickerhamomyces anomalus
Author(s) -
Restuccia Cristina,
Muccilli Serena,
Palmeri Rosa,
Randazzo Cinzia L.,
Caggia Cinzia,
Spagna Giovanni
Publication year - 2011
Publication title -
fems yeast research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.991
H-Index - 92
eISSN - 1567-1364
pISSN - 1567-1356
DOI - 10.1111/j.1567-1364.2011.00738.x
Subject(s) - biology , esterase , brine , fermentation , food science , internal transcribed spacer , enzyme , yeast , hydrolysis , enzyme assay , strain (injury) , biochemistry , microbiology and biotechnology , ribosomal rna , gene , chemistry , organic chemistry , anatomy
An efficient β‐glucosidase (βG)‐producing strain, Wickerhamomyces anomalus BS81, was isolated from naturally fermented olive brine and identified based on PCR/restriction fragment length polymorphism of the rDNA internal transcribed spacer and sequence analysis of the D1/D2 region of the 26S rRNA gene. The hydrolytic activity of the βG had an optimum pH of 8.5 and an optimum temperature of 35 °C. The enzyme had high substrate specificity and high catalytic efficiency ( K m 0.99 mM, V max 14 U g −1 of cells) for p ‐nitrophenyl‐β‐ d ‐glucopyranoside. The enzyme was activated by increasing concentrations of NaCl, with maximum activity at 150 g L −1 NaCl. Although βGs have been purified and characterized from several other sources, the W. anomalus βG is unique among βGs because its relative maximum activity occurs at alkaline pH and 35 °C. Moreover, the yeast strain has esterase activity that acts synergistically with βG to degrade oleuropein to debitter table olives and olive oil.