Co-immobilization of β-xylosidase and endoxylanase on zirconium based metal–organic frameworks for improving xylosidase activity at high temperature and in acetone.

[Display omitted] • β-xylosidase and endoxylanase were co-immobilized on UiO-66-NH 2 by simple mixing. • Co-immobilized β-xylosidase showed enhanced activity at higher temperature. • Co-immobilized β-xylosidase showed better performances in high concentration of acetone. • 52% β-xylosidase and 70% endoxylanase activity were remained after five recycles. Improving the activity of β-xylosidase at high temperature and organic solvents is important for the conversion of xylan, phytochemicals and some hydroxyl-containing substances to produce xylose and bioactive substances. In this study, a β-xylosidase R333H and an endoxylanase were simultaneously co-immobilized on the metal–organic framework UiO-66-NH 2. Compared with the single R333H immobilization system, the co-immobilization enhanced the activity of R333H at high temperature and high concentration of acetone, and the relative activities at 95 °C and 50% acetone solution were >95%. The K m value of co-immobilized R333H towards p-Nitrophenyl-β-D-xylopyranoside (pNPX) shifted from 2.04 to 0.94 mM, which indicated the enhanced affinity towards pNPX. After 5 cycles, the relative activities of the co-immobilized enzymes towards pNPX and corncob xylan were 52% and 70% respectively, and the accumulated amount of reducing sugars obtained by co-immobilized enzymes degrading corncob xylan in 30% (v/v) acetone solution was 1.7 times than that with no acetone. [ABSTRACT FROM AUTHOR]