A β-xylosidase from cell wall of maize: Purification, properties and its use in hydrolysis of plant cell wall

Abstract

To study the potential of plant glycoside hydrolase for hemicelluloses hydrolysis, a β-xylosidase with molecular weight of 68.5 kDa was purified from the maize during senescent stage. The optimal conditions for the β-xylosidase were 37 °C and pH 4.5. In absence of substrate, the β-xylosidase was comparatively stable at 37 °C and pH 4.5–5.5. At the optimum condition, the K m and k cat values of the β-xylosidase against p-nitrophenyl-xyloside were 2.5 mM and 6.5 s −1, respectively. The enzyme activity was promoted by LiCl, CaCl 2, MnCl 2, MgCl 2, KCl, and NaCl, however severely inhibited by CuCl 2, ZnCl 2, AgNO 3, HgCl 2, and NiCl 2. The purified β-xylosidase was active against xylobiose, xylotriose, xylotetraose, and xylopentaose. In hydrolysis of corn stover hemicellulose, the xylose production increased by 94.9% and 140% when Trichoderma reesei hemicellulase supplemented with purified β-xylosidase and crude cell wall proteins of corn stover, respectively. The biochemical characterization of the maize β-xylosidase makes it a promising candidate enzyme additive for hemicelluloses hydrolysis.